TWI611594B - Photoelectric conversion element, image capture element, optical sensor - Google Patents

Abstract

An object of the present invention is to provide a photoelectric conversion element including a photoelectric conversion film exhibiting excellent heat resistance and responsiveness, and a photographing element and a light sensor including the photoelectric conversion element. The photoelectric conversion element of the present invention is a photoelectric conversion element in which a conductive film, a photoelectric conversion film including a photoelectric conversion material, and a transparent conductive film are sequentially laminated. The photoelectric conversion material includes a compound selected from the group consisting of a compound represented by the general formula (1) At least one compound X of the group consisting of the compound represented by the general formula (2) and the compound represented by the general formula (3).

Description

Photoelectric conversion element, photographic element, light sensor

The invention relates to a photoelectric conversion element, a photographing element, and a light sensor.

The existing photo sensor is an element in which a photodiode (PD) is formed on a semiconductor substrate such as silicon (Si). The solid-state imaging element is widely used as a planar solid-state imaging element. The planar solid-state imaging element is two-dimensionally grounded. The PDs are arranged, and the signal charge generated by each PD is read out by the circuit.

In order to realize a color solid-state imaging element, a color filter that transmits light of a specific wavelength is generally arranged on the light incident surface side of the flat-type solid-state imaging element. A single-plate solid-state imaging element widely used in digital cameras and the like is now widely known, and regularly arranges two PDs arranged in two dimensions to transmit blue (B) light, green (G) light, and red (R) Color filters for light.

In this single-plate type solid-state imaging element, light that does not pass through a color filter is not used, and light utilization efficiency is poor. In recent years, in the progress of multi-pixelization, the pixel size has become smaller, a decrease in the open area ratio, and a decrease in the light collection efficiency have become problems.

In order to solve these disadvantages, a structure is known in which a photoelectric conversion film or a photoelectric conversion film of amorphous silicon is formed on a signal readout substrate.

There are several known examples of a photoelectric conversion element, a photographing element, and a light sensor using a photoelectric conversion film.

For example, in Patent Document 1, a photoelectric conversion film containing a compound (3) and the like represented by the following formula is disclosed in the Example column, and it is mainly described that it has a high photoelectric conversion efficiency. In addition, Patent Documents 2 and 3 also disclose photoelectric conversion elements containing a diketopyrrolopyrrole compound.

[Prior technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2006-339424

[Patent Document 2] Japanese Patent Laid-Open No. 2010-192782

[Patent Document 3] Japanese Patent Laid-Open No. 2003-346926

In recent years, as the performance of photographic elements, light sensors, etc. has improved, It is also required to improve various characteristics such as heat resistance and response speed required for the photoelectric conversion films used in these. For example, when the photoelectric conversion element is used in various applications such as a photographic element or a photovoltaic cell, the self-made process is suitable, and in terms of performance, the photoelectric conversion element is required to exhibit high heat resistance. More specifically, as a process for forming a photographic element, there are many steps for performing a heat treatment (setting a color filter, providing a protective film, a soldering element, and the like), and the photoelectric conversion element is required to show even after these steps. Excellent characteristics (response speed, low dark current characteristics, etc.).

The inventors of the present invention used the compounds specifically disclosed in Patent Documents 1 to 3 (for example, the above-mentioned Compound 3) to produce a photoelectric conversion film. As a result, they found that the heat resistance and response speed did not necessarily reach the recently required The level needs to be further improved.

An object of the present invention is to provide a photoelectric conversion element including a photoelectric conversion film exhibiting excellent heat resistance and responsiveness in view of the above-mentioned facts.

It is another object of the present invention to provide a photographing element and a light sensor including a photoelectric conversion element.

The present inventors made diligent research on the above-mentioned problems, and as a result, they found that the above-mentioned problems can be solved by the following methods: the diketopyrrolopyrrole compound contained in the photoelectric conversion film, or the An aromatic ring-containing amine group is introduced into a predetermined position of a compound in which an aromatic ring is further condensed between two pyrrole rings of a pyrrolopyrrole.

That is, the above-mentioned problems can be solved by the means shown below.

(1) A photoelectric conversion element, which is a photoelectric conversion element in which a conductive film, a photoelectric conversion film including a photoelectric conversion material, and a transparent conductive film are sequentially laminated, and the photoelectric conversion material includes a component selected from a general formula (1) described later. At least one compound X of the group consisting of a compound represented by), a compound represented by general formula (2) described later, and a compound represented by general formula (3) described later.

(2) The photoelectric conversion element according to (1), wherein the compound X is a compound represented by the general formula (4) described later.

(3) The photoelectric conversion element according to (1) or (2), wherein Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , And at least one of R ¹³ and R ¹⁴ is bonded to each other to form a ring.

(4) The photoelectric conversion element according to any one of (1) to (3), wherein X ¹ and X ² are O.

(5) The photoelectric conversion element according to any one of (1) to (4), wherein the photoelectric conversion film further contains an organic n-type compound.

(6) The photoelectric conversion element according to (5), wherein the organic n-type compound includes fullerenes, and the fullerenes include fullerenes and derivatives thereof.

(7) The photoelectric conversion element according to (6), wherein the molar ratio of the compound X to the fullerenes (the molar amount of the fullerenes / the molar amount of the compound X) is 1.0 or more.

(8) The photoelectric conversion element according to any one of (1) to (7), wherein A charge blocking film is disposed between the conductive film and the transparent conductive film.

(9) A photographic element including the photoelectric conversion element according to any one of (1) to (8).

(10) A light sensor including the photoelectric conversion element according to any one of (1) to (8).

According to the present invention, a photoelectric conversion element including a photoelectric conversion film exhibiting excellent heat resistance and responsiveness can be provided.

