JP2014078670A - Semiconductor device manufacturing method, photoelectric converter, solar cell, and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a photoelectric converter having higher photoelectric conversion performance.SOLUTION: In a method for manufacturing a semiconductor device provided with a semiconductor layer including a first semiconductor material and a second semiconductor material, one of which is an electron donor and the other is an electron acceptor, a manufacturing process of the semiconductor layer comprises a step of forming a layer including the first semiconductor material and a third material by evaporating the first semiconductor material and the third material, and a replacement step of replacing the third material with the second semiconductor material in the layer including the first semiconductor material and the third material, where the third material is a compound satisfying at least one of the following conditions. (1) A compound whose glass transition temperature by differential scanning calorimetry (DSC method) is 80°C to 200°C inclusive. (2) A compound whose crystallization temperature by differential scanning calorimetry (DSC method) is 180°C to 300°C inclusive.

Description

  The present invention relates to a semiconductor device manufacturing method, a photoelectric conversion element, a solar cell, and a solar cell module.

  In recent years, solar cells including photoelectric conversion elements using organic materials have been developed. Such a photoelectric conversion element usually has an active layer that absorbs light and two electrodes. As the active layer, there is a bulk heterojunction type using a system in which a mixture of an electron donor and an electron acceptor is phase-separated. Carriers due to light absorption are thought to be generated mainly at the contact interface between the electron donor phase and the electron acceptor phase in the active layer. Therefore, in order to increase the efficiency of the device, the contact area between both phases should be increased. Is essential.

  As a method for controlling the phase separation structure of an organic thin film, Patent Document 1 discloses that a mixture of a structure forming material such as polystyrene and a curable first functional material such as P3HT is phase-separated in a direction along the substrate surface. After the deposition, the structure-forming material is removed and the first functional material is cured, and then a second functional material such as PCBM is deposited to form a porous structure of the first functional material. A method of intruding the functional material is described.

  Patent Document 2 discloses a method of manufacturing a semiconductor device including a semiconductor layer including a first semiconductor material and a second semiconductor material, one of which is an electron donor and the other is an electron acceptor. A method for manufacturing a semiconductor device, comprising: a step of replacing the third material with the second semiconductor material for a layer including the first semiconductor material and a third material that is not a semiconductor material. Has been.

Special table 2008-523571 JP 2010-192891 A

In the method disclosed in Patent Document 1, heat curing and UV curing are listed as methods for curing the first functional material, but it is difficult to sufficiently cure the first functional material by this method, When the second functional material is deposited, the first functional material may be dissolved.
In the method disclosed in Patent Document 2, a phase separation structure can be obtained. From the viewpoint of improving the photoelectric conversion efficiency by increasing the contact area between the electron donor and the electron acceptor, the phase separation structure is finer. Is required to control.

That is, in the manufacture of semiconductor devices, particularly photoelectric conversion elements, the semiconductor layer and the method for manufacturing the semiconductor layer are important for determining the performance. Is insufficient, and further improvement is necessary for the practical application of photoelectric conversion elements.
An object of the present invention is to manufacture a semiconductor device in which a phase separation structure between a first semiconductor material and a second semiconductor material in a semiconductor layer is controlled. In particular, an object is to produce a photoelectric conversion element with improved photoelectric conversion efficiency.

In view of the above circumstances, the present inventors have conducted extensive studies to improve the photoelectric conversion efficiency by better controlling the phase separation structure in the method for forming an active layer using a latent pigment, and as a result, the glass transition temperature or the crystallization temperature. The present inventors have found that the object of the present invention can be achieved by using a third material having a specific range in forming a semiconductor layer. That is, the gist of the present invention is as follows.
[1] A method for manufacturing a semiconductor device comprising a semiconductor layer containing a first semiconductor material and a second semiconductor material, one of which is an electron donor and the other is an electron acceptor,
The manufacturing process of the semiconductor layer includes a step of depositing the first semiconductor material and a third material to form a layer including the first semiconductor material and the third material, and the first semiconductor material; A replacement step of replacing the third material with the second semiconductor material for a layer containing the third material;
The method for manufacturing a semiconductor device, wherein the third material is a compound satisfying at least one of the following conditions.

(1) A compound having a glass transition temperature of 80 ° C. or higher and 200 ° C. or lower by differential scanning calorimetry (DSC method) (2) A crystallization temperature of 180 ° C. or higher and 300 ° C. or lower by differential scanning calorimetry (DSC method) The compound [2] method for manufacturing a semiconductor device according to [1], wherein the third material is a compound satisfying the conditions (1) and (2).
[3] The method for manufacturing a semiconductor device according to [1] or [2], wherein the third material is represented by the following formula (1) or (2).

(In formula (1), X represents a trivalent group, and A ^{1 to} A ³ each independently represents an aromatic group which may have a substituent.)

(In formula (2), p represents an integer of 1 or more, R ¹¹ and R ¹² each independently represent an arbitrary substituent, and R ¹¹ and R ¹² may be bonded to each other to form a ring. When p is 2 or more, the plurality of R ¹¹ and the plurality of R ¹² may each independently be different, and R ¹³ may be a p-valent hydrocarbon group or substituent which may have a substituent. P-valent heterocyclic group which may have a p-valent heterocyclic group or a hydrocarbon group which may have a substituent and at least one of a heterocyclic group which may have a substituent connected Y represents an atom selected from Group 16 elements of the periodic table.)
[4] In the replacement step, the third material is applied to the second semiconductor by applying a solution of the second semiconductor material to a layer including the first semiconductor material and the third material. The method for manufacturing a semiconductor device according to any one of [1] to [3], wherein the semiconductor device is replaced with a material.
[5] The replacing step includes the step of eluting and removing the third material from the layer containing the first semiconductor material and the third material using a solvent of the third material, Including the step of containing the second semiconductor material by applying a solution of the second semiconductor material to the layer from which the third material has been removed. ] The manufacturing method of the semiconductor device as described in any one of.
[6] The first semiconductor material is hardly soluble or insoluble in a solvent in the solution of the second semiconductor material, and the third material is acceptable in a solvent in the solution of the second semiconductor material. The method for producing a semiconductor device according to any one of [1] to [5], wherein the semiconductor device is melted.
[7] The method for manufacturing a semiconductor device according to [5], wherein the first semiconductor material is hardly soluble or insoluble in the solvent of the third material.
[8] The method for manufacturing a semiconductor device according to any one of [1] to [7], wherein the semiconductor device is a photoelectric conversion element.
[9] A solar cell comprising a photoelectric conversion element produced by the production method according to [8].
[10] A solar cell module comprising the solar cell according to [9].

  According to the manufacturing method of the present invention, the first semiconductor material in the semiconductor layer can be efficiently crystallized. Moreover, in the case of the manufacturing method of a photoelectric conversion element, a photoelectric conversion element with high photoelectric conversion performance can be provided.

It is a schematic cross section of the photoelectric conversion element which concerns on 1st Embodiment. It is a schematic cross section of the photoelectric conversion element which concerns on 2nd Embodiment. It is a schematic cross section of the photoelectric conversion element which concerns on 3rd Embodiment. It is a schematic cross section of the photoelectric conversion element which concerns on 4th Embodiment. It is a schematic cross section of the solar cell as one embodiment concerning the present invention. It is a schematic cross section of the solar cell module as one embodiment concerning the present invention.

<1. Semiconductor Device According to the Present Invention>
A semiconductor device according to the present invention is a semiconductor device comprising a semiconductor layer including a first semiconductor material and a second semiconductor material, one of which is an electron donor and the other is an electron acceptor, A step of manufacturing a semiconductor layer, the step of depositing the first semiconductor material and the third material to form a layer including the first semiconductor material and the third material; and the first semiconductor material and the first material And a replacement step of replacing the third material with the second semiconductor material for the layer containing the third material, wherein the third material is a compound that satisfies at least one of the following conditions: It is obtained by a manufacturing method.

(1) A compound having a glass transition temperature of 80 ° C. or higher and 200 ° C. or lower by differential scanning calorimetry (DSC method) (2) A crystallization temperature of 180 ° C. or higher and 300 ° C. or lower by differential scanning calorimetry (DSC method) A certain compound There is no restriction | limiting in particular in the kind of semiconductor device concerning this invention. Examples include a light emitting element, a switching element, a photoelectric conversion element, an optical sensor using photoelectric conductivity, and the like.

Examples of the light emitting element include various light emitting elements used for display devices. Specific examples include a liquid crystal display element, a polymer dispersion type liquid crystal display element, an electrophoretic display element, an electroluminescent element, an electrochromic element, and the like.
Specific examples of the switching element include a diode (pn junction diode, Schottky diode, MOS diode, etc.), a transistor (bipolar transistor, field effect transistor (FET), etc.), a thyristor, and a composite element thereof (for example, TTL). Etc.).

Specific examples of the photoelectric conversion element include a thin film solar cell, a charge coupled device (CCD), a photomultiplier tube, and a photocoupler. Moreover, what utilized these photoelectric conversion elements is mentioned as an optical sensor using photoelectric conductivity.
Below, the photoelectric conversion element manufactured by the manufacturing method concerning each embodiment of the present invention is explained in detail with reference to drawings. The embodiments described below are merely exemplary embodiments (representative examples) of the present invention, and the present invention is not limited to the following embodiments.

<2. Photoelectric conversion element>
The photoelectric conversion element manufactured by the manufacturing method according to the present invention includes an active layer including a first semiconductor material and a second semiconductor material, one of which is an electron donor and the other is an electron acceptor. Several embodiments of the photoelectric conversion element according to the present invention will be described below.
As shown in FIGS. 1 to 4, the photoelectric conversion element 100 according to the first to fourth embodiments of the present invention includes a substrate 101, an electrode 102, a buffer layer 103, an active layer 104, a buffer layer 105, and an electrode 106. Have. The active layer 104 of the photoelectric conversion element 100 according to the first embodiment includes an active layer (i-layer) 104c. The active layer 104 of the photoelectric conversion element 100 according to the second embodiment includes an active layer (p-layer) 104a and an active layer (i-layer) 104c. The active layer 104 of the photoelectric conversion element 100 according to the third embodiment includes an active layer (i-layer) 104c and an active layer (n-layer) 104b. The active layer 104 of the photoelectric conversion element 100 according to the fourth embodiment includes an active layer (p-layer) 104a, an active layer (i-layer) 104c, and an active layer (n-layer) 104b.

In the photoelectric conversion element according to another embodiment of the present invention, the substrate 101 is disposed not on the electrode 102 side but on the electrode 106 side. That is, the photoelectric conversion element according to another embodiment has a structure in which the electrode 102, the buffer layer 103, the active layer 104, the buffer layer 105, the electrode 106, and the substrate 101 are stacked.
The photoelectric conversion element according to the present invention may not include any of the substrate 101, the buffer layer 103, and the buffer layer 105. Further, the light receiving surface of the photoelectric conversion element may be on the electrode 102 side or on the electrode 106 side.
Hereinafter, each of the above-described layers will be described in detail.

