JP6090166B2 - Organic photoelectric conversion device and solar cell using the same - Google Patents

Description

  The present invention relates to an organic photoelectric conversion element and a solar cell using the same. In more detail, this invention relates to the means for improving the photoelectric conversion efficiency of an organic photoelectric conversion element.

  In recent years, in order to cope with global warming, reduction of carbon dioxide emissions has been strongly desired. In addition, fossil fuels such as oil, coal, and natural gas are expected to be depleted in the near future, and there is an urgent need to secure alternative earth-friendly energy resources. Therefore, development of power generation technology using sunlight, wind power, geothermal energy, nuclear power, and the like has been actively carried out, and solar power generation technology is particularly attracting attention because of its high safety.

  In solar power generation, light energy is directly converted into electric power using a photoelectric conversion element (for example, a solar cell) utilizing the photovoltaic effect. Generally, a photoelectric conversion element has a structure in which a photoelectric conversion layer (light absorption layer) is sandwiched between a pair of electrodes, and light energy is converted into electric energy in the photoelectric conversion layer. The photoelectric conversion element is a silicon-based photoelectric conversion element using single-crystal / polycrystalline / amorphous Si, GaAs, CIGS (copper (Cu), indium (In), depending on the material used for the photoelectric conversion layer and the form of the element. Compound-based photoelectric conversion elements using a compound semiconductor such as gallium (Ga) and selenium (Se)), dye-sensitized photoelectric conversion elements (Gretzel cells), and the like have been proposed and put to practical use.

  However, the cost of generating electricity using these photoelectric conversion elements is still higher than the price of electricity generated and transmitted using fossil fuel, which has hindered widespread use. In addition, since heavy glass must be used for the substrate, reinforcement work is required at the time of installation, which is one of the factors that raise the power generation cost.

  In such a situation, as a technology capable of achieving a power generation cost lower than the power generation cost by fossil fuel, an electron donor layer (p-type semiconductor layer) and an electron acceptor layer (n A bulk heterojunction photoelectric conversion element sandwiching a photoelectric conversion layer formed by mixing with a semiconductor layer is proposed, and a photoelectric conversion efficiency exceeding 5% has been reported (for example, see Non-Patent Document 1). . In addition, for the purpose of improving the durability as a photoelectric conversion element, each layer is laminated in the reverse order of a normal organic thin film type photoelectric conversion element, electrons are taken out from the transparent electrode side, and a stable metal electrode having a deep work function. An organic thin film photoelectric conversion element having a so-called reverse layer configuration in which holes are taken out from the side has also been proposed (see, for example, Patent Document 1).

  Since this bulk heterojunction organic photoelectric conversion element is light and flexible, it is expected to be applied to various products. In addition, since the structure is relatively simple and the photoelectric conversion layer can be formed by applying a p-type organic semiconductor material and an n-type organic semiconductor material, it is suitable for mass production and for the early diffusion of solar cells due to cost reduction. Is also considered to contribute. More specifically, in a bulk heterojunction photoelectric conversion element, the electrodes (anode and cathode), the metal oxide layer constituting the hole transport layer, and the like can be formed by a method other than the coating process (for example, a vacuum deposition method or the like). ). On the other hand, other layers can be formed using a coating process. Therefore, it is expected that the production of the bulk heterojunction photoelectric conversion element can be performed at high speed and at low cost, and it is considered that there is a possibility that the above-described problem of power generation cost can be solved. Further, unlike the production of conventional silicon-based photoelectric conversion elements, compound-based photoelectric conversion elements, dye-sensitized photoelectric conversion elements, etc., it does not necessarily involve a manufacturing process at a temperature higher than 160 ° C. It is expected that it can be formed on a lightweight plastic substrate.

  In addition, as an organic photoelectric conversion element, an organic photoelectric conversion element using a heat conversion organic semiconductor layer using a precursor of a benzotetraporphyrin compound and a fullerene derivative has also been proposed (see, for example, Patent Document 4). .

  Further, in the photoelectric conversion element, in order to effectively utilize sunlight widely distributed from ultraviolet rays to visible light and infrared rays, a tandem element configuration in which a plurality of photoelectric conversion layers are stacked is also widely known. Also, a tandem element configuration has been proposed (see, for example, Patent Document 2).

  However, the organic photoelectric conversion element has improved photoelectric conversion efficiency and durability because the photoelectric conversion efficiency and durability against heat and light are not sufficient as compared with other types of photoelectric conversion elements. An organic photoelectric conversion element has been desired.

  Conventionally, in so-called normal layer type organic photoelectric conversion elements, an intermediate layer (also referred to as an electron transport layer or a hole blocking layer) for adjusting the work function of the cathode is inserted between the cathode and the organic photoelectric conversion layer. Thus, it has been reported that the charge separation efficiency is improved and the conversion efficiency is improved. For example, a layer made of bathocuproine (BCP) (for example, see Patent Document 3), a layer made of a compound having a side chain having an ammonium salt in the main chain of a conjugated polymer compound (for example, Non-Patent Document 2, Non-Patent Document) Reference 3 and Non-Patent Document 4), compounds having a side chain having two dimethylamino groups in the main chain of a conjugated polymer compound (for example, see Non-Patent Documents 5 and 6) and the like have been proposed. . As disclosed in these Non-Patent Documents 2 to 6, the dipole layer forms a shift of the vacuum level between the electrode and the power generation layer, and when viewed from the power generation layer, the metal having an effective shallower work function. It is expected that an effect similar to that used as an electrode can be obtained, and studies are underway.

JP 2009-146981 A International Publication No. 2007/076427 US Pat. No. 6,658,0027 B2 JP 2008-016834 A

Nature Mat. , Vol. 6 (2007), p. 497 J. et al. Am. Chem. Soc. 2011, 133, p. 8416-8419 Appl. Phys. Lett. vol. 95, p. 043301 (2009) Adv. Funct. Mat. 2010, p. 1977 Adv. Mater. 2011, 23, p. 3086-3089 Advanced Materials, 2011 (Vol 23, no. 40), p. 4636-4643

  However, the conventionally proposed technique using the intermediate layer still has low charge transport performance and insufficient conversion efficiency. In addition, since the conventional technique has little effect of shallowing the work function of the cathode, it is necessary to use a metal (for example, aluminum) having a shallow work function and a small ionization potential (that is, easily oxidized) as a constituent material of the cathode. . For this reason, the electrical properties of the device deteriorate due to the decrease in conductivity due to the oxidation of the cathode, or the contact resistance at the interface significantly increases due to the deepening of the work function, and there is a problem in durability.

  In addition, for such a problem of durability, ordinary organic photoelectric conversion elements are stacked in the reverse order, and electrons are extracted from the transparent electrode side, and holes are extracted from the stable metal electrode side having a deep work function. An organic photoelectric conversion element having a so-called reverse layer configuration has been proposed. In the organic photoelectric conversion element having the reverse layer structure, it is not necessary to use a metal having a shallow work function that is unstable and easily oxidized, and deterioration due to the electrode is suppressed, so that the lifetime is significantly increased. Can be improved. However, due to the use of a metal having a deep work function in the photoelectric conversion element of the reverse layer configuration, the built-in electric field, which is the work function difference between the transparent electrode and the counter electrode, becomes smaller, compared to the normal layer configuration. There was a problem that conversion efficiency was lowered.

  In addition, organic photoelectric conversion elements are also expected to have high productivity in a roll-to-roll coating process on plastic substrates. Even when manufactured by such a process, organic photoelectric conversion elements with excellent conversion efficiency and durability are expected. A conversion element is also desired.

  The present invention has been made in view of the above problems, and an object thereof is to provide an organic photoelectric conversion element having high photoelectric conversion efficiency and excellent durability, and a solar cell using the organic photoelectric conversion element. .

  In order to solve the above problems, the present inventors have conducted intensive research. As a result, it has been found that the above problem can be solved by including a polymer compound having a side chain having a specific structure in an intermediate layer other than the photoelectric conversion layer, and the present invention has been completed.

  That is, the above-described problems of the present invention include a cathode, an anode, a photoelectric conversion layer including a p-type organic semiconductor material and an n-type organic semiconductor material interposed between the cathode and the anode, the cathode, and the anode. An organic photoelectric conversion element having an intermediate layer other than the photoelectric conversion layer interposed between and wherein at least one of the intermediate layers has a structure represented by the following general formula (1) as a side chain It solves by the organic photoelectric conversion element containing the high molecular compound to contain.

It is the cross-sectional schematic which represented typically the normal layer type organic photoelectric conversion element based on other one Embodiment of this invention. It is the cross-sectional schematic which represented typically the reverse layer type organic photoelectric conversion element based on other one Embodiment of this invention. It is the cross-sectional schematic which represented typically the organic photoelectric conversion element provided with the tandem-type photoelectric conversion layer based on other one Embodiment of this invention. In Example 7, it is a figure which shows the absorption spectrum before and behind overcoating the coating film of the compound 3 with o-dichlorobenzene, and the absorption spectrum before and after being immersed in o-dichlorobenzene for 1 minute.

  Hereinafter, preferred embodiments of the present invention will be described. A first aspect of the present invention includes a cathode, an anode, a photoelectric conversion layer including a p-type organic semiconductor material and an n-type organic semiconductor material interposed between the cathode and the anode, the cathode, and the anode. An organic photoelectric conversion element having an intermediate layer other than the photoelectric conversion layer interposed therebetween, wherein at least one of the intermediate layers has the structure represented by the general formula (1) as a side chain. It is an organic photoelectric conversion element characterized by containing the polymer compound to contain.

  According to the present invention, an organic photoelectric conversion element having high photoelectric conversion efficiency and excellent durability, and a solar cell using the organic photoelectric conversion element are provided.

  Hereinafter, the present embodiment will be described with reference to the accompanying drawings. However, the technical scope of the present invention should be determined by the description of the scope of claims, and is not limited to the following embodiments. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

<Organic photoelectric conversion element>
FIG. 1 is a schematic cross-sectional view schematically showing a normal layer type organic photoelectric conversion element according to an embodiment of the present invention. The organic photoelectric conversion element 10 in FIG. 1 corresponds to the configuration of, for example, the organic photoelectric conversion element 105 manufactured in Example 1 described later. Specifically, the organic photoelectric conversion element 10 of FIG. 1 includes an anode (first electrode) 11, a hole transport layer 26, a photoelectric conversion layer 14, an electron transport layer 27, and a cathode (second electrode) on a substrate 25. Electrode) 12 is laminated in this order. As an example, the electron transport layer 27 contains a polymer compound (preferably a conjugated polymer compound) including the structure represented by the general formula (1) as a side chain.

  When the organic photoelectric conversion element 10 shown in FIG. 1 is operated, light is irradiated from the substrate 25 side. In the present embodiment, the anode 11 is made of a transparent electrode material (for example, ITO) so that the irradiated light reaches the photoelectric conversion layer 14. The light irradiated from the substrate 25 side reaches the photoelectric conversion layer 14 through the transparent anode 11 and the hole transport layer 26.

  The photoelectric conversion layer 14 includes a p-type organic semiconductor material and an n-type organic semiconductor material. When light is incident on the photoelectric conversion layer 14, electrons of the p-type organic semiconductor material are in the highest occupied orbit (hereinafter “HOMO”). Is also excited to the lowest unoccupied orbit (hereinafter also referred to as “LUMO”), and then the electrons move to the conduction band of the n-type organic semiconductor material. Thereafter, the electrons move through the electron transport layer 27 and the cathode 12 and then move to the conduction band of the p-type organic semiconductor material via the external circuit. Then, electrons generated in the conduction band of the p-type organic semiconductor material move to the LUMO level.

  On the other hand, when light is incident on the photoelectric conversion layer 14, holes generated at the HOMO level of the p-type organic semiconductor material pass through the hole transport layer 26 and the anode 11 and then pass through an external circuit to be n-type. Move to the valence band of organic semiconductor materials. In this way, a photocurrent flows in the photoelectric conversion layer 14 and power generation is performed. Since it is considered that such photoelectric charge separation is promoted as the contact interface between the p-type organic semiconductor material and the n-type organic semiconductor material increases, in the present invention, the p-type organic semiconductor material and the n-type organic semiconductor material are used. It is particularly preferable to use a bulk heterojunction photoelectric conversion layer 14 in which are uniformly mixed. However, it is not limited only to such a form.

  The hole transport layer 26 is formed of a material having a high hole mobility, and has a function of efficiently transporting holes generated at the pn junction interface of the photoelectric conversion layer 14 to the anode 11. . On the other hand, in the present embodiment, as described above, the electron transport layer 27 contains a polymer compound (preferably a conjugated polymer compound) including the structure represented by the general formula (1) as a side chain. . Since the polymer compound containing the structure represented by the general formula (1) as a side chain is a material having a high electron mobility, the electron transport layer 27 is an electron generated at the pn junction interface of the photoelectric conversion layer 14. Can be efficiently transported to the cathode 12.

  FIG. 2 is a schematic cross-sectional view schematically showing a reverse layer type organic photoelectric conversion element according to another embodiment of the present invention. The organic photoelectric conversion element 20 in FIG. 2 corresponds to the configuration of, for example, the organic photoelectric conversion element 305 manufactured in Example 3 described later. The organic photoelectric conversion element 20 in FIG. 2 has the anode 11 and the cathode 12 disposed at opposite positions as compared with the organic photoelectric conversion element 10 in FIG. 1, and the hole transport layer 26, the electron transport layer 27, and the like. Are different in that they are arranged at the opposite positions. 2 has a configuration in which the cathode 12, the electron transport layer 27, the photoelectric conversion layer 14, the hole transport layer 26, and the anode 11 are laminated on the substrate 25 in this order. ing. With this configuration, electrons generated at the pn junction interface of the photoelectric conversion layer 14 are transported to the cathode 12 through the electron transport layer 27, and holes are transported to the anode 11 through the hole transport layer 26. Transported. In the embodiment shown in FIG. 2 as well, the electron transport layer 27 contains a polymer compound (preferably a conjugated polymer compound) containing the structure represented by the general formula (1) as a side chain. Preferably it is.

  FIG. 3 is a schematic cross-sectional view schematically showing an organic photoelectric conversion element including a normal layer tandem (multi-junction type) photoelectric conversion layer according to another embodiment of the present invention. The organic photoelectric conversion element 30 in FIG. 3 corresponds to the configuration of, for example, the organic photoelectric conversion element 403 manufactured in Example 4 described later. Compared with the organic photoelectric conversion element 10 in FIG. 1, the organic photoelectric conversion element 30 in FIG. 3 replaces the photoelectric conversion layer 14 with a first photoelectric conversion layer 14 a, a second photoelectric conversion layer 14 b, and these The difference is that a laminate with the charge recombination layer 38 interposed between the two photoelectric conversion layers (14a, 14b) is disposed. Here, the charge recombination layer 38 includes a second electron transport layer 38a disposed on the first photoelectric conversion layer 14a side and a second hole disposed on the second photoelectric conversion layer 14b side. It consists of two layers, the transport layer 38b. In the tandem organic photoelectric conversion element 30 shown in FIG. 3, photoelectric conversion materials (p-type organic semiconductor material and n-type having different absorption wavelengths) are respectively formed in the first photoelectric conversion layer 14 a and the second photoelectric conversion layer 14 b. By using an organic semiconductor material), light in a wider wavelength range can be efficiently converted into electricity.

  In the organic photoelectric conversion element 30 shown in FIG. 3, the anode 11 and the cathode 12 are disposed at opposite positions, and the hole transport layer 26 and the electron transport layer 27 are disposed at opposite positions. If the electron transport layer 38a and the second hole transport layer 38b are disposed at opposite positions, a reverse layer tandem type (multi-junction type) photoelectric conversion element is obtained. The reverse layer tandem type (multi-junction type) photoelectric conversion element corresponds to the configuration of, for example, the organic photoelectric conversion element 503 manufactured in Example 5 described later.

  Among the above embodiments, the organic photoelectric conversion element of the present invention is preferably a normal layer type organic photoelectric conversion element shown in FIG. 1 or a reverse layer type organic photoelectric conversion element shown in FIG. It is particularly preferable that the organic layer is a normal layer type organic photoelectric conversion element.

  In the form shown in FIGS. 1 to 3 described above, the electron transport layer contains a polymer compound containing the structure represented by the general formula (1) as a side chain. That is, in these forms, the intermediate layer is an electron transport layer. However, in the present invention, the “intermediate layer” refers to an arbitrary layer interposed between one electrode and the photoelectric conversion layer, or when there are a plurality of photoelectric conversion layers, the plurality of photoelectric conversion layers are connected to each other. Means any layer interposed between the two. Therefore, in the present invention, at least one of the intermediate layers satisfying the above definition only needs to contain a polymer compound containing a structure represented by the general formula (1) as a side chain, and only the above-described embodiments. It is not limited to the interpretation.

  According to the present invention, the intermediate layer such as the electron transport layer described above contains the polymer compound containing the structure represented by the general formula (1) as a side chain, so that the photoelectric conversion efficiency is high and the durability is excellent. An organic photoelectric conversion device can be provided. In particular, a polymer compound (preferably a conjugated polymer compound) in which the electron transport layer of a normal layer type organic photoelectric conversion element as shown in FIG. 1 has a structure represented by the general formula (1) as a side chain as an intermediate layer. ) Is particularly preferred. This is because, according to such a form, the side chain in the polymer compound containing the structure represented by the general formula (1) as the side chain is efficiently arranged around the main chain. This is thought to be because the contact efficiency between the electrode and the electrode increases, and the resistance at the interface is reduced. Moreover, in the said embodiment, the mechanism by adjusting the work function of the constituent material of an electrode appropriately is estimated. That is, in the normal layer type organic photoelectric conversion element as shown in FIG. 1, when the electron transport layer in contact with the cathode contains a polymer compound having a structure represented by the general formula (1) as a side chain, the structure of the cathode The compound acts so that the work function of the material becomes shallow, which makes it excellent in durability and photoelectric conversion efficiency even when using a metal such as silver or gold having a higher ionization potential and a deep work function than aluminum. An organic photoelectric conversion element maintained at a high value can be provided.

  Hereinafter, each structure of the organic photoelectric conversion element which concerns on this invention is demonstrated in detail.

[Electron transport layer (also referred to as hole blocking layer or hole blocking layer (HBL))]
The organic photoelectric conversion element of this form can contain an electron carrying layer as needed. The electron transport layer has a function of transporting electrons and has a property of extremely small ability to transport holes (for example, 1/100 or less of the mobility of electrons). The electron transport layer is provided between the photoelectric conversion layer and the cathode, and prevents the recombination of electrons and holes by blocking the movement of holes while transporting electrons to the cathode. it can. As a result, a photoelectric conversion element having a high open circuit voltage and a high fill factor can be obtained.

  In the embodiment shown in FIGS. 1 to 3, as described above, the electron transport layer contains a polymer compound containing a structure represented by the following general formula (1) as a side chain.

That is, it is preferable that the intermediate layer is an electron transport layer that exists between the photoelectric conversion layer and the second electrode, particularly, between the photoelectric conversion layer and the cathode (anode). This is because the polymer compound forms a dipole layer and has an effect of making the work function of the electrode viewed from the power generation layer pseudo-shallow, so that carriers can be extracted more easily. If the work function is too deep and functions as a trap when transporting holes from the photoelectric conversion layer, it is formed on the hole transport layer between the hole transport layer and the power generation layer (photoelectric conversion layer). It is also possible to improve the electrical connection.

(High molecular compound containing the structure represented by the general formula (1) as a side chain)
Hereinafter, the “polymer compound containing a structure represented by the general formula (1) as a side chain” which is a characteristic configuration of the present invention will be described in detail. According to one embodiment of the present invention, a polymer compound including the structure represented by the general formula (1) as a side chain is also provided.

In the general formula (1), L1 represents a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, or a substituted or unsubstituted carbon atom number. 2-20 alkynylene groups, substituted or unsubstituted arylene groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroarylene groups having 1 to 30 carbon atoms, alkyleneoxy groups having 1 to 20 carbon atoms, and Represents a divalent linking group selected from the group consisting of-(L1 _' )-(OR) _p- .

When L ₁ is — (L _{1 ′} ) — (OR) _p —, L _{1 ′} is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted carbon atom number of 6 Represents an arylene group of ˜30, or a single bond. L _{1 ′} is preferably a single bond, a linear or branched alkylene group having 1 to 15 carbon atoms, or an arylene group having 6 to 18 carbon atoms, and preferably a single bond, 1 to 1 carbon atoms. More preferably, they are 8 linear or branched alkylene groups, o-, m-, p-phenylene groups. R represents an ethylene group, a trimethylene group or a propylene group. R preferably represents an ethylene group or a propylene group, and more preferably represents an ethylene group. p represents the repeating number of the alkylene oxide group (—OR—) in — (L _{1 ′} ) — (OR) _p —, is an integer of 1 to 5, and is preferably an integer of 1 to 3, More preferably, it is 1 or 2.

  In the present specification, the “alkylene group having 1 to 20 carbon atoms” is not particularly limited, and is a linear or branched alkylene group having 1 to 20 carbon atoms. Examples include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a propylene group, an ethylethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, and an octamethylene group. Among these, a linear or branched alkylene group having 1 to 15 carbon atoms is preferable, and a linear or branched alkylene group having 1 to 8 carbon atoms is more preferable.

  In the present specification, the “cycloalkylene group having 3 to 20 carbon atoms” is not particularly limited, and examples thereof include a cyclopentylene group, a cyclohexylene group, and a cycloheptylene group.

  In the present specification, the “alkynylene group having 2 to 20 carbon atoms” is not particularly limited, and examples thereof include ethynylene group, 1-propynylene group, 1-butynylene group, 1-pentynylene group, 1-hexynylene group, 2 -Butynylene group, 2-pentynylene group, 1-methylethynylene group, 3-methyl-1-propynylene group, 3-methyl-1-butynylene group and the like can be mentioned.

  In the present specification, the “arylene group having 6 to 30 carbon atoms” is not particularly limited, and examples thereof include o-phenylene group, m-phenylene group, p-phenylene group, naphthalenediyl group, anthracenediyl group, and naphthacenediyl. Group, pyrenediyl group, naphthylnaphthalenediyl group, biphenyldiyl group (for example, [1,1′-biphenyl] -4,4′-diyl group, 3,3′-biphenyldiyl group, 3,6-biphenyldiyl group, etc. ), Terphenyldiyl group, quaterphenyldiyl group, kinkphenyldiyl group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group, deciphenyldiyl group and the like.