Furthermore, the present invention can provide a photographing element and a light sensor including a photoelectric conversion element.

10a, 10b ‧‧‧ photoelectric conversion element

11‧‧‧Lower electrode (conductive film)

12‧‧‧photoelectric conversion film

15‧‧‧upper electrode (transparent conductive film)

16A‧‧‧Electronic blocking film

16B‧‧‧hole blocking film

100‧‧‧Photographic element

101‧‧‧ substrate

102‧‧‧ Insulation

103‧‧‧ connecting electrode

104‧‧‧pixel electrode (lower electrode)

105‧‧‧Connection Department

106‧‧‧Connection Department

107‧‧‧photoelectric conversion film

108‧‧‧ Counter electrode (upper electrode)

109‧‧‧Buffer layer

110‧‧‧Sealing layer

111‧‧‧ Color Filter (CF)

112‧‧‧ partition

113‧‧‧Light-shielding layer

114‧‧‧ protective layer

115‧‧‧ Counter electrode voltage supply unit

116‧‧‧readout circuit

1 (a) and 1 (b) are cross-sectional views each schematically showing a configuration example of a photoelectric conversion element.

FIG. 2 is a schematic cross-sectional view of one pixel of a photographing element.

Hereinafter, preferred embodiments of the photoelectric conversion element of the present invention will be described.

First, the features of the present invention which are compared with the prior art will be described in detail.

As described above, in the present invention, it has been found that by using a diketopyrrolopyrrole compound contained in a photoelectric conversion film or two pyrrole rings of a diketopyrrolopyrrole A desired effect can be obtained by introducing an amine group containing an aromatic ring at a predetermined position in a compound having an aromatic ring that is further condensed in between. It is speculated that by introducing such an aromatic ring-containing amine group, the molecular weight of the compound used is increased and the interaction between the compounds is moderately increased, and the degree of freedom of the molecule is reduced by the introduction of a large number of ring structures. As a result, heat resistance is improved. Furthermore, it is estimated that by introducing an amine group containing an aromatic ring, the skeleton of the hole can be stably held to protrude to the outside of the molecule, the exchange of holes between the molecules is facilitated, and as a result, the response speed is improved.

Hereinafter, preferred embodiments of the photoelectric conversion element of the present invention will be described with reference to the drawings. 1 (a) and 1 (b) are cross-sectional views schematically showing an embodiment of a photoelectric conversion element according to the present invention.

The photoelectric conversion element 10 a shown in FIG. 1 (a) has a structure in which a conductive film (hereinafter also referred to as a lower electrode) 11 that functions as a lower electrode is sequentially laminated, and a layer formed on the lower electrode 11 is formed. The electron blocking film 16A, the photoelectric conversion film 12 formed on the electron blocking film 16A, and a transparent conductive film (hereinafter also referred to as an upper electrode) 15 functioning as an upper electrode.

FIG. 1 (b) shows a configuration example of another photoelectric conversion element. The photoelectric conversion element 10 b shown in FIG. 1 (b) has a configuration in which an electron blocking film 16A, a photoelectric conversion film 12, a hole blocking film 16B, and an upper electrode 15 are sequentially laminated on the lower electrode 11. In addition, the lamination order of the electron blocking film 16A, the photoelectric conversion film 12, and the hole blocking film 16B in FIGS. 1 (a) and 1 (b) may be reversed depending on the application and characteristics. For example, the positions of the electron blocking film 16A and the photoelectric conversion film 12 may be reversed.

In the configuration of the photoelectric conversion element 10a (10b), it is preferable that The conductive film 15 is illuminated so that light is incident on the photoelectric conversion film 12.

Furthermore, when the photoelectric conversion element 10a (10b) is used, an electric field can be applied. In this case, the conductive film 11 and the transparent conductive film 15 are used as a pair of electrodes. It is preferable to apply a voltage of 1 × 10 ^-5 V / cm to 1 × 10 ⁷ V / cm between the pair of electrodes. electric field. From the viewpoint of performance and power consumption, an electric field of 1 × 10 ^-4 V / cm to 1 × 10 ⁶ V / cm is preferable, and 1 × 10 ^-3 V / cm to 5 × 10 ⁵ V is particularly preferable. / cm of electric field.

The voltage application method is applied so that the electron blocking film 16A side becomes a cathode and the photoelectric conversion film 12 side becomes an anode in FIGS. 1 (a) and 1 (b). In the case where the photoelectric conversion element 10a (10b) is used as a light sensor, and when it is incorporated in a photographing element, a voltage can be applied by the same method.

Hereinafter, the form of each layer (the photoelectric conversion film 12, the electron blocking film 16A, the lower electrode 11, the upper electrode 15, the hole blocking film 16B, etc.) constituting the photoelectric conversion element 10a (10b) will be described in detail.

First, the photoelectric conversion film 12 will be described in detail.

[Photoelectric conversion film]

The photoelectric conversion film 12 is selected from the group consisting of a compound represented by the general formula (1) described later, a compound represented by the general formula (2) described later, and a compound represented by the general formula (3) described later. At least one compound X is used as a film of a photoelectric conversion material. By using this compound X, a photoelectric conversion film exhibiting excellent heat resistance and high-speed response is obtained.

First, the general formula (1) to the general formula (3) used in the photoelectric conversion film 12 The compounds represented are detailed.

In the general formulae (1) to (3), R ¹ and R ² each independently represent an alkyl group, an aryl group, or a heteroaryl group. Among them, an alkyl group is preferred in terms of ease of synthesis and more excellent properties (heat resistance and responsiveness) of the photoelectric conversion film.