<2.1 Substrate (101)>
The substrate 101 serves as a support for the photoelectric conversion element 100. There is no particular limitation on the material of the substrate 101, but when the substrate 101 is on the light receiving surface side of the photoelectric conversion element 100, it is preferable to use a highly light-transmitting material for the substrate 101. As the substrate 101, a colored one or a colorless one can be used. As a specific example of the substrate 101, a quartz or glass plate or a plastic film or sheet is used. In particular, the use of a glass plate as the substrate 101 is preferable in terms of strength. In addition, it is preferable in terms of lightness to use a transparent synthetic resin substrate such as polyester, polymethacrylate, polycarbonate, or polysulfone as the substrate 101. The substrate 101 may have a multilayer structure including a plurality of layers.

  The substrate 101 preferably has a high barrier property. Here, the barrier property refers to the ability to block a gas such as oxygen or water vapor. It is preferable that the gas barrier property of the substrate 101 is high from the viewpoint of reducing the possibility that the photoelectric conversion element 100 is deteriorated by the gas passing through the substrate 101. When a synthetic resin substrate is used as the substrate 101, for example, by providing a dense silicon oxide film or the like on one surface or both surfaces of the synthetic resin substrate, the gas barrier property of the substrate 101 can be improved.

<2.2 Electrodes (102, 106)>
The electrodes 102 and 106 are terminals for taking out electricity generated in the photoelectric conversion element 100 from the outside. One of the electrodes 102 and 106 is an anode (an electrode that collects holes, an anode), and the other is a cathode (an electrode that collects electrons, a cathode). In the following description, it is assumed that the electrode 102 is an anode and the electrode 106 is a cathode. However, the electrode 102 may be a cathode and the electrode 106 may be an anode. The electrode located on the light receiving surface side of the photoelectric conversion element 100 preferably has translucency.

[2.2.1 Anode (102)]
The anode 102 collects holes that are carriers generated in the active layer 104. Although the material of the anode 102 is not particularly limited, for example, a metal oxide such as indium tin oxide or indium zinc oxide can be used. The anode 102 can be formed by, for example, a coating method such as a spin coating method, a sputtering method, a vacuum evaporation method, or the like.

  When the anode 102 is positioned on the light receiving surface side of the photoelectric conversion element 100, it is preferable that the transmittance of visible light (light having a wavelength of 360 to 830 nm) of the anode 102 is 60% or more from the viewpoint of improving the photoelectric conversion efficiency. 80% or more is more preferable. The thickness of the anode 102 is not particularly limited, but is preferably 10 nm or more, and more preferably 50 nm or more from the viewpoint of strength. On the other hand, from the viewpoint of lightness, it is preferably 1000 nm or less, and more preferably 300 nm or less. The anode 102 may be colored or colorless.

[2.2.2 Cathode (106)]
The cathode 106 collects electrons that are carriers generated in the active layer 104. The material of the cathode 106 is not particularly limited. For example, a metal or alloy such as magnesium, indium, calcium, aluminum, or silver, or a transparent oxide semiconductor such as indium tin oxide or indium zinc oxide is used as the active layer. It is preferable because electrons generated by charge separation in 104 can be received efficiently. The cathode 106 can be formed by, for example, a coating method such as a spin coating method or an inkjet method, a sputtering method, a vacuum evaporation method, or the like.

  When the cathode 106 is positioned on the light receiving surface side of the photoelectric conversion element 100, the visible light (light with a wavelength of 360 to 830 nm) transmittance of the cathode 106 is preferably 60% or more from the viewpoint of improving the photoelectric conversion efficiency. 80% or more is more preferable. The thickness of the cathode 106 is not particularly limited, but is preferably 10 nm or more, and more preferably 50 nm or more from the viewpoint of strength. On the other hand, from the viewpoint of lightness, it is preferably 1000 nm or less, and more preferably 300 nm or less. The cathode 106 may be colored or colorless.

<2.3 Buffer layer (103, 105)>
The buffer layers 103 and 105 are for efficiently transporting carriers (electrons or holes) generated by charge separation in the active layer 104 to the electrodes 102 and 106. In this specification, the buffer layer that transports holes to the anode is referred to as an anode buffer layer. A buffer layer that transports electrons to the cathode is called a cathode buffer layer. Usually, the anode buffer layer is in contact with the active layer and the anode, and the cathode buffer layer is in contact with the active layer and the cathode.
Hereinafter, the anode buffer layer and the cathode buffer layer will be described in more detail. In the following description, it is assumed that the electrode 102 is an anode and the electrode 106 is a cathode. That is, in this case, the buffer layer 103 is an anode buffer layer, and the buffer layer 105 is a cathode buffer layer.

[2.3.1 Anode buffer layer (103)]
The material used for the anode buffer layer 103 is not particularly limited as long as it can transport holes generated in the active layer to the anode. By having such an anode buffer layer 103, holes can be smoothly transported from a layer adjacent to the anode buffer layer 103 to another layer adjacent to the anode buffer layer 103. For example, the anode buffer layer 103 can efficiently transport holes generated in the active layer 104 to the anode while suppressing deactivation due to recombination or the like. For this reason, the photoelectric conversion characteristics of the photoelectric conversion element 100 according to each embodiment can be improved. The material used for the anode buffer layer 103 preferably has high hole mobility and high conductivity. Furthermore, the material used for the anode buffer 103 layer preferably has a small hole injection barrier with the anode.

  As a material of the anode buffer layer 103, for example, a conjugated polymer compound, particularly a conductive polymer can be used. As an example of the conductive polymer, poly (3,4-ethylenedioxythiophene) poly (styrenesulfonic acid) (abbreviation PEDOT: PSS), which is a polythiophene mixed with an electron-accepting compound, and an electron-accepting compound are mixed Examples include polyaniline and polypyrrole.

Examples other than the conductive polymer include metal oxides, such as molybdenum trioxide (MoO ₃ ), vanadium pentoxide (V ₂ O ₅ ), tungsten oxide (WO ₃ ), or nickel oxide (NiO). Be
When the anode buffer layer 103 is positioned on the light receiving surface side with respect to the active layer 104, the anode buffer layer 103 preferably has a light-transmitting property. In this case, the sunlight transmittance of the anode buffer layer 103 is preferably 60% or more, and more preferably 80% or more. As more sunlight is transmitted, more light reaches the active layer 104, so that the photoelectric conversion efficiency is expected to improve.

A method for forming the anode buffer layer 103 is arbitrary, and examples thereof include a wet coating method such as a spin coating method or an inkjet method, or a vacuum deposition method. From the viewpoint of ensuring the uniformity of the anode buffer layer 103 in order to increase the open-circuit voltage by covering the active layer 104, the thickness of the anode buffer layer 103 is preferably 3 nm or more, and more preferably 10 nm or more. preferable. Moreover, from the viewpoint of reducing the electrical resistance and increasing the fill factor, the thickness of the anode buffer layer 103 is preferably 200 nm or less, and more preferably 100 nm or less.
The anode buffer layer 103 may be composed of one type of material, or may be composed of two or more types of materials combined at an arbitrary ratio.

[2.3.2 Cathode buffer layer (105)]
The cathode buffer layer 105 has a function of efficiently transporting electrons generated in the active layer 104 to the cathode 106. From this point of view, the cathode buffer layer 105 material preferably has a larger optical gap than the active layer 104 material in order to prevent exciton diffusion. The material of the cathode buffer layer 105 preferably has a high electron transport property and effectively lowers the work function of the cathode 106. The cathode buffer layer 105 is preferably in close physical contact with the adjacent active layer 104 and cathode 106.

  From these viewpoints, as the material of the cathode buffer layer 105, among inorganic compounds, metal oxides exhibiting n-type semiconductor characteristics such as zinc oxide or titanium oxide (for example, Appl. Phys. Lett. 2008, 92, Inorganic salts such as lithium fluoride and cesium fluoride (for example, described in SE Shahen et al., Appl. Phys. Lett., 78, 841-843, 2001) are preferable. Among organic compounds, a phenanthroline compound such as bathocuproine (BCP) (for example, described in S. Uchida et al. Appl. Phys. Lett. 84, 4218-4220, 2004.) or a phosphine oxide compound and It is preferable to use a compound having a heavy bond (for example, described in International Publication No. 2012/102390). More preferably, a compound having a phosphorus atom and a double bond such as a phosphine oxide compound is more preferable in terms of improving the conversion efficiency.

Examples of the method for forming the cathode buffer layer 105 include a wet coating method such as a spin coating method or an inkjet method, or a vacuum deposition method. The thickness of the cathode buffer layer 105 is not particularly limited, but is preferably 1 nm or more and more preferably 2 nm or more from the viewpoint of completely covering the active layer 104. On the other hand, from the viewpoint of reducing internal resistance and preventing a decrease in fill factor (FF), the thickness is preferably 100 nm or less, and more preferably 50 nm or less.
When the cathode buffer layer 105 is positioned on the light receiving surface side of the photoelectric conversion element 100 with respect to the active layer 104, the cathode buffer layer 105 preferably has a light-transmitting property, specifically visible light (wavelength 360 to 360). (Light of 830 nm) is preferably 60% or more, and more preferably 80% or more.

<2.4 Active layer (104)>
The active layer 104 includes a first semiconductor material and a second semiconductor material, one of which is an electron donor and the other is an electron acceptor. As the semiconductor material used for the active layer 104, at least one material can efficiently absorb light having a wavelength from the visible region to the near infrared region, and efficiently transports holes or electrons induced by light. It is preferable that the material has a high mobility.

  The photoelectric conversion element 100 according to the first to fourth embodiments includes a bulk heterojunction active layer 104. The active layer 104 of the bulk heterojunction photoelectric conversion element includes an active layer (i-layer) 104c that is a semiconductor layer including a first semiconductor material and a second semiconductor material. When the first semiconductor material and the second semiconductor material form a phase separation structure, the contact area between the two increases, and charge separation is performed more efficiently. From this point of view, in the active layer (i-layer) 104c, the first semiconductor material and the second semiconductor material are phase-separated so that each has a size of about the exciton diffusion length, for example, about 10 nm. It is preferable.

[2.4.1 First semiconductor material]
The first semiconductor material is an electron donor or electron acceptor. Here, the electron donor is a material that usually shows p-type semiconductor characteristics in a solid state, and the electron acceptor is a material that usually shows n-type semiconductor characteristics in a solid state. The first semiconductor material may be composed of one compound or a mixture of a plurality of compounds.

The first semiconductor material is preferably an organic semiconductor material in that film formation by vacuum deposition is easy. The first semiconductor material exhibits semiconductor characteristics. Specifically, the carrier mobility of the layer formed of the first semiconductor material is preferably 1 × 10 ⁻⁶ cm ² / Vs or more. An example of a method for measuring carrier mobility is an FET method, which can be performed by a method described in a known document (Japanese Patent Laid-Open No. 2010-045186).