  In the present specification, the “heteroarylene group having 1 to 30 carbon atoms” is not particularly limited. For example, a carbazole ring, a carboline ring, a diazacarbazole ring (also referred to as a monoazacarboline ring, which constitutes a carboline ring) A ring structure in which one of the carbon atoms is replaced by a nitrogen atom), triazole ring, pyrrole ring, pyridine ring, pyrazine ring, quinoxaline ring, thiophene ring, oxadiazole ring, dibenzofuran ring, dibenzothiophene ring, indole ring And divalent groups derived from the group consisting of

In the present specification, the “alkyleneoxy group having 1 to 20 carbon atoms” means “—O-alkylene-” or “-alkylene-O—”. In this case, the alkylene group has 1 to 20 carbon atoms. An alkylene group. Here, the alkylene group having 1 to 20 carbon atoms is not particularly limited, for example, alkylene groups similar to that described above L ₁ are exemplified. A linear or branched alkylene group having 1 to 15 carbon atoms is preferable, and a linear or branched alkylene group having 1 to 8 carbon atoms is more preferable. More specifically, methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butoxy group, isobutoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group, heptyloxy group, octyloxy group 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3,7-dimethyloctyloxy group, lauryloxy group, trifluoromethoxy group, pentafluoroethoxy group, perfluorobutoxy group, perfluorohexyl group, perfluorooctyl group , A divalent group obtained by removing one hydrogen atom from an alkyloxy group such as a methoxymethyloxy group and a 2-methoxyethyloxy group.

The alkylene group, cycloalkylene group, alkynylene group, arylene group, heteroarylene group, and alkyleneoxy group as L ₁ may be substituted with the following appropriate substituents. In addition to the following substituent group, an alkylene group as L _1, a cycloalkylene group, an alkynylene group, an arylene group, (especially if L ₁ is "substituted alkylene") heteroarylene group, alkyleneoxy group In addition to those described above, the substituent for substituting the alkylene group may be a structure represented by the general formula (1) (see exemplary compound 53 described later).

(Substituent)
The alkylene group, cycloalkylene group, alkynylene group, arylene group, heteroarylene group, and alkyleneoxy group as L ₁ may have a substituent at any position. Examples of such substituents include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group). Group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1, 3-butadienyl group, 2-pentenyl group, isopropenyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon group (aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group) For example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, Enthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc., aromatic heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group) Group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) ), A phthalazinyl group, etc.), a heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), an alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, Hexyloxy group, Octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group) Propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (for example, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (For example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (for example, phenyl Ruoxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group) , Dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl) Group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acylo Si group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group) Dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.) Carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group) Cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, Ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl) Group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2- Pyridylsulfinyl group etc.), alkylsulfonyl group (eg methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group etc.), arylsulfonyl group or heteroarylsulfonyl group (eg , Phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group) , Anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group) Pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphono And polymerizable groups (for example, acryloyl group, methacryloyl group, epoxy group, oxetane group, isocyanate group, alkoxysilane group, etc.). In the above, the same substituent is not substituted. That is, a substituted alkyl group is not substituted with an alkyl group. Of these, the substituent is preferably a halogen atom, a cyano group, a hydroxy group or a nitro group, more preferably a fluorine atom, a cyano group, a hydroxy group or a nitro group. These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

L ₁ is preferably a substituted or unsubstituted linear or branched alkylene group having 1 to 20 carbon atoms, — (L _{1 ′} ) — (OR) _p — [where L _{1 ′} is a single bond A linear or branched alkylene group having 1 to 15 carbon atoms or an arylene group having 6 to 18 carbon atoms; R represents an ethylene group or a propylene group; p is an integer of 1 to 3 ], A substituted or unsubstituted arylene group. L ₁ is more preferably a substituted or unsubstituted linear or branched alkylene group having 1 to 15 carbon atoms, — (L _{1 ′} ) — (OR) _p — [where L _{1 ′} is a single A bond, a linear or branched alkylene group having 1 to 15 carbon atoms or an arylene group having 6 to 18 carbon atoms; R represents an ethylene group or a propylene group; p is an integer of 1 to 3 A substituted or unsubstituted arylene group. L ₁ is more preferably a linear or branched alkylene group substituted or unsubstituted with a substituent of the formula having 1 to 8 carbon atoms: -L ₁ -N (L ₂ ) (L ₃ ),- (L _{1 ′} ) — (OR) _p — [where L _{1 ′} represents a single bond, a linear or branched alkylene group having 1 to 8 carbon atoms, or an o-, m-, or p-phenylene group. Yes; R represents an ethylene group; p is 1 or 2]. A form in which L ₁ is an unsubstituted alkylene group having 1 to 6 carbon atoms (methylene group, ethylene group, trimethylene group, propylene group, etc.) is also a preferred form.

In general formula (1), L ₂ is:

It is group represented by these. L ₂ may be in the form of a salt (ammonium salt) in which the nitrogen atom (N) is positively charged and an ion pair is formed with the counter ion (anion).

Here, L ₁ has the same definition as described above. Further, L ₁ in L ₂ may be the same as each other as L ₁ in the general formula (1), may be different. Further, even when L ₂ is repeatedly used, L ₁ may be the same as or different from each other.

L ₄ represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted carbon atom having 6 to 6 carbon atoms. 30 aryl group, a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, or an _{L 2.} However, the two L ₄ bonded to the nitrogen atom (N) are not both hydrogen atoms. Also, to the two L ₄ may be the same as each other or may be different. Furthermore, when _{L 4} is _{L 2, L 2} may be the same original _{L 2} and as _{L 4,} may be different. Of these, L ₄ is preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, an amino group (but not —NH ₂ ), or an alkylamino group. Alternatively, an unsubstituted alkyl group having 1 to 8 carbon atoms and a dialkylamino group are more preferable.

Note that L ₂ is in the form of a salt (ammonium salt), for example, a form in which a nitrogen atom (N) is positively charged and forms an ion pair with a counter ion (anion) as in Compound 30 below. Means. Here, when L ₂ is in the form of an ammonium salt, a counter ion (anion) that forms an ion pair is not particularly limited, but a halogen atom (fluorine atom, chlorine atom, bromine atom), sulfate ion, nitrate ion, Tetrafluoroborate ion, hexafluorophosphoric acid and the like can be mentioned.

  In the present specification, the “alkyl group having 1 to 20 carbon atoms” is not particularly limited, and is a linear or branched alkyl group having 1 to 20 carbon atoms. For example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, neopentyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, 1,3-dimethylbutyl group, 1-isopropylpropyl group, 1,2-dimethylbutyl group, n-heptyl group, 1,4-dimethylpentyl group 3-ethylpentyl group, 2-methyl-1-isopropylpropyl group, 1-ethyl-3-methylbutyl group, n-octyl group, 2-ethylhexyl group, 3-methyl-1-isopropylbutyl group, 2-methyl- 1-isopropyl group, 1-t-butyl-2-methylpropyl group, n-nonyl group, 3,5,5-trimethylhexyl group n- decyl group, isodecyl group, n- undecyl, 1-methyldecyl group, n- dodecyl group, n- hexadecyl group, 2-hexyl decyl group. Among these, from the viewpoint of improving the solubility, an alkyl group having 1 to 12 carbon atoms is preferable, and an alkyl group having 1 to 8 carbon atoms is more preferable. For example, methyl, ethyl, iso-propyl Tert-butyl, n-octyl, n-decyl, n-hexadecyl, 2-ethylhexyl, 2-hexyldecyl and the like. The alkyl group is particularly preferably a methyl group, an ethyl group, or a propyl group.

  In the present specification, the “cycloalkyl group having 3 to 20 carbon atoms” is not particularly limited, and examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group. Among these, a cycloalkyl group having 4 to 8 carbon atoms is preferable from the viewpoint of improving solubility.

  In the present specification, the “aryl group having 6 to 30 carbon atoms” is not particularly limited, and examples thereof include non-condensed hydrocarbon groups such as a phenyl group, a biphenyl group, and a terphenyl group; a pentarenyl group, an indenyl group, Naphtyl group, azulenyl group, heptaenyl group, biphenylenyl group, fluorenyl group, acenaphthylenyl group, preadenenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group , Condensed polycyclic hydrocarbon groups such as triphenylenyl group, pyrenyl group, chrycenyl group, naphthacenyl group and the like.

  In the present specification, the “heteroaryl group having 1 to 20 carbon atoms” is not particularly limited. For example, pyridyl group, pyrimidyl group, pyrazinyl group, triazinyl group, furanyl group, pyrrolyl group, thiophenyl group (thienyl group) Group), quinolyl group, furyl group, piperidyl group, coumarinyl group, silafluorenyl group, benzofuranyl group, benzimidazolyl group, benzoxazolyl group, benzthiazolyl group, dibenzofuranyl group, benzothiophenyl group, dibenzothiophenyl group, indolyl Group, carbazolyl group, pyrazolyl group, imidazolyl group, oxazolyl group, isoxazolyl group, thiazolyl group, indazolyl group, benzothiazolyl group, pyridazinyl group, cinnolyl group, quinazolyl group, quinoxalyl group, phthalazinyl group, phthalazine dionyl group, Talamidyl group, chromonyl group, naphtholactamyl group, quinolonyl group, naphthalidinyl group, benzimidazolonyl group, benzoxazolonyl group, benzothiazolonyl group, benzothiazothionyl group, quinazolonyl group, quinoxalonyl group, phthalazonyl group, Dioxopyrimidinyl group, pyridonyl group, isoquinolonyl group, isoquinolinyl group, isothiazolyl group, benzisoxazolyl group, benzisothiazolyl group, indazironyl group, acridinyl group, acridonyl group, quinazoline dionyl group, quinoxaline dionyl group, benzo Examples thereof include an oxazine dionyl group, a benzoxazinonyl group, a naphthalimidyl group, a dithienocyclopentadienyl group, a dithienosilacyclopentadienyl group, a dithienopyrrolyl group, and a benzodithiophenyl group.

The alkyl group, cycloalkyl group, aryl group, and heteroaryl group as L ₄ may be substituted with an appropriate substituent. As the substituent in this case, the groups described above as the substituent in L ₁ can be similarly employed.

In the general formula (1), L ₃ has the same definition as L ₄ described above.

  In the present invention, the general formula (1) is:

It is. In the general formula (1), L ₂ is:

It is group represented by these. Therefore, general formula (1) is:

It can be expressed as. For example, when at least one of the two L ₄ is L ₂ , the general formula (1) is:

It can be expressed as. Again, for example, when at least one of the two _{L 4} is _{L 2,} the general formula (1) is:

That is, if the case where “at least one of L ₄ is L ₂ ” is repeated, the range of the structure represented by the general formula (1) diverges infinitely and cannot be determined. Therefore, in the present invention, the structure represented by the general formula (1):

By defining the upper limit of the number of nitrogen atoms (N) in the chain having the largest number of nitrogen atoms (N) as 5 or less, the divergence of the structure of the side chain is prohibited and expressed by the general formula (1) The range of structures to be performed can be determined. On the other hand, the lower limit of the number of nitrogen atoms (N) is theoretically two. Therefore, it is essential that the number of the nitrogen atoms (N) is 2 to 5. The number of nitrogen atoms (N) is preferably 2 to 4, more preferably 2 to 3, and most preferably 2.

  The structure represented by the general formula (1) is bonded as a side chain to the main chain of the polymer compound. Here, there is no restriction | limiting in particular about the specific form of the principal chain of a high molecular compound, The conventionally well-known knowledge in this technical field can be referred suitably.

  The polymer compound main chain is classified into two types, a non-conjugated polymer and a conjugated polymer, which function in both, but are conjugated polymer main chains in order to obtain higher carrier transportability. Is preferred.

  Examples of the conjugated polymer include polythiophenes (including basic polythiophenes (hereinafter the same)), polypyrroles, polyindoles, polycarbazoles, polyanilines, polyacetylenes, polyfurans, polyparaphenylene vinylenes, polyazulenes. , Polyparaphenylenes, polyparaphenylene sulfides, polyisothianaphthenes, polythiazyls, polyfluorenes, polysilafluorenes, polyphosphafluorenes, polycyclopentadithiophenes, polydithienosylols, and Conjugated polymer compounds containing these copolymers can be used.

  In addition, as the non-conjugated polymer, for example, poly (meth) acrylates, polystyrenes, polyalkyl ethers, polyalkylene terephthalates, polyamines, and a polymer compound containing these copolymers can be used.

  The main chain of the polymer compound may be composed of a single conjugated polymer or a single non-conjugated polymer, or from a plurality of types of conjugated polymers or a plurality of types of non-conjugated polymers. It may be constituted, or may be a mixture of single or plural kinds of non-conjugated polymers and single or plural kinds of conjugated polymers.

  In one embodiment of the present invention, the main chain is preferably a polymer compound (preferably a conjugated polymer compound) having a structural unit represented by the following general formula (2).

In the general formula (2), M ₁ and M ₂ each independently represent an aryl group or a heteroaryl group which is a monocyclic ring or a condensed ring, and Z represents a structure represented by the general formula (1). A and b each independently represent a positive real number satisfying the relationship of a> 0, b ≧ 0, and a + b = 1.0. N represents the number of Z bonded to M ₁ and is ₁ , 2 or 3.

Examples of the conjugated polymer compound represented by M ₁ and M ₂ in the general formula (2) are listed below, but the present invention is not limited thereto. For example, polythiophenes, polypyrroles, polyindoles, polycarbazoles, polyfurans, polyazulenes, polyparaphenylenes, polyisothianaphthenes, polyfluorenes, polysilafluorenes, polyphosphafluorenes, polycyclohexane Examples thereof include conjugated polymer compounds including pentadithiophenes, polydithienosilols, and copolymers thereof.

  In addition, when the structure represented by the general formula (1) is bonded as a side chain of the polymer compound, one or more side chains (general formula) with respect to one atom of the main chain to which the side chain is bonded. (The structure represented by (1)) can be bonded. Here, when a plurality of side chains are bonded to one atom of the main chain, the plurality of side chains may be the same as or different from each other. Moreover, it is preferable that one or more amino groups contained in the structure represented by the general formula (1) are contained per one aromatic ring of the main chain, and more preferably 1.5 or more. That is, in a preferred embodiment of the present invention, the polymer compound according to the present invention contains an aromatic ring in the main chain, and a primary to quaternary amino group as a substituent is 1.5 per aromatic ring. Have more than one. As described later, the work function of the electrode in contact with the intermediate layer containing the polymer compound is preferably −4.5 eV or less when measured by photoelectron spectroscopy. Thereby, an organic photoelectric conversion element is excellent in photoelectric conversion efficiency and durability. Here, although the mechanism by which the organic photoelectric conversion element of the present embodiment has the above effect is not clear, it is estimated as follows. However, the present invention is not limited to the following estimation. That is, the polymer compound has a structure in which primary to quaternary amino groups, which are highly polar side chains, are arranged at high density around the polymer compound main chain. As a result, even if a metal having a deep work function and stable to oxidation is used for the electrode, the intermediate layer functions as a dipole layer, so that a built-in electric field between the other electrode can be sufficiently secured. Is done. Therefore, an organic photoelectric conversion element having an intermediate layer containing the polymer compound between the photoelectric conversion layer and the electrode exhibits a sufficient built-in electric field improvement effect even for a conductive substance that is stable against oxidation. An organic photoelectric conversion element excellent in photoelectric conversion efficiency and durability can be provided.

  Here, the aromatic ring constituting the main chain of the polymer compound is not particularly limited, and examples thereof include an aromatic ring main chain represented by the following formula. In the following formula, R represents a substituent.

  In this embodiment, the polymer compound has 1.5 or more primary to quaternary amino groups as substituents per aromatic ring. Here, “the number of amino groups per aromatic ring” means that a 5-membered ring or 6-membered ring having 6 π electrons is counted as one, and the number of amino groups present per one aromatic ring. Number (average number). For example, benzene, pyridine, pyridazine, pyrimidine, pyrazine, thiophene, furan, pyrrole and the like are counted as one. Biphenyl, bithiophene and the like in which they are linked, and naphthalene, thienothiophene, benzothiophene and the like in which they are condensed are counted as two. The fluorene ring is counted as two because the central cyclopentane ring is not aromatic, but the carbazole ring is counted as three because the central pyrrole ring is aromatic. That is, in the present specification, the aromatic ring is counted as follows.

  In the amino group, the hydrogen atom of these aromatic ring main chains may be substituted directly or via a divalent linking group. At this time, any of a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary amino group (ammonium group) may be used, but at least one of the amino groups is a tertiary amino group. Preferably, at least 30% of all amino groups are tertiary amino groups, more preferably at least 40% of all amino groups are tertiary amino groups, and at least 50% of all amino groups are 3 A tertiary amino group is more preferred, and all amino groups are particularly preferably tertiary amino groups. A polymer compound having many tertiary amino groups is excellent in solubility, coatability, and durability of the resulting organic photoelectric conversion element. The amino group being a quaternary amino group (ammonium group) means that the amino group is in the form of a salt as shown in the following compound 14, for example. That is, the structural unit constituting the main chain of the polymer compound according to the present invention includes the case where the amino group in the structural unit is in the form of a salt. Here, examples of the anion that forms a salt with a quaternary amino group (ammonium group) are not particularly limited, but include a halogen atom (fluorine atom, chlorine atom, bromine atom), sulfate ion, nitrate ion, tetrafluoroborate ion. And hexafluorophosphoric acid. Among these, a halogen atom is preferable, and a bromine atom is particularly preferable.

  In the present embodiment, 1.5 or more amino groups exist as substituents per aromatic ring in the main chain of the polymer compound. Preferably, the amino group is preferably present as a substituent in the order of 2 or more, 3 or more, 4 or more per aromatic ring in the main chain of the polymer compound. With the number (density) of amino groups in such a range, good solubility, coatability, and durability of the obtained organic photoelectric conversion element can be improved. Moreover, in order to obtain high durability, it is effective to perform the application under nitrogen without moisture and oxygen, but there is a problem that the application under nitrogen tends to cause repellency. However, by increasing the number (density) of amino groups as in the present invention, the occurrence of repelling can be suppressed even when coating is performed under nitrogen. Here, the upper limit of the number of amino groups present per aromatic ring is not particularly limited, but is preferably 15 or less, and more preferably 7 or less, from a synthetic viewpoint. An organic photoelectric conversion element having an intermediate layer containing a polymer compound having an aromatic ring having an amino group in such a range in its main chain between the photoelectric conversion layer and the electrode has a stable conductivity against oxidation. It also exhibits a sufficient built-in electric field improvement effect for substances, and has excellent photoelectric conversion efficiency and durability. In addition, since such a polymer compound is dissolved in a highly polar organic solvent such as alcohol or fluorinated alcohol, the intermediate layer is easily formed by a direct coating method on a photoelectric conversion layer that does not dissolve in a highly polar solvent. it can.

  More preferably, the main chain of the polymer compound preferably has a structural unit represented by the following general formula (3).

In the general formula (3), X ₁ represents a nitrogen atom, a carbon atom, a silicon atom or a phosphorus atom (including a trivalent phosphorus atom and a pentavalent phosphorus atom; in the case of a pentavalent phosphorus atom, X ₁ is , P (═O) —R is preferably a group derived from a phosphine oxide compound. Here, X ₁ in each structural unit may be the same or different. Preferably X ₁ is a carbon atom. When X ₁ is a carbon atom, a polymer compound having an amino group with a uniform and high-density surface can be obtained with the polymer compound as the center, and the polarization of the dipole layer can be further increased. The stability of the organic photoelectric conversion element to be obtained can be increased.

  Moreover, in General formula (3), Z represents the structure represented by the said General formula (1).

Furthermore, in General formula (3), n represents the number of Z couple | bonded with X1, and is ₁ , 2, or 3. That is, when X ₁ represents a phosphorus atom, n is 1 or 3, when X ₁ represents a carbon atom or a silicon atom, n is 2, and when X ₁ represents a nitrogen atom. In the formula, n is 1.

In the general formula (3), A and B each independently represent a 6-membered aromatic hydrocarbon ring, a 5-membered aromatic heterocycle, or a 6-membered aromatic heterocycle. As an example of satisfying these definitions, the 6-membered aromatic hydrocarbon ring includes a benzene ring. Examples of the 5-membered aromatic heterocycle or 6-membered aromatic heterocycle include oxazole ring, oxadiazole ring, oxatriazole ring, isoxazole ring, tetrazole ring, thiadiazole ring, thiatriazole ring, and isothiazole. A ring, a thiophene ring, a furan ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, a triazole ring, and the like. Each of these rings may have a substituent at any position. As the substituent in ring A and ring B in the general formula (3), the groups exemplified in the column of (substituent) as the substituent for L ₁ in the general formula (1) can be similarly employed.

  More preferably, the polymer compound has a structural unit (including a salt form) represented by the following general formula (4).

In the general formula _(4), L 1, _{L 2,} and _{L 3} are the same as defined in the general formula (1). Here, L ₁ in each structural unit may be the same or different. When n is 2 or more (when X ₁ is a carbon atom, a silicon atom or a phosphorus atom), each L ₁ may be the same or different.

In the general formula (4), X ₁ represents a nitrogen atom, a carbon atom, a silicon atom, or a phosphorus atom (including a trivalent phosphorus atom and a pentavalent phosphorus atom; in the case of a pentavalent phosphorus atom, X ₁ Represents a group derived from a phosphine oxide compound of P (═O) —R). Here, X ₁ in each structural unit may be the same or different. Preferably X ₁ is a carbon atom. When X ₁ is a carbon atom, a polymer compound having an amino group with a uniform and high-density surface can be obtained with the polymer compound as the center, and the polarization of the dipole layer can be further increased. The stability of the organic photoelectric conversion element to be obtained can be increased.

In the general formula (4), n represents the number of substituents: -L ₁ -N (L ₂ ) (L ₃ ) bonded to X ₁ and is ₁ , 2 or 3. That is, when X ₁ represents a phosphorus atom, n is 1 or 3, when X ₁ represents a carbon atom or a silicon atom, n is 2, and when X ₁ represents a nitrogen atom. In the formula, n is 1.

In the general formula (4), _{Y 1} and _{Y 2, -C (R 3) = C} (R 4) -, - C (R 5) = N -, - represents a O- or -S-. Here, Y ₁ and Y ₂ may be the same or different. Y ₁ and Y ₂ in each structural unit may be the same or different. Preferably, Y ₁ and Y ₂ are each independently —CH═CH—, —CH═N— or —S—. More preferably, Y ₁ and Y ₂₂ are each independently —CH═CH— or —S—, and particularly preferably Y ₁ and Y ₂ are —S—. Y ₁ and Y ₂ are —S—, that is, by introducing a polythiophene system into the polymer main chain, the carrier transport capability is improved, and the power generation layer and the p-type semiconductor material have a similar structure. Since the affinity between the layers is increased, high efficiency and durability can be obtained. Here, R _{3 to} R ₅ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, and a substituted group. Alternatively, it represents an unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms. Preferably, R _{3 to} R ₅ are each independently a hydrogen atom, an alkyl group, and an amino group, and more preferably a hydrogen atom.

  More preferably, the polymer compound has a structural unit (including a salt form) represented by the following general formula (5).

Such a polymer compound having an amino group having two or more generations of branches is a polymer compound having an amino group with a uniform and high-density surface centering on the polymer compound, and further dipolarizing the dipole layer. The stability (durability) of the obtained organic photoelectric conversion element can be further increased.