The number of carbons in the alkyl group is not particularly limited, and from the viewpoint of more excellent characteristics (heat resistance and responsiveness) of the photoelectric conversion film, it is preferably 1 to 10, more preferably 1 to 6, and even more preferably It's 1 ~ 3. The alkyl group may have any of a linear structure, a branched structure, and a cyclic structure.

Preferred examples of the alkyl group include methyl, ethyl, n-propyl, n-butyl, and n-hexyl.

The number of carbon atoms in the aryl group is not particularly limited, and from the viewpoint of better characteristics (heat resistance and responsiveness) of the photoelectric conversion film, it is preferably 6 to 30, and more preferably 6 to 18. The aryl group may have a single ring structure, or a condensed ring structure formed by condensing two or more rings, and may have a substituent W described later.

Examples of the aryl group include phenyl, naphthyl, anthryl, fluorenyl, phenanthryl, methylphenyl, dimethylphenyl, biphenyl, and fluorenyl. Phenyl, naphthyl, or Anthracenyl.

The number of carbon atoms in the heteroaryl group (monovalent aromatic heterocyclic group) is not particularly limited, and from the viewpoint of better characteristics (heat resistance and responsiveness) of the photoelectric conversion film, it is preferably 3 to 30, more The best is 3 ~ 18. The heteroaryl group may have a substituent W described later.

Heteroaryl groups also include heteroatoms in addition to carbon and hydrogen atoms. Examples of the heteroatoms include nitrogen, sulfur, oxygen, selenium, tellurium, phosphorus, silicon, or boron. It is a nitrogen atom, a sulfur atom, or an oxygen atom. The number of heteroatoms contained in the heteroaryl group is not particularly limited, but is usually about 1 to 10, and preferably 1 to 4.

The number of ring members of a heteroaryl group is not particularly limited. A 3-membered ring to a 8-membered ring is preferred, a 5-membered ring to a 7-membered ring is even more preferred, and a 5-membered to 6-membered ring is particularly preferred.

Examples of the heteroaryl group include pyridyl, quinolyl, isoquinolyl, acridinyl, phenanthridinyl, pteridinyl, pyrazinyl, quinoxalinyl, and pyrimidinyl , Quinazolinyl, pyridazinyl, fluorenyl, phthalazinyl, triazinyl, oxazolyl, benzoxazolyl, thiazolyl, benzothiazolyl, imidazolyl, benzimidazolyl, pyrazole Base, indazolyl, isoxazolyl, benzoisoxazolyl, isothiazolyl, benzoisothiazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, furanyl, benzene Benzofuryl, thienyl, benzothienyl, dibenzofuranyl, dibenzothienyl, pyrrolyl, indolyl, imidazopyridyl, carbazolyl, and the like.

The substituent W in this specification is described.

Examples of the substituent W include a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group, a bicycloalkenyl group), an alkynyl group, an aryl group, and a heterocyclic group (also (Can be described as heterocyclyl), cyano, hydroxyl, nitro, carboxyl, alkoxy, aryloxy, silyloxy, heterocyclooxy, fluorenyloxy, carbamateoxy, alkoxycarbonyl Oxy, aryloxycarbonyloxy, amine (including aniline), ammonium, fluorenylamino, aminecarbonylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfamoyl Amine, alkyl, or arylsulfonylamino, mercapto, alkylthio, arylthio, heterocyclicthio, sulfamoyl, sulfo, alkyl, or arylsulfinyl, alkyl, or Arylsulfonyl, fluorenyl, aryloxycarbonyl, alkoxycarbonyl, carbamoyl, aryl or heterocyclic azo, phosphoimino, phosphino, phosphinoyl , Phosphinyloxy, phosphinylamino, phosphono, silane, hydrazine, urea, borate (-B (OH) ₂ ), phosphate (-OPO (OH () _2), sulfate _{(sulfato) - OSO 3 H)} , take other well-known Groups.

The details of the substituent W are described in paragraph [0023] of Japanese Patent Laid-Open No. 2007-234651.

R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent an alkyl group, an aryl group or a heteroaryl group. In addition, at least one of R ¹¹ and R ¹² and at least one of R ¹³ and R ¹⁴ each represent an aryl group or a heteroaryl group. Among these, R ¹¹ , R ¹² , R ^13, and R ^{14 are} preferably an aryl group, from the viewpoint that the characteristics (heat resistance and responsiveness) of the photoelectric conversion film are more excellent.

R ^11, R ^12, R ^13, and Definition of a suitable shape alkyl, aryl, and heteroaryl groups represented by R ¹⁴ to R ¹ and the above-described alkyl group, aryl group and heteroaryl group represented by R ² are defined and The appropriate shape is the same.

Ar ¹ and Ar ² each independently represent an arylene group or an arylene group. Among them, Ar ¹ and Ar ^{2 are} preferably an arylene group from the viewpoint that the characteristics (heat resistance and responsiveness) of the photoelectric conversion film are more excellent.

The number of carbons in the arylidene group is not particularly limited, and from the viewpoint of better characteristics (heat resistance and responsiveness) of the photoelectric conversion film, it is preferably 6 to 30, and more preferably 6 to 20.

二基、聯伸三苯二基、苯并蒽二基、苯并菲二基等。 Examples of the arylene group include phenylene, biphenylene, terphenylene, naphthyl, anthracenyl, phenanthryl, fluorenediyl, fluorenediyl, fluorenediyl ,

Diyl, diphenyltriphenylene, benzoanthracene diyl, benzophenanthryl diyl and the like.

The number of carbons in the extended heteroaryl group is not particularly limited, and from the viewpoint of more excellent characteristics (heat resistance and responsiveness) of the photoelectric conversion film, it is preferably 1 to 20, and more preferably 2 to 12.