  As will be described later, when the active layer (i-layer) 104c is formed, the third material is replaced with the second semiconductor material for the layer including the first semiconductor material and the third material. Processing is performed. Here, when the third material is replaced with the second semiconductor material using the solution of the second semiconductor material, the first semiconductor material is hardly soluble or insoluble in the solvent in the solution of the second semiconductor material. Preferably there is. When the third material is eluted and removed using the third material solvent, the first semiconductor material is preferably hardly soluble or insoluble in the third material solvent. In the present specification, the compound being hardly soluble or insoluble means that the solubility of the compound is less than 0.1% by weight. From this viewpoint, the first semiconductor material preferably has a low solubility in a general solvent. Specifically, the solubility in toluene is usually less than 1.0% by weight, preferably less than 0.1% by weight.

In the case where the first semiconductor material is an electron donor, the first semiconductor material is a compound that has a sublimation property that allows vacuum deposition, has a solubility in an appropriate range, and functions as an electron donor. If there is no particular limitation.
It is preferable that the first semiconductor material can efficiently supply electrons to the second semiconductor material and efficiently transport holes to the electrode. Examples of the first semiconductor material that is an electron donor include a phthalocyanine compound or a metal complex thereof, or a macrocyclic compound such as a porphyrin compound such as tetrabenzoporphyrin or a metal complex thereof; a condensed fragrance such as naphthacene, pentacene, or pyrene. Group hydrocarbons; oligothiophenes containing four or more thiophene rings such as α-sexithiophene; at least one of thiophene ring, benzene ring, fluorene ring, naphthalene ring, anthracene ring, thiazole ring, thiadiazole ring and benzothiazole ring Including 4 or more in total, and the like. Among these, from the viewpoint of solubility, a phthalocyanine compound or a metal complex thereof, a porphyrin compound such as tetrabenzoporphyrin or a metal complex thereof, and a compound such as an oligothiophene are preferable. Specific examples of the compounds are shown below, but are not limited to the following compounds.

In the case where the first semiconductor material is an electron acceptor, the first semiconductor material is a compound that has a sublimation property that allows vacuum deposition, has a solubility in an appropriate range, and functions as an electron acceptor. If there is no particular limitation. It is preferable that the first semiconductor material can efficiently receive electrons from the second semiconductor material and efficiently transport the electrons to the electrode. As an example of the first semiconductor material that is an electron acceptor, specific examples of the inorganic semiconductor material include n-type metal oxides such as MoO ₃ , V ₂ O _{5, and} WO _{3 that} can be vacuum deposited. .

Specific examples of the organic semiconductor material include a phthalocyanine compound or a metal complex thereof, a porphyrin compound such as tetrabenzoporphyrin or a metal complex thereof, and the like, a macrocyclic compound substituted with a halogen atom such as a fluorine atom; a fullerene compound Quinolinol derivative metal complex represented by 8-hydroxyquinoline aluminum; condensed ring tetracarboxylic acid diimides such as naphthalenetetracarboxylic acid diimide or perylenetetracarboxylic acid diimide; perylene diimide derivative, terpyridine metal complex, tropolone metal complex, flavonol metal Complexes, perinone derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazole derivatives, benzthiazole derivatives, benzothiadiazole derivatives, oxadiazole derivatives, Diazole derivatives, triazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, benzoquinoline derivatives, bipyridine derivatives or borane derivatives; all fluorines of condensed polycyclic aromatic hydrocarbons such as anthracene, pyrene, naphthacene or pentacene And the like. Among these, from the point of low solubility in organic solvents, macrocyclic compounds substituted with a halogen atom such as a fluorine atom, such as a phthalocyanine compound or a metal complex thereof, or a porphyrin compound such as tetrabenzoporphyrin or a metal complex thereof, fullerene compounds such as C ₆₀ and _{C 70,} perylenediimides derivatives.

[2.4.2 Second semiconductor material]
The second semiconductor material is an electron acceptor when the first semiconductor material is an electron donor, and is an electron donor when the first semiconductor material is an electron acceptor. The second semiconductor material may be composed of one compound or a mixture of a plurality of compounds. The second semiconductor material is preferably an organic semiconductor material in terms of easy coating and film formation. The second semiconductor material exhibits semiconductor characteristics. Specifically, the carrier mobility of a layer formed of the second semiconductor material is preferably 1 × 10 ⁻⁶ cm ² / Vs or higher. An example of a method for measuring carrier mobility is an FET method, which can be performed by a method described in a known document (Japanese Patent Laid-Open No. 2010-045186).

It is preferable that the second semiconductor material has a high solubility in a general solvent in that a layer containing the second semiconductor material can be easily formed by a coating method. Specifically, the solubility in toluene at 25 ° C. is preferably 0.1% by weight or more, and more preferably 1.0% by weight or more.
When the second semiconductor material is an electron donor, the second semiconductor material is not particularly limited as long as it is a compound that functions as an electron donor. It is preferable that the second semiconductor material can efficiently supply electrons to the first semiconductor material and efficiently transport holes to the electrode. As an example of the second semiconductor material which is an electron donor, specifically, a condensed aromatic hydrocarbon such as naphthacene, pentacene or pyrene; an oligothiophene containing four or more thiophene rings such as α-sexithiophene A thiophene ring, a benzene ring, a fluorene ring, a naphthalene ring, an anthracene ring, a thiazole ring, a thiadiazole ring and a benzothiazole ring, and a total of four or more linked; a phthalocyanine compound or a metal complex thereof; Or a macrocyclic compound such as a porphyrin compound such as tetrabenzoporphyrin or a metal complex thereof; squarylium; a conjugated polymer semiconductor such as polythiophene, polyfluorene, polyparaphenylene vinylene, polythienylene vinylene, polyacetylene, or polyaniline; And the like; le groups or other substituents polymeric semiconductors such as oligothiophene substituted.

  Preferable examples of the electron donor include a low molecular compound having solubility (such as oligothiophene or squarylium) or a conjugated polymer compound. Specific examples of the conjugated polymer compound include those having polythiophene, polyparaphenylene vinylene, or polyfluorene as a basic skeleton. Specific examples are shown below. However, the conjugated polymer compound used as the electron donor is not limited to the following compounds. In the following formula, parentheses indicate a repeating unit.

When the second semiconductor material is an electron acceptor, the second semiconductor material is not particularly limited as long as it is a compound that functions as an electron acceptor. It is preferable that the second semiconductor material can efficiently receive electrons from the first semiconductor material and efficiently transport the electrons to the electrode. Specific examples of the second semiconductor material that is an electron acceptor include fullerene compounds; quinolinol derivative metal complexes typified by 8-hydroxyquinoline aluminum; naphthalene tetracarboxylic acid diimide or perylene tetracarboxylic acid diimide. Condensed ring tetracarboxylic acid diimides; perylene diimide derivatives, terpyridine metal complexes, tropolone metal complexes, flavonol metal complexes, perinone derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazole derivatives, benzthiazole derivatives, benzothiadiazole derivatives, oxadiazole derivatives , Thiadiazole derivatives, triazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, benzoquinolines Conductor, bipyridine derivatives or borane derivatives; anthracene, pyrene, total fluoride condensed polycyclic aromatic hydrocarbons such as naphthacene or pentacene; single-walled carbon nanotubes; n-type polymer (n-type polymer semiconductor compound) and the like.

The electron acceptor is preferably fullerene or a fullerene derivative. Here, the fullerene is a carbon cluster having a closed shell structure, and the carbon number of the fullerene is not particularly limited as long as it is usually an even number of 60 to 130. Examples of fullerenes include C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C ₉₄ , C ₉₆ and higher carbon clusters having more carbon than these. . Among these, _C60 or _C70 is preferable. As the fullerene, some carbon-carbon bonds on the fullerene ring may be broken. Some carbon atoms may be replaced with other atoms. Furthermore, a metal atom, a non-metal atom, or an atomic group composed of these may be included in the fullerene cage.

  The fullerene derivative is a fullerene having a substituent, and examples of the substituent include an alkyl group having 1 to 20 carbon atoms which may have a substituent. Examples of the substituent that the alkyl group has include an aromatic group, an alkyloxycarbonyl group, or a silyl group. Specific examples of the substituent include a silylmethyl group such as a phenyldimethylsilylmethyl group or an o-anisyldimethylsilylmethyl group, or a methylene group such as a methoxycarbonylpropyl (phenyl) methylene group.

  Examples of fullerenes and fullerene derivatives used as electron acceptors are shown below. However, fullerenes or fullerene derivatives used as electron acceptors are not limited to the following compounds.

In order for the electron acceptor to efficiently receive electrons from the electron donor, it is preferable that the molecular orbital level of the electron donor and the molecular orbital level of the electron acceptor have a predetermined relationship. Specifically, for the first semiconductor material and the second semiconductor material, it is preferable that the LUMO energy level of the electron donor is 0.3 eV or more higher than the LUMO energy level of the electron acceptor. The electron affinity of the body is preferably 0.3 eV or higher than the electron affinity of the electron donor. Furthermore, in order to efficiently transport electrons, the electron mobility of the electron acceptor is preferably 1 × 10 ⁻⁴ cm ² / V · s or more.

[2.4.3 Second semiconductor material precursor]
The second semiconductor material can also be obtained by converting a second semiconductor material precursor having a chemical structure different from that of the second semiconductor material. The use of the second semiconductor material precursor is preferable in terms of improving the replacement efficiency with a third material described later. The second semiconductor material precursor and the method for obtaining the second semiconductor material from the precursor are not particularly limited, but specifically described in JP-A-2007-324587 or JP-A-2011-119648. The following materials and methods can be employed.

The second semiconductor material has a high solubility, and in the case of an electron donor, a low-molecular compound having solubility such as oligothiophene or squarylium; polythiophene, polyparaphenylene vinylene or polyfluorene as a basic skeleton As the electron acceptor, a fullerene derivative is preferable.
[2.4.4 Method of forming active layer]
A method for forming an active layer in the photoelectric conversion element having the structure shown in FIG. 2 will be described.

The active layer 104 includes (1) a step of forming a layer containing the first semiconductor material and the third material by a vacuum deposition method, and (2) a layer containing the first semiconductor material and the third material. On the other hand, it is formed by a method including a replacement step of replacing the third material with the second semiconductor material. Hereinafter, each of these steps will be described, and then the third material will be described.
(1) First, a layer including the first semiconductor material and the third material is formed using the first semiconductor material and the third material by a vacuum evaporation method.

Examples of the vacuum evaporation method include a binary simultaneous evaporation method and a flash evaporation method.
In the case of the binary simultaneous vapor deposition method, the first semiconductor material and the third material are used as separate vapor deposition sources, and the vapor deposition rate is independently controlled to mix the first semiconductor material and the third material. The composition ratio is set and vacuum deposition is performed.
In the case of flash vapor deposition, vacuum vapor deposition is performed by mixing the first semiconductor material and the third material at a predetermined composition ratio to form a single vapor deposition source.

The composition ratio between the first semiconductor material and the third material is determined so that the third material is replaced by the second semiconductor material in a later step, and the electron donor and the electron in the active layer 104 The ratio to the receptor is determined to be a preferable value.
The weight ratio of the third material to the first semiconductor material in the mixed film of the first semiconductor material and the third material to be formed is usually 0.2 or more, preferably 0.3 or more, more preferably 0. On the other hand, it is usually 5 or less, preferably 4 or less, more preferably 3 or less.