In the general formula (5), _{Y 3} and _{Y 4, -C (R 10) = C} (R 11) -, - C (R 12) = N -, - represents a O- or -S-. Here, Y ₃ and Y ₄ may be the same or different. Y ₃ and Y ₄ in each structural unit may be the same or different. Y ₃ and Y ₄ have the same definition as Y ₁ and Y ₂ in the general formula (4), and thus the description thereof is omitted here. Preferably, Y ₃ and Y ₄ are each independently —CH═CH—, —CH═N— or —S—. More preferably, Y ₃ and Y ₄ are each independently —CH═CH— or —S—, and particularly preferably Y ₃ and Y ₄ are —S—. Z ₃ and Z ₄ are —S—, that is, by introducing a polythiophene system into the polymer main chain, the carrier transport capability is improved, and the power generation layer and the p-type semiconductor material have a similar structure. Since the affinity between the layers is increased, high efficiency and durability can be obtained.

X ₂ represents a nitrogen atom, a carbon atom or a silicon atom. Here, X ₂ in each structural unit may be the same or different. Preferably, _{X 2} is carbon atom. When X ₂ is a carbon atom, the polymer compound can have a uniform and high-density amino group centered on the polymer compound, and the polarization of the dipole layer can be further increased. The stability of the organic photoelectric conversion element to be obtained can be increased. n represents the number of substituents: -L ₅ -N (L ₆ -N (R ₈ ) (R ₉ )) (L ₇ -N (R ₆ ) (R ₇ )) bonded to X ₂ ; 2 or 3. That is, when X ₂ represents a phosphorus atom, n is 3, when X ₂ represents a carbon atom or a silicon atom, n is 2, and when X ₂ represents a nitrogen atom. , N is 1.

L _{5 to} L ₇ are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, or a substituted or unsubstituted carbon atom. An alkynylene group having 2 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms, and a substituted or unsubstituted carbon atom having 1 to 20 carbon atoms Represents a divalent linking group selected from the group consisting of an alkyleneoxy group and — (L _{1 ′} ) — (OR) _p —. Here, L _{5 to} L ₇ may be the same or different. In addition, L _{5 to} L ₇ in each structural unit may be the same or different. When n is 2 (when X ₂ is a carbon atom or a silicon atom), each of L _{5 to} L ₇ may be the same or different. Since L _{5 to} L ₇ have the same definition as L ₁ in the general formula (1), description thereof is omitted here.

L ₅ represents a substituted or unsubstituted linear or branched alkylene group having 1 to 15 carbon atoms, — (L _{1 ′} ) — (OR) _p — [where L _{1 ′} represents a single bond, carbon A linear or branched alkylene group having 1 to 15 atoms or an arylene group having 6 to 18 carbon atoms; R represents an ethylene group or a propylene group; p is an integer of 1 to 3; It is preferably a substituted or unsubstituted arylene group, and is substituted or unsubstituted linear or branched with a substituent of the formula having 1 to 8 carbon atoms: -L ₁ -N (L ₂ ) (L ₃ ) Chain alkylene group, — (L _{1 ′} ) — (OR) _p — [where L _{1 ′} is a single bond, a linear or branched alkylene group having 1 to 8 carbon atoms, or o—, m— , P-phenylene group; R represents an ethylene group; p is 1 or 2] There it is more preferable. L ₆ and L ₇ are each a substituted or unsubstituted linear or branched alkylene group having 1 to 8 carbon atoms, — (L _{1 ′} ) — (OR) _p — [where L _{1 ′} is A single bond, a linear or branched alkylene group having 1 to 8 carbon atoms or an o-, m-, or p-phenylene group; R represents an ethylene group; p is 1 or 2] Preferably, it is a linear or branched alkylene group having 1 to 6 carbon atoms (for example, methylene group, ethylene group, trimethylene group, tetramethylene group, propylene group, ethylethylene group, pentamethylene group, hexamethylene group). Group), and the above-described alkylene group substituted with a substituent of the formula: -L ₁ -N (L ₂ ) (L ₃ ) is more preferable.

R _{6 to} R ₉ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, substituted or unsubstituted. Or an aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, or L ₂ described above. Here, R _{6 to} R ₉₂ may be the same or different. Further, R _{6 to} R ₉ in each structural unit may be the same or different. The alkyl group, cycloalkyl group, aryl group, and heteroaryl group in R _{6 to} R ₉ have the same definition as L ₄ in the general formula (1), and L ₂ is in the general formula (1). Since the definition is the same as L ₂ in FIG.

R _{10 to} R ₁₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, substituted or unsubstituted. Represents an aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms. Here, R _{6 to} R ₁₂ may be the same or different. In addition, R _{6 to} R ₁₂ in each structural unit may be the same or different. Since R _{6 to} R ₁₂ have the same definition as L ₄ in the general formula (1), description thereof is omitted here.

As described above, in a preferred embodiment of the present invention, there are 1.5 or more amino groups as substituents per aromatic ring in the main chain of the polymer compound. For this reason, as shown in the following compounds 28 and 29, at least one of R _{6 to} R ₉ may be an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group substituted with an amino group. For example, at least one of R _{6 to} R ₉ is preferably a group represented by the formula: — [LN (R)] _{p ′} -LN (R) (R ′). In the above formula, each of L, R and R ′ may be the same or different. L is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, substituted Or a divalent linkage selected from an unsubstituted heteroarylene group having 1 to 30 carbon atoms, a substituted or unsubstituted alkyleneoxy group having 1 to 20 carbon atoms, and-(L1 _' )-(OR) _p-. Represents a group. The alkylene group, cycloalkylene group, arylene group, heteroarylene group, alkyleneoxy group, and-(L _{1 '} )-(OR ₁₅ ) _p -are the same as defined in the general formula (1). Omitted. L is preferably a substituted or unsubstituted alkylene group having 1 to 8 carbon atoms, and includes a methylene group, an ethylene group, a trimethylene group or a tetramethylene group, and a formula: -L ₁ -N (L ₂ ) (L It is more preferable that it is the said alkylene group substituted by the substituent of ₃ ). R and R ′ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted group. A substituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, or a formula:-[LN (R)] _{p '} -LN (R) ( R ′) represents a group represented by Here, since the substituents of R and R ′ are the same as those in the general formula (1) and the like, description thereof is omitted here. R and R ′ are preferably an alkyl group having 1 to 8 carbon atoms or a group represented by the formula: — [LN (R)] _{p ′} -LN (R) (R ′). , An alkyl group having 1 to 3 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group) or a formula:-[LN (R)] _{p '} -LN (R) (R') It is more preferred that p ′ represents the number of repetition of the formula: —L—N (R) —, and can be appropriately selected depending on the desired number of amino groups present in the main chain of the polymer compound. In one embodiment of the present invention, for example, p ′ is preferably an integer of 0 to 5, more preferably an integer of 1 to 4, and particularly preferably an integer of 2 to 3.

The polymer compound according to the present invention preferably has a structural unit represented by the general formula (2) or (3) or (4) or (5). Here, the polymer compound according to the present invention may be a homopolymer composed of a structural unit represented by the general formula (2) or (3) or (4) or (5). Or the copolymer (copolymer) comprised from the 2 or more types of structural unit shown by the said General formula (2) or (3) or (4) or (5) may be sufficient. In addition to the structural unit represented by the above general formula (2) or (3) or (4) or (5), the polymer compound according to the present invention may have another structural unit having no amino group (hereinafter, (It may also be simply referred to as “another structural unit”) to form a copolymer. Here, the other structural units are not particularly limited, and examples thereof include the following structural units. In the following structural units, Y represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted carbon. It represents an aryl group having 6 to 30 atoms, a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, or — (L _{1 ′} ) — (OR) _p H. Here, since the definition of each substituent is the same as the definition in the said General formula (1), description is abbreviate | omitted here. Further, when there are a plurality of Y, each Y may be the same or different. When the polymer compound according to the present invention has other structural units, the content of the other structural units is not particularly limited as long as the effect of the polymer compound according to the present invention is not impaired, but other structures are not limited. The content of the monomer derived from the unit is preferably 10 to 75 mol%, more preferably 20 to 50 mol% in the monomer derived from all the structural units.

  More specifically, the polymer compound according to the present invention includes those having the following structure. The present invention is not limited to these. In addition, in this specification, a compound is prescribed | regulated by the following compound number. In the structure below, “N / A” represents the number of primary to quaternary amino groups per aromatic ring present in each polymer compound.

  In addition, when the main chain of the polymer compound includes a plurality of structural units, the bonding form of the plurality of structural units is not particularly limited, and may be bonded randomly or alternately. The blocks for each structural unit may be combined. Moreover, these polymer compounds may be used alone or in combination of two or more.

  There is no restriction | limiting in particular about the manufacturing method of the high molecular compound which contains the structure represented by General formula (1) which concerns on this invention as a side chain, A conventionally well-known knowledge (for example, ADVANCED MATERIALS 2007, 19, 2010 etc.), below-mentioned Those skilled in the art can easily synthesize by referring appropriately to the knowledge described in the synthesis examples in the column of Examples.

(Molecular weight of polymer compound (polymer or copolymer))
The molecular weight of the polymer compound according to the present invention is not particularly limited, but when defining by practical molecular weight, the polymer compound containing the structure represented by the general formula (1) according to the present invention as a side chain is: The weight average molecular weight is preferably 3000 or more, more preferably 4000 or more, and still more preferably 5000 or more. Here, although the upper limit of the weight average molecular weight of a high molecular compound is not specifically limited, From a viewpoint of ensuring solubility, it is preferable that it is 50000 or less, and it is more preferable that it is 30000 or less.

  The weight average molecular weight can be measured by gel permeation chromatography (GPC), but some compounds do not dissolve in THF, so the molecular weight of the main chain is one step before the compound according to the present invention. The molecular weight may be confirmed by measuring with a precursor of (a compound in which the substituent is an ω-bromoalkyl group). The polymer compound according to the present invention is obtained from the precursor by a polymer reaction, and the length of the main chain does not change greatly. Therefore, the weight average molecular weight of the polymer compound is the weight average molecular weight of the precursor. Can be easily guessed from.

  The weight average molecular weight (Mw) of the polymer compound containing the structure represented by the general formula (1) according to the present invention as a side chain is measured by GPC (gel permeation chromatography) using THF (tetrahydrofuran) as a column solvent. Can be used for molecular weight measurement.

  Specifically, 1 ml of THF (using a degassed sample) is added to 1 mg of a measurement sample, and the sample is stirred using a magnetic stirrer at room temperature to be sufficiently dissolved. Subsequently, after processing with a membrane filter having a pore size of 0.45 μm to 0.50 μm, it is injected into a GPC (gel permeation chromatograph) apparatus.

  GPC measurement conditions are measured by stabilizing the column at 40 ° C., flowing THF (tetrahydrofuran) at a flow rate of 1 ml / min, and injecting about 100 μl of a sample having a concentration of 1 mg / ml.

  As the column, it is preferable to use a combination of commercially available polystyrene gel columns. For example, Shodex GPC KF-801, 802, 803, 804, 805, 806, 807 manufactured by Showa Denko KK, TSKgel G1000H, G2000H, G3000H, G4000H, G5000H, G6000H, G7000H, TSK guard, etc. manufactured by Tosoh Corporation A combination of these is preferred.

  As the detector, a refractive index detector (RI detector) or a UV detector is preferably used. In the measurement of the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve created using monodisperse polystyrene standard particles. About 10 points are preferably used as polystyrene for preparing a calibration curve. In the present invention, the molecular weight is measured under the following measurement conditions.

(Measurement condition)
Equipment: Tosoh High Speed GPC Equipment HLC-8220GPC
Column: TOSOH TSKgel Super HM-M
Detector: RI and / or UV
Eluent flow rate: 0.6 ml / min Sample concentration: 0.1% by mass
Sample volume: 100 μl
Calibration curve: prepared with standard polystyrene: standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation) Mw = 100000 to 500-500 calibration curves (also referred to as calibration curves) were used to calculate the molecular weight. . It is preferable that the 13 samples are substantially equally spaced.

  In addition to the polymer compound according to the present invention, the electron transport layer may be used in combination with other electron transport materials generally used for the electron transport layer. However, from the viewpoint of sufficiently exerting the effects of the present invention, in the material constituting the electron transport layer, the main component is a polymer compound containing the structure represented by the general formula (1) as a side chain. Is preferred. Specifically, the proportion of the polymer compound containing the structure represented by the general formula (1) as a side chain with respect to 100% by mass of the material constituting the electron transport layer is preferably 50% by mass or more. More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more, Especially preferably, it is 95 mass% or more, Most preferably, it is 100 mass%.

  Here, as other electron transport materials as described above, materials that can be used in this technical field can be appropriately employed. For example, octaazaporphyrin, a perfluoro body of a p-type semiconductor (perfluoropentacene, perfluorophthalocyanine, etc.) can be used. Similarly, the HOMO level of the p-type organic semiconductor material used for the photoelectric conversion layer The electron transport layer having a deep HOMO level is provided with a hole blocking function having a rectifying effect so that holes generated in the photoelectric conversion layer do not flow to the cathode side. Therefore, more preferably, a material deeper than the HOMO level of the n-type semiconductor is used as the electron transport material. Examples of such electron transport materials include phenanthrene compounds such as bathocuproine, n-type semiconductor materials such as naphthalenetetracarboxylic acid anhydride, naphthalenetetracarboxylic acid diimide, perylenetetracarboxylic acid anhydride, perylenetetracarboxylic acid diimide, and oxidation. N-type inorganic oxides such as titanium, zinc oxide, and gallium oxide, and alkali metal compounds such as lithium fluoride, sodium fluoride, and cesium fluoride can be used. Moreover, the n-type organic-semiconductor material used for the photoelectric converting layer may be contained in an electron carrying layer.

  In addition, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the like may be used.

  In addition, in the oxadiazole derivatives exemplified for the hole transport material, thiadiazole derivatives in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and quinoxaline derivatives having a quinoxaline ring known as an electron-withdrawing group are also included in electron transport. It can be used as a material. Furthermore, a polymer material in which a structural unit contained in the compound is introduced into a polymer chain, or a polymer material having the compound as a main chain of the polymer can be used as an electron transport material.

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq3), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum. , Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metal of these metal complexes is In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material. In addition, metal-free phthalocyanine or metal phthalocyanine, or a compound in which the terminal of these compounds is substituted with an alkyl group or a sulfonic acid group can be preferably used as an electron transporting material.

  In addition, an electron transport material having high n property doped with impurities can also be used. For example, JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like. Specific examples include N, N′-bis (3-methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (TPD) and 4,4′-bis [N- (naphthyl)- Aromatic diamine compounds such as N-phenyl-amino] biphenyl (α-NPD) and derivatives thereof, oxazole, oxadiazole, triazole, imidazole, imidazolone, stilbene derivative, pyrazoline derivative, tetrahydroimidazole, polyarylalkane, butadiene, 4 , 4 ′, 4 ″ -tris (N- (3-methylphenyl) N-phenylamino) triphenylamine (m-MTDATA), porphine, tetraphenylporphine copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, etc. Compounds, triazole derivatives, It is possible to use oxazizazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, annealed amine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, etc. In the polymer material, polymers such as phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, diacetylene, and derivatives thereof can be preferably used.

  In addition, these electron transport materials may be used individually by 1 type, and may use 2 or more types together. It is also possible to form an electron transport layer by stacking two or more layers made of each material. However, the electron transport layer containing the polymer compound according to the present invention is preferably adjacent to the cathode (anode).

  Although the thickness (thickness at the time of drying) of an electron carrying layer does not have a restriction | limiting in particular, Usually, it is 1-2000 nm. From the viewpoint of further improving the leak prevention effect, the thickness is preferably 3 nm or more. Further, from the viewpoint of maintaining high transmittance and low resistance, the thickness is preferably 1000 nm or less, and more preferably 200 nm or less. More preferably, it is the range of 5-20 nm.

In general, the conductivity of the electron transport layer is preferably as high as possible. However, if the conductivity is too high, the ability to prevent holes from moving may be reduced, and rectification may be reduced. Therefore, the conductivity of the electron transport layer is preferably 10 ⁻⁵ to 1 S / cm, and more preferably 10 ⁻⁴ to 10 ⁻² S / cm.

[electrode]
The organic photoelectric conversion element of this embodiment essentially includes an anode (cathode) 11 and a cathode (anode) 12. As described above, the carriers (holes / electrons) generated in the photoelectric conversion layer 14 drift between the electrodes, and the holes reach the anode 11 and the electrons reach the cathode 12. In the present invention, an electrode through which holes mainly flow is called an anode, and an electrode through which electrons mainly flow is called a cathode. In the case of adopting a tandem configuration, a tandem configuration can be achieved by using a charge recombination layer (also referred to as an intermediate electrode). Furthermore, from the functional aspect of whether or not the electrode has translucency, the translucent electrode is sometimes referred to as a transparent electrode, and the non-translucent electrode is sometimes referred to as a counter electrode. In the case of a normal layer type organic photoelectric conversion element, the anode is usually a transparent electrode having a light transmitting property and the cathode is a counter electrode having no light transmitting property.

  There is no restriction | limiting in particular in the material used for the electrode of this form, The electrode material which can be used in this technical field can be employ | adopted suitably. In the present invention, the intermediate layer (for example, the electron transport layer 27) contains a polymer compound containing the structure represented by the general formula (1) as a side chain, so that an electrode in contact with the intermediate layer (for example, As the cathode, it is possible to use a metal having a large ionization potential and a deep work function instead of aluminum which has a small ionization potential and is easily oxidized.

  In the following, the case of a normal layer type organic photoelectric conversion element which is a preferred embodiment of the present invention will be described. However, in the case of a reverse layer type organic photoelectric conversion element, it is the same except that the electrode configuration is reversed. In the case of a tandem type organic photoelectric conversion element, the same applies as described below.

  The anode 11 in the normal layer type organic photoelectric conversion element 10 shown in FIG. 1 has a relatively large absolute value of work function (for example, work function is −4.5 eV or less, preferably −4.7 eV or less), It can be composed of a transparent electrode material (which can transmit light of 380 to 800 nm). On the other hand, the cathode 12 has a relatively small absolute value of the work function (for example, the work function is −) while taking into account a pseudo shift (0.2 to 0.7 eV) of the work function due to the intermediate layer of the present invention. 4.5 eV or less, preferably less than −4.5 eV), and an electrode material that is substantially stable against oxidation can be used. For example, in the case of an electrode obtained by applying Exemplified Compound 3 of the present invention on ITO and silver with a film thickness of 5 nm, when viewed from the power generation layer due to a pseudo shift of the work function, −4.1 to −4.3 eV It can be regarded as an electrode, and can obtain a sufficient built-in electric field potential difference from the anode (-4.7 to -5.1 eV) and the hole transport layer (-5.2 to -5.5 eV).

In such a normal layer type organic photoelectric conversion element 10, examples of the electrode material used for the anode (first electrode, transparent electrode) 11 include metals such as gold, silver, platinum, and nickel; indium tin oxide Examples thereof include transparent conductive metal oxides such as an object (ITO), SnO ₂ , ZnO, and indium zinc oxide (IZO); carbon materials such as metal nanowires and carbon nanotubes. It is also possible to use a conductive polymer as the anode electrode material. Examples of the conductive polymer that can be used for the anode include polypyrrole, polyaniline, polythiophene, polythienylene vinylene, polyazulene, polyisothianaphthene, polycarbazole, polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, polyphenylacetylene, polydiacetylene. , Polynaphthalene, and derivatives thereof. Among these, it is preferable to use an inorganic substance such as a metal from the viewpoint of hole extraction performance and durability. These electrode materials may be used alone or as a mixture of two or more materials. It is also possible to form an electrode by laminating two or more layers made of each material. The thickness of the anode (transparent electrode) is not particularly limited, but is usually 10 nm to 5 μm, preferably 50 to 200 nm.

  On the other hand, in the normal layer type organic photoelectric conversion element, as an electrode material used for the cathode (second electrode, counter electrode) 12, a metal, an alloy, an electronic conductive compound, and these having a small absolute value of work function Can be used. If a metal is used among these materials, light incident from the anode (transparent electrode) side and transmitted without being absorbed by the photoelectric conversion layer can be reflected by the cathode (counter electrode) and reused for photoelectric conversion. It is possible to improve the photoelectric conversion efficiency.

Specifically, silver, gold, platinum, nickel, aluminum, sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, indium, lithium / aluminum mixture, rare earth metal and the like.

  In addition, according to this embodiment, since the electron transport layer 27 contains the polymer compound including the structure represented by the general formula (1) as a side chain, the ionization potential is small as a constituent material of the cathode. Instead of aluminum that is easily oxidized, it is possible to use a metal having a large ionization potential and a deep work function. That is, in one embodiment of the present invention, the anode is a transparent electrode, and the constituent material of the cathode contains a metal that is equivalent to aluminum or has a higher ionization potential than aluminum. More preferably, the anode is a transparent electrode, and the constituent material of the cathode contains a metal having a higher ionization potential than aluminum. Here, the first ionization potential of aluminum is 138 kcal / mol. The ionization potential of calcium is 140 kcal / mol. Examples of these stable metals having a larger ionization potential than those that are easily oxidized include silver (174 kcal / mol), gold (212 kcal / mol), platinum (208 kcal / mol), nickel (176 kcal / mol), copper (178 kcal). / Mol), zinc (216 kcal / mol) and the like. When such a metal having a first ionization potential higher than about 170 kcal / mol is used, a highly durable organic photoelectric conversion element can be obtained. In particular, from the viewpoint of hole extraction performance and electrical conductivity, the constituent material of the cathode preferably contains silver, gold or copper. More preferably, it is silver or copper, and conversion efficiency and durability can be improved by using silver or copper as a cathode.

  In the case of a compound-based electrode such as ITO, ionization energy cannot be measured, so that a preferable electrode material can be selected in terms of work function. Preferably, among the electrodes, the work function of a single electrode in contact with the intermediate layer containing the conjugated polymer compound of the present invention is −4.5 eV or less as measured by photoelectron spectroscopy. In the normal layer type organic photoelectric conversion element shown in FIG. 1, the intermediate layer containing the polymer compound according to the present invention is an electron transport layer, and the electrode in contact with the intermediate layer corresponds to a cathode. Here, when the work function of the electrode in contact with the intermediate layer exceeds −4.5 eV when measured by photoelectron spectroscopy, the cathode has low conductivity due to oxidation due to oxygen intrusion or the work function becomes deep. There is a risk that the contact resistance of the element will greatly increase, the electrical characteristics of the element will deteriorate, and the durability will decrease significantly. The work function of the electrode in contact with the intermediate layer is more preferably less than −4.5 eV, and even more preferably −4.7 eV or less. Here, the lower limit of the work function of the electrode in contact with the intermediate layer is not particularly limited, but is preferably −5.5 eV or more, and more preferably −5.0 eV or more. By disposing the electrode having such a work function so as to be in contact with the intermediate layer, the organic photoelectric conversion element exhibits a sufficient built-in electric field improving effect, and is excellent in photoelectric conversion efficiency and durability.