Examples of the extended heteroaryl group include extended pyridyl, extended quinolinyl, extended isoquinolinyl, acridine diyl, morphinyl diyl, pyrazine diyl, quinoxaline diyl, pyrimidine diyl, and triazine di Base, imidazole diyl, pyrazole diyl, oxadiazole diyl, triazole diyl, furfuryl, thienyl, pyrrole diyl, indole diyl, carbazole diyl, and the like.

X ¹ and X ² each independently represent O (oxygen atom), S (sulfur atom), or NR ^A. Among these, from the viewpoint that the characteristics (heat resistance and responsiveness) of the photoelectric conversion film are more excellent, O (oxygen atom) or S (sulfur atom) is preferred, and O (oxygen atom) is more preferred.

R ^A represents an alkyl group, an aryl group, or a heteroaryl group. Among these, an alkyl group is preferable from the point which the characteristic (heat resistance and responsiveness) of a photoelectric conversion film is more excellent.

The definitions and suitable forms of the alkyl, aryl, and heteroaryl groups represented by R ^A are the same as the definitions and suitable forms of the alkyl, aryl, and heteroaryl groups represented by R ¹ and R ² described above.

Q is selected from the group represented by the general formula (A), the group represented by the general formula (B), the group represented by the general formula (C), the group represented by the general formula (D), and the general formula (E) Any one of the groups of the indicated basis.

In the general formulae (A) to (E), R ^Q1 to R ^Q22 each independently represent a hydrogen atom or a substituent. Examples of the substituent include the above-mentioned substituent W, and examples thereof include an alkyl group, an alkoxy group, and a halogen atom. Among these, R ^Q1 to R ^{Q22 are more} preferably a hydrogen atom from the viewpoint that the characteristics (heat resistance or responsiveness) of the photoelectric conversion element are more excellent.

In addition, the carbon atoms represented by * 1 to * 4 in the general formulae (A) to (E) and the carbon atoms represented by * 1 to * 4 in the general formulae (1) to (3), respectively. correspond. More specifically, the following is an example of a structural formula when a group represented by the general formula (A) to the general formula (E) is introduced into Q in the general formula (1) to the general formula (3).

[Chemical 4]

In the general formulae (1) to (3), Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , R ¹³ and R ^{14 are} also They can be bonded to each other to form a ring. In addition, at the time of bonding, it is preferable that Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and R ¹⁴ be directly and directly with each other. Alternatively, a ring is formed through a linking group, and from the viewpoint that the characteristics (heat resistance and responsiveness) of the photoelectric conversion film are more excellent, it is more preferable that the ring is formed by direct bonding.

By forming this ring structure, the heat resistance of the compounds represented by the general formulae (1) to (3) is improved, and a photoelectric conversion element can be manufactured with a high evaporation rate under high temperature conditions, and the responsiveness can be further improved.

The structure of the linking group is not particularly limited, and examples thereof include an oxygen atom, a sulfur atom, an alkylene group, a silylene group, an alkylene group, a cycloalkylene group, a cycloalkylene group, an alkylene group, A valent heterocyclic group, an imino group, or a combination of these groups, and these groups may further have a substituent. Preferred are alkylene, silylene, alkylene, cycloalkyl, cycloalkenyl, alkylene, and the like.

The structure of the formed ring is not particularly limited, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a triphenylene ring, a thick tetraphenyl ring, a biphenyl ring, a pyrrole ring, and a furan. Ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, indoxazine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzene Benzofuran ring, quinazine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, morphine ring, acridine Ring, morpholine ring, thianthrene ring, chromene ring, xanthene ring, phenoxaline ring, phenothiazine ring, morphazine ring, ring A pentane ring, a cyclohexane ring, a pyrrolidine ring, a piperidine ring, a tetrahydrofuran ring, a tetrahydropyran ring, a tetrahydrothiophene ring, a tetrahydrothioan ring, and the like.

In addition, it is preferred that at least one of Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , and R ¹¹ and R ¹² be bonded to each other to form a ring, and Ar ² and R ¹³ , Ar ² and R ¹⁴ , And at least one of R ¹³ and R ¹⁴ is bonded to each other to form a ring. With this configuration, the heat resistance and responsiveness of the photoelectric conversion film are further improved.

n represents 0 or 1. Among these, from the viewpoint that the characteristics (heat resistance or responsiveness) of the photoelectric conversion element are more excellent, n is preferably 0.

When n is 1, the formula (1A) to the formula (3E) are exemplified. Shown compound.

In addition, when n is 0, the carbon atom represented by * 1 and the carbon atom represented by * 3 become the same carbon atom, and the carbon atom represented by * 2 and the carbon atom represented by * 4 become the same carbon atom. That is, in the general formulae (1) to (3), when n = 0, the compounds represented by the following general formulae (4) to (6) are shown.

The definition of each group in the general formulae (4) to (6) is as described above.

Among them, the compound represented by the general formula (4) is particularly preferable from the viewpoint that the effect of the present invention is more excellent. The compound represented by the general formula (4) is a so-called diketopyrrolopyrrole compound.

The compounds represented by the general formulae (1) to (3) are exemplified below.

[Chemical 6]

[Chemical 9]

[Chemical 17]

[Chemical 23]

It is preferable that the compounds represented by the general formulae (1) to (3) have a maximum absorption in the ultraviolet-visible absorption spectrum of 400 nm or more and less than 720 nm. From the viewpoint of absorbing light in the visible region in a wide range, the peak wavelength (maximum absorption wavelength) of the absorption spectrum is more preferably 450 nm or more and 700 nm or less, even more preferably 480 nm or more and 700 nm or less, and particularly preferably 510 nm. Above and below 680nm.