  The composition of the mixed film of the first semiconductor material and the third material may be uniform in the depth direction of the film or may have a composition distribution such as a gradient composition. Due to the gradient composition, an increase in contact area between the first semiconductor material and the second semiconductor material replaced with the third material occurs at the interface between the first semiconductor material and the second semiconductor material. It is preferable in terms of improving both the increase in charge transfer efficiency and the balance.

  As a method for specifically achieving the gradient composition, for example, in the case of the binary co-evaporation method, each deposition rate of the first semiconductor material and the third material is changed continuously or stepwise to a desired composition ratio. The method of changing so that it may become is mentioned. In the case where the first semiconductor material is an electron donating material, the composition of the first semiconductor material is increased on the anode side, and the composition of the first semiconductor material is relatively decreased continuously or stepwise. The desired gradient composition can be achieved.

The thickness of the mixed film of the first semiconductor material and the third material to be formed is set in consideration of a sufficient light absorption amount and carrier mobility of the semiconductor material. Usually, it is set in the range of 20 to 200 nm.
(2) Next, the third material is replaced with the second semiconductor material in the layer including the first semiconductor material and the third material. As a first method, a layer containing the first semiconductor material and the third material is treated with a solution of the second semiconductor material, so that the third material is at least partly the second semiconductor material. Can be substituted. Specifically, a solution of the second semiconductor material may be applied to a layer including the first semiconductor material and the third material. If the solubility of the third material in the solvent used in the solution containing the second semiconductor material is greater than the solubility of the second semiconductor material, the substitution can be performed simultaneously with the application.

  Here, the first semiconductor material is hardly soluble or insoluble in the solvent in the solution of the second semiconductor material, and the third material is soluble in the solvent in the solution of the second semiconductor material. It is preferable to select a solvent in the solution of the second semiconductor material. In the present specification, the compound being hardly soluble or insoluble means that the solubility of the compound is less than 0.1% by weight. Further, in this specification, that the compound is soluble means that the solubility of the compound is 0.1% by weight or more. When a suitable range of the solubility of the third material in the solvent in the solution of the second semiconductor material is given, it is usually 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1.0% by weight. % Or more.

  As a second method, after the layer containing the first semiconductor material and the third material is treated with a solvent of the third material to at least partially elute and remove the third material, By treatment with a solution containing a semiconductor material, the third material can be replaced with the second semiconductor material. Specifically, a solution containing the second semiconductor material may be applied to the layer containing the first semiconductor material and the third material after applying the solvent of the third material.

Here, the solvent of the third material is selected so that the first semiconductor material is hardly soluble or insoluble in the solvent of the third material and the third material is soluble in the solvent of the third material. It is preferable to do. The preferable range of the solubility of the third material in the solvent of the third material is usually 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1.0% by weight or more. .
The method of substituting with the second semiconductor material can be performed by any known method. For example, it can be performed by a wet coating method such as a spin coating method, a casting method, a blade coating method, an ink jet method, or a gravure printing method.

  By the above-described forming method, the active layer (p− layer) 104a made of the first semiconductor material and the active layer (n− layer) 104b made of the second semiconductor material are compared with the conventional stacked structure. The contact area between the donor and the electron acceptor is greatly increased. Note that the active layer (n− layer) 104b may be formed by forming a layer containing a second semiconductor material precursor and converting the second semiconductor material precursor into an electron acceptor.

When the first semiconductor material is an electron acceptor, an active layer (n-layer) made of the first semiconductor material is formed, and then the second semiconductor material is replaced with an electron donor. Note that a second semiconductor material precursor can also be used, and the third material can be replaced by applying a soluble second semiconductor material precursor.
As described above, it is possible to form a nanometer-sized phase separation structure as an advantage of forming a mixed layer of a first semiconductor material and a specific third material described later by a vacuum deposition method. And / or it is possible to apply a gradient composition of the first semiconductor material in the film thickness direction during vacuum deposition.
In order to stack the second semiconductor material on the nanostructure made of such a fine first semiconductor material, the wet coating method is suitable for maximizing the contact between the two semiconductors.

[2.4.5 Third material]
The third material is a compound that satisfies at least one of the following conditions.
(1) A compound having a glass transition temperature of 80 ° C. or higher and 200 ° C. or lower by differential scanning calorimetry (DSC method) (2) A crystallization temperature of 180 ° C. or higher and 300 ° C. or lower by differential scanning calorimetry (DSC method) A certain compound Preferably it is a compound which satisfy | fills the conditions of said (1) and (2).

  In order to obtain high photoelectric conversion characteristics, the first semiconductor material needs to be crystallized. The properties of the crystals obtained are greatly affected by the thermal and mechanical properties of the coexisting material (third material). In order to form an active layer that gives highly efficient photoelectric conversion characteristics, crystal growth is controlled so that the crystal size of the first semiconductor material is about 10 nm, which is normally assumed as the exciton diffusion length. is important. When the first semiconductor material is crystallized, the inventors of the present application can control the crystal growth satisfactorily when the third material has a uniform amorphous property, and highly efficient photoelectric conversion. It was found that an element can be obtained. That is, it is considered that the first semiconductor material can control the crystal growth satisfactorily by growing the crystal using the third material in an amorphous state as a matrix. For this reason, it is thought that it is preferable as a 3rd material which has a high glass transition temperature and / or has amorphous property stable at high temperature (crystallization temperature is 180-300 degreeC).

  The glass transition temperature (hereinafter also referred to as Tg) of the third material by differential scanning calorimetry (DSC method) is 80 ° C. or higher, preferably 100 ° C. or higher, particularly preferably 120 ° C. or higher. On the other hand, the upper limit of the glass transition temperature is not particularly limited, but is 200 ° C. or lower, preferably 180 ° C. or lower, more preferably 160 ° C. or lower. The glass transition temperature determined by the third material differential scanning calorimetry (DSC method) is within the above range, which is preferable in forming the nanophase separation structure of the first semiconductor material.

  The crystallization transition temperature (hereinafter sometimes referred to as Tc) of the third material by differential scanning calorimetry (DSC method) is usually 180 ° C. or higher, preferably 200 ° C. or higher, particularly preferably 220 ° C. or higher. is there. On the other hand, the upper limit of the crystallization temperature is not particularly limited, but is usually 300 ° C. or lower, preferably 280 ° C. or lower, more preferably 260 ° C. or lower. The crystallization temperature by the third material differential scanning calorimetry (DSC method) is in the above range, which is preferable for forming the nanophase separation structure of the first semiconductor material.

  In the present specification, the glass transition temperature is defined as a point at which specific heat is changed by a temperature at which local molecular motion is initiated by thermal energy in an amorphous solid compound. When the temperature rises further than the glass transition temperature, the solid structure changes and crystallization occurs (this temperature is defined as the crystallization temperature (Tc)). When the temperature rises further, it generally melts at the melting point (Tm) and changes to a liquid state. However, these phase transitions may not be observed due to molecular decomposition or sublimation at high temperatures. As a measuring method of the glass transition temperature and the crystallization temperature, a DSC method may be mentioned.

  The DSC method is a thermophysical property measurement method (differential scanning calorimetry method) defined in JIS K-0129 “General Rules for Thermal Analysis”. The glass transition temperature can be measured by the DSC method as the temperature at which the specific heat changes. In order to determine the glass transition temperature more clearly, it is preferable to perform measurement after quenching a sample once heated to a temperature higher than the glass transition point. For example, this method can be implemented by a method described in a publicly known document (Japanese Patent Laid-Open No. 2011-119648).

Further, when the third material is measured by the DSC method, it is preferable that the melting point does not exist below the glass transition temperature. The melting point means that the crystalline solid is melted. Normally, the temperature of the sample does not increase even when heat is applied during melting at the melting point. The absence of a melting point below the glass transition temperature indicates that the third material is an amorphous material.
From the viewpoint of high stability and less damage to the active layer, the HOMO level of the third material is preferably deeper than the HOMO level of the electron donor that forms the active layer. The LUMO level of the third material is preferably shallower than the LUMO level of the electron acceptor forming the active layer.

The molecular weight of the third material is not particularly limited, but is usually 400 or more, preferably 500 or more, and is usually 1500 or less, preferably 1000 or less. The molecular weight within this range is preferable in that the glass transition temperature becomes sufficiently high and the conversion efficiency of the obtained photoelectric conversion element can be improved.
The third material is not particularly limited as long as the above conditions are satisfied.

Especially, since the compound represented by the following general formula (1) or (2) has appropriate sublimation properties, the first semiconductor material and the following general formula can be obtained by co-evaporation with the first semiconductor material. It is preferable in that a mixed film containing the compound represented by (1) or (2) can be formed uniformly.
As the third material, one compound represented by the general formula (1) or (2) may be used alone, or a plurality of compounds may be mixed and used.

In formula (1), X represents a trivalent group, and A ^{1 to} A ³ each independently represents an aromatic group which may have a substituent.
In the formula (1), X represents a trivalent group. The trivalent group refers to a group bonded to ^three substituents A ^{1 to} A ^3, and examples thereof include a trivalent inorganic group and a trivalent organic group. Examples of the trivalent inorganic group include those in which three oxygen atoms are bonded to a single atom or a metal atom.

  Examples of the single atom include trivalent atoms such as a boron atom, a nitrogen atom, an aluminum atom, an indium atom, a gallium atom, and an iridium atom. Among these, a boron atom, a nitrogen atom, an aluminum atom, or an indium atom is preferable. By X being these atoms, it is expected that the amorphous nature of the third material is improved. More preferably, X is a nitrogen atom.

Examples of those in which three oxygen atoms are bonded to the metal atom include AlO _{3 and} BO ₃ , and the metal atom is bonded to A ^{1 to} A ³ through the oxygen atom.
Examples of the trivalent organic group include a trivalent aromatic group and a trivalent aryloxy group.
As an aromatic group, the aromatic hydrocarbon group or aromatic heterocyclic group which may have a substituent is mentioned. Specific examples of the aromatic group include trivalent substituents obtained by removing three hydrogen atoms from an aromatic compound such as benzene, biphenyl, furan, thiophene or pyridine. Examples of the substituent that the aromatic hydrocarbon group or the aromatic heterocyclic group may have include a halogen atom such as a fluorine atom or an alkyl group having 1 to 6 carbon atoms such as a methyl group. .

Examples of the aryloxy group include trivalent groups in which three —O— groups are bonded to an aromatic compound.
The aromatic hydrocarbon group and the aromatic heterocyclic group may form a condensed polycyclic aromatic group. Examples of the ring that forms the condensed polycyclic aromatic group include an aliphatic hydrocarbon ring, an aliphatic heterocyclic ring, an aromatic hydrocarbon ring, and an aromatic heterocyclic ring.