  Here, although the work function varies slightly depending on the measurement method, the “work function” used in the present specification is a sufficiently high vacuum using a photoelectron spectrometer (manufactured by ULVAC-PHI, PHI1800). It means the average value of 3 to 5 samples measured by photoelectron spectroscopy.

  The work function of each electrode material according to the measurement method is shown in Table 1 below.

  As shown in the above table, one embodiment of the present invention is characterized by using a metal material having a work function that is the same as or deeper than that of zinc. Thereby, it can prevent that a counter electrode is oxidized and deteriorates with time.

  Specifically, gold (-5.1 eV), silver (-4.7 eV), copper (-4.7 eV), zinc (-4.5 eV), platinum (-6.3 eV), nickel (-5. Metal such as 0 eV); indium tin oxide (ITO) (-4.8 eV), ZnO (-4.5 eV), molybdenum oxide (-5.4 eV), indium zinc oxide (IZO) (-5.3 eV), etc. Examples of the conductive metal oxides include nanowires and nanoparticles of the above metals. In addition, in the above, the inside of () shows the work function of each material. Among these, indium tin oxide (ITO), molybdenum oxide, copper, silver, and gold are preferable, indium tin oxide (ITO), molybdenum oxide, copper, and silver are more preferable, and silver is particularly preferable. By using such a material for the electrode, the counter electrode is prevented from being oxidized and deteriorated with time, the stability (durability) of the electrode is improved, and the organic photoelectric conversion element has a sufficient built-in electric field improving effect. Can exhibit excellent photoelectric conversion efficiency and durability. In this embodiment, the material used for the electrode in contact with the intermediate layer is not particularly limited as long as the work function is −4.5 eV or less (deep). On the other hand, there is no restriction | limiting in particular in the material used for the other electrode, The electrode material which can be used in this technical field can be employ | adopted suitably.

  As described above, the work function may vary by about ± 0.3 eV depending on the measurement method and the surface treatment state of the thin film (with or without ozone oxidation, etc.). It can also be determined (however, it can be applied only to metal elements).

  These electrode materials may be used alone or as a mixture of two or more materials. It is also possible to form an electrode by laminating two or more layers made of each material. The thickness of the cathode (counter electrode) is not particularly limited, but is usually 5 nm to 5 μm, preferably 50 to 200 nm.

  In the reverse layer type organic photoelectric conversion element shown in FIG. 2, the cathode 12 is located on the substrate 25 side on which light is incident, and the anode 11 is located on the opposite side. Therefore, the anode 11 in the reverse layer type shown in FIG. 2 has a relatively large absolute value of the work function, and is usually composed of an electrode material having low translucency. On the other hand, the cathode 12 has a relatively small absolute value of the work function and is made of a transparent electrode material.

  In such a reverse layer type organic photoelectric conversion element, examples of the electrode material used for the anode (counter electrode) include gold, silver, platinum, and nickel. Among these, silver is preferably used from the viewpoints of hole extraction performance, light reflectance, and durability against oxidation and the like. These electrode materials may be used alone or as a mixture of two or more materials. It is also possible to form an electrode by laminating two or more layers made of each material. The thickness of the anode (counter electrode) is not particularly limited, but is usually 10 nm to 5 μm, preferably 50 to 200 nm.

  On the other hand, as an electrode material used for the cathode (transparent electrode) in the reverse layer type organic photoelectric conversion element, for example, metals such as gold, silver, copper, platinum, rhodium, ruthenium, aluminum, magnesium and indium, metal Compounds, and alloys; carbon materials such as carbon nanoparticles, carbon nanowires, and carbon nanostructures. These electrode materials may be used alone or as a mixture of two or more materials. It is also possible to form an electrode by laminating two or more layers made of each material. Among these, it is preferable to use carbon nanowires because a transparent and highly conductive cathode can be formed by a coating method. In addition, when a metal material is used, an auxiliary electrode having a thickness of about 1 to 20 nm is formed on the side facing the anode (counter electrode) using, for example, aluminum, an aluminum alloy, silver, a silver compound, or the like. Then, a cathode (transparent electrode) can be obtained by providing a conductive polymer film exemplified as the anode (transparent electrode) material of the above-mentioned normal layer type organic photoelectric conversion element. The thickness of the cathode (transparent electrode) is not particularly limited, but is usually 10 nm to 5 μm, preferably 50 to 200 nm.

  In the reverse layer type organic photoelectric conversion element shown in FIG. 2, the intermediate layer containing the polymer compound according to the present invention is an electron transport layer, and the electrode in contact with the intermediate layer corresponds to an anode. Therefore, as an electrode material used for the anode (counter electrode), it is preferable to use metals, alloys, electronic conductive compounds, and mixtures thereof having a work function of −4.5 eV or less.

[Photoelectric conversion layer]
The organic photoelectric conversion element 10 of the present embodiment essentially includes a photoelectric conversion layer 14 between the cathode 12 and the anode 11 described above. The photoelectric conversion layer has a function of converting light energy into electric energy using the photovoltaic effect. The photoelectric conversion layer essentially includes a p-type organic semiconductor material and an n-type organic semiconductor material as a photoelectric conversion material. When light is absorbed by these photoelectric conversion materials, excitons are generated, which are separated into holes and electrons at the pn junction interface.

<P-type semiconductor material>
Examples of the p-type organic semiconductor material used for the photoelectric conversion layer according to the present invention include various condensed polycyclic aromatic low-molecular compounds and conjugated polymers (p-type conjugated polymer compounds).

  Examples of the condensed polycyclic aromatic low molecular weight compound include anthracene, tetracene, pentacene, hexacene, heptacene, chrysene, picene, fluorene, pyrene, peropyrene, perylene, terylene, quaterylene, coronene, ovalene, thacumanthracene, bisanthene, zeslene. , Heptazethrene, pyranthrene, violanthene, isoviolanthene, cacobiphenyl, anthradithiophene, etc., porphyrin, copper phthalocyanine, tetrathiafulvalene (TTF) -tetracyanoquinodimethane (TCNQ) complex, bisethylenetetrathiafulvalene ( BEDTTTTF) -perchloric acid complexes, and derivatives and precursors thereof.

  Examples of the derivative having the above-mentioned condensed polycycle include WO 03/16599 pamphlet, WO 03/28125 pamphlet, US Pat. No. 6,690,029, JP 2004-107216 A. A pentacene derivative having a substituent described in JP-A-2003-136964, a pentacene precursor described in US Patent Application Publication No. 2003/136964, and the like; Amer. Chem. Soc. , Vol. 127, no. 14, p 4986, J. MoI. Amer. Chem. Soc. , Vol. 123, p9482; Amer. Chem. Soc. , Vol. 130 (2008), no. 9, acene compounds substituted with a trialkylsilylethynyl group described in p2706 and the like. Alternatively, as described in US Patent Application Publication No. 2003/136964, Japanese Patent Application Laid-Open No. 2008-16834, etc., a soluble substituent reacts and becomes insoluble by applying energy such as heat (pigment) Material) and the like.

  As the conjugated polymer, for example, a polythiophene such as poly-3-hexylthiophene (P3HT) and an oligomer thereof, or a technical group described in Technical Digest of the International PVSEC-17, Fukuoka, Japan, 2007, P1225. Polythiophene, Nature Material, (2006) vol. 5, p328, polythiophene-thienothiophene copolymer, polythiophene-diketopyrrolopyrrole copolymer described in WO2008 / 000664, Adv. Mater. , 2007, p4160, a polythiophene-thiazolothiazole copolymer, Nature Mat. , Vol. 6 (2007), p497 described in PCPDTBT, etc., polypyrrole and its oligomer, polyaniline, polyphenylene and its oligomer, polyphenylene vinylene and its oligomer, polythienylene vinylene and its oligomer, polyacetylene, polydiacetylene, Examples thereof include polymer materials such as σ-conjugated polymers such as polysilane and polygermane.

  In addition, oligomeric materials instead of polymer materials include thiophene hexamer α-sexual thiophene α, ω-dihexyl-α-sexual thiophene, α, ω-dihexyl-α-kinkethiophene, α, ω-bis (3 Oligomers such as -butoxypropyl) -α-sexithiophene can be preferably used.

  More preferably, it is a copolymer having an electron donating group (donor unit) and an electron withdrawing group (acceptor unit) in the main chain as a p-type conjugated polymer. More specifically, the p-type conjugated polymer has a structure in which donor units and acceptor units are alternately arranged. Thus, by arranging the donor unit and the acceptor unit alternately, the absorption region of the p-type organic semiconductor can be expanded to a long wavelength region. That is, since the p-type conjugated polymer can absorb light in a long wavelength region (for example, 700 to 1000 nm) in addition to the absorption region (for example, 400 to 700 nm) of the conventional p-type organic semiconductor, It becomes possible to efficiently absorb radiant energy over a wide range of the optical spectrum.

  The donor unit that can be included in the p-type conjugated polymer is a unit in which the LUMO level or the HOMO level is shallower than a hydrocarbon aromatic ring (benzene, naphthalene, anthracene, etc.) having the same number of π electrons. If there is, it can be used without restriction. For example, a unit including a thiophene ring, a furan ring, a pyrrole ring, a hetero 5-membered ring such as cyclopentadiene, silacyclopentadiene, and a condensed ring thereof.

  Specific examples include fluorene, silafluorene, carbazole, dithienocyclopentadiene, dithienosylcyclopentadiene, dithienopyrrole, and benzodithiophene.

  On the other hand, acceptor units that can be included in the p-type conjugated polymer include, for example, quinoxaline skeleton, pyrazinoquinoxaline skeleton, benzothiadiazole skeleton, benzooxadiazole skeleton, benzoselenadiazole skeleton, benzotriazole skeleton, pyrido Thiadiazole skeleton, thienopyrazine skeleton, phthalimide skeleton, 3,4-thiophenedicarboxylic acid imide skeleton, isoindigo skeleton, thienothiophene skeleton, diketopyrrolopyrrole skeleton, 4-acyl-thieno [3,4-b] thiophene skeleton, thienopyrrole A dione skeleton, a thiazolothiazole skeleton described in WO 2011/085004, a pyrazolo [5,1-c] [1,2,4] triazole skeleton, Am. Chem. Soc. , 2011, 133 (25), pp9638, and the like.

  In addition, the donor unit or acceptor unit contained in the p-type conjugated polymer of this embodiment may be used alone or in combination of two or more.

  In the present embodiment, preferable p-type conjugated polymers include Nature Material, (2006) vol. 5, a polythiophene-thienothiophene copolymer described in p328, a polythiophene-diketopyrrolopyrrole copolymer described in WO08 / 000664, a thiazolothiazole derivative described in WO2011 / 085004, Adv . Mater. , 2007, p4160, a polythiophene-thiazolothiazole copolymer, Nature Mat. vol. 6 (2007), p497, the dithienocyclopentadiene derivative described in PCPDTBT and the like; Am. Chem. Soc. , 2011, 133 (25), pp9638, dithienocyclopentadiene derivatives such as US Patent No. 8008421, dithienosilole derivatives described in US Patent No. 8008421, and the like.

  Among these, a material that can form a thick power generation layer with high mobility as described in Non-Patent Document 2 (Appl. Phys. Lett. Vol. 98, p043301) is preferable. By using a material that can form a thick power generation layer, it is possible to obtain high external quantum efficiency in all spectral regions, and because the mobility is high even when the power generation layer is thick (the built-in electric field is reduced), the fill factor is Since it does not decrease, both high external quantum efficiency and fill factor can be achieved, and a highly efficient device can be obtained.

  Specifically, it is preferable that the p-type organic semiconductor material has a structure represented by the following general formula (6).

In the general formula (6), X ₃ represents a carbon atom, a silicon atom, or a germanium atom. In the general formula (6), a compound in which X ₃ is a silicon atom is preferable because synthesis is easy and a crystal having high mobility and high mobility can be easily obtained.

In the general formula (6), R ₁₃ and R ₁₄ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms. Represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms. Here, R ₁₃ and R ₁₄ may be the same or different. Further, R ₁₃ and R ₁₄ in each structural unit may be the same or different. In the general formula (6), the substituted or unsubstituted alkyl group has the same definition as the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms in the general formula (1). Omitted. Similarly, the cycloalkyl group, the aryl group and the heteroaryl group in the general formula (6) are each a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms in the general formula (1). The description is omitted here because it is the same definition as the substituted or unsubstituted aryl group having 6 to 30 carbon atoms and the substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

  In another embodiment, the p-type organic semiconductor material preferably has a structure represented by the following general formula (9).

In the general formula (9), R ₁₈ and R ₁₉ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms ( Alkyl ether group), a substituted or unsubstituted alkyl ester group having 1 to 20 carbon atoms, or an alkylcarbonyl group, and R ₁₈ and R ₁₉ may be bonded to each other to form a ring. Here, R ₁₈ and R ₁₉ may be the same or different. Further, R ₁₈ and R ₁₉ in each structural unit may be the same or different. In the general formula (9), the substituted or unsubstituted alkyl group has the same definition as the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms in the general formula (1). Omitted.

  In the above general formula (6) and chemical formula (9), examples of the substituent optionally present in the alkyl group, cycloalkyl group, aryl group, heteroaryl group, or alkylsilyl group include a halogen atom (fluorine atom). , Chlorine atom, bromine atom, iodine atom), acyl group, alkyl group, phenyl group, alkoxy group, halogenated alkyl group, halogenated alkoxy group, nitro group, amino group, alkylamino group, alkylcarbonylamino group, arylamino Groups, arylcarbonylamino groups, carbonyl groups, alkoxycarbonyl groups, alkylaminocarbonyl groups, alkoxysulfonyl groups, alkylthio groups, carbamoyl groups, aryloxycarbonyl groups, oxyalkyl ether groups, cyano groups, etc., but are not limited thereto. Be done Not to.

  The alkoxy group having 1 to 20 carbon atoms is not particularly limited, and examples thereof include methoxy group, ethoxy group, isopropoxy group, tert-butoxy group, n-octyloxy group, n-decyloxy group, and n-hexa. A decyloxy group, 2-ethylhexyloxy group, 2-hexyldecyloxy group, etc. are mentioned.

  The alkyl ester group having 1 to 20 carbon atoms is a group in which “—COO—” or “—OCO—” is bonded to an alkyl group having 1 to 19 carbon atoms (alkyl-COO— or alkyl-OCO—). A group in which “—COO—” or “—OCO—” is bonded to the alkyl group exemplified above.

  The alkylcarbonyl group having 1 to 20 carbon atoms is a group in which “—CO—” is bonded to an alkyl group having 1 to 19 carbon atoms (a group represented by alkyl-CO—). And a group in which “—CO—” is bonded to the alkyl group.

  The structures represented by the general formulas (6) and (9) function as a donor unit, and a thiophene structure with high mobility condenses to have a large π-conjugated plane, but the solubility is imparted by a substituent. Has been. Since such a donor unit is excellent in both solubility and mobility, the photoelectric conversion efficiency can be further improved.

  In another embodiment, the p-type organic semiconductor material preferably has a structure represented by the following general formula (7). A P-type organic semiconductor material having these units has high mobility, high open-circuit voltage, and can absorb a wide absorption wavelength.

  In still another embodiment, the p-type organic semiconductor material preferably has a structure represented by the following general formula (8). A P-type organic semiconductor material having these units has a high mobility and an open circuit voltage can be increased.

In the general formula (8), Y ₅ and Y ₆ each independently represent —C (R ₁₇ ) ═ or —N═. Here, Y ₅ and Y ₆ may be the same or different. Y ₅ and Y ₆ in each structural unit may be the same or different. However, Y ₅ and Y ₆ are preferably the same from the viewpoint of improving mobility (improving crystallinity and symmetry). When -Y ₅ = and -Y ₆ = is -C _{(R 17)} is a = the general formula (8) represents a thienothiophene ring structure, if = -Y ₅ = and -Y ₆ are -N = General formula 2 represents a thiazolothiazole ring structure. Among, -Y ₅ = and -Y ₆ = is preferably -N =. This is because, when -Y ₅ = and -Y ₆ = is -N =, since the planarity is higher than when -C (R ³ ) =, high mobility is easily obtained. This is because the photoelectric conversion efficiency and durability can be further improved. Further, the HOMO level can be made deeper, which is preferable.

In the general formula (7) or (8), R _{15 to} R ₁₇ are each independently a hydrogen atom (H), a halogen atom (F, Cl, Br, or I), a substituted or unsubstituted carbon An alkyl group having 1 to 20 atoms, a fluorinated alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a fluorinated cycloalkyl group having 3 to 20 carbon atoms, and 1 to 1 carbon atoms. 20 alkoxy groups, fluorinated alkoxy groups having 1 to 20 carbon atoms, fluorinated alkylthio groups having 1 to 20 carbon atoms, aryl groups having 6 to 30 carbon atoms, fluorinated aryl groups having 6 to 30 carbon atoms Represents a heteroaryl group having 1 to 20 carbon atoms or a fluorinated heteroaryl group having 1 to 20 carbon atoms. R ₁₅ and R ₁₆ in the general formula (7) may be the same or different. Further, R ₁₅ and R ₁₆ in each structural unit may be the same or different. However, R ₁₅ and R ₁₆ are preferably the same from the viewpoint of improving mobility (improving crystallinity and symmetry).

In the general formula (7) or (8), the substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, and heteroaryl group have the same definition as L ₄ in the general formula (1). The description is omitted here.

  In the general formula (7) or (8), the halogen atom is not particularly limited and may be any of a fluorine atom (F), a chlorine atom (Cl), a bromine atom (Br), and an iodine atom (I). Also good. Among these, a fluorine atom (F) or a chlorine atom is preferable and a fluorine atom (F) is preferable from the viewpoint that side reactions hardly occur during polymerization (Br and I may react with tin). More preferred.

Although there is no restriction | limiting in particular as said C1-C20 fluorinated alkyl group, For example, the group by which at least 1 of the hydrogen atom contained in the alkyl group illustrated above was substituted by the fluorine atom is mentioned. Among these, from the viewpoint of achieving a higher V _oc (deep HOMO level), the carbon atom closest to the bonding site with the ring (naphthobisbenzothiadiazole ring, thiazolothiazole ring, thienothiophene ring) (that is, in the alkyl group) It is preferable that only the 1st-position carbon atom is a group substituted with a fluorine atom. Specifically, fluoromethyl group, 1-fluoroethyl group, 1-fluoropropyl group, 1-fluorobutyl group, 1-fluorooctyl group, 1-fluorodecyl group, 1-fluorohexadecyl group, 1-fluoro- Monofluoroalkyl groups such as 2-ethylhexyl group and 1-fluoro-2-hexyldecyl group; difluoromethyl group, 1,1-difluoroethyl group, 1,1-difluoropropyl group, 1,1-difluorobutyl group, 1 , 1-difluorooctyl group, 1,1-difluorodecyl group, 1,1-difluorohexadecyl group, 1,1-difluoro-2-ethylhexyl group, 1,1-difluoro-2-hexyldecyl group, etc. Group; a trifluoroalkyl group such as a trifluoromethyl group, and the like. Moreover, it is preferable that it is a C1-C3 fluorinated alkyl group from a viewpoint of maintaining the applicability | paintability of an upper layer. Such a number of carbon atoms is sufficiently shorter than other soluble groups (substituents for imparting solubility generally use C6 or more) and have little influence on the upper layer coating property. It is. Of these, a trifluoromethyl group having 1 carbon atom is more preferable.

The fluorinated cycloalkyl group having 3 to 20 carbon atoms is not particularly limited, and examples thereof include a group in which at least one hydrogen atom contained in the cycloalkyl group exemplified above is substituted with a fluorine atom. . Among these, from the viewpoint of achieving higher V _oc (deep HOMO level), it is preferable that all the hydrogen atoms contained in the cycloalkyl group exemplified above are groups substituted with fluorine atoms. In view of this, the number and position of fluorine atoms are preferably adjusted appropriately. Moreover, it is preferable that it is a C4-C8 fluorinated cycloalkyl group from a viewpoint of improving solubility.

The fluorinated aryl group having 6 to 30 carbon atoms is not particularly limited, and examples thereof include a group in which at least one hydrogen atom contained in the aryl group exemplified above is substituted with a fluorine atom. Among these, from the viewpoint of achieving higher V _oc (deep HOMO level), it is preferable that all the hydrogen atoms contained in the aryl group exemplified above are groups substituted with fluorine atoms. In view of the above, the number and position of fluorine atoms are preferably adjusted appropriately.

The fluorinated heteroaryl group having 1 to 20 carbon atoms is not particularly limited, and examples thereof include a group in which at least one hydrogen atom contained in the heteroaryl group exemplified above is substituted with a fluorine atom. . Among these, from the viewpoint of achieving higher V _oc (deep HOMO level), it is preferable that all of the hydrogen atoms contained in the heteroaryl group exemplified above are groups substituted with fluorine atoms. In view of this, the number and position of fluorine atoms are preferably adjusted appropriately.

In addition, the substituent optionally present in R _{15 to} R ₁₇ is not particularly limited, and examples thereof include an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an acyl group, and an alkoxycarbonyl group. Group, amino group, alkoxy group, cycloalkyloxy group, aryloxy group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio Group, arylthio group, silyl group, sulfonyl group, sulfinyl group, ureido group, phosphoric acid amide group, halogen atom, hydroxyl group, mercapto group, cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfi group It can be exemplified group, a hydrazino group, and an imino group.

  The structure represented by the general formula (7) or (8) functions as an acceptor unit. By having the conjugated polymer compound having these structures in the photoelectric conversion layer of the organic photoelectric conversion element, it becomes possible to improve the film forming property of the layer adjacent to the photoelectric conversion layer.

  Among them, the p-type organic semiconductor material contained in the photoelectric conversion layer is preferably a structure represented by the following general formula (6), a structure represented by the following general formula (7), and a structure represented by the following general formula (8). At least one of the following.

  More preferably, it is a p-type organic semiconductor material including both the structures represented by the general formulas (7) and (8). Such a p-type organic semiconductor material includes a second charge transport layer formed on the power generation layer (an electron transport layer / hole blocking layer in a normal layer configuration, a hole transport layer / in a reverse layer configuration, Even if the polar solvent (water, alcohol solvent) used for forming the electronic block layer is formed under extremely dry conditions such as in a glove box, it does not repel during application. Can be formed.

  The molecular weight of the conjugated polymer (p-type conjugated polymer compound) is not particularly limited, but the number average molecular weight is preferably 5,000 to 500,000, more preferably 10,000 to 100,000, and 15,000 to 50,000. More preferably it is. When the number average molecular weight is 5000 or more, the effect of improving the fill factor becomes more remarkable. On the other hand, when the number average molecular weight is 500,000 or less, the solubility of the p-type conjugated polymer is improved, so that productivity can be increased. In addition, in this specification, the value measured by gel permeation chromatography (GPC) is employ | adopted for a number average molecular weight.