The maximum absorption wavelength of a compound can be measured using a chloroform solution of the compound and UV-2550 manufactured by Shimadzu Corporation. The concentration of the chloroform solution is preferably 5 × 10 ^-5 mol / l ~ 1 × 10 ^-7 mol / l, and more preferably 3 × 10 ^-5 mol / l ~ 2 × 10 ^-6 mol / l, particularly preferably It is 2 × 10 ^-5 mol / l ~ 5 × 10 ^-6 mol / l.

The compounds represented by the general formulae (1) to (3) have a maximum absorption in the ultraviolet-visible absorption spectrum of 400 nm or more and less than 720 nm. The Mohr absorption coefficient of the maximum absorption wavelength is preferably 10,000 mol ^-1 . l. cm ^-1 or more. In order to make the film thickness of the photoelectric conversion film thin, and to make an element with high charge trapping efficiency, high-speed response, and high sensitivity characteristics, a material with a large Mohr absorption coefficient is preferred. The Mohr absorption coefficient of the compounds represented by the general formulae (1) to (3) is more preferably 30,000 mol ^-1 . l. cm ^-1 or more, more preferably 50,000 mol ^-1 . l. cm ^-1 or more. Molar absorption coefficients of the compounds represented by the general formulae (1) to (3) were measured using a chloroform solution.

The larger the difference between the melting point and the evaporation temperature (melting point-evaporation temperature) of the compounds represented by the general formulae (1) to (3), the more difficult it is to decompose during evaporation, and it can be increased by applying a high temperature Evaporation speed. The difference between the melting point and the evaporation temperature (melting point-evaporation temperature) is preferably 40 ° C or higher, more preferably 50 ° C or higher, even more preferably 60 ° C or higher, and particularly preferably 80 ° C or higher.

The molecular weight of the compound represented by the general formula (1) to the general formula (3) is preferably 300 to 1500, more preferably 500 to 1,000, and particularly preferably 500 to 900. If the molecular weight of the compound is 1500 or less, the vapor deposition temperature does not increase, and it is difficult to cause decomposition of the compound. When the molecular weight of the compound is 300 or more, the glass transition point of the vapor-deposited film does not decrease, and it is difficult to reduce the heat resistance of the device.

The glass transition point (Tg) of the compounds represented by the general formulae (1) to (3) is preferably 95 ° C or higher, more preferably 110 ° C or higher, and even more preferably 135 ° C or higher. It is 150 ° C or more, and most preferably 160 ° C or more. When the glass transition point becomes higher, the heat resistance of the element is improved, which is preferable.

The compounds represented by the general formulae (1) to (3) are particularly useful as a material for a photoelectric conversion film used in a photographic element, a light sensor, or a photovoltaic cell. In general, the compound represented by the general formula (1) functions as an organic p-type compound in a photoelectric conversion film. In addition, it can also be used as a coloring material, a liquid crystal material, an organic semiconductor material, an organic light-emitting element material, and Charge transfer materials, medical materials, fluorescent diagnostic reagent materials, etc.

(other materials)

The photoelectric conversion film may further contain a photoelectric conversion material of an organic p-type compound or an organic n-type compound.

Organic p-type semiconductors (compounds) are donor organic semiconductors (compounds), and mainly refer to organic compounds represented by hole-transporting organic compounds and having the property of easily supplying electrons. More specifically, it refers to an organic compound having a small free potential when two types of organic materials are used in contact. Therefore, if the donor organic compound is an organic compound having an electron donating property, any organic compound can be used. For example, a triarylamine compound, a benzidine compound, a pyrazoline compound, a styrylamine compound, a fluorene compound, a triphenylmethane compound, a carbazole compound, or the like can be used.

、吡咯并吡啶、噻二唑并吡啶、二苯并氮呯、三苯并氮呯等)、聚伸芳基化合物、茀化合物、環戊二烯化合物、矽烷化合物、具有含氮雜環化合物作為配位基的金屬錯合物等。 The organic n-type semiconductor (compound) is an acceptor organic semiconductor, and mainly refers to an organic compound represented by an electron-transporting organic compound and having a property of easily accepting electrons. More specifically, it refers to an organic compound having a large electron affinity when used in contact with two kinds of organic compounds. Therefore, if the acceptor organic semiconductor is an organic compound having electron acceptability, any organic compound can be used. Preferred are fullerenes or fullerene derivatives, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, fused tetraphenyl derivatives, fluorene derivatives, fluorene derivatives, fluoranthene derivatives) Compounds), 5- to 7-membered heterocyclic compounds containing nitrogen, oxygen, and sulfur atoms (e.g., pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine , Oxoline, isoquinoline, pyridine, acridine, phenazine, morpholine, tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole, benzimidazole, benzotriazole, benzoxazole, Benzothiazole, carbazole, purine, triazolopyridazine, triazolopyrimidine, tetrazaindene, oxadiazole, imidazopyridine,

, Pyrrolopyridine, thiadiazolopyridine, dibenzoazepine, tribenzoazepine, etc.), polyarylidene compounds, fluorene compounds, cyclopentadiene compounds, silane compounds, and nitrogen-containing heterocyclic compounds as Metal complexes of ligands and the like.

The organic n-type compound is preferably fullerenes selected from the group consisting of fullerenes and fullerene derivatives. The so-called fullerene indicates fullerene C _60, fullerene C _70, fullerene C _76, fullerene C _78, fullerene C _80, fullerene C _82, fullerene C _84, fullerene alkenyl C _90, fullerene C _96, fullerene C _240, fullerene C _540, a mixed fullerene, the fullerene derivative is represented by the so-called on the fullerene addition these compounds have a substituent. The substituent is preferably an alkyl group, an aryl group, or a heterocyclic group. The fullerene derivative is preferably a compound described in Japanese Patent Laid-Open No. 2007-123707.