Examples of the aliphatic hydrocarbon ring include a cyclopentane ring and a cyclohexane ring. Examples of the aliphatic heterocyclic ring include a tetrahydrofuran ring, a tetrahydrothiophene ring, and a pyrrolidine ring. Examples of the aromatic hydrocarbon ring include a benzene ring. Examples of the aromatic heterocycle include a pyridine ring, thiophene ring, furan ring, pyrrole ring, oxazole ring, thiazole ring, oxadiazole ring, thiadiazole ring, pyrazine ring, pyrimidine ring, pyrazole ring or imidazole ring. . Among these, a pyridine ring or a thiophene ring is preferable.

The number of rings of the condensed polycyclic aromatic group is usually 2 or more, preferably 3 or more, and is usually 10 or less, preferably 8 or less, more preferably 6 or less. The number of rings of the condensed polycyclic aromatic group is preferably within the above range from the viewpoint of the amorphous nature of the third compound.
Specific examples of the condensed polycyclic aromatic group include, for example, condensed polycyclic rings such as phenanthrin, anthracene, pyrene, fluoranthene, naphthacene, perylene, pentacene, triferylene, phenoxazine, phenothiazine, acridine, phenanthridine, and phenanthroline. And trivalent substituents obtained by removing three hydrogen atoms from an aromatic compound.

X preferably has a starburst structure. In this specification, the starburst structure refers to a three-fold symmetric structure. More specifically, X has a starburst structure when a molecule that is three-fold symmetric is obtained when any ^three identical atoms as A ^{1 to} A ³ are bonded to X. Shall. It is preferable that X has a starburst structure in that the π-conjugated system can spread evenly around X in the compound of formula (I). Examples of such X include aromatic hydrocarbon groups such as 1,3,5-benzenetriyl group or 2,6,10-triphenylenetriyl group; aromatic complex such as 1,3,5-triazinetriyl group. A cyclic group; a nitrogen atom; a nitrogen atom substituted with three aromatic groups; and the like. Specific examples of X having a starburst type structure include the following.

  X is preferably a monocyclic aromatic group which may have a substituent or a nitrogen atom. Examples of the monocyclic aromatic group include a 6-membered aromatic hydrocarbon group or an aromatic heterocyclic group. A monocyclic aromatic group is more preferably a 1,3,5-benzenetriyl group or a 1,3,5-triazinetriyl group. Examples of the substituent that the monocyclic aromatic group may have include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogen atom, preferably a halogen atom, and particularly preferably a fluorine atom. .

A ^{1 to} A ³ each independently represents an aromatic group which may have a substituent. It is preferable that A ^{1 to} A ³ are aromatic groups in that the number of π-conjugated electrons increases and the glass transition temperature can be increased. A ¹ to A ³ may be the same or different, but in that amorphous property may be improved, it is preferable A ¹ to A ³ are identical. The fact that X is a starburst structure and A ^{1 to} A ³ are the same is that the compound represented by the general formula (I) has a starburst structure, so that the third material is more stable. It is more preferable in that it can have an amorphous property.

  Examples of the aromatic group include an aromatic hydrocarbon group and an aromatic heterocyclic group. The aromatic hydrocarbon group preferably has 6 to 30 carbon atoms, and is a monocyclic aromatic hydrocarbon group such as a phenyl group; naphthyl group (1-naphthyl group or 2-naphthyl group), anthryl group (2-anthryl group) Group or an 9-anthryl group) or an aromatic condensed ring group such as a fluorenyl group. As the aromatic heterocyclic group, those having 2 to 30 carbon atoms are preferable, and thienyl group, furyl group, pyridyl group, thiazolyl group, oxazolyl group, pyrazinyl group, pyrimidinyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridazinyl group. , Isothiazolyl group, isoxazolyl group, imidazolyl group, quinolyl group, isoquinolyl group, indolyl group, 2-benzothiazolyl group, benzo [b] thienyl group, benzo [b] furanyl group or carbazolyl group.

  Further, the aromatic group may be a ring-linked aromatic group in which at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group is linked by two or more via a direct bond or a single atom. Examples of the single atom include a trivalent atom such as a nitrogen atom or a boron atom, or a divalent atom such as an oxygen atom or a sulfur atom. Examples of the ring-linked aromatic group linked through a direct bond include a biphenylyl group, a p-terphenylyl group, an N-carbazolylphenyl group, and an anthracenylphenyl group. Examples of the ring-linked aromatic group linked through a single atom include a diphenylaminophenyl group, a naphthalenylphenylaminophenyl group, and a diphenylborylphenyl group.

The substituent that the aromatic group may have is not particularly limited as long as the effects of the present invention are not impaired, but a hydroxyl group; a halogen atom such as a fluorine atom or a chlorine atom; an alkyl group such as a methyl group or an ethyl group An alkenyl group such as a vinyl group; an alkoxycarbonyl group having 1 to 6 carbon atoms such as a methoxycarbonyl group or an ethoxycarbonyl group; an alkoxy group such as a methoxy group or an ethoxy group; an aryloxy group such as a phenoxy group; Arylalkyloxy group; dialkylamino group such as dimethylamino group, diethylamino group, diisopropylamino group, dibenzylamino group or diphenethylamino group; diarylamino group such as diphenylamino group or carbazolyl group; acyl group such as acetyl group; Trifluoromethyl group, etc. Alkyl group; a cyano group; an aromatic group; a nitro group; alkylenedioxy group having 1 to 3 carbon atoms such as methylenedioxy group or ethylenedioxy, and the like. From the viewpoint of improving the solubility in an organic solvent, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms is preferable, and an aromatic group having 2 to 12 carbon atoms from the viewpoint of increasing the glass transition temperature. Is preferred.
When A ^{1 to} A ³ are aromatic groups, the carbon atom of the aromatic group may be bonded to X, or the hetero atom of the aromatic group such as a nitrogen atom may be bonded to X. Good.
Specific examples of A ^{1 to} A ³ include the following groups, but are not limited thereto.

Among these, A ^{1 to} A ³ are more preferably ring-linked aromatic groups. It is preferable that A ^{1 to} A ³ are ring-linked aromatic groups in that they can have stable amorphous properties.
More specifically, each of A ^{1 to} A ³ is preferably represented by -A ¹¹ -A ¹² , -A ²¹ -A ²² , and -A ³¹ -A ³² .
A ¹¹ , A ²¹ and A ³¹ each independently represents a monocyclic aromatic group which may have a substituent. The monocyclic aromatic group is preferably a 5-membered or 6-membered aromatic hydrocarbon group or a 5-membered or 6-membered aromatic heterocyclic group, more preferably a 6-membered aromatic hydrocarbon group. Group or an aromatic heterocyclic group, more preferably a phenylenediyl group, and particularly preferably a p-phenylenediyl group. Examples of the substituent that the monocyclic aromatic group may have include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogen atom, preferably a halogen atom, and particularly preferably a fluorine atom. .

A ¹² , A ²² and A ³² each independently represents an aromatic group which may have a substituent or a diarylamino group which may have a substituent. Examples of the aromatic group include an aromatic hydrocarbon group and an aromatic heterocyclic group. The aromatic hydrocarbon group preferably has 6 to 30 carbon atoms, and is a monocyclic aromatic hydrocarbon group such as a phenyl group; naphthyl group (1-naphthyl group or 2-naphthyl group), anthryl group (2-anthryl group) Group or 9-anthryl group), or aromatic condensed ring group such as fluorenyl group. As the aromatic heterocyclic group, those having 2 to 30 carbon atoms are preferable, and thienyl group, furyl group, pyridyl group, thiazolyl group, oxazolyl group, pyrazinyl group, pyrimidinyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridazinyl group. , Isothiazolyl group, isoxazolyl group, imidazolyl group, quinolyl group, isoquinolyl group, indolyl group, 2-benzothiazolyl group, benzo [b] thienyl group, benzo [b] furanyl group or carbazolyl group.

A diarylamino group is an amino group substituted with two aromatic groups which may be different from each other. Examples of the aromatic group that the diarylamino group may have include those listed as examples of A ¹² , A ²² and A ³² .
Examples of the substituent that the aromatic group or diarylamino group may have include those listed as the substituents that the aromatic group may have regarding A ^{1 to} A ³ .

Particularly preferred examples of A ¹² , A ²² and A ³² include phenyl group, p-biphenyl group, N-carbazolyl group, N-phenothiazinyl group, diphenylamino group, naphthylphenylamino group, phenyltolylamino group, and the like. Can be mentioned.
Below, the preferable example in Formula (1) is given.

In formula (2), p represents an integer of 1 or more, R ¹¹ and R ¹² each independently represent an arbitrary substituent, and R ¹¹ and R ¹² may be bonded to each other to form a ring. When p is 2 or more, the plurality of R ¹¹ and the plurality of R ¹² may be independently different from each other. R ¹³ represents a p-valent hydrocarbon group which may have a substituent, a p-valent heterocyclic group which may have a substituent, or a hydrocarbon group which may have a substituent and a substituent. It represents a p-valent group in which at least one of the heterocyclic groups which may have a group is linked. Y represents an atom selected from Group 16 elements of the Periodic Table.

In formula (2), p represents an integer of 1 or more. p is usually 6 or less, preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less from the viewpoint that film formation by vacuum deposition can be facilitated.
R ¹¹ and R ¹² each independently represents an arbitrary substituent. The type of substituent is not particularly limited as long as a solution containing the third compound can be produced, but has a hydroxy group, an optionally substituted hydrocarbon group, and a substituent. Preferred are an alkoxy group, an aryloxy group which may have a substituent, or a heterocyclic group which may have a substituent.

Examples of the hydrocarbon group include an aliphatic hydrocarbon group and an aromatic hydrocarbon group.
Examples of the aliphatic hydrocarbon group include a saturated aliphatic hydrocarbon group and an unsaturated aliphatic hydrocarbon group.
Examples of the saturated aliphatic hydrocarbon group include an alkyl group and a cycloalkyl group. As an alkyl group, a C1-C20 thing is preferable, for example, a methyl group, an ethyl group, i-propyl group, t-butyl group, or a hexyl group etc. are mentioned. As the cycloalkyl group, those having 3 to 20 carbon atoms are preferable, and examples thereof include a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group.

  Examples of the unsaturated aliphatic hydrocarbon group include an alkenyl group, a cycloalkenyl group, and an alkynyl group. As the alkenyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include a vinyl group and a styryl group. The cycloalkenyl group preferably has 3 to 20 carbon atoms, and examples thereof include a cyclopropenyl group, a cyclopentenyl group, and a cyclohexenyl group. As the alkynyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include a methylethynyl group. Examples of the alkynyl group having a substituent include a silylethynyl group such as a trimethylsilylethynyl group.

Of the aliphatic hydrocarbon groups, a saturated aliphatic hydrocarbon group is preferable, and an alkyl group is more preferable.
As the aromatic hydrocarbon group, those having 6 to 30 carbon atoms are preferable, for example, phenyl group, naphthyl group, phenanthryl group, biphenylenyl group, triphenylenyl group, anthryl group, pyrenyl group, fluorenyl group, azulenyl group, acenaphthenyl group. Fluoranthenyl group, naphthacenyl group, perylenyl group, pentacenyl group or quarterphenyl group. Of these, a phenyl group, a naphthyl group, a phenanthryl group, a triphenylenyl group, an anthryl group, a pyrenyl group, a fluorenyl group, an acenaphthenyl group, a fluoranthenyl group, or a perylenyl group is preferable.