  In addition, although it is preferable that the photoelectric converting layer in this invention essentially contains the p-type conjugated polymer mentioned above, it may contain other p-type organic-semiconductor materials. Examples of such other p-type organic semiconductor materials include triarylamine compounds, benzidine compounds, pyrazoline compounds, styrylamine compounds, hydrazone compounds, triphenylmethane compounds, carbazole compounds, polysilane compounds, thiophene compounds, phthalocyanine compounds, Cyanine compounds, merocyanine compounds, oxonol compounds, polyamine compounds, indole compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, Fluoranthene derivatives) and metal complexes having a nitrogen-containing heterocyclic compound as a ligand. However, from the viewpoint of remarkably expressing the effects of the present invention, the mass ratio of the conjugated polymer (p-type conjugated polymer compound) in the p-type organic semiconductor material contained in the photoelectric conversion layer is preferably 5 More preferably, it is 10 mass% or more, More preferably, it is 50 mass% or more, Especially preferably, it is 90 mass% or more, Most preferably, it is 100 mass%.

  In the present invention, the band gap of the p-type organic semiconductor material contained in the photoelectric conversion layer is preferably 1.8 eV or less, and more preferably 1.6 to 1.1 eV. When the band gap is 1.8 eV or less, sunlight can be widely absorbed. On the other hand, when the band gap is 1.1 eV or more, the open circuit voltage Voc (V) is easily generated, and the conversion efficiency can be improved. In this embodiment, only one p-type organic semiconductor may be used alone, or two or more p-type organic semiconductors may be used in combination.

<N-type semiconductor material>
The n-type organic semiconductor material used for the photoelectric conversion layer of this embodiment is not particularly limited as long as it is an acceptor (electron-accepting) organic compound, and materials that can be used in this technical field can be appropriately employed. . As such a compound, for example, a perfluoro product in which a hydrogen atom of the p-type organic semiconductor material is substituted with a fluorine atom, such as fullerene, carbon nanotube, and octaazaporphyrin (for example, perfluoropentacene or perfluorophthalocyanine), Examples thereof include aromatic carboxylic acid anhydrides such as naphthalenetetracarboxylic acid anhydride, naphthalenetetracarboxylic acid diimide, perylenetetracarboxylic acid anhydride, and perylenetetracarboxylic acid diimide, and polymer compounds containing an imidized product thereof as a skeleton.

  Of these, fullerenes, carbon nanotubes, or derivatives thereof are preferably used from the viewpoint that charge separation can be efficiently performed with a p-type organic semiconductor material at high speed (up to 50 fs). More specifically, fullerene C60, fullerene C70, fullerene C76, fullerene C78, fullerene C84, fullerene C240, fullerene C540, mixed fullerene, fullerene nanotube, multi-walled carbon nanotube, single-walled carbon nanotube, carbon nanohorn (conical type), etc. , And some of these are hydrogen atoms, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), substituted or unsubstituted alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, And a fullerene derivative substituted with a cycloalkyl group, a silyl group, an ether group, a thioether group, an amino group, or the like.

  In particular, [6,6] -phenyl C61-butyric acid methyl ester (abbreviation PCBM; PC61BM), [6,6] -phenyl C61-butyric acid-nbutyl ester (PCBnB), [6,6] -phenyl C61-butyric acid-isobutyl ester (PCBiB), [6,6] -phenyl C61-butyric acid-n-hexyl ester (PCBH), [6,6] -phenyl C71-butyric acid methyl ester (abbreviation PC71BM) Adv. Mater. , Vol. 20 (2008), p2116, aminated fullerene described in JP-A 2006-199674, metallocene fullerene described in JP-A 2008-130889, US Pat. No. 7,329,709 A fullerene having a cyclic ether group described in the specification; Am. Chem. Soc. 2009, 131, 16048. It is preferable to use a fullerene derivative whose solubility is improved by a substituent such as the alkylsilylated fullerene described in 1). In this embodiment, the n-type organic semiconductor material may be used alone or in combination of two or more.

  The junction form of the p-type organic semiconductor and the n-type organic semiconductor in the photoelectric conversion layer of this embodiment is not particularly limited, and may be a planar heterojunction or a bulk heterojunction. A planar heterojunction is a junction in which a p-type organic semiconductor layer containing a p-type organic semiconductor and an n-type organic semiconductor layer containing an n-type organic semiconductor are stacked, and the surface where these two layers contact is the pn junction interface. It is a form. On the other hand, a bulk heterojunction (bulk heterojunction) is formed by applying a mixture of a p-type organic semiconductor and an n-type organic semiconductor, and the domain of the p-type organic semiconductor and the n-type organic semiconductor in this single layer. And have a microphase separation structure. Therefore, in a bulk heterojunction, as compared with a planar heterojunction, many pn junction interfaces exist throughout the layer. Therefore, most of the excitons generated by light absorption can reach the pn junction interface, and the efficiency leading to charge separation can be increased. For these reasons, the junction between the p-type organic semiconductor and the n-type organic semiconductor in the photoelectric conversion layer of this embodiment is preferably a bulk heterojunction.

  In the present invention, the mixing ratio of the p-type organic semiconductor material and the n-type organic semiconductor material contained in the photoelectric conversion layer is preferably in the range of 2: 8 to 8: 2, more preferably 3: 7 to 7 in terms of mass ratio. : 3 range. Moreover, the film thickness of a photoelectric converting layer becomes like this. Preferably it is 50-400 nm, More preferably, it is 80-300 nm.

  The photoelectric conversion layer may contain an inorganic p-type semiconductor material and an n-type semiconductor material as necessary.

[Hole transport layer (also called electron blocking layer)]
The organic photoelectric conversion element of this form can contain a positive hole transport layer as needed. The hole transport layer has a function of transporting holes and a property of extremely small ability to transport electrons (for example, 1/10 or less of the mobility of holes). The hole transport layer is provided between the photoelectric conversion layer and the anode and prevents recombination of electrons and holes by blocking the movement of electrons while transporting holes to the anode. Can do.

  There is no restriction | limiting in particular in the hole transport material used for a hole transport layer, The material which can be used in this technical field can be employ | adopted suitably. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives , Stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  In addition, porphyrin compounds, aromatic tertiary amine compounds, styrylamine compounds, and the like can be used. Of these, aromatic tertiary amine compounds are preferably used. In some cases, the hole transport layer may be formed using an inorganic compound such as a metal oxide such as molybdenum, vanadium, or tungsten, or a mixture thereof.

  Among these metal oxides, vanadium oxide, molybdenum oxide, and the like are preferable in that the work function is appropriate. However, it is generally known that a metal having a large oxidation number, particularly molybdenum oxide, has a large change in work function after vapor deposition (Appl. Phys. Lett. 96, p243307, 2010) and is good immediately after vapor deposition (˜− It is known that the work function that was 5.4 eV) suddenly becomes deeper (˜−6.0 eV) when exposed to oxygen or the like, and becomes a trap for carrier transport. Even when such an unstable hole transport layer with a rapid change with time is formed, when the conjugated polymer compound thin film of the present invention is formed, the abrupt change in the work function is suppressed, and a metal as the hole transport layer is suppressed. The durability of the organic thin film photoelectric conversion element using an oxide can be increased.

  Furthermore, a polymer material in which a structural unit contained in the above compound is introduced into a polymer chain, or a polymer material having the above compound as the main chain of the polymer can also be used as a hole transport material. JP-A-11-251067, J. Org. Huang et. al. , Applied Physics Letters, 80 (2002), p. A p-type hole transport material as described in 139 can also be used.

  Alternatively, a hole transport material having a high p property doped with impurities can be used. For example, JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like. Among these, PEDOT (poly-3,4-ethylenedioxythiophene) -PSS (polystyrene sulfonic acid) and polyaniline are preferable.

  In addition, these hole transport materials may be used individually by 1 type, and may use 2 or more types together. It is also possible to form a hole transport layer by laminating two or more layers made of each material. The method for forming the hole transport layer is not particularly limited, and a known production method can be applied in the same manner or appropriately modified.

  The thickness (dry film thickness) of the hole transport layer is not particularly limited, but is usually 1 to 2000 nm. From the viewpoint of further improving the leak prevention effect, the thickness is preferably 5 nm or more. Further, from the viewpoint of maintaining high transmittance and low resistance, the thickness is preferably 1000 nm or less, and more preferably 200 nm or less.

In general, the conductivity of the hole transport layer is preferably as high as possible. However, if the conductivity is too high, the ability to prevent electrons from moving may be reduced, and rectification may be reduced. Therefore, the conductivity of the hole transport layer is preferably 10 ⁻⁵ to 1 S / cm, and more preferably 10 ⁻⁴ to 10 ⁻² S / cm.

[Charge recombination layer; intermediate electrode]
In a tandem type (multi-junction type) organic photoelectric conversion element having two or more (two in FIG. 3) photoelectric conversion layers as shown in FIG. 3, a charge recombination layer (intermediate electrode) is provided between the photoelectric conversion layers. 38 is arranged.

  When the photoelectric conversion element according to the present invention has such a charge recombination layer 38, as shown in FIG. 3, the charge recombination layer 38 is disposed on the first photoelectric conversion layer 14a side. The second electron transport layer 38a and the second hole transport layer 38b disposed on the second photoelectric conversion layer 14b side are preferable.

  In such a form, there is no particular limitation on the specific form of the material constituting the second electron transport layer 38a and the second hole transport layer 38b, but each of the hole transport layer and the electron transport layer described above. These constituent materials can be used in appropriate combinations.

  In one embodiment of the present invention, the charge recombination layer (intermediate electrode) 38 preferably contains a polymer compound having a structure represented by the general formula (1) as a side chain. That is, in one embodiment of the present invention, at least two photoelectric conversion layers are disposed via the intermediate layer, and the intermediate layer interposed between the two photoelectric conversion layers is represented by the general formula ( A polymer compound containing the structure represented by 1) as a side chain is contained. Furthermore, the charge recombination layer (intermediate electrode) 38 has a layer containing the polymer compound according to the present invention, and is preferably used as an electron transport layer. That is, the intermediate layer (charge recombination layer (intermediate electrode) 38) interposed between the two photoelectric conversion layers has at least a hole transport layer and an electron transport layer, and the electron transport layer of the intermediate layer includes A polymer compound containing the structure represented by the general formula (1) as a side chain is contained. Specifically, when the charge recombination layer (intermediate electrode) 38 has a laminated structure of a hole transport layer and an electron transport layer as shown in FIG. 3, the electron transport layer is represented by the general formula (1). It is preferable to contain the high molecular compound which contains the structure made as a side chain.

  On the other hand, in the embodiment shown in FIG. 3, it is preferable to use a p-type conductive polymer material having high conductivity and high acidity as a constituent material of the hole transport layer. That is, in one embodiment of the present invention, the hole transport layer of the intermediate layer interposed between two photoelectric conversion layers contains a p-type conductive polymer material. As a p-type conductive polymer material with high conductivity and high acidity. Examples thereof include conductive polymers such as PEDOT (poly-3,4-ethylenedioxythiophene) -PSS (polystyrene sulfonic acid) and polyaniline. A hole transport layer containing a p-type conductive polymer material having high conductivity and high acidity and an electron transport layer containing a polymer compound represented by the general formula (1) are usually a normal layer tandem. In the mold, the hole transport layer is stacked and then the electron transport layer is manufactured by stacking. In the reverse layer tandem type, the electron transport layer is stacked and then the hole transport layer is stacked. Here, the coating liquid containing the p-type conductive polymer material having high conductivity and high acidity for forming the hole transport layer usually has a relatively low pH. Therefore, the film surface pH of the formed hole transport layer is also relatively small. Therefore, such a hole transport layer can usually cause deterioration of an adjacent electron transport layer, but the polymer compound represented by the general formula (1) has a high resistance to an acid, and thus has such a structure. Since it is difficult to deteriorate even when used as a charge recombination layer (intermediate electrode) in the tandem organic photoelectric conversion element, it is preferable (especially when used as an electron transport layer in the charge recombination layer). Specifically, in a preferred embodiment of the present invention, the film surface pH of the second hole transport layer 38b constituting the charge recombination layer 38 is preferably 4 or less, more preferably 3 or less, Particularly preferably, it is 2.5 or less. In addition, although there is no restriction | limiting in particular about the lower limit of the said film surface pH, From a durable viewpoint, Preferably it is 1.0 or more, More preferably, it is 1.5 or more.

  The pH of the hole transport layer forming coating solution and the film surface pH of the hole transport layer can be measured by known methods. The film surface pH of the hole transport layer is, for example, after forming the hole transport layer, dropping a certain amount of pure water on the film surface, destroying the film surface, and allowing to stand for 30 minutes, then dropping to one drop type pH The pH can also be measured with a pHBOY-P2 (manufactured by Shindengen Electric Industry Co., Ltd.).

  As described above, the preferred embodiment of the present invention has been described with reference to FIG. 3 by taking as an example the case where the charge recombination layer 38 includes the second electron transport layer 38a and the second hole transport layer 38b. The present invention is not limited to such a form, and a form in which the charge recombination layer 38 made of a single layer is interposed between two adjacent photoelectric conversion layers can also be adopted. In such a form, the material constituting the charge recombination layer is not particularly limited as long as it is a material having both conductivity and translucency, and ITO, AZO, FTO, and titanium oxide exemplified as the above electrode materials. Transparent metal oxides such as Ag, Al and Au, carbon materials such as carbon nanoparticles and carbon nanowires, and conductive polymers such as PEDOT: PSS and polyaniline can be used. These materials may be used alone or in combination of two or more. It is also possible to form a charge recombination layer by laminating two or more layers made of each material.

  The electric conductivity of the charge recombination layer is preferably high from the viewpoint of charge transport. Specifically, it is preferably 5 to 50000 S / cm, more preferably 100 to 10,000 S / cm. The thickness of the charge recombination layer is not particularly limited, but is preferably 1 to 1000 nm, and preferably 5 to 50 nm. Leakage can be suppressed by setting the thickness to 1 nm or more. On the other hand, the transparency can be increased by setting the thickness to 1000 nm or less.

[substrate]
The organic photoelectric conversion element according to the present invention may include a substrate as necessary. The substrate has a role as a member to be coated with a coating solution when the electrode is formed by a coating method.

  When light that is photoelectrically converted enters from the substrate side, the substrate is preferably a member that can transmit the light that is photoelectrically converted, that is, a member that is transparent to the wavelength of the light to be photoelectrically converted. As the substrate, for example, a glass substrate, a resin substrate and the like are preferably mentioned, but it is desirable to use a transparent resin film from the viewpoint of light weight and flexibility.

  There is no restriction | limiting in particular in the transparent resin film which can be preferably used as a transparent substrate by this invention, The material, a shape, a structure, thickness, etc. can be suitably selected from well-known things. For example, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) modified polyester, polyethylene (PE) resin film, polypropylene (PP) resin film, polystyrene resin film, polyolefin resins such as cyclic olefin resin Film, vinyl resin film such as polyvinyl chloride, polyvinylidene chloride, polyether ether ketone (PEEK) resin film, polysulfone (PSF) resin film, polyether sulfone (PES) resin film, polycarbonate (PC) resin film, A polyamide resin film, a polyimide resin film, an acrylic resin film, a triacetyl cellulose (TAC) resin film, and the like can be given. If the resin film transmittance of 80% or more at ~800nm), can be preferably applied to a transparent resin film according to the present invention. Among these, from the viewpoint of transparency, heat resistance, ease of handling, strength and cost, it is preferably a biaxially stretched polyethylene terephthalate film, a biaxially stretched polyethylene naphthalate film, a polyethersulfone film, or a polycarbonate film, and biaxially stretched. More preferred are polyethylene terephthalate films and biaxially stretched polyethylene naphthalate films.

  The transparent substrate used in the present invention can be subjected to a surface treatment or an easy adhesion layer in order to ensure the wettability and adhesiveness of the coating solution. A conventionally well-known technique can be used about a surface treatment or an easily bonding layer. For example, the surface treatment includes surface activation treatment such as corona discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, and laser treatment. Examples of the easy adhesion layer include polyester, polyamide, polyurethane, vinyl copolymer, butadiene copolymer, acrylic copolymer, vinylidene copolymer, and epoxy copolymer.

  Further, for the purpose of suppressing the permeation of oxygen and water vapor, a barrier coat layer may be formed in advance on the transparent substrate, or a hard coat layer may be formed in advance on the opposite side to which the transparent conductive layer is transferred. Good.

[Other layers]
The organic photoelectric conversion device of this embodiment may further include other members (other layers) in addition to the above-described members (each layer) in order to improve photoelectric conversion efficiency and improve the lifetime of the device. . Examples of other members include a hole injection layer, an electron injection layer, an exciton block layer, a UV absorption layer, a light reflection layer, and a wavelength conversion layer. Further, a layer such as a silane coupling agent may be provided in order to make the metal oxide fine particles unevenly distributed in the upper layer more stable. Further, a metal oxide layer may be laminated adjacent to the photoelectric conversion layer of the present invention.

  Moreover, the organic photoelectric conversion element of this invention may have various optical function layers for the purpose of more efficient light reception of sunlight. Examples of the optical functional layer include a light condensing layer such as an antireflection film and a microlens array, and a light diffusion layer that can scatter light reflected by the cathode and enter the power generation layer again.

  Various known antireflection layers can be provided as the antireflection layer. For example, when the transparent resin film is a biaxially stretched polyethylene terephthalate film, the refractive index of the easy adhesion layer adjacent to the film is 1.57. It is more preferable to set it to ˜1.63 because the interface reflection between the film substrate and the easy adhesion layer can be reduced and the transmittance can be improved. The method for adjusting the refractive index can be carried out by appropriately adjusting the ratio of the oxide sol having a relatively high refractive index such as tin oxide sol or cerium oxide sol and the binder resin. The easy adhesion layer may be a single layer, but may be composed of two or more layers in order to improve adhesion.

  As the condensing layer, for example, it is processed so as to provide a structure on the microlens array on the sunlight receiving side of the support substrate, or the amount of light received from a specific direction is increased by combining with a so-called condensing sheet. Conversely, the incident angle dependency of sunlight can be reduced.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  Examples of the light scattering layer include various antiglare layers, layers in which nanoparticles or nanowires such as metals or various inorganic oxides are dispersed in a colorless and transparent polymer, and the like.

<Film forming method / Surface treatment method>
There is no restriction | limiting in particular about the manufacturing method of the organic photoelectric conversion element which concerns on this invention. For example, as a method for forming a photoelectric conversion layer containing a p-type organic semiconductor material and an n-type organic semiconductor material, an intermediate layer (a hole transport layer, an electron transport layer, a charge recombination layer), or an electrode, a vapor deposition method or a coating method Examples of the method include a casting method and a spin coating method. Among these, as a formation method of a photoelectric converting layer, a vapor deposition method, the apply | coating method (a cast method and a spin coat method are included) etc. are illustrated preferably. Among these, the coating method is preferable in order to increase the area of the interface where holes and electrons are separated by charge and to produce a device having high photoelectric conversion efficiency. The coating method is also excellent in production speed.

  As a method for forming the intermediate layer (hole transport layer, electron transport layer, charge recombination layer), a coating method is preferable. In addition, since the high molecular compound which contains the structure represented by General formula (1) contained in an intermediate layer as a side chain is soluble in a solvent, it is suitable for forming an intermediate layer by the apply | coating method.

  Although there is no restriction | limiting in the coating method used in this case, For example, a spin coat method, the cast method from a solution, a dip coat method, a blade coat method, a wire bar coat method, a gravure coat method, a spray coat method etc. are mentioned. Furthermore, patterning can also be performed by a printing method such as an ink jet method, a screen printing method, a relief printing method, an intaglio printing method, an offset printing method, or a flexographic printing method.

  After coating, it is preferable to perform heating in order to cause removal of residual solvent, moisture and gas, and improvement of mobility and absorption longwave due to crystallization of the semiconductor material. When annealing is performed at a predetermined temperature during the manufacturing process, a part of the particles is microscopically aggregated or crystallized and the photoelectric conversion layer can have an appropriate phase separation structure. As a result, the carrier mobility of the photoelectric conversion layer is improved and high efficiency can be obtained.

  The photoelectric conversion layer may be composed of a layer in which a p-type semiconductor material and an n-type semiconductor material are mixed, but may have a plurality of layers having different mixing ratios in the film thickness direction or a gradation structure with a mixing ratio.

  Examples of the method for forming the electron transport layer containing the polymer compound of the present invention include a vapor deposition method and a coating method (including a casting method and a spin coating method). Of these, the coating method is preferred. The coating method is also excellent in production speed. Examples of the method for forming the electron transport layer when forming the electron transport layer by a coating method include, for example, dissolving the polymer compound according to the present invention and, if necessary, another electron transport material in an appropriate solvent to transport the electron. A layer forming solution is prepared. Next, there is a method in which this solution is applied on a substrate, dried, and then heat-treated. Here, the solvent for dissolving the polymer compound according to the present invention and, if necessary, other electron transport materials is not particularly limited as long as it can dissolve these materials, but alcohols such as isopropanol and n-butanol. Alcohols substituted with halogen atoms such as hexafluoroisopropanol and tetrafluoropropanol; dimethyl sulfoxide, dimethylformamide and the like. Of these, alcohols substituted with halogen atoms, particularly alcohols substituted with fluorine atoms are preferably used in consideration of coating properties due to surface tension, drying speed, and the like. That is, the intermediate layer (particularly, the electron transport layer) is preferably formed by a coating process using a solvent containing an alcohol substituted with a fluorine atom. In this case, the concentration of the polymer compound and, if necessary, the other electron transporting material is not particularly limited. For example, the concentration in the solution is 0.5 to 0.005% by mass. In this embodiment, the coating method is not limited, and examples thereof include spin coating, casting from a solution, dip coating, blade coating, wire bar coating, gravure coating, and spray coating. Furthermore, patterning can also be performed by a printing method such as an ink jet method, a screen printing method, a relief printing method, an intaglio printing method, an offset printing method, or a flexographic printing method. The heat treatment conditions after coating are not particularly limited as long as the electron transport layer can be formed. For example, the heat treatment temperature is preferably room temperature (25 ° C.) to 180 ° C., more preferably 60 to 120 ° C. It is. The heat treatment time is preferably 10 seconds to 10 minutes, more preferably 30 seconds to 5 minutes.

  The polymer compound according to the present invention may be used in combination with a crosslinking agent since the molecular weight is increased and the charge transport property is increased by crosslinking in the coating film formation or after formation by using the crosslinking agent in combination. Examples of the crosslinking agent include known crosslinking agents such as an epoxy crosslinking agent, an oxetane crosslinking agent, an isocyanate crosslinking agent, an alkoxysilane crosslinking agent, and a vinyl crosslinking agent. Moreover, in order to accelerate | stimulate reaction, it is preferable to use together a polyhydric alcohol compound, a polyvalent amine compound, a polyvalent thiol compound, etc.