The photoelectric conversion film preferably has a bulk heterostructure formed in a state where the compound X and the fullerenes are mixed. The bulk heterostructure is a layer in which a p-type organic semiconductor (compound X) and an n-type organic semiconductor are mixed and dispersed in a photoelectric conversion film, and can be formed by any of a wet method and a dry method, and is preferably It is formed by a co-evaporation method. By including the heterojunction structure, the shortcomings of the short carrier diffusion length of the photoelectric conversion film can be compensated, and the photoelectric conversion efficiency of the photoelectric conversion film can be improved. In addition, the bulk heterojunction structure is described in detail in [0013] to [0014] of Japanese Patent Laid-Open No. 2005-303266.

Relative to the above-mentioned compound X, the organic n-type compound in the photoelectric conversion film The molar ratio (organic n-type compound / the above-mentioned compound X) is preferably 1.0 or more, more preferably 1 or more and 10 or less, even more preferably 2 or more and 8 or less.

The photoelectric conversion film containing the compound X and the organic n-type compound of the present invention is a non-luminescent film, and has a characteristic different from that of an organic light emitting diode (OLED). When the non-luminescent film is a film having a light emitting quantum efficiency of 1% or less, it is preferably 0.5% or less, and more preferably 0.1% or less.

(Film forming method)

The photoelectric conversion film 12 can be formed by a dry film formation method or a wet film formation method. Specific examples of the dry film formation method include a physical vapor deposition (PVD) method such as a vacuum evaporation method, a sputtering method, an ion plating method, and a molecular beam epitaxy (MBE) method, or Chemical vapor deposition (CVD) methods such as plasma polymerization. As the wet film formation method, a casting method, a spin coating method, a dipping method, an LB method, or the like is used. A dry film-forming method is preferable, and a vacuum evaporation method is more preferable. When forming a film by a vacuum vapor deposition method, manufacturing conditions such as a degree of vacuum and a vapor deposition temperature can be set in accordance with a conventional method.

The thickness of the photoelectric conversion film 12 is preferably 10 nm or more and 1000 nm or less, more preferably 50 nm or more and 800 nm or less, and particularly preferably 100 nm or more and 500 nm or less. When it is set to 10 nm or more, a suitable dark current suppression effect can be obtained; when it is set to 1000 nm or less, a suitable photoelectric conversion efficiency can be obtained.

[electrode]

The electrodes (the upper electrode (transparent conductive film) 15 and the lower electrode (conductive film) 11) include a conductive material. Conductive materials can use metals, alloys, and metal oxidation Materials, conductive compounds, or mixtures thereof.

In order to enter light from the upper electrode 15, the upper electrode 15 must be sufficiently transparent to the light to be detected. Specific examples include conductive metal oxides such as tin oxide (ATO, FTO) doped with antimony or fluorine, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). Metal thin films of gold, silver, chromium, nickel, etc., as well as mixtures or laminates of these metals with conductive metal oxides, inorganic conductive materials such as copper iodide, copper sulfide, organics such as polyaniline, polythiophene, polypyrrole, etc. Conductive materials, and these laminates with ITO. From the viewpoints of high conductivity and transparency, a transparent conductive metal oxide is preferred.

In general, if the conductive film is made thinner than a certain range, the resistance value will increase sharply. Among the solid-state imaging elements containing the photoelectric conversion element of this embodiment, the sheet resistance is preferably 100Ω / □ ~ 10000Ω / □, and there is a large degree of freedom in the range of film thicknesses that can be reduced. In addition, the thinner the upper electrode (transparent conductive film) 15 is, the less the amount of light absorbed is, and the light transmittance is generally increased. The increase in light transmittance increases the light absorption in the photoelectric conversion film 12 and increases the photoelectric conversion capability, so it is very good. As the thickness of the thin film is increased, the thickness of the upper electrode 15 is preferably 5 nm to 100 nm, and more preferably 5 nm to the thickness of the upper electrode 15 in consideration of suppression of leakage current, increase in resistance value of the film, and increase in transmittance. 20nm.

The lower electrode 11 may have transparency depending on the application, and may instead use a material that is opaque and reflects light. Specific examples include conductive metal oxides such as tin oxide (ATO, FTO) doped with antimony or fluorine, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). Gold, silver, Metals such as chromium, nickel, titanium, tungsten, aluminum, and conductive compounds such as oxides or nitrides of these metals (for example, titanium nitride (TiN) can be cited as an example), and these metals and conductive metal oxides can also be mentioned Mixtures or laminates, inorganic conductive materials such as copper iodide, copper sulfide, organic conductive materials such as polyaniline, polythiophene, polypyrrole, and these laminates with ITO or titanium nitride.

The method of forming the electrode is not particularly limited, and can be appropriately selected depending on the electrode material. Specific examples include wet methods such as printing methods and coating methods, physical methods such as vacuum evaporation, sputtering, and ion plating, and chemical methods such as CVD and plasma CVD.

When the material of the electrode is ITO, the electron beam method, the sputtering method, the resistance heating evaporation method, the chemical reaction method (sol-gel method, etc.), and the method of applying a dispersion of indium tin oxide can be used. form. In addition, a film made using ITO may be subjected to an ultraviolet (UltraViolet, UV) -ozone treatment, a plasma treatment, or the like. When the material of the electrode is TiN, various methods including a reactive sputtering method are used, and UV-ozone treatment, plasma treatment, and the like can be performed.

[Charge blocking film: electron blocking film, hole blocking film]

The photoelectric conversion element of the present invention may include a charge blocking film. By including this film, the characteristics (photoelectric conversion efficiency, response speed, etc.) of the obtained photoelectric conversion element are more excellent. Examples of the charge blocking film include an electron blocking film and a hole blocking film. Each film is described in detail below.