An alkoxy group or an aryloxy group is preferable in terms of improving solubility, and an alkoxy group is more preferable.
As the alkoxy group, those having 1 to 20 carbon atoms are preferable. For example, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, t-butoxy group, benzyl Examples thereof include a linear or branched alkoxy group such as an oxy group or an ethylhexyloxy group.

As the aryloxy group, those having 2 to 20 carbon atoms are preferable, and examples thereof include a phenoxy group, a naphthyloxy group, a pyridyloxy group, a thiazolyloxy group, an oxazolyloxy group, and an imidazolyloxy group. Of these, a phenoxy group or a pyridyloxy group is preferable.
Examples of the heterocyclic group include an aliphatic heterocyclic group and an aromatic heterocyclic group.

As the aliphatic heterocyclic group, those having 2 to 30 carbon atoms are preferable, and examples thereof include a pyrrolidinyl group, piperidinyl group, piperazinyl group, tetrahydrofuranyl group, dioxanyl group, morpholinyl group, and thiomorpholinyl group. Of these, a pyrrolidinyl group, a piperidinyl group, or a piperazinyl group is preferable.
As the aromatic heterocyclic group, those having 2 to 30 carbon atoms are preferable. For example, pyridyl group, thienyl group, furyl group, pyrrolyl group, oxazolyl group, thiazolyl group, oxadiazolyl group, thiadiazolyl group, pyrazinyl group, pyrimidinyl group , Pyrazolyl group, imidazolyl group, benzothienyl group, dibenzofuryl group, dibenzothienyl group, phenylcarbazolyl, phenoxathiinyl group, xanthenyl group, benzofuranyl group, thianthenyl group, indolizinyl group, phenoxazinyl group, phenothiazinyl group, acridinyl Group, phenanthridinyl group, phenanthrolinyl group, quinolyl group, isoquinolyl group, indolyl group, quinoxalinyl group and the like. Among them, pyridyl group, pyrazinyl group, pyrimidinyl group, pyrazolyl group, quinolyl group, isoquinolyl group, imidazolyl group, acridinyl group, phenanthridinyl group, phenanthrolinyl group, quinoxalinyl group, dibenzofuryl group, dibenzothienyl group, A phenylcarbazolyl, xanthenyl group or phenoxazinyl group is preferred.

Further, the aromatic hydrocarbon group and the aromatic heterocyclic group may be a condensed polycyclic aromatic group. The ring forming the condensed polycyclic aromatic group may be an aliphatic ring which may have a substituent, an aromatic hydrocarbon ring which may have a substituent, or a substituent. Good aromatic heterocycles.
Examples of the aliphatic ring include a cyclopentane ring and a cyclohexane ring. Examples of the aromatic hydrocarbon ring include a benzene ring. Examples of the aromatic heterocycle include a pyridine ring, thiophene ring, furan ring, pyrrole ring, oxazole ring, thiazole ring, oxadiazole ring, thiadiazole ring, pyrazine ring, pyrimidine ring, pyrazole ring or imidazole ring. . Among these, a pyridine ring or a thiophene ring is preferable.

Examples of the condensed polycyclic aromatic group include a condensed polycyclic aromatic hydrocarbon group or a condensed polycyclic aromatic heterocyclic group. The number of rings of the condensed polycyclic aromatic group is usually 2 or more, preferably 3 or more, and is usually 10 or less, preferably 8 or less, more preferably 6 or less. It is preferable that the number of the rings of the condensed polycyclic aromatic group is in the above range from the viewpoint that appropriate solubility can be obtained.
Examples of the condensed polycyclic aromatic hydrocarbon group include phenanthryl group, anthryl group, pyrenyl group, fluoranthenyl group, naphthacenyl group, perylenyl group, pentacenyl group, and triphenylenyl group. Examples of the condensed polycyclic aromatic heterocyclic group include a phenoxazinyl group, a phenothiazinyl group, an acridinyl group, a phenanthridinyl group, and a phenanthrolinyl group.

  The condensed polycyclic aromatic group may be a group derived from the following condensed polycyclic aromatic compound, for example, a group obtained by removing a hydrogen atom from the following condensed polycyclic aromatic compound, but is not limited thereto. There is no. Moreover, in the following condensed polycyclic aromatic compound, the atom bonded to the phosphorus atom is not particularly limited.

At least one of R ¹¹ and R ¹² may have a saturated aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a substituent. It is more preferable that it is a good aromatic heterocyclic group. When at least one of R ¹¹ and R ¹² is a saturated aliphatic hydrocarbon group, solubility is improved, which is preferable in that film formation by coating is facilitated. On the other hand it is preferable that at least one of R ¹¹ and R ¹² is an aromatic group, and more preferably at least one of R ¹¹ and R ¹² is a fused polycyclic aromatic group. This is because the third compound having an aromatic group has a strong interaction with the first semiconductor compound (or precursor), and includes the first semiconductor compound (or precursor) and the third compound. The reason is considered to be that it is easy to obtain a phase separation structure suitable for a semiconductor device. From this viewpoint, it is preferable that both R ¹¹ and R ¹² are aromatic groups, and it is more preferable that both R ¹¹ and R ¹² are the same aromatic group, and both R ¹¹ and R ¹² are both Are more preferably the same fused polycyclic aromatic group, and it is particularly preferred that both R ¹¹ and R ¹² are the same fused polycyclic aromatic hydrocarbon group.

R ¹¹ and R ¹² may be bonded to each other to form a ring. When p is 2 or more, the third compound has a plurality of R ¹¹ and a plurality of R ¹² , but the plurality of R ¹¹ and the plurality of R ¹² may be independently different from each other.
In the general formula (2), R ¹³ has a p-valent hydrocarbon group which may have a substituent, a p-valent heterocyclic group which may have a substituent, or a substituent. It represents a p-valent group in which at least one of a hydrocarbon group which may have a substituent and a heterocyclic group which may have a substituent is connected.

  Examples of the p-valent group in which at least one of a hydrocarbon group which may have a substituent and a heterocyclic group which may have a substituent are connected to each other in two or more include, for example, a substituent. It has a p-valent group obtained by removing p hydrogen atoms from a compound in which two or more heterocyclic groups which may have a good hydrocarbon group and / or a substituent are linked by a direct bond, or a substituent. P from compounds in which two or more hydrocarbon groups and / or optionally substituted heterocyclic groups may be linked via an alkylene group, a silylene group, an amino group, an oxygen atom or a sulfur atom And a p-valent group obtained by removing the hydrogen atom.

Examples of the hydrocarbon groups include monovalent hydrocarbon group or a divalent or more hydrocarbon groups corresponding to that described for R ¹¹ and R ^12. The hydrocarbon group is usually 6 or less, preferably 5 or less, and more preferably 3 or less. Examples of the hydrocarbon group include an aliphatic hydrocarbon group and an aromatic hydrocarbon group as in R ¹¹ and R ¹² .
Examples of the heterocyclic group include the monovalent heterocyclic groups described for R ¹¹ and R ¹² or the corresponding divalent to hexavalent heterocyclic groups. As the type of the heterocyclic group, an aliphatic heterocyclic group or an aromatic heterocyclic group can be used in the same manner as R ¹¹ and R ¹² .

Further, the aromatic hydrocarbon group and the aromatic heterocyclic group may be a condensed polycyclic aromatic group. Examples of the condensed polycyclic aromatic group include the monovalent condensed polycyclic aromatic group described for R ¹¹ and R ¹² , or the corresponding divalent or higher-valent condensed polycyclic aromatic group. The condensed polycyclic aromatic group is usually 6 or less, preferably 5 or less, more preferably 3 or less.
When R ¹³ is a divalent group, specific examples of R ¹³ include the following, but are not limited thereto.

R ¹³ is preferably a p-valent group obtained by linking a p-valent aromatic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. It is.
The term “which may have a substituent” in the description of R ¹¹ , R ¹² and R ¹³ means that it may have one or more substituents. This substituent is not particularly limited, but is a halogen atom, hydroxyl group, cyano group, amino group, carboxyl group, carbonyl group, sulfonyl group, silyl group, boryl group, nitrile group, alkyl group, alkenyl group, alkynyl group, alkoxy group. Group, an aromatic hydrocarbon group or an aromatic heterocyclic group.

As the halogen atom, a fluorine atom is preferable.
Examples of the amino group include aromatic substituted amino groups such as a diphenylamino group, a ditolylamino group, and a carbazolyl group.
As the carbonyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include an acetyl group and an ethylcarbonyl group.

As the silyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include a trimethylsilyl group and a triphenylsilyl group.
The boryl group is preferably a group having 2 to 20 carbon atoms, and examples thereof include an aromatic group-substituted boryl group such as a dimesitylboryl group.
As an alkyl group, a C1-C20 thing is preferable, for example, a methyl group, an ethyl group, i-propyl group, t-butyl group, or a cyclohexyl group etc. are mentioned.

As the alkenyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include a vinyl group, a styryl group, and a diphenylvinyl group.
As the alkynyl group, those having 2 to 20 carbon atoms are preferable, and examples thereof include an ethynyl group, a methylethynyl group, a phenylethynyl group, and the like, and a trimethylsilylethynyl group having a substituent.

As the alkoxy group, those having 2 to 20 carbon atoms are preferable. For example, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, ethylhexyloxy group, benzyloxy And a linear or branched alkoxy group such as a group or a t-butoxy group.
As the aromatic hydrocarbon group, those having 6 to 20 carbon atoms are preferable, and these are not limited to monocyclic groups, and are not limited to monocyclic aromatic hydrocarbon groups, condensed polycyclic aromatic hydrocarbon groups or ring-linked aromatic groups. Any of group hydrocarbon groups may be used.

  Examples of the monocyclic aromatic hydrocarbon group include a phenyl group. Examples of the condensed polycyclic aromatic hydrocarbon group include a biphenyl group, a phenanthryl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyrenyl group, and a perylenyl group. Examples of the ring-linked aromatic hydrocarbon group include a biphenyl group and terphenyl. Among these, a phenyl group or a naphthyl group is preferable.

  As the aromatic heterocyclic group, those having 2 to 20 carbon atoms are preferable, for example, pyridyl group, thienyl group, furyl group, oxazolyl group, thiazolyl group, oxadiazolyl group, benzothienyl group, dibenzofuryl group, dibenzothienyl group. , Pyrazinyl group, pyrimidinyl group, pyrazolyl group, imidazolyl group, phenylcarbazolyl group and the like. Among these, a pyridyl group, a thienyl group, a benzothienyl group, a dibenzofuryl group, a dibenzothienyl group, or a phenanthryl group is preferable.

  In the general formula (2), Y represents an atom selected from Group 16 elements of the periodic table. In this specification, the periodic table refers to a recommended version of IUPAC 2005 (Recommendations of IUPAC 2005). Specific examples of Y include an oxygen atom, a sulfur atom, and a selenium atom. Of these, an oxygen atom or a sulfur atom is preferable, and an oxygen atom is particularly preferable.