(Patterning)
In the organic photoelectric conversion device according to the present invention, the electrode, photoelectric conversion layer, and intermediate layer (hole transport layer, electron transport layer, etc.) may be patterned as necessary. There is no restriction | limiting in particular and a well-known method can be applied suitably. For example, if it is a soluble material such as a photoelectric conversion layer and a transport layer, only unnecessary portions may be wiped after the entire surface application such as die coating or dip coating, or it is applied using a method such as an ink jet method or a screen printing method. Sometimes direct patterning may be used. On the other hand, in the case of an insoluble material such as an electrode material, mask evaporation can be performed when the electrode is vacuum-deposited, or patterning can be performed by a known method such as etching or lift-off. Alternatively, the pattern may be formed by transferring a pattern formed on another substrate.

(Sealing)
Further, in order to prevent the produced organic photoelectric conversion element from being deteriorated by oxygen, moisture, etc. in the environment, the organic photoelectric conversion element can be sealed not only by the organic photoelectric conversion element but also by a technique known in the technical field such as an organic electroluminescence element. preferable. For example, a method of sealing a cap made of aluminum or glass by bonding with an adhesive, a plastic film on which a gas barrier layer such as aluminum, silicon oxide, or aluminum oxide is formed and an organic photoelectric conversion element are pasted with an adhesive. Method, spin coating of organic polymer material (polyvinyl alcohol, etc.) with high gas barrier property, inorganic thin film (silicon oxide, aluminum oxide, etc.) or organic film (parylene etc.) with high gas barrier property are deposited under vacuum And a method of laminating these in a composite manner.

(Use of organic photoelectric conversion device)
According to the other form of this invention, the solar cell which has the above-mentioned organic photoelectric conversion element is provided. Since the organic photoelectric conversion element used for this form has the outstanding photoelectric conversion efficiency and durability (heat resistance, light resistance), it can be used suitably for the solar cell which uses this as an electric power generation element.

  Moreover, according to the further another form of this invention, the optical sensor array by which the organic photoelectric conversion element mentioned above is arranged in the array form is provided. That is, the organic photoelectric conversion element of this embodiment can also be used as an optical sensor array that converts an image projected on the optical sensor array into an electrical signal using the photoelectric conversion function.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

[Synthesis Example 1: Synthesis of Exemplified Compound 3]
Adv. Mater. Compound A was synthesized with reference to 2007, 19, 2010. The weight average molecular weight of Compound A was 4400.

1.0 g of this compound A and 9.0 g of 3,3′-iminobis (N, N-dimethylpropylamine) manufactured by Aldrich are dissolved in 100 ml of tetrahydrofuran and 100 ml of N, N-dimethylformamide and stirred at room temperature for 48 hours. Went. After completion of the reaction, the solvent was distilled off under reduced pressure, and further reprecipitation was carried out in water to obtain 1.3 g of Exemplified Compound 3 (yield 90%). The structure of the obtained compound was identified by ¹ H-NMR. The results are shown below.
7.6-8.0 ppm (br), 2.88 ppm (br), 2.18 ppm (m), 2.08 ppm (s), 1.50 ppm (m), 1.05 ppm (br).

[Synthesis Example 2: Synthesis of Exemplified Compound 34]
Compound B was prepared according to Eur. J. et al. Org. Chem. 2011, p. 1482 was synthesized as a reference.

  1.0 g of compound A and 8.0 g of compound B were dissolved in 100 ml of tetrahydrofuran and 100 ml of N, N-dimethylformamide, and stirred at room temperature for 48 hours. After completion of the reaction, the solvent was distilled off under reduced pressure, and reprecipitation was further performed in water to obtain 1.65 g of Exemplified Compound 34 (yield 80%).

[Synthesis Example 3: Synthesis of Exemplary Compound 7]
Synthesis, 1978, p. With reference to 155, the cyano group was reduced. 1.0 g of Exemplified Compound 34 and 480 mg of cobalt (II) chloride hexahydrate were dissolved in 100 ml of methanol, 6.0 g of sodium borohydride was added little by little, and the mixture was stirred at room temperature for 2 hours. After completion of the reaction, the reaction mixture was neutralized with concentrated hydrochloric acid and the solvent was distilled off. The solid was added with an aqueous ammonia solution and tetrahydrofuran to extract the organic layer, dried over magnesium sulfate and then the solvent was distilled off. 8 g was obtained (yield 80%).

  Subsequently, J.M. Med. Chem. 2011, 54, p. With reference to 2183, 5.0 ml of formic acid was added to 50 ml of an aqueous formaldehyde solution of 0.5 g of compound C, and reacted at 100 ° C. for 3 hours. After completion of the reaction, after distilling off the solvent, 0.5 g of Exemplified Compound 7 was obtained by reprecipitation in water (yield 83%).

[Synthesis Example 4: Synthesis of Exemplified Compound 25]
Macromolecules 2003, 36, p. Compound L was synthesized with reference to 61. The weight average molecular weight of Compound L was 12000. 0.5 g of this compound L and 4.5 g of 3,3′-iminobis (N, N-dimethylpropylamine) manufactured by Aldrich are dissolved in 50 ml of tetrahydrofuran and 50 ml of N, N-dimethylformamide and stirred at room temperature for 48 hours. Went. After completion of the reaction, the solvent was distilled off under reduced pressure, and reprecipitation was further performed in water to obtain 0.65 g of Exemplified Compound 25 (yield 90%).

[Synthesis Example 5: Synthesis of Exemplary Compound 48]
J. et al. Am. Chem. Soc. 2005, 127, p. Compound D with reference to 7762, Chemische Berichte; vol. 122; (1989); p. Compound E was synthesized with reference to 2413.

  Compound D (1.4 g, 2.5 mmol) was dissolved in dehydrated tetrahydrofuran (100 ml), cooled to -78 ° C., 1.4 M tBuLi solution (7.0 ml, 10 mmol) was added, and the mixture was stirred for 1 hour. 7.5 mmol) was added, and the mixture was stirred at room temperature for a whole day and night. After completion of the reaction, an aqueous sodium bicarbonate solution and ethyl acetate were added for extraction, and the organic layer was dried and evaporated, followed by purification by silica gel column chromatography to obtain 0.62 g of Compound F (yield 40%). .

0.62 g of compound F is dissolved in dehydrated toluene, 0.32 g of bis (trimethyltin), 20 ml of tetrahydrofuran (THF), 10 ml of N-methyl-2-pyrrolidone (NMP), 100 mg of Pd (PPh ₃ ) ₄ , copper iodide (I) 0.02 g was put into a Schlenk tube, and the inside was purged with nitrogen, and polymerization was carried out by heating at 80 ° C. for 48 hours. After completion of the reaction, after cooling to room temperature, when the reaction solution is poured into a 5% aqueous potassium fluoride solution, a polymer solid is precipitated, and after filtration and recovery, washing with water, methanol and acetone and drying under reduced pressure give Compound G. 360 mg was obtained (yield 90%).

  Exemplified compound 48 was obtained by using Compound G obtained instead of Compound A in Synthesis Example 1 (Synthesis of Exemplified Compound 3) described above.

[Synthesis Example 6: Synthesis of Exemplary Compound 52]
Compound A (1.0 g), Aldrich diethanolamine (2.5 g), and 3,3′-iminobis (N, N-dimethylpropylamine) (4.5 g) were dissolved in tetrahydrofuran (100 ml) and N, N-dimethylformamide (100 ml). Stirring was performed at room temperature for 48 hours. After completion of the reaction, the solvent was distilled off under reduced pressure, and reprecipitation was further performed in water to obtain 1.1 g of Exemplified Compound 52 (yield 85%).

  [Synthesis Example 7: Synthesis of Exemplified Compound 27]

  Compound A (1.0 g) and Aldrich N, N, N′-trimethylethylenediamine (5.5 g) were dissolved in tetrahydrofuran (100 ml) and N, N-dimethylformamide (100 ml), and the mixture was stirred at room temperature for 48 hours. After completion of the reaction, the solvent was distilled off under reduced pressure, and reprecipitation was further performed in water to obtain 1.0 g of Exemplified Compound 27 (yield 90%).

  [Synthesis Example 8: Synthesis of Exemplified Compound 53]

  With reference to JP-A-2-108688, 3-hydroxy-1,5-dibromopentane (Compound X) was synthesized. Furthermore, Adv. Was used except that this compound X was used in place of 9-hydroxyheptadecane. Mater. 2007, 19, p. Compounds Y and Y ′ were synthesized in the same manner as 2295.

Compound Y (550 mg), Compound Y ′ (720 mg), Pd ₂ (dba) ₃ (4.5 mg), and Tris (p-tolyl) phosphine (6.1 mg) were dissolved in dehydrated toluene (10 ml), and 3.4 ml of degassed 20% tetra A methylammonium aqueous solution was added, and the reaction was performed at 100 ° C. for 72 hours under nitrogen.

  After completion of the reaction, 660 mg of Compound Z was obtained by reprecipitation in a mixed solvent of methanol: water = 10: 1 (yield 85%). The number average molecular weight of Compound Z was 5100.

  660 mg of the obtained compound Z and 4.0 g of 3,3′-iminodipropionitrile manufactured by Aldrich were dissolved in 100 ml of tetrahydrofuran and 100 ml of N, N-dimethylformamide, and stirred at room temperature for 48 hours. After completion of the reaction, the solvent was distilled off under reduced pressure, and reprecipitation was performed in water to obtain 0.90 g of Exemplified Compound 53 (yield 90%).

[Synthesis Example 9: Synthesis of Comparative Compound 2]
J. et al. Am. Chem. Soc. 2011, 133, p. According to 8416-8419 (non-patent document 2), the following comparative compound 2 having 1.0 amino group per aromatic ring was synthesized. Comparative compound 2 had a weight average molecular weight of 8,900.

[Synthesis Example 10: Synthesis of Comparative Compound 3]
Adv. Funct. Mat. 2010, p. According to 1977 (non-patent document 4), the following comparative compound 3 having 1/2 amino group per aromatic ring was synthesized. Comparative compound 3 had a weight average molecular weight of 6,400.

[Synthesis Example 11: Synthesis of Comparative Compound 4]
Adv. Mater. 2011, 23, p. According to 3086-3089 (nonpatent literature 5), the following comparative compound 4 which has a 1/2 amino group per aromatic ring was synthesize | combined. Comparative compound 4 had a weight average molecular weight of 6,200.

[Synthesis Example 12: Synthesis of Compound 9]
Compound 9 was synthesized by the following reaction.

  Macromolecules 2007, 40, p. With reference to 1981, Compound H was synthesized.

  1.8 g of this compound H, 9.6 g of 1,6-dibromohexane and 2.5 g of potassium hydroxide were dissolved in 50 ml of dimethyl sulfoxide and reacted at 60 ° C. for 6 hours. After completion of the reaction, ethyl acetate and brine are added to the reaction product and washed with water. The organic layer is dried and evaporated, and purified by silica gel column chromatography and preparative GPC (LC-91XX NEXT) manufactured by Japan Analytical Industry. This gave 1.8 g of compound I (yield 50%).

  The resulting compound I (1.8 g) was added to chloroform (20 ml), acetic acid (20 ml) and N-bromosuccinimide (NBS) (1.57 g), and the mixture was stirred at room temperature (25 ° C.) for 6 hours to carry out the reaction. After completion of the reaction, brine and chloroform were added and washed, and the organic layer was dried and evaporated, and purified by silica gel column chromatography to obtain 2.1 g of Compound J (yield 90%).

  Compound 9 was obtained in the same manner as in Synthesis Example 5 except that Compound J obtained here was used instead of Compound F in Synthesis Example 5.

[Synthesis Example 13: Synthesis of Comparative Compound 5]
Appl. Phys. Lett. vol. 95, p. The following comparative compound 5 having 2/3 amino groups per aromatic ring was synthesized according to 043301 (Non-patent Document 3). Comparative compound 5 had a weight average molecular weight of 4900.

  [Synthesis Example 13: Synthesis of Compound 61]

  1.0 g of poly (vinyl benzyl chloride), 60/40 3,4 isomer mixture (number average molecular weight 55000), and 3,3′-iminobis (N, N-dimethylpropylamine) (Aldrich) 9.0 g) was dissolved in a mixed solvent of 100 ml of tetrahydrofuran and 100 ml of N, N-dimethylformamide and stirred at room temperature (25 ° C.) for 48 hours to carry out the reaction. After completion of the reaction, the solvent was distilled off under reduced pressure, and reprecipitation was further performed in water to obtain 1.8 g of Exemplified Compound 41 (yield 95%).

[Example 1]
《Preparation of bulk heterojunction organic photoelectric conversion element with normal layer configuration》
(Synthesis of p-type organic semiconductor material A)
The following p-type organic semiconductor material A was synthesized with reference to US Pat. The number average molecular weight was 35000.

[Production of Organic Photoelectric Conversion Elements 101 to 107]
(Formation of transparent electrode)
An indium tin oxide (ITO) transparent conductive film deposited on a PET substrate with a thickness of 150 nm (sheet resistance 12 Ω / □) is patterned to a width of 10 mm using a normal photolithography technique and wet etching. An electrode was formed. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried by nitrogen blowing, and finally subjected to ultraviolet ozone cleaning.

(Formation of hole transport layer)
Next, as a hole transport layer, PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) composed of a conductive polymer and a polyanion, and isopropanol are included. A liquid was prepared and applied and dried using a blade coater so that the dry film thickness was about 30 nm. Thereafter, heat treatment was performed with 120 ° C. hot air for 20 seconds to form a hole transport layer.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere. First, the substrate was heat-treated at 120 ° C. for 3 minutes in a nitrogen atmosphere.

(Formation of organic photoelectric conversion layer)
Subsequently, 0.6% by mass of p-type organic semiconductor material A, 1.2% by mass of PC71BM (nanospectra E110 manufactured by Frontier Carbon), which is an n-type organic semiconductor material, is added to o-dichlorobenzene, 1,8-octanedithiol. After preparing an organic photoelectric conversion material composition solution mixed with 3.0% by mass and stirring (60 minutes) while heating to 100 ° C. in an oven to dissolve p-type organic semiconductor material A and PC71BM, While filtering with a 0.45 μm filter, it was applied using a blade coater so that the dry film thickness was about 100 nm, and dried at 95 ° C. for 2 minutes to form an organic photoelectric conversion layer.

(Electron transport layer)
Subsequently, the compound shown in Table 2 was dissolved in hexafluoroisopropanol so as to be 0.02% by mass, a solution was prepared, and the coating film was dried using a blade coater so that the dry film thickness was about 5 nm. Thereafter, heat treatment was performed with warm air at 100 ° C. for 2 minutes to form an electron transport layer.

(Formation of second electrode)
Next, the substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum vapor deposition machine is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Al metal is deposited at a deposition rate of 2 nm / second, A second electrode was formed.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sandwiched between ^two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m ² / d), UV After sealing using a curable resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1), it was taken out into the atmosphere, and organic photoelectric conversion elements 101 to 107 having a light receiving portion of about 10 × 10 mm size were produced. .

[Production of Organic Photoelectric Conversion Elements 108 to 119]
Organic photoelectric conversion elements 108 to 119 were produced in the same manner as the organic photoelectric conversion elements 101 to 107 except that the second electrode was changed from Al metal to the following Ag metal.

(Formation of second electrode of organic photoelectric conversion elements 108 to 119)
The substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Ag metal is deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

[Production of organic photoelectric conversion elements 120 to 126]
Organic photoelectric conversion elements 120 to 126 were produced in the same manner as the organic photoelectric conversion elements 101 to 107 except that the second electrode was changed from Al metal to the following Au metal.

(Formation of second electrodes of organic photoelectric conversion elements 120 to 126)
The substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then Au metal is deposited to 100 nm at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

[Production of Organic Photoelectric Conversion Elements 127 to 133]
Organic photoelectric conversion elements 120 to 126 were produced in the same manner as the organic photoelectric conversion elements 101 to 107 except that the second electrode was changed from Al metal to the following Cu metal.

(Formation of second electrodes of organic photoelectric conversion elements 127 to 133)
The substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, the element was set so that the shadow mask with a width of 10 mm was orthogonal to the transparent electrode, and the inside of the vacuum deposition apparatus was depressurized to 10 ⁻³ Pa or less, and then 100 nm of Cu metal was deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

<< Evaluation of organic photoelectric conversion element >>
(Evaluation of photoelectric conversion efficiency)
Each organic photoelectric conversion element manufactured above is irradiated with light of 100 mW / cm ² of solar simulator (AM1.5G filter), and a mask with an effective area of 1 cm ² is overlaid on the light receiving part, and the short circuit current density Jsc (MA / cm ² ), open circuit voltage Voc (V), and fill factor (fill factor) FF were measured for each of the four light receiving portions formed on the same element, and the average value was obtained. Moreover, photoelectric conversion efficiency (eta) (%) was calculated | required according to Formula (1) from the calculated | required short circuit current density Jsc, the open circuit voltage Voc, and the fill factor FF. Here, it shows that energy conversion efficiency (photoelectric conversion efficiency) is so favorable that the number of photoelectric conversion efficiency (eta) (%) is large.

  It shows that energy conversion efficiency (photoelectric conversion efficiency) is so favorable that the number of photoelectric conversion efficiency (eta) (%) is large.

(Evaluation of durability of photoelectric conversion efficiency)
The organic photoelectric conversion element for which the photoelectric conversion efficiency was evaluated was heated to 80 ° C. with a resistor connected between the anode and the cathode, and 100 mW / cm of a solar simulator (AM1.5G filter). After continuing to be exposed for 1000 h with light of ² intensity, the organic photoelectric conversion element was cooled to room temperature, and the four light receiving parts formed on the organic photoelectric conversion element in the same manner as the evaluation of the photoelectric conversion efficiency, The photoelectric conversion efficiency η (%) was determined according to the above formula (1). Subsequently, the relative efficiency reduction rate of the conversion efficiency was calculated by the following formula (2) to obtain an average value, and this was used as a measure of the durability of the photoelectric conversion efficiency.

  It represents that it is excellent in durability of energy conversion efficiency (durability of photoelectric conversion efficiency), so that the relative efficiency fall rate (%) of conversion efficiency is small.

  The results obtained as described above are shown in Table 2.

  As is clear from the results shown in Table 2, the organic photoelectric conversion element of the present invention has higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example, and is excellent in durability of photoelectric conversion efficiency. I understand that. It can also be seen that even when Ag or Au having a large ionization potential is used for the second electrode, it has a higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example and is excellent in durability of the photoelectric conversion efficiency.

[Example 2]
<< Preparation of Heat Conversion Organic Photoelectric Conversion Element with Normal Layer Structure >>
[Production of Organic Photoelectric Conversion Elements 201-207]
(Formation of transparent electrode)
An indium tin oxide (ITO) transparent conductive film deposited on a glass substrate with a thickness of 110 nm (sheet resistance 13 Ω / □) is patterned to a width of 2 mm using a normal photolithography technique and hydrochloric acid etching, and transparent An electrode was formed.

  The patterned transparent electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

(Formation of hole transport layer)
Next, PEDOT-PSS (CLEVIOS (registered trademark) P VP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) made of a conductive polymer and a polyanion is used as a hole transport layer. Then, the film was spin-coated at 140 ° C. in the air for 10 minutes to form a hole transport layer.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere. First, the substrate was heat-treated at 180 ° C. for 3 minutes in a nitrogen atmosphere.

(Formation of organic photoelectric conversion layer)
A solution obtained by dissolving 0.5% by weight of the following compound (P1) in a 1: 2 mixed solvent (weight) of chloroform / monochlorobenzene was filtered, and the obtained filtrate was spin-coated at 1500 rpm and heated at 180 ° C. for 20 minutes. . As a result, a layer (p-type semiconductor layer) of about 25 nm of tetrabenzoporphyrin compound (P2) having a thickness of about 25 nm was formed on the hole extraction layer.

  A solution prepared by dissolving 0.6% by weight of compound (P1) and 1.4% by weight of fullerene derivative 1 in a 1: 1 mixed solvent (weight) of chloroform / monochlorobenzene was prepared and filtered. Under a nitrogen atmosphere, the obtained filtrate was spin-coated on the p-type semiconductor layer at 1500 rpm and heated at 180 ° C. for 20 minutes. Thus, a mixture layer containing tetrabenzoporphyrin (compound (P2)) of about 100 nm and fullerene derivative 1 was formed on the p-type semiconductor layer.

  Next, a solution in which 1.2% by weight of fullerene derivative 1 was dissolved in toluene was prepared and filtered, and the filtrate obtained in a nitrogen atmosphere was spin-coated at 3000 rpm and subjected to heat treatment at 120 ° C. for 5 minutes. Thereby, a layer of fullerene derivative 1 of about 50 nm was formed on the mixture layer.

  Note that the mass ratio of the P-type semiconductor (P2) to the n-type semiconductor (fullerene derivative 1) in the photoelectric conversion layer was 3: 7.

(Electron transport layer)
Then, the compound of Table 3 was melt | dissolved in hexafluoroisopropanol so that it might become 0.02 mass%, the solution was prepared, and it applied and dried using the blade coater so that the dry film thickness might be set to about 5 nm. Thereafter, heat treatment was performed with warm air at 100 ° C. for 2 minutes to form an electron transport layer.

(Formation of second electrode)
Next, the substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 2 mm is orthogonal to the transparent electrode, and reducing the pressure inside the vacuum vapor deposition machine to 10 ⁻³ Pa or less, 100 nm of Al metal is vapor deposited at a deposition rate of 2 nm / second, A second electrode was formed.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was sealed with an aluminum cap and a UV curable resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1) in a nitrogen atmosphere, and then taken out into the atmosphere. Organic photoelectric conversion elements 201 to 207 having a size of 2 mm square were produced.

[Production of organic photoelectric conversion elements 208 to 215]
Organic photoelectric conversion elements 208 to 215 were produced in the same manner as the organic photoelectric conversion elements 201 to 207 except that the second electrode was changed from Al metal to the following Ag metal.

(Formation of second electrodes of organic photoelectric conversion elements 208 to 215)
The substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 2 mm is orthogonal to the transparent electrode and reducing the pressure inside the vacuum vapor deposition machine to 10 ⁻³ Pa or less, 100 nm of Ag metal was vapor deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

<< Evaluation of organic photoelectric conversion element >>
The photoelectric conversion efficiency and the durability of the photoelectric conversion efficiency were evaluated in the same manner as in Example 1 except that the mask having an effective area of 1 cm ² was changed to a mask having a 4.0 mm ² mask. The obtained results are shown in Table 3.