(Electronic blocking film)

An electron-donating organic material can be used in the electron blocking film. Specifically, low molecular Materials can use N, N'-bis (3-methylphenyl)-(1,1'-biphenyl) -4,4'-diamine (TPD) or 4,4'-bis [N- ( (Naphthyl) -N-phenyl-amino] biphenyl (α-NPD) and other aromatic diamine compounds, oxazole, oxadiazole, triazole, imidazole, imidazolone, stilbene derivative, pyrazoline Derivatives, tetrahydroimidazole, polyarylalkanes, butadiene, 4,4 ', 4 "-tris (N- (3-methylphenyl) -N-phenylamino) triphenylamine (m -MTDATA), porphyrin, porphyrin, copper tetraphenylporphyrin, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide and other porphyrin compounds, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkanes Derivatives, pyrazoline derivatives, pyrazolinone derivatives, phenylenediamine derivatives, arylamine derivatives, amine-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, pyrene Ketone derivatives, fluorene derivatives, silazane derivatives, etc., polymer materials can be phenylene vinylene, fluorene, carbazole, indole, fluorene, pyrrole, picoline, thiophene, acetylene, A polymer or a derivative thereof such as diacetylene. Even if it is not an electron-donating compound, if Sufficient hole transporting compound may be used. Specifically preferred is Japanese Patent Laid-Open Patent Publication No. 2008-72090 [0083] - Compound [0089] are described.

It is also preferable that the electron blocking film contains a compound represented by the general formula (F-1). By using this compound, the response speed of the obtained photoelectric conversion film is more excellent, and the non-uniformity of the response speed between manufacturing lots is further suppressed.

[Chemical 24]

(In the general formula (F-1), R " ₁₁ to R" ₁₈ and R _'11 to R' ₁₈ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amine group, These groups may further have a substituent. Any one of R " ₁₅ to R" ₁₈ is connected to any one of R _'15 to R' ₁₈ to form a single bond. A ₁₁ and A ₁₂ are each independently Represents a group represented by the following general formula (A-1), and is substituted as any one of R " ₁₁ to R" ₁₄ and R _'11 to R' _14. Y each independently represents a carbon atom and a nitrogen atom , Oxygen atom, sulfur atom, or silicon atom, which may further have a substituent)

(In the general formula (A-1), Ra ₁ to Ra ₈ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a heterocyclic group, and these may further have a substituent. * Indicates a bonding position Xa represents a single bond, an oxygen atom, a sulfur atom, an alkylene group, a silylene group, an alkylene group, a cycloalkylene group, a cycloalkylene group, an alkylene group, a divalent heterocyclic group, or an imino group These may further have a substituent. S ₁₁ each independently represents the following substituent (S ₁₁ ) and is substituted as any one of Ra ₁ to Ra _8. n ′ represents an integer of 0 to 4)

(R ' ₁ to R' ₃ each independently represent a hydrogen atom or an alkyl group)

In the general formula (F-1), R " ₁₁ to R" ₁₈ and R _'11 to R' ₁₈ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amine group, or These mercapto groups may further have a substituent. Specific examples of the further substituent include the above-mentioned substituent W, preferably a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amine group, or a mercapto group, and more preferably a halogen atom, an alkyl group, or an aromatic group. Group, or heterocyclic group, more preferably a fluorine atom, an alkyl group, or an aryl group, particularly preferably an alkyl group or an aryl group, and most preferably an alkyl group.

R " ₁₁ ~ R" ₁₈ and R _'11 ~ R' _{18 are} preferably a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group which may have a substituent, more preferably a hydrogen atom and may have a substitution. The carbon number of the group is an alkyl group having 1 to 18 carbon atoms, the aryl group having 6 to 18 carbon atoms, or the heterocyclic group having 4 to 16 carbon atoms. Among them, it is preferable that the substituents represented by the general formula (A-1) independently independently substitute R " ₁₂ and R _'12 , and the more preferable ones are the substituents independently represented by the general formula (A-1). R _"12 and _{R '12, R" 11,} R "13 ~ R" 18, R' 11, R '13 ~ R' 18 is a hydrogen atom, it can be a substituent having a carbon number of alkyl group having 1 to 18 It is particularly preferred that the substituents represented by the general formula (A-1) independently substitute R " ₁₂ and R _'12 , R" _11, R " ₁₃ ~ R" ₁₈ , R' _11, R _'13 ~ R _'18 is a hydrogen atom.

Y each independently represents a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom, and these may further have a substituent. That is, Y represents a divalent linking group containing a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom. Among them, -C (R _'21 ) (R' ₂₂ )-, -Si (R _'23 ) (R' ₂₄ )-, -N (R _'20 )-, and more preferably -C (R _{'21) (R' 22)} -, - N (R '20) -, particularly preferably is _{-C (R' 21) (R} '22) -.

R _'20 to R' ₂₄ each independently represent a hydrogen atom, a halogen atom, or an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amine group, or a mercapto group which may have a substituent. Specific examples of the further substituent include the substituent W. R _'20 to R' _{24 are} preferably a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group which may have a substituent, more preferably a hydrogen atom and a carbon number of 1 to 18 which may also have a substituent. Alkyl group, aryl group having 6 to 18 carbon atoms, or heterocyclic group having 4 to 16 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 18 carbon atoms which may have a substituent Particularly preferred is an alkyl group having 1 to 18 carbon atoms.

Ra ₁ to Ra ₈ in the general formula (A-1) each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amine group, or a mercapto group which may have a substituent. Specific examples of the further substituent include the substituent W. Moreover, a plurality of these substituents may be bonded to each other to form a ring.