Among the compounds represented by the general formula (2), a phosphine compound having a double bond between a phosphorus atom substituted with an aryl group and an atom selected from Group 16 elements of the periodic table is more preferable. Examples thereof include a phosphine oxide compound substituted with an aryl group or a phosphine sulfide compound substituted with an aryl group.
More preferable examples include triarylphosphine oxide compounds, triarylphosphine sulfide compounds, aromatic hydrocarbon compounds having two or more diarylphosphine oxide groups, aromatic hydrocarbon compounds having two or more diarylphosphine sulfide groups, and diarylphosphine. And aromatic heterocyclic compounds having two or more oxide groups. Here, the aryl group refers to an aromatic hydrocarbon group or an aromatic heterocyclic group. When two or more aryl groups are present, each aryl group may be different from each other. The aryl group may be substituted with an alkyl group substituted with a fluorine atom such as a fluorine atom, a hydroxy group or a perfluoroalkyl group.

  Among triarylphosphine oxide compounds and triarylphosphine sulfide compounds, particularly preferred examples include triarylphosphine oxide compounds or triarylphosphine sulfide compounds having an aryl group having 2 to 20 carbon atoms. Among aromatic hydrocarbon compounds having two or more diarylphosphine oxide groups and aromatic hydrocarbon compounds having two or more diarylphosphine sulfide groups, diarylphosphine having an aryl group having 2 to 20 carbon atoms is particularly preferable. Examples thereof include an aromatic hydrocarbon compound or aromatic heterocyclic compound having 2 to 30 carbon atoms and having 2 or more and 4 or less oxide groups or diarylphosphine sulfide groups.

  Specific examples of the compound represented by the general formula (2) (Y represents an atom selected from Group 16 elements of the periodic table such as oxygen, sulfur or selenium) are exemplified below.

(Method for producing third compound)
There is no limitation in particular as a manufacturing method of the compound represented by General formula (2), and the compound used as the raw material. For example, publicly known documents (International Publication No. 2011/016430, JP 2011-046697 A, Journal of the American Chemical Society, 128 (17), 5672-5679, 2006, Organic
Letters, 10 (20), 4737-4640, 2008).

  As described above, the third material is at least partially eluted and removed by the solution of the second semiconductor material or the solvent of the third material. From this viewpoint, it is preferable that the third material has a high solubility in a general solvent. Specifically, the solubility of the third material in toluene at 25 ° C. is usually 0.1% by weight or more, preferably 0.5% by weight or more, more preferably 1% by weight or more.

<3. Solar cell>
The photoelectric conversion element according to each of the above-described embodiments is preferably used as a solar cell, particularly a solar cell element of a thin film solar cell. FIG. 5 is a cross-sectional view schematically showing the configuration of a thin film solar cell as one embodiment of the present invention. As shown in FIG. 5, the thin film solar cell 14 of this embodiment includes a weather-resistant protective film 1, an ultraviolet cut film 2, a gas barrier film 3, a getter material film 4, a sealing material 5, and a solar cell element. 6, a sealing material 7, a getter material film 8, a gas barrier film 9, and a back sheet 10 are provided in this order. And light is irradiated from the side (downward in the figure) where the weather-resistant protective film 1 is formed, and the solar cell element 6 generates power. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 10 described later, the getter material film 8 and / or the gas barrier film 9 may not be used depending on the application. Good.

For the above-described configuration and manufacturing method thereof, well-known techniques can be used. Specifically, those described in publicly known documents such as International Publication No. 2011/016430 or International Publication No. 2012/102390 can be employed. .
There is no restriction | limiting in the use of the solar cell which concerns on this invention, especially the thin film solar cell 14 mentioned above, It can use for arbitrary uses. Examples of the field to which the thin-film solar cell according to the present invention is applied include building material solar cells, automobile solar cells, interior solar cells, railway solar cells, marine solar cells, airplane solar cells, and spacecrafts. Solar cells, solar cells for home appliances, solar cells for mobile phones, solar cells for toys, and the like.

  The solar cell according to the present invention, particularly a thin-film solar cell, may be used as it is, or a solar cell may be installed on a substrate and used as a solar cell module. For example, as schematically shown in FIG. 6, a solar cell module 13 provided with a thin film solar cell 14 on a substrate 12 may be prepared and used at a place of use. For the substrate 12, well-known techniques can be used. Specifically, those described in publicly known documents such as International Publication No. 2011/016430 or International Publication No. 2012/102390 can be employed.

  As a specific example, when a building material plate is used as the base material 12, a solar cell panel can be produced as the solar cell module 13 by providing the thin film solar cell 14 on the surface of the plate material.

EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example.
[Synthesis Example 1]
<Synthesis of titanyl phthalocyanine (PC-7)>
Titanyl phthalocyanine (PC-7) was synthesized according to the description in JP-A-9-87536.

[Synthesis Example 2]
<Synthesis of BINAPO>
BINAPO was synthesized according to WO 2011/016430.

[Synthesis Example 3]
<Synthesis of POPy ₂ >
POPy ₂ was synthesized according to International Publication No. 2011/016430.

[Synthesis Example 4]
<Synthesis of C ₆₀ (QM) ₂ >
C ₆₀ (QM) ₂ was synthesized according to International Publication No. 2011/016430.

[Synthesis Example 5]
<Synthesis of CF ₃ -POPy ₂ >
CF ₃ -POPy ₂₂ was synthesized according to WO 2011/016430.

[Synthesis Example 6]
<Synthesis of Bicycloporphyrin Compound (CP)>

Tetrakis (bicyclo [2.2.2] octadiene) porphyrin (CP) was synthesized with reference to the description in JP-A-2003-304014.
<Measurement of Glass Transition Temperature (Tg) and Crystallization Temperature (Tc) by DSC Method>
Samples described in Table 1 to about 4mg placed in an aluminum sample container, using a differential thermal scanning calorimeter of SII Nano Technology Co., Ltd., _{N 2} gas 50 ml / min, heating rate 10 ° C. / min It was calculated | required by measuring on condition of this. The results are shown in Table 1.

From the above results, it can be seen that the sample is the third material according to the present application.
[Example 1]
A photoelectric conversion element having the structure shown in FIG. 1 was produced by the following method. A 145 nm thick indium tin oxide (ITO) transparent conductive film deposited on a glass substrate (sheet resistance: 8.4Ω) is patterned to form a 2 mm wide stripe using normal photolithography and hydrochloric acid etching. Thus, a transparent electrode 102 was formed. The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with a surfactant, water with ultrapure water, and ultrasonic cleaning with ultrapure water, then dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

Next, the substrate is placed in a vacuum vapor deposition apparatus, and vanadium pentoxide (V ₂ O ₅ ) is synthesized as a first semiconductor material as an anode buffer material in a metal boat disposed in the vacuum vapor deposition apparatus. Using the titanyl phthalocyanine (PC-7) obtained in Example 1 as the third material, the phosphine compound (BINAPO) obtained in Synthesis Example 2 was separately added. After performing rough evacuation of the vacuum deposition apparatus with an oil rotary pump, evacuation was performed using a cryopump until the degree of vacuum in the vacuum deposition apparatus was 1.2 × 10 ⁻⁴ Pa. First, a metal boat was heated to deposit molybdenum trioxide (MoO ₃ ) on the anode ITO (102) as an anode buffer layer (103). The degree of vacuum during the deposition was 1.6 × 10 ⁻⁴ Pa, the deposition rate was 0.1 nm / second, and the film thickness was 10 nm. Next, when the active layer (104) is formed, the following titanyl phthalocyanine (PC-7) and phosphine compound (BINAPO) are respectively binary at a deposition rate of 0.15 nm / second and 0.15 nm / second. A mixed film was formed by co-evaporation. The degree of vacuum at the time of vapor deposition was 1.1 × 10 ⁻⁴ Pa and the film thickness was 100 nm.

Here, the substrate was taken out from the vacuum deposition apparatus into a glove box, and a toluene solution containing 1.0 wt% of C ₆₀ PCBM (frontier carbon) having the following structural formula was spin-coated on the substrate. The spin speed was 1000 rpm. Through this coating step, the phosphine compound (BINAPO) as the third material was replaced with PCBM as the second semiconductor material to form an active layer (104).

Again, the substrate formed up to the active layer (104) was placed in vacuum vapor deposition, and the phosphine compound (POPy ₂ ) obtained in Synthesis Example 3 was placed as a cathode buffer material in a metal boat placed in the vacuum vapor deposition apparatus. It was. After performing rough evacuation of the vacuum deposition apparatus with an oil rotary pump, evacuation was performed using a cryopump until the degree of vacuum in the vacuum deposition apparatus was 1.2 × 10 ⁻⁴ Pa. Here, the metal boat was heated to deposit the phosphine compound (POPy ₂ ). The degree of vacuum during the deposition was 1.5 × 10 ⁻⁴ Pa, the deposition rate was 0.1 nm / second, and the film thickness was 6.0 nm. Thus, the cathode buffer layer (105) was formed on the active layer (104).

Subsequently, as a mask for the upper electrode, a 2 mm wide stripe-shaped shadow mask was placed in close contact with the element so as to be orthogonal to the ITO stripe of the transparent electrode 102 and placed in a vacuum deposition chamber different from the previous one. And it exhausted until the vacuum degree in a vacuum evaporation system was set to 2.5x10 < ^-4 > Pa similarly to the time of lamination | stacking of the cathode buffer layer 105. FIG. Thereafter, aluminum was vapor-deposited on the cathode buffer layer 105 at a vapor deposition rate of 0.3 nm / second so as to have a film thickness of 80 nm, whereby the cathode 106 was formed. The degree of vacuum during the deposition was 1.6 × 10 ⁻⁴ Pa.

The device thus obtained was taken out into a glove box, and then subjected to a heat treatment (post-annealing treatment) at 120 ° C. for 5 minutes. As described above, a photoelectric conversion element having a light receiving area portion having a size of 5 mm × 5 mm was obtained.
The photoelectric conversion element was irradiated with light from a solar simulator (AM1.5G) at an irradiation intensity of 100 mW / cm ² to measure voltage-current characteristics. The open-circuit voltage (Voc) of the photoelectric conversion element is 0.65 V, the short-circuit current density (Jsc) is 14.2 mA / cm ² , the fill factor (FF) is 0.48, and the energy conversion efficiency (PCE) is 4.4%. there were.

[Comparative Example 1]
A photoelectric conversion element was produced in the same manner as in Example 1 except that the third material was not used when forming the active layer (104).
The photoelectric conversion element was irradiated with light from a solar simulator (AM1.5G) at an irradiation intensity of 100 mW / cm ² to measure voltage-current characteristics. The open-circuit voltage (Voc) of the photoelectric conversion element is 0.66 V, the short-circuit current density (Jsc) is 11.6 mA / cm ² , the fill factor (FF) is 0.42, and the energy conversion efficiency (PCE) is 3.2%. there were.