  As is clear from the results shown in Table 3, the organic photoelectric conversion element of the present invention has higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example even in the coating conversion type, and durability of the photoelectric conversion efficiency. It turns out that it is excellent in property. It can also be seen that even when Ag having a large ionization potential is used for the second electrode, it has a higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example and is excellent in durability of the photoelectric conversion efficiency.

[Example 3]
<< Preparation of bulk heterojunction organic photoelectric conversion element with reverse layer structure >>
[Production of Organic Photoelectric Conversion Elements 301 to 308]
(Formation of transparent electrode)
An indium tin oxide (ITO) transparent conductive film deposited on a PET substrate with a thickness of 150 nm (sheet resistance 12 Ω / □) is patterned to a width of 10 mm using a normal photolithography technique and wet etching. An electrode was formed. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried by nitrogen blowing, and finally subjected to ultraviolet ozone cleaning.

(Electron transport layer)
Subsequently, the compound of Table 4 was melt | dissolved in hexafluoroisopropanol so that it might become 0.02 mass%, the solution was prepared, and it applied and dried using the blade coater so that the dry film thickness might be set to about 5 nm. Thereafter, heat treatment was performed with warm air at 100 ° C. for 2 minutes to form an electron transport layer.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere.

(Formation of organic photoelectric conversion layer)
Next, an organic photoelectric conversion material obtained by mixing 0.6% by mass of p-type organic semiconductor material A and 1.2% by mass of PC71BM (nanospectra E110 manufactured by Frontier Carbon), which is an n-type organic semiconductor material, in o-dichlorobenzene. After preparing the composition solution and stirring (60 minutes) while heating to 100 ° C. in an oven to dissolve the p-type organic semiconductor material A and PC71BM, the dry film thickness is reduced while filtering through a 0.45 μm filter. It apply | coated using the blade coater so that it might become about 100 nm, and it dried at 95 degreeC for 2 minute (s), and formed the organic photoelectric converting layer into a film.

(Formation of hole transport layer)
Subsequently, as a hole transport layer, PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) composed of a conductive polymer and a polyanion, and isopropanol are used. A liquid containing the mixture was prepared and applied and dried using a blade coater so that the dry film thickness was about 30 nm. Thereafter, heat treatment was performed with 120 ° C. hot air for 20 seconds to form a hole transport layer.

(Formation of second electrode)
Next, the substrate on which the hole transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Ag metal is deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sandwiched between ^two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m ² / d), UV After sealing using a curable resin (manufactured by Nagase ChemteX Corp., UV RESIN XNR5570-B1), it was taken out into the atmosphere, and organic photoelectric conversion elements 301 to 308 having a light receiving portion of about 10 × 10 mm size were produced. .

<< Evaluation of organic photoelectric conversion element >>
The photoelectric conversion efficiency and the durability of the photoelectric conversion efficiency were evaluated in the same manner as in Example 1. Table 4 shows the obtained results.

  As is clear from the results shown in Table 4, the organic photoelectric conversion element of the present invention has higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example even in the reverse layer configuration, and durability of the photoelectric conversion efficiency. It turns out that it is excellent in property.

[Example 4]
<< Preparation of tandem organic photoelectric conversion element with normal layer structure >>
[Production of Organic Photoelectric Conversion Elements 401 to 403]
(Formation of transparent electrode)
An indium tin oxide (ITO) transparent conductive film deposited on a PET substrate with a thickness of 150 nm (sheet resistance 12 Ω / □) is patterned to a width of 10 mm using a normal photolithography technique and wet etching. An electrode was formed. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried by nitrogen blowing, and finally subjected to ultraviolet ozone cleaning.

(Formation of first hole transport layer)
Next, as a hole transport layer, PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) composed of a conductive polymer and a polyanion, and isopropanol are included. A liquid was prepared and applied and dried using a blade coater so that the dry film thickness was about 30 nm. Thereafter, a first hole transport layer was formed by heat treatment with warm air of 120 ° C. for 20 seconds.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere. First, the substrate was heat-treated at 120 ° C. for 3 minutes in a nitrogen atmosphere.

(Formation of first organic photoelectric conversion layer)
Next, an organic photoelectric conversion material obtained by mixing 0.6% by mass of p-type organic semiconductor material A and 1.2% by mass of PC71BM (nanospectra E110 manufactured by Frontier Carbon), which is an n-type organic semiconductor material, in o-dichlorobenzene. After preparing the composition solution and stirring (60 minutes) while heating to 100 ° C. in an oven to dissolve the p-type organic semiconductor material A and PC71BM, the dry film thickness is reduced while filtering through a 0.45 μm filter. The film was applied using a blade coater so as to have a thickness of about 100 nm and dried at 95 ° C. for 2 minutes to form a first organic photoelectric conversion layer.

(Formation of first electron transport layer)
Subsequently, the compound described in Table 5 was dissolved in hexafluoroisopropanol so as to be 0.02% by mass, a solution was prepared, and coating and drying were performed using a blade coater so that the dry film thickness was about 5 nm. Thereafter, heat treatment was performed for 2 minutes with 100 ° C. warm air to form a first electron transport layer.

(Formation of second hole transport layer)
Next, as a hole transporting layer, a solution containing HIL691 solution (manufactured by Plextronics, trade name Plexcore HIL691) and isopropanol was prepared, and applied and dried using a blade coater so that the dry film thickness was about 30 nm. Thereafter, a second hole transport layer was formed by heat treatment with warm air of 120 ° C. for 20 seconds. The film surface pH of this second hole transport layer was 7.

(Formation of second organic photoelectric conversion layer)
Next, p-type organic semiconductor material P3HT (manufactured by BASF: regioregular poly-3-hexylthiophene) is added to o-dichlorobenzene by 1.0 mass%, and n-type organic semiconductor material is PCBM (manufactured by Frontier Carbon Corporation). E100H: 6,6-phenyl-C61-butyric acid methyl ester) was mixed at 0.8% by mass, and an organic photoelectric conversion material composition solution was prepared and stirred (60 minutes) while heating to 100 ° C. in an oven. After dissolving P3HT and PCBM, it is applied with a blade coater so as to have a dry film thickness of about 100 nm while being filtered with a 0.45 μm filter, dried at 95 ° C. for 2 minutes, and second organic photoelectric A conversion layer was formed.

(Formation of second electron transport layer)
Then, the compound of Table 5 was melt | dissolved in hexafluoroisopropanol so that it might become 0.02 mass%, the solution was prepared, and it applied and dried using the blade coater so that the dry film thickness might be set to about 5 nm. Thereafter, heat treatment was performed for 2 minutes with warm air at 100 ° C. to form a second electron transport layer.

(Formation of second electrode)
Next, the substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum vapor deposition machine is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Al metal is deposited at a deposition rate of 2 nm / second, A second electrode was formed.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sandwiched between ^two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m ² / d), UV After sealing using a curable resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1), it was taken out into the atmosphere, and organic photoelectric conversion elements 401 to 403 having a light receiving portion of about 10 × 10 mm size were produced. .

[Preparation of organic photoelectric conversion element 404]
An organic photoelectric conversion element 404 was produced in the same manner as the organic photoelectric conversion element 403 except that the second electrode was changed from Al metal to the following Ag metal.

(Formation of second electrode of organic photoelectric conversion element 404)
The substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Ag metal is deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

[Production of Organic Photoelectric Conversion Element 405]
An organic photoelectric conversion element 405 was produced in the same manner as the organic photoelectric conversion element 404 except that the first electron transport layer was changed to the following TiOx layer.
[Formation of First Electron Transport Layer of Organic Photoelectric Conversion Element 405]
The substrate on which the first photoelectric conversion layer is formed is once returned to the atmosphere, and a solution obtained by diluting titania sol (PASOL HPW-10R manufactured by Catalytic Chemical Industry Co., Ltd.) four times with water so that the dry film thickness is about 30 nm. The film was applied using a blade coater and heated in the atmosphere at 120 ° C. for 10 minutes to obtain a first electron transport layer made of TiOx. Thereafter, the substrate was brought back into the glove box, and thereafter, the work was performed in a nitrogen atmosphere.

[Production of organic photoelectric conversion elements 406 to 410]
The organic photoelectric conversion element was prepared in the same manner as the organic photoelectric conversion elements 404 to 405 except that the compounds shown in Table 5 were used for forming the first electron transport layer and the second hole transport layer was changed to the following. 406 to 410 were produced.

[Formation of Second Hole Transport Layer of Organic Photoelectric Conversion Elements 406 to 410]
As a hole transport layer, a liquid containing PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) composed of a conductive polymer and a polyanion, and isopropanol. It was prepared and applied and dried using a blade coater so that the dry film thickness was about 30 nm. Thereafter, a second hole transport layer was formed by heat treatment with warm air of 120 ° C. for 20 seconds. The film surface pH of this hole transport layer was 2.

<< Evaluation of organic photoelectric conversion element >>
Evaluation of photoelectric conversion efficiency and durability of photoelectric conversion efficiency were performed in the same manner as in Example 1. The results obtained are shown in Table 5.

  As is clear from the results shown in Table 5, the organic photoelectric conversion element of the present invention has higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example even in the tandem type of the normal layer configuration, and photoelectric conversion. It turns out that the durability of efficiency is excellent. It can also be seen that even when Ag having a large ionization potential is used for the second electrode, it has a higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example and is excellent in durability of the photoelectric conversion efficiency. Moreover, even when used for the second electron transport layer constituting the charge recombination layer between the photoelectric conversion layers, and even when the film surface pH of the second hole transport layer is low, high photoelectric conversion efficiency (energy) It can be seen that the conversion efficiency is excellent and the photoelectric conversion efficiency is excellent.

[Example 5]
<< Production of tandem organic photoelectric conversion element with reverse layer structure >>
[Production of Organic Photoelectric Conversion Element 501]
(Formation of transparent electrode)
Under the atmosphere, a silver nanoparticle paste 1 (M-Dot SLP manufactured by Mitsuboshi Belting) was placed on a PET substrate using a gravure printing tester K303MULTICOATER manufactured by RK Print Coat Instruments Ltd. with a line width of 50 μm, a height of 0.8 μm, and an interval. After printing a 1.0 mm fine wire grid, a drying process was performed at 110 ° C. for 5 minutes to produce an auxiliary electrode. A transparent electrode layer coating solution having the following composition was applied on a substrate provided with an auxiliary electrode so as to have a wet film thickness of 10 μm, and dried at 90 ° C. for 1 minute. Then, the heat processing for 30 minutes were performed at 120 degreeC using the electric furnace, and the transparent electrode layer was formed.

Transparent electrode layer coating liquid Conductive polymer dispersion (Clevios TH510; manufactured by HC Starck, solid content 1.7% by mass) 17.6 g
Water-soluble binder WP-1 aqueous solution (number average molecular weight 33700, molecular weight distribution 2.4, solid content 20% by mass) 3.5 g
Dimethyl sulfoxide 1.0g

(Formation of first electron transport layer)
A compound described in Table 6 was dissolved in hexafluoroisopropanol so as to be 0.02% by mass, a solution was prepared, and dried using a blade coater so that the dry film thickness was about 5 nm. Thereafter, heat treatment was performed for 2 minutes with 100 ° C. warm air to form a first electron transport layer.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere.

(Formation of first organic photoelectric conversion layer)
Next, p-type organic semiconductor material P3HT (manufactured by BASF: regioregular poly-3-hexylthiophene) is added to o-dichlorobenzene by 1.0 mass%, and n-type organic semiconductor material is PCBM (manufactured by Frontier Carbon Corporation). E100H: 6,6-phenyl-C61-butyric acid methyl ester) was mixed at 0.8% by mass, and an organic photoelectric conversion material composition solution was prepared and stirred (60 minutes) while heating to 100 ° C. in an oven. After dissolving P3HT and PCBM, it is applied with a blade coater so as to have a dry film thickness of about 100 nm while being filtered with a 0.45 μm filter, dried at 95 ° C. for 2 minutes, and the first organic photoelectric A conversion layer was formed.

(Formation of first hole transport layer)
Next, as a hole transport layer, PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) composed of a conductive polymer and a polyanion, and isopropanol are included. A liquid was prepared and applied and dried using a blade coater so that the dry film thickness was about 30 nm. Thereafter, heat treatment was performed with warm air of 120 ° C. for 20 seconds to form a first hole transport layer.

(Formation of second electron transport layer)
Then, the compound of Table 6 was melt | dissolved in hexafluoroisopropanol so that it might become 0.02 mass%, the solution was prepared, and it applied and dried using the blade coater so that the dry film thickness might be set to about 5 nm. Thereafter, the second electron transport layer was formed by heat treatment with warm air of 100 ° C. for 2 minutes.

(Formation of second organic photoelectric conversion layer)
Next, an organic photoelectric conversion material obtained by mixing 0.6% by mass of p-type organic semiconductor material A and 1.2% by mass of PC71BM (nanospectra E110 manufactured by Frontier Carbon), which is an n-type organic semiconductor material, in o-dichlorobenzene. After preparing the composition solution and stirring (60 minutes) while heating to 100 ° C. in an oven to dissolve the p-type organic semiconductor material A and PC71BM, the dry film thickness is reduced while filtering through a 0.45 μm filter. It apply | coated using the blade coater so that it might be set to about 100 nm, and it dried for 2 minutes at 95 degreeC, and formed the 2nd organic photoelectric converting layer into a film.

(Formation of second hole transport layer)
Next, as a hole transport layer, PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) composed of a conductive polymer and a polyanion, and isopropanol are included. A liquid was prepared and applied and dried using a blade coater so that the dry film thickness was about 30 nm. Then, the second hole transport layer was formed by heat treatment with warm air of 120 ° C. for 20 seconds.

(Formation of second electrode)
The substrate on which the electron transport layer was formed was placed in a vacuum deposition apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Ag metal is deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sandwiched between ^two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m ² / d), UV After sealing using a curable resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1), it was taken out in the atmosphere, and an organic photoelectric conversion element 501 having a light receiving portion of about 10 × 10 mm size was produced.

[Preparation of Organic Photoelectric Conversion Element 502]
An organic photoelectric conversion element 502 was produced in the same manner as the organic photoelectric conversion element 404 except that the first and second electron transport layers were changed to the following TiOx layers.

[Formation of First Electron Transport Layer of Organic Photoelectric Conversion Element 502]
On a substrate on which a transparent electrode was formed, a solution obtained by diluting titania sol (PASOL HPW-10R manufactured by Catalytic Chemical Industry Co., Ltd.) 4 times with water was applied using a blade coater so that the dry film thickness was about 30 nm. Heating was performed in the atmosphere at 120 ° C. for 10 minutes to obtain a first electron transport layer. Thereafter, the substrate was brought into the glove box, and thereafter the work was performed in a nitrogen atmosphere.

[Formation of Second Electron Transport Layer of Organic Photoelectric Conversion Element 502]
The substrate on which the first hole transport layer is formed is once returned to the atmosphere, and a solution obtained by diluting titania sol (PASOL HPW-10R manufactured by Catalyst Chemical Industry Co., Ltd.) four times with water has a dry film thickness of about 30 nm. As described above, the coating was performed using a blade coater and heated in the atmosphere at 120 ° C. for 10 minutes to obtain a first electron transporting layer. Thereafter, the substrate was brought back into the glove box, and thereafter, the work was performed in a nitrogen atmosphere.

[Production of Organic Photoelectric Conversion Elements 503 to 505]
Organic photoelectric conversion elements 503 to 505 were prepared in the same manner as the organic photoelectric conversion element 501 except that the compounds shown in Table 6 were used for forming the first and second electron transport layers.

<< Evaluation of organic photoelectric conversion element >>
The photoelectric conversion efficiency and the durability of the photoelectric conversion efficiency were evaluated in the same manner as in Example 1. The results obtained are shown in Table 6.

  As is clear from the results shown in Table 6, the organic photoelectric conversion element of the present invention has higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example even in the tandem type of the reverse layer configuration, and photoelectric conversion. It turns out that the durability of efficiency is excellent.

[Example 6]
《Preparation of bulk heterojunction organic photoelectric conversion element with normal layer configuration》
[Production of Organic Photoelectric Conversion Elements 601 to 607]
(Formation of transparent electrode)
An indium tin oxide (ITO) transparent conductive film deposited on a PET substrate with a thickness of 150 nm (sheet resistance 12 Ω / □) is patterned to a width of 10 mm using a normal photolithography technique and wet etching. An electrode was formed. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried by nitrogen blowing, and finally subjected to ultraviolet ozone cleaning.

(Formation of hole transport layer)
Next, this transparent substrate was placed in a vacuum deposition apparatus. After depressurizing the inside of the vacuum deposition apparatus to 10 ⁻³ Pa or less, MoO ₃ was deposited by 15 nm at a deposition rate of 0.5 nm / second to form a first hole transport layer.

  Then, the compound of Table 7 was melt | dissolved in hexafluoroisopropanol so that it might become 0.02 mass%, the solution was prepared, and it applied and dried using the blade coater so that the dry film thickness might be set to about 30 nm. Thereafter, heat treatment was performed with warm air at 100 ° C. for 2 minutes to form a second hole transport layer.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere.

(Formation of organic photoelectric conversion layer)
Next, an organic photoelectric conversion material obtained by mixing 0.6% by mass of p-type organic semiconductor material A and 1.2% by mass of PC71BM (nanospectra E110 manufactured by Frontier Carbon), which is an n-type organic semiconductor material, in o-dichlorobenzene. After preparing the composition solution and stirring (60 minutes) while heating to 100 ° C. in an oven to dissolve the p-type organic semiconductor material A and PC71BM, the dry film thickness is reduced while filtering through a 0.45 μm filter. It apply | coated using the blade coater so that it might become about 100 nm, and it dried at 95 degreeC for 2 minute (s), and formed the organic photoelectric converting layer into a film.

(Electron transport layer)
Then, the compound of Table 7 was melt | dissolved in hexafluoroisopropanol so that it might become 0.02 mass%, the solution was prepared, and it applied and dried using the blade coater so that the dry film thickness might be set to about 5 nm. Thereafter, heat treatment was performed with warm air at 100 ° C. for 2 minutes to form an electron transport layer.

(Formation of second electrode)
Next, the substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Ag metal is deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sandwiched between ^two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m ² / d), UV After sealing using a curable resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1), it was taken out into the atmosphere, and organic photoelectric conversion elements 601 to 607 having a light receiving portion of about 10 × 10 mm size were produced. .

<< Evaluation of organic photoelectric conversion element >>
The photoelectric conversion efficiency and the durability of the photoelectric conversion efficiency were evaluated in the same manner as in Example 1. The results obtained are shown in Table 7.

  As is clear from the results shown in Table 7, the organic photoelectric conversion element of the present invention has higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example even when used in the hole transport layer, and photoelectric It can be seen that the conversion efficiency is excellent.

[Example 7]
<< Confirmation of Laminate Application of Compound of the Present Invention >>
The quartz glass substrate was cleaned in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

  On the cleaned substrate, the compound 3 synthesized in Synthesis Example 1 was dissolved in hexafluoroisopropanol so as to be 0.1% by mass to prepare a solution. This solution was applied and dried on the quartz glass substrate using a blade coater adjusted to 65 ° C. so that the dry film thickness was about 20 nm. Then, the coating film of the compound 3 was formed by heat-processing for 2 minutes with 100 degreeC warm air.

  In FIG. 4, the spectrum of this coating film is a blue dotted line (immediately after coating) spectrum. In addition, a spectrum obtained by re-applying only o-dichlorobenzene on this coating film is a spectrum of a yellow broken line (coating with oDCB 65C), and a film obtained by immersing this coating film in o-dichlorobenzene for 1 minute is a red solid line (oDCB). (Immersion) spectrum. The results shown in FIG. 4 indicate that the coating film of the conjugated polymer compound (compound 3) according to the present invention does not dissolve in o-dichlorobenzene generally used for coating a photoelectric conversion layer. It is. Therefore, it is considered that a photoelectric conversion layer can be easily formed on the photoelectric conversion layer on the coating film without correlation mixing on the photoelectric conversion layer by a coating method.

[Example 8]
<< Preparation of normal layer type bulk heterojunction organic photoelectric conversion element >>
[Production of organic photoelectric conversion elements 1 to 16]
(P-type semiconductor material)
A p-type organic semiconductor material B was synthesized with reference to Non-Patent Document 2 (Appl. Phys. Lett. Vol. 98, p.043301) and International Publication No. 2011/085004. In addition, the number average molecular weight of the following p-type organic-semiconductor material B was 43000.

(Formation of transparent electrode)
A first indium tin oxide (ITO) transparent conductive film deposited on a glass substrate with a thickness of 150 nm (sheet resistance 12 Ω / □) is patterned to a width of 10 mm using a normal photolithography technique and wet etching. The electrode was formed. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

(Formation of hole transport layer)
Next, PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) made of a conductive polymer and a polyanion is 2.0 as a hole transport layer. An isopropanol solution containing by mass% was prepared, and the substrate was applied and dried using a blade coater whose temperature was adjusted to 65 ° C. so that the dry film thickness was about 30 nm. Thereafter, heat treatment was carried out with warm air of 120 ° C. for 20 seconds to form a hole transport layer on the first electrode.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere.

  First, the substrate was heat-treated at 120 ° C. for 3 minutes in a nitrogen atmosphere.

(Formation of photoelectric conversion layer)
Next, 0.8% by mass of KP115 (p-type organic semiconductor material B), which is a p-type organic semiconductor material, and PC61BM (nanospectra E100H made by Frontier Carbon), which is an n-type organic semiconductor material, are added to o-dichlorobenzene. An organic photoelectric conversion material composition solution in which 6% by mass was mixed was prepared, and was completely dissolved by stirring (60 minutes) while heating to 100 ° C. on a hot plate, so that the dry film thickness was about 170 nm. The substrate was applied using a blade coater adjusted to 80 ° C. and dried for 2 minutes to form a photoelectric conversion layer on the hole transport layer.

(Electron transport layer)
Subsequently, the compounds shown in Table 8 and the comparative compound were dissolved in hexafluoroisopropanol so as to be 0.02% by mass, respectively, to prepare solutions. This solution was applied and dried using a blade coater whose temperature was adjusted to 65 ° C. so that the dry film thickness was about 5 nm. Thereafter, heat treatment was performed for 2 minutes with warm air at 100 ° C. to form an electron transport layer on the photoelectric conversion layer.

(Formation of second electrode)
Next, the substrate on which the electron transport layer was formed was placed in a vacuum deposition apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then the second described in Table 8 at a deposition rate of 2 nm / second. Each electrode material was deposited to a thickness of 100 nm to form a second electrode on the electron transport layer.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sandwiched between ^two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m ² / d), UV After sealing using a curable resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1), it was taken out into the atmosphere, and organic photoelectric conversion elements 801 to 816 having a light receiving portion of about 10 × 10 mm size were produced. .

<< Evaluation of organic photoelectric conversion element >>
(Evaluation of photoelectric conversion efficiency)
The photoelectric conversion efficiency was evaluated in the same manner as in Example 1. Table 8 shows the obtained results.

(Evaluation of durability of photoelectric conversion efficiency)
The durability of photoelectric conversion efficiency was evaluated in the same manner as in Example 1. The durability of the device was evaluated with LT80 as the time when the relative efficiency decrease rate was 80%.

  Table 8 shows the results obtained as described above.

  As is clear from the results shown in Table 8, the organic photoelectric conversion element of the present invention has higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example, and is excellent in durability of photoelectric conversion efficiency. I understand. It can also be seen that even when Ag having a large ionization potential is used for the second electrode, it has a higher photoelectric conversion efficiency (energy conversion efficiency) than the comparative example and is excellent in durability of the photoelectric conversion efficiency.

  Furthermore, from Table 8, the organic photoelectric conversion elements 6 to 16 of the present invention using the conjugated polymer compound according to the present invention and a metal having a work function of −4.5 or less as the cathode show the initial photoelectric conversion efficiency. It can be seen that it is also excellent in durability.

  On the other hand, the organic photoelectric conversion elements 804 and 809 using aluminum as an electrode having a low work function and a high internal electric field as an electrode, but having low initial stability, have low durability. . In addition, the organic photoelectric conversion elements 801 to 803 and 805 using the comparative compounds 1 to 4 in which the number of amino groups per aromatic ring is less than 1.5 are stable with a deep work function in the electrodes. On the other hand, it can be seen that even when silver having a small internal electric field is used for the electrode, the photoelectric conversion efficiency is low and the durability is insufficient.

[Example 9]
<< Production of reverse layer type bulk heterojunction organic photoelectric conversion element >>
[Preparation of organic photoelectric conversion element 17]
(Formation of transparent electrode)
An indium tin oxide (ITO) transparent conductive film deposited on a PET substrate with a thickness of 150 nm (sheet resistance 12 Ω / □) is patterned to a width of 10 mm using a normal photolithography technique and wet etching. The electrode was formed. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

(Electron transport layer)
Subsequently, the compound 3 was dissolved in hexafluoroisopropanol so that it might become 0.02 mass%, and the solution was prepared. This solution was applied and dried using a blade coater so that the dry film thickness was about 5 nm. Thereafter, heat treatment was performed for 2 minutes with 100 ° C. warm air to form an electron transport layer on the first electrode.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere.

(Formation of photoelectric conversion layer)
Then, p-type organic semiconductor material KP115 (p-type organic semiconductor material B) is 0.6 mass% and PC61BM (frontier carbon nanom spectra E100H) is 1. An organic photoelectric conversion material composition solution in which 2% by mass was mixed was prepared and stirred (60 minutes) while heating to 100 ° C. in an oven to dissolve KP115 (p-type organic semiconductor material B) and PC61BM. While filtering with a .45 μm filter, it was applied using a blade coater so that the dry film thickness was about 100 nm, and dried at 95 ° C. for 2 minutes to form a photoelectric conversion layer on the electron transport layer. .

(Formation of hole transport layer)
Subsequently, PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) made of a conductive polymer and a polyanion is used as a hole transport layer. An isopropanol solution containing 0% by mass was prepared and applied and dried using a blade coater so that the dry film thickness was about 30 nm. Then, it heat-processed for 20 second with a 120 degreeC warm air, and formed the positive hole transport layer on the said photoelectric converting layer.

(Formation of second electrode)
Next, the substrate on which the hole transport layer was formed was placed in a vacuum deposition apparatus. Then, the element was set so that the shadow mask with a width of 10 mm was orthogonal to the transparent electrode, and the inside of the vacuum deposition apparatus was depressurized to 10 ⁻³ Pa or less, and then the Ag metal was deposited to 100 nm at a deposition rate of 0.5 nm / second. Then, a second electrode was formed on the hole transport layer.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was transferred to a nitrogen chamber, and sandwiched between two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m 2 / d), and UV curing was performed. After sealing using a resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1), it was taken out in the atmosphere, and an organic photoelectric conversion element 817 having a light receiving portion of about 10 × 10 mm size was produced.

<< Evaluation of organic photoelectric conversion element >>
Thus, about the obtained organic photoelectric conversion element 817, evaluation of photoelectric conversion efficiency and durability of photoelectric conversion efficiency were performed like Example 8. FIG. Table 9 shows the obtained results. In addition, in the following Table 9, the result of the organic photoelectric conversion element 809-812 of Example 8 which uses the same compound 3 for a comparison is described collectively.

  Table 9 shows that the conjugated polymer compound 15 according to the present invention has both high photoelectric conversion efficiency and durability even in the reverse layer configuration in which electrons are extracted from the transparent electrode (ITO) side. However, it can be seen from Table 9 that the organic photoelectric conversion element 817 is slightly inferior in photoelectric conversion efficiency and durability as compared with the organic photoelectric conversion element 11 using silver as an electrode. From this, it is considered that the normal layer type organic photoelectric conversion element is superior in photoelectric conversion efficiency and durability to the reverse layer type organic photoelectric conversion element.

[Example 10]
《Preparation of bulk heterojunction organic photoelectric conversion element with normal layer configuration》
[Production of Organic Photoelectric Conversion Elements 801, 803, 805]
(Synthesis of p-type organic semiconductor material C)

  J. et al. AM. CHEM. SOC. Compound Q was synthesized with reference to 2009, 131, 7514. 1.40 g (2.4 mmol) of compound Q and 363 mg (1.1 mmol) of compound R are dissolved in 50 ml of toluene, and 95 mg of tris (dibenzylideneacetone) dipalladium (0) and 126 mg of tris (o -Tolyl) phosphine was added. The solution was purged with nitrogen for an additional 15 minutes. Thereafter, the solution was heated to 110 to 120 ° C. and reacted for 4 hours. After allowing to cool, toluene was distilled off, and purification was performed by silica gel column chromatography using an eluent of toluene: heptane = 100: 0 to 100: 10 to obtain 370 mg of Compound S (yield 34%).

  370 mg (0.37 mmol) of Compound S was dissolved in 20 ml of THF, 145 mg (0.82 mmol) of N bromosuccinimide (NBS) was added, and the mixture was stirred at 50 ° C. for 3.5 hours. After completion of the reaction, the solvent was distilled off, and the residue was purified by silica gel column chromatography with an eluent of toluene: heptane = 100: 0 to 100: 10 to obtain 350 mg of Compound T (yield 81%). HNMR (CDCl3) = 8.34 ppm, 2H, d, 7.09 ppm, 2H, d, 1.49 ppm, 4H, m, 1.2-1.4 ppm, 32H, br, 1.0-1.1 ppm, 8H , M, 0.84 ppm, 12H, t.

  175 mg (0.15 mmol) of Compound T and 153 mg (0.15 mmol) of Compound U were dissolved in 20 ml of anhydrous toluene. After purging this solution with nitrogen, 3.9 mg (0.0042 mmol) of tris (dibenzylideneacetone) dipalladium (0) and 10 mg (0.033 mmol) of tris (o-tolyl) phosphine were added. This solution was purged with argon for an additional 15 minutes. Thereafter, the solution was heated to 110 to 120 ° C. and reacted for 72 hours. Furthermore, in order to perform an end cap, 2-tributyltin thiophene (11 mg, 0.03 mmol) was added and refluxed for 10 hours. Further 2-bromothiophene (10 mg, 0.06 mmol) was added and refluxed for 10 hours. After completion of the reaction, reprecipitation in methanol (500 ml), and the polymer product collected by filtration was extracted with Soxhlet extraction using methanol, acetone, heptane, chloroform, and then orthodichlorobenzene, and reprecipitated in methanol. Was performed to obtain 290 mg of a pure polymer (p-type organic semiconductor material C; Mn = 26000).

(Synthesis of p-type organic semiconductor material D)
In the synthesis of the p-type organic semiconductor material C, the compound W (HNMR (CDCl3) = 7.95 ppm (2H), s, 2.62 ppm which is a monomer is similarly used except that the following compound V is used instead of the compound Q. (4H), d, 1.84 ppm (2H), m, 1.35-1.25 ppm (48H), br, 0.85 ppm (12H), m.) The p-type organic semiconductor material D was obtained by copolymerization (yield 250 mg, Mn = 37000).

  (Synthesis of p-type organic semiconductor material E)

  J. et al. Am. Chem. Soc. , 2011, 133 (25), pp9638, and compound X was synthesized. HNMR (CDCl3) = 9.01 ppm (2H), s, 7.95 ppm (2H), s, 2.62 ppm (4H), d, 1.84 ppm (2H), m, 1.35 to 1.25 ppm (80H ), Br, 0.85 ppm (12H), m.

  The compound X (310 mg, 0.25 mmol) and the compound U (256 mg, 0.25 mmol) were dissolved in 20 ml of anhydrous toluene. After purging the solution with nitrogen, 6.3 mg (0.007 mmol) of tris (dibenzylideneacetone) dipalladium (0) and 16.7 mg (0.055 mmol) of tris (o-tolyl) phosphine were added. It was. This solution was purged with argon for an additional 15 minutes. Thereafter, the solution was heated to 110 to 120 ° C. and reacted for 72 hours. Furthermore, in order to perform an end cap, 2-tributyltin thiophene (11 mg, 0.03 mmol) was added and refluxed for 10 hours. Further 2-bromothiophene (10 mg, 0.06 mmol) was added and refluxed for 10 hours. After completion of the reaction, reprecipitation in methanol (500 ml), and the polymer product collected by filtration was extracted with Soxhlet extraction using methanol, acetone, heptane, chloroform, and then orthodichlorobenzene, and reprecipitated in methanol. To obtain 220 mg of a pure polymer (p-type organic semiconductor material E; Mn = 29000).

(Formation of transparent electrode)
A first indium tin oxide (ITO) transparent conductive film deposited on a glass substrate with a thickness of 150 nm (sheet resistance 12 Ω / □) is patterned to a width of 10 mm using a normal photolithography technique and wet etching. The electrode was formed. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

(Formation of hole transport layer)
Next, PEDOT-PSS (CLEVIOS (registered trademark) PVP AI 4083, manufactured by Helios Co., Ltd., conductivity 1 × 10 ⁻³ S / cm) made of a conductive polymer and a polyanion is 2.0 as a hole transport layer. An isopropanol solution containing by mass% was prepared, and the substrate was applied and dried using a blade coater whose temperature was adjusted to 65 ° C. so that the dry film thickness was about 30 nm. Thereafter, heat treatment was carried out with warm air of 120 ° C. for 20 seconds to form a hole transport layer on the first electrode.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere.

  First, the substrate was heat-treated at 120 ° C. for 3 minutes in a nitrogen atmosphere.

(Formation of photoelectric conversion layer)
Next, an organic material obtained by mixing 0.72% by mass of the p-type organic semiconductor material shown in Table 10 and 1.08% by mass of n-type organic semiconductor material PC61BM (frontier carbon nanom spectra E100H) in o-dichlorobenzene. A photoelectric conversion material composition solution was prepared, stirred (60 minutes) while being heated to 100 ° C. on a hot plate and completely dissolved, and then the temperature of the substrate was adjusted to 80 ° C. so that the dry film thickness was about 150 nm. The film was applied using a blade coater and dried for 2 minutes to form a photoelectric conversion layer on the hole transport layer.

(Electron transport layer)
Then, the compound of Table 10 was melt | dissolved in hexafluoroisopropanol so that it might become 0.02 mass%, respectively, and the solution was prepared. This solution was applied and dried using a blade coater whose temperature was adjusted to 65 ° C. so that the dry film thickness was about 5 nm. Thereafter, heat treatment was performed for 2 minutes with warm air at 100 ° C. to form an electron transport layer on the photoelectric conversion layer.

(Formation of second electrode)
Next, the substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Ag metal is deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sandwiched between ^two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m ² / d), UV After sealing using a curable resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1), the organic photoelectric conversion elements 901, 903, and 905 having a light receiving portion of about 10 × 10 mm size are taken out into the atmosphere. Produced.

[Production of Organic Photoelectric Conversion Elements 901, 903, 905]
(Formation of transparent electrode)
An indium tin oxide (ITO) transparent conductive film deposited on a PET substrate with a thickness of 150 nm (sheet resistance 12 Ω / □) is patterned to a width of 10 mm using a normal photolithography technique and wet etching. An electrode was formed. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried by nitrogen blowing, and finally subjected to ultraviolet ozone cleaning.

(Electron transport layer)
Next, the compound shown in Table 10 was dissolved in hexafluoroisopropanol so as to be 0.02% by mass, a solution was prepared, and coating and drying were performed using a blade coater so that the dry film thickness was about 5 nm. Thereafter, heat treatment was performed with warm air at 100 ° C. for 2 minutes to form an electron transport layer.

  After this, the substrate was brought into the glove box and operated under a nitrogen atmosphere.

(Formation of organic photoelectric conversion layer)
Next, an organic material obtained by mixing 0.72% by mass of the p-type organic semiconductor material shown in Table 10 and 1.08% by mass of n-type organic semiconductor material PC61BM (frontier carbon nanom spectra E100H) in o-dichlorobenzene. A photoelectric conversion material composition solution was prepared, stirred (60 minutes) while being heated to 100 ° C. on a hot plate and completely dissolved, and then the temperature of the substrate was adjusted to 80 ° C. so that the dry film thickness was about 150 nm. The film was applied using a blade coater and dried for 2 minutes to form a photoelectric conversion layer on the electron transport layer.

(Formation of hole transport layer)
Next, this transparent substrate was placed in a vacuum deposition apparatus. After depressurizing the inside of the vacuum deposition apparatus to 10 ⁻³ Pa or less, MoO ₃ was deposited by 15 nm at a deposition rate of 0.5 nm / second to form a hole transport layer on the photoelectric conversion layer.

(Formation of second electrode)
Next, the substrate on which the electron transport layer was formed was placed in a vacuum evaporation apparatus. Then, after setting the element so that the shadow mask with a width of 10 mm is orthogonal to the transparent electrode, the inside of the vacuum deposition apparatus is depressurized to 10 ⁻³ Pa or less, and then 100 nm of Ag metal is deposited at a deposition rate of 0.5 nm / second. Thus, the second electrode was formed.

(Sealing of organic photoelectric conversion elements)
The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sandwiched between ^two 3M Ultra Barrier Solar Film UBL-9L (water vapor transmission rate <5 × 10 ⁻⁴ g / m ² / d), UV After sealing using a cured resin (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1), the organic photoelectric conversion elements 902, 904, and 906 having a light receiving portion of about 10 × 10 mm size are taken out into the atmosphere. Produced.

<< Evaluation of organic photoelectric conversion element >>
The photoelectric conversion efficiency was evaluated in the same manner as in Example 1. Table 10 shows the obtained results.

  From Table 10, when a compound having a thiazolothiazole group or a naphthobisbenzothiazole group (more preferably a thiazolothiazole group, particularly preferably both of these groups) is used as a P-type semiconductor material It is confirmed that higher photoelectric conversion efficiency can be achieved.

10, 20, 30 organic photoelectric conversion element,
11 Anode,
12 cathode,
14 photoelectric conversion layer,
14a 1st photoelectric conversion layer,
14b second photoelectric conversion layer,
25 substrate 26 hole transport layer,
26a inorganic material layer,
26b organic material layer,
27 electron transport layer,
38 charge recombination layer,
38a second electron transport layer,
38b Second hole transport layer.

Claims (22)

A polymer compound containing a structure represented by the following general formula (1) as a side chain and further having a main unit having a structural unit (including a salt form) represented by the following general formula (3):
Where
L ₁ is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted alkynylene group having 2 to 20 carbon atoms, A substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms, an alkyleneoxy group having 1 to 20 carbon atoms, and — (L _{1 ′} ) —. (OR) _p- represents a divalent linking group selected from the group consisting of _p- (wherein L _{1 ′} represents a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon atom) An arylene group of several 6 to 30 or a single bond, R represents an ethylene group, a trimethylene group or a propylene group, and p is an integer of 1 to 5),
L ₂ is:
Where
L ₁ has the same definition as above,
L ₄ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted carbon atom. Represents an aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, or L ₂ (however, two L ₄ bonded to N are not hydrogen atoms) ,
A group (including a salt form) represented by
L ₃ has the same definition as L ₄ above.
And the number of nitrogen atoms (N) in the chain having the most nitrogen atoms (N) in the structure represented by the general formula (1) is 2 to 5,
Where
X ₁ represents a charcoal MotoHara child,
Z represents the structure represented by the general formula (1),
n represents the number of Z bonded to X ₁ and is ₁ , 2 or 3;
A and B each independently represent a 6-membered aromatic hydrocarbon ring, a 5-membered aromatic heterocycle, or a 6-membered aromatic heterocycle. The polymer compound according to claim 1, wherein the main chain of the polymer compound has a structural unit (including a salt form) represented by the following general formula (4).
Where
L ₁ , L ₂ , and L ₃ have the same definition as above,
X ₁ represents a charcoal MotoHara child,
Y ₁ and Y ₂ each independently represent —C (R ₃ ) ═C (R ₄ ) —, —C (R ₅ ) ═N—, —O— or —S—,
R _{3 to} R ₅ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted group. And an aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; and n is 1, 2 or 3. The polymer compound according to claim 1 or 2, wherein a main chain of the polymer compound has a structural unit (including a salt form) represented by the following general formula (5).
Where
L _{5 to} L ₇ are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, or a substituted or unsubstituted carbon atom. An alkynylene group having 2 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms, an alkyleneoxy group having 1 to 20 carbon atoms, And a divalent linking group selected from the group consisting of — (L _{1 ′} ) — (OR) _p — (wherein L _{1 ′} represents a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms) Represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a single bond, R represents an ethylene group, a trimethylene group or a propylene group, and p is an integer of 1 to 5);
X ₂ represents a carbon MotoHara child;
Y ₃ and Y ₄ each independently represent —C (R ₁₀ ) ═C (R ₁₁ ) —, —C (R ₁₂ ) ═N—, —O— or —S—;
R _{6 to} R ₉ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, substituted or unsubstituted. An aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, or L ₂ above,
R _{10 to} R ₁₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, substituted or unsubstituted. Represents an aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, and n is 1, 2 or 3. In the general formula (4) or (5), Y ₁ and Y ₂ , or Y ₃ and Y ₄ are each independently —CH═CH—, —CH═N— or —S—. The polymer compound according to claim 2 or 3. A cathode,
The anode,
A photoelectric conversion layer including a p-type organic semiconductor material and an n-type organic semiconductor material interposed between the cathode and the anode;
An intermediate layer other than the photoelectric conversion layer interposed between the cathode and the anode,
An organic photoelectric conversion element having
The organic photoelectric conversion element in which at least 1 of the said intermediate | middle layer contains the high molecular compound of any one of Claims 1-4 . The organic photoelectric conversion device according to claim 5 , wherein the main chain of the polymer compound further has a structural unit represented by the following general formula (2):
Where
M ₁ and M ₂ each independently represents an aryl group or a heteroaryl group which is a single ring or a condensed ring;
Z represents the structure represented by the general formula (1),
a and b each independently represent a positive real number satisfying a relationship of a> 0, b ≧ 0, a + b = 1.0,
n represents the number of Z bonded to M ₁ and is ₁ , 2 or 3. The intermediate layer includes a polymer compound having an aromatic ring in the main chain and having 1.5 or more primary to quaternary amino groups as substituents per aromatic ring,
The organic photoelectric conversion element according to claim 5 or 6 , wherein a work function of an electrode in contact with the intermediate layer is -4.5 eV or less as measured by photoelectron spectroscopy. The organic photoelectric conversion device according to claim 5, wherein the polymer compound contained in the intermediate layer has two or more amino groups per aromatic ring of the main chain. The organic photoelectric conversion element according to claim 7 or 8 , wherein at least one of the amino groups is a tertiary amino group. The polymer compound contained in the intermediate layer has an aromatic three or more amino groups per ring in the main chain, an organic photoelectric conversion device according to any one of claims 5-9. The organic photoelectric conversion element according to any one of claims 5 to 10 , wherein the intermediate layer is an electron transport layer. The intermediate layer and the contact electrode, indium tin oxide (ITO), molybdenum oxide, containing copper or silver, an organic photoelectric conversion device according to any one of claims 5-11. The intermediate layer in contact with the electrode comprises silver, an organic photoelectric conversion device according to any one of claims 5-12. The anode is a transparent electrode;
The organic photoelectric conversion element according to any one of claims 5 to 13 , wherein the constituent material of the cathode contains a metal which is equivalent to aluminum or has a higher ionization potential than aluminum. The constituent material of the cathode contains silver, gold or copper, an organic photoelectric conversion device according to any one of claims 5-14. The p-type organic semiconductor material contained in the photoelectric conversion layer is at least one of a structure represented by the following general formula (6), a structure represented by the following general formula (7), and a structure represented by the following general formula (8). one having the organic photoelectric conversion device according to any one of claims 5-15.
Where
X ₃ represents a carbon atom, a silicon atom, or a germanium atom,
R ₁₃ and R ₁₄ each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, or a substituted or unsubstituted carbon atom. An aryl group of 6 to 30 or a substituted or unsubstituted heteroaryl group of 1 to 30 carbon atoms;
Y ₅ and Y ₆ each independently represent —C (R ₁₇ ) ═ or —N═,
R _{15 to} R ₁₇ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a fluorinated alkyl group having 1 to 20 carbon atoms, or 3 carbon atoms. -20 cycloalkyl group, fluorinated cycloalkyl group having 3 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, fluorinated alkoxy group having 1 to 20 carbon atoms, fluorinated group having 1 to 20 carbon atoms. Alkylthio group, aryl group having 6 to 30 carbon atoms, fluorinated aryl group having 6 to 30 carbon atoms, heteroaryl group having 1 to 20 carbon atoms, or fluorinated heteroaryl group having 1 to 20 carbon atoms Represents. At least two layers of the photoelectric conversion layer are arranged via the intermediate layer,
The organic layer according to any one of claims 5 to 16 , wherein the intermediate layer interposed between the two photoelectric conversion layers contains the polymer compound according to any one of claims 1 to 4. Photoelectric conversion element. The intermediate layer interposed between two photoelectric conversion layers has at least a hole transport layer and an electron transport layer;
The electron transport layer having the said intermediate layer contains a polymer compound according to any one of claims 1-4, organic photoelectric conversion device according to claim 17. The organic photoelectric conversion element according to claim 17 or 18 , wherein the hole transport layer of the intermediate layer interposed between two photoelectric conversion layers contains a p-type conductive polymer material. The organic photoelectric conversion element according to claim 19 , wherein a film surface pH of the hole transport layer of the intermediate layer interposed between the two photoelectric conversion layers is 4 or less. The organic photoelectric conversion element according to any one of claims 5 to 20 , wherein the intermediate layer is formed by a coating process using a solvent containing an alcohol substituted with a fluorine atom. Having an organic photoelectric conversion device according to any one of claims 5-21, the solar cell.