[Example 2]
A photoelectric conversion element having the structure shown in FIG. 1 was produced by the following method. A 145 nm thick indium tin oxide (ITO) transparent conductive film deposited on a glass substrate (sheet resistance: 8.4Ω) is patterned to form a 2 mm wide stripe using normal photolithography and hydrochloric acid etching. Thus, a transparent electrode 102 was formed. The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with a surfactant, water with ultrapure water, and ultrasonic cleaning with ultrapure water, then dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

On this transparent substrate, PEDOT: PSS (product name: CLEVIOS AI 4083 manufactured by Heraeus Co., Ltd.), which is a conductive polymer, is formed as an anode buffer layer 103 by spin coating (rotation speed: 5000 rpm) so as to have a film thickness of 20 nm. Then, after heating and drying at 120 ° C. for 10 minutes in the air, heat treatment was performed at 180 ° C. for 3 minutes in nitrogen.
Next, the substrate is placed in a vacuum deposition apparatus, and tetrabenzoporphyrin (BP-1) is used as a first semiconductor material and a carbazole compound is used as a third material in a metal boat disposed in the vacuum deposition apparatus. (T-1) (made by Lumtec) was put separately. After performing rough evacuation of the vacuum deposition apparatus with an oil rotary pump, evacuation was performed using a cryopump until the degree of vacuum in the vacuum deposition apparatus was 1.2 × 10 ⁻⁴ Pa. When forming the active layer (104), the tetrabenzoporphyrin (BP-1) and the carbazole compound (T-1) shown below are respectively binary at a deposition rate of 0.03 nm / second and 0.06 nm / second. A mixed film was formed by co-evaporation. The degree of vacuum during deposition was 1.1 × 10 ⁻⁴ Pa, the substrate temperature was 25 ° C., and the film thickness was 150 nm.

Here, the substrate was taken out from the vacuum deposition apparatus into a glove box and heated on a hot plate at 190 ° C. for 20 minutes. Next, 0.75 wt% of a toluene solution containing a fullerene compound represented by the following structural formula was spin-coated on the substrate. The spin speed was 1500 rpm. By this coating process, the carbazole compound (T-1: (4,4 ′, 4 ″ -tri-9-carbazolyltriphenylamine), which is the third material, is converted into the second semiconductor material, the synthesis example. The fullerene compound (C ₆₀ (QM) ₂ ) obtained in 4 was substituted to form an active layer (104).

Again, the substrate formed up to the active layer (104) was placed in vacuum deposition, and the phosphine compound (CF ₃ -POPy ₂ ) obtained in Synthesis Example 5 was used as a cathode buffer material in a metal boat placed in the vacuum deposition apparatus. ) After performing rough evacuation of the vacuum deposition apparatus with an oil rotary pump, evacuation was performed using a cryopump until the degree of vacuum in the vacuum deposition apparatus was 1.2 × 10 ⁻⁴ Pa. Here, the metal boat was heated to deposit the phosphine compound (CF ₃ -POPy ₂ ). The degree of vacuum during the deposition was 1.5 × 10 ⁻⁴ Pa, the deposition rate was 0.1 nm / second, and the film thickness was 4.5 nm. Thus, the cathode buffer layer (105) was formed on the active layer (104).

Subsequently, as a mask for the upper electrode, a 2 mm wide stripe-shaped shadow mask was placed in close contact with the element so as to be orthogonal to the ITO stripe of the transparent electrode 102 and placed in a vacuum deposition chamber different from the previous one. And it exhausted until the vacuum degree in a vacuum evaporation system became 1.2x10 < ^-4 > Pa similarly to the time of lamination | stacking of the cathode buffer layer 105. FIG. Thereafter, aluminum was vapor-deposited on the cathode buffer layer 105 at a vapor deposition rate of 0.3 nm / second so as to have a film thickness of 80 nm, whereby the cathode 106 was formed. The degree of vacuum at the time of vapor deposition was 1.4 × 10 ⁻⁴ Pa.

The device thus obtained was taken out into a glove box and then subjected to a heat treatment (post-annealing treatment) at 210 ° C. for 5 minutes. As described above, a photoelectric conversion element having a light receiving area portion having a size of 5 mm × 5 mm was obtained.
The photoelectric conversion element was irradiated with light from a solar simulator (AM1.5G) at an irradiation intensity of 100 mW / cm ² to measure voltage-current characteristics. The open-circuit voltage (Voc) of the photoelectric conversion element is 0.76 V, the short-circuit current density (Jsc) is 8.5 mA / cm ² , the fill factor (FF) is 0.62, and the energy conversion efficiency (PCE) is 4.1%. there were.

[Example 3]
Using tetrabenzoporphyrin (BP-1) as the first semiconductor material, carbazole compound (T-1) as the third material, and a deposition rate ratio of BP-1 and T-1 of 2: 1 and a film of 60 nm Next, a gradient composition is applied in the film thickness direction of the first semiconductor material in three steps with a deposition rate ratio of 1: 1 at 60 nm and finally a deposition rate ratio of 1: 2 and a thickness of 60 nm. Otherwise, a photoelectric conversion element was produced in the same manner as in Example 2.
The photoelectric conversion element was irradiated with light from a solar simulator (AM1.5G) at an irradiation intensity of 100 mW / cm ² to measure voltage-current characteristics. The open-circuit voltage (Voc) of the photoelectric conversion element is 0.76 V, the short-circuit current density (Jsc) is 10.0 mA / cm ² , the fill factor (FF) is 0.59, and the energy conversion efficiency (PCE) is 4.5%. there were.

[Comparative Example 2]
A photoelectric conversion element was produced in the same manner as in Example 2 except that the third material was not used when forming the active layer (104).
The photoelectric conversion element was irradiated with light from a solar simulator (AM1.5G) at an irradiation intensity of 100 mW / cm ² to measure voltage-current characteristics. The open-circuit voltage (Voc) of the photoelectric conversion element is 0.72 V, the short-circuit current density (Jsc) is 4.7 mA / cm ² , the fill factor (FF) is 0.66, and the energy conversion efficiency (PCE) is 2.2%. there were.

[Comparative Example 3]
In the same manner as in Example 2, a substrate on which 20 nm of PEDOT: PSS (manufactured by Heraeus, product name CLEVIOS AI 4083) was formed as an anode buffer layer was produced.
Next, a solution obtained by dissolving the bicycloporphyrin compound (CP) obtained in Synthesis Example 6 in a mixed solvent of chlorobenzene and chloroform (weight ratio of 2: 1) to 0.5 wt% was used as an anode buffer layer. 103 was spin-coated (rotation speed: 500 rpm). After the application, heat treatment was performed on a hot plate at 180 ° C. for 20 minutes. By this heat treatment, the brown bicycloporphyrin compound (CP) film was thermally converted into a green tetrabenzoporphyrin (BP-1) film. Thus, a crystalline active layer 104 having an average film thickness of 25 nm was obtained.

A fullerene compound was spin-coated on the active layer (104) in the same manner as in Example 2, and then the same cathode buffer layer and aluminum were deposited in a vacuum deposition apparatus to complete a photoelectric conversion element.
The photoelectric conversion element was irradiated with light from a solar simulator (AM1.5G) at an irradiation intensity of 100 mW / cm ² to measure voltage-current characteristics. The open-circuit voltage (Voc) of the photoelectric conversion element is 0.83 V, the short-circuit current density (Jsc) is 6.1 mA / cm ² , the fill factor (FF) is 0.72, and the energy conversion efficiency (PCE) is 3.6%. there were.
As described above, it has been found that a photoelectric conversion element exhibiting high photoelectric conversion characteristics can be obtained by forming an active layer using the third material according to the present application.

DESCRIPTION OF SYMBOLS 100 Photoelectric conversion element 101 Substrate 102 Electrode 103 Buffer layer 104a Active layer (p-layer)
104b Active layer (n-layer)
104c Active layer (i-layer)
DESCRIPTION OF SYMBOLS 105 Buffer layer 106 Electrode 1 Weatherproof protective film 2 Ultraviolet cut film 3,9 Gas barrier film 4,8 Getter material film 5,7 Sealing material 6 Solar cell element 10 Back sheet 11 Sealing material 12 Base material 13 Solar cell module 14 Thin film Solar cell

Claims (10)

A method of manufacturing a semiconductor device comprising a semiconductor layer comprising a first semiconductor material and a second semiconductor material, one of which is an electron donor and the other is an electron acceptor,
The manufacturing process of the semiconductor layer includes a step of depositing the first semiconductor material and a third material to form a layer including the first semiconductor material and the third material, and the first semiconductor material; A replacement step of replacing the third material with the second semiconductor material for a layer containing the third material;
The method for manufacturing a semiconductor device, wherein the third material is a compound satisfying at least one of the following conditions.
(1) A compound having a glass transition temperature of 80 ° C. or higher and 200 ° C. or lower by differential scanning calorimetry (DSC method) (2) A crystallization temperature of 180 ° C. or higher and 300 ° C. or lower by differential scanning calorimetry (DSC method) A compound   The method for manufacturing a semiconductor device according to claim 1, wherein the third material is a compound that satisfies the conditions (1) and (2). The manufacturing method of the semiconductor device of Claim 1 or 2 with which a 3rd material is represented by following formula (1) or (2).

(In formula (1), X represents a trivalent group, and A ^{1 to} A ³ each independently represents an aromatic group which may have a substituent.)

(In formula (2), p represents an integer of 1 or more, R ¹¹ and R ¹² each independently represent an arbitrary substituent, and R ¹¹ and R ¹² may be bonded to each other to form a ring. When p is 2 or more, the plurality of R ¹¹ and the plurality of R ¹² may each independently be different, and R ¹³ may be a p-valent hydrocarbon group or substituent which may have a substituent. P-valent heterocyclic group which may have a p-valent heterocyclic group or a hydrocarbon group which may have a substituent and at least one of a heterocyclic group which may have a substituent connected Y represents an atom selected from Group 16 elements of the periodic table.)   In the replacing step, the second material is replaced with the second semiconductor material by applying a solution of the second semiconductor material to a layer including the first semiconductor material and the third material. The manufacturing method of the semiconductor device as described in any one of Claims 1-3 characterized by the above-mentioned. The replacing step includes a step of eluting and removing the third material from the layer containing the first semiconductor material and the third material using a solvent of the third material, and the third step in the step. Applying the second semiconductor material solution to the layer from which the material has been removed to contain the second semiconductor material. The manufacturing method of the semiconductor device of description.   The first semiconductor material is hardly soluble or insoluble in a solvent in the solution of the second semiconductor material, and the third material is soluble in a solvent in the solution of the second semiconductor material. The method for manufacturing a semiconductor device according to claim 1, wherein the method is a semiconductor device manufacturing method.   6. The method of manufacturing a semiconductor device according to claim 5, wherein the first semiconductor material is hardly soluble or insoluble in a solvent of the third material.   The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor device is a photoelectric conversion element.   A solar cell comprising a photoelectric conversion element manufactured by the manufacturing method according to claim 8.   A solar cell module comprising the solar cell according to claim 9.

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