Ra ₁ to Ra _{8 are} preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heterocyclic group having 4 to 16 carbon atoms, and more preferably Is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 14 carbon atoms, and more preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 6 to 10 carbon atoms Aryl. Alkyl groups may also have branches.

Preferable specific examples include a hydrogen atom, methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, phenyl, or naphthyl.

Further, it is particularly preferable that Ra ₃ and Ra ₆ are hydrogen atoms or alkyl groups having 1 to 6 carbon atoms, and Ra ₁ , Ra ₂ , Ra ₄ , Ra ₅ , Ra ₇ , and Ra ₈ are hydrogen atoms.

Xa represents a single bond, an oxygen atom, a sulfur atom, an alkylene group, a silylene group, an alkenyl group, a cycloalkylene group, a cycloalkenyl group, an alkylene group, a divalent heterocyclic group, or an imino group, and these It may further have a substituent.

Xa is preferably a single bond, an alkylene group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an arylene group having 6 to 14 carbon atoms, and a heterocyclic ring having 4 to 13 carbon atoms. Group, oxygen atom, sulfur atom, imine group (for example, phenylimide group, methylimide group, third butyl group) having a hydrocarbon group (preferably aryl group or alkyl group) having 1 to 12 carbon atoms Imine), or silylene, more preferably a single bond, an oxygen atom, and an alkylene group having 1 to 6 carbon atoms (e.g., methylene, 1,2-ethylene, 1,1-dimethyl) Methylene), an alkenyl group having 2 carbon atoms (e.g. -CH ₂ = CH _2- ), and an arylene group having 6 to 10 carbon atoms (e.g. 1,2-phenylene, 2,3-phenylene) Naphthyl), or silylene, and more preferably a single bond, an oxygen atom, or an alkylene group having 1 to 6 carbon atoms (e.g., methylene, 1,2-ethylene, 1,1-dimethyl) Methylene). These substituents may further have a substituent W.

Specific examples of the group represented by the general formula (A-1) include the following examples of N1 to N11 示 基。 Showed base. But it is not limited to these bases. The group represented by the general formula (A-1) is preferably N-1 to N-7, more preferably N-1 to N-6, more preferably N-1 to N-3, and particularly preferably It is N-1 ~ N-2, and the best is N-1.

In the substituent (S ₁₁ ), R ′ ₁ represents a hydrogen atom or an alkyl group. R _'1 is preferably methyl, ethyl, propyl, isopropyl, butyl, or tert-butyl, more preferably methyl, ethyl, propyl, isopropyl, or tertiary butyl The methyl group is more preferably a methyl group, an ethyl group, an isopropyl group, or a third butyl group, and particularly preferably a methyl group, an ethyl group, or a third butyl group.

R ' ₂ represents a hydrogen atom or an alkyl group. R ′ _{2 is} preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, or a third butyl group, and still more preferably a hydrogen atom, a methyl group, an ethyl group, or a propyl group, More preferred are a hydrogen atom and a methyl group, and particularly preferred is a methyl group.

R ' ₃ represents a hydrogen atom or an alkyl group. R _'3 is preferably a hydrogen atom, or a methyl, more preferably methyl.

R ' ₁ to R' ₃ may be bonded to each other to form a ring. In the case of forming a ring, the number of ring members is not particularly limited, and a 5-member ring or a 6-member ring is preferable, and a 6-member ring is more preferable.

S ₁₁ represents the aforementioned substituent (S ₁₁ ), and is substituted as any one of Ra ₁ to Ra ₈ . It is preferable that at least any one of Ra ₃ and Ra ₆ in the general formula (A-1) independently represents the substituent (S ₁₁ ).

The substituents (S ₁₁ ) are preferably the following (a) to (x), more preferably (a) to (j), more preferably (a) to (h), and particularly preferably (a) to (f), more preferably (a) to (c), and most preferably (a).

[Chemical 28]

n 'each independently represents an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 2, even more preferably 1 to 2, and particularly preferably 2.

The general formula (A-1) may be a group represented by the following general formula (A-3), a group represented by the following general formula (A-4), or a group represented by the following general formula (A-5) Represented base.

[Chemical 29]

(In general formula (A-3) to general formula (A-5), Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , Ra ₅₅ to Ra ₅₈ each independently represent a hydrogen atom. , Halogen atom, or alkyl group, which may further have a substituent. * Indicates a bonding position. Xc ₁ , Xc ₂ , and Xc ₃ each independently represent a single bond, an oxygen atom, a sulfur atom, an alkylene group, or an alkylene group. Silyl group, alkenyl group, cycloalkylene group, cycloalkenyl group, arylene group, divalent heterocyclic group, or imino group, which may further have a substituent. Z ₃₁ , Z ₄₁ , and Z ₅₁ each independently represents a cycloalkyl ring, an aromatic hydrocarbon ring, or an aromatic heterocyclic ring, and these may further have a substituent)

In the general formulae (A-3) to (A-5), Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , and Ra ₅₅ to Ra ₅₈ each independently represent a hydrogen atom, A halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), or an alkyl group. Considering the reason that if the substituent is low in polarity, the hole is facilitated, a hydrogen atom or an alkyl group is preferred, and a hydrogen atom is more preferred.

When Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , Ra ₅₅ to Ra ₅₈ represent alkyl groups, the alkyl group is preferably an alkyl group having 1 to 18 carbon atoms. An alkyl group having 1 to 12 carbon atoms is more preferable, and an alkyl group having 1 to 6 carbon atoms is even more preferable. Specifically, methyl, ethyl, propyl, butyl, hexyl, or cyclohexyl is preferred.

In the general formulae (A-3) to (A-5), the adjacent groups in Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , and Ra ₅₅ to Ra ₅₈ are adjacent to each other. They may also be bonded to each other to form a ring. Examples of the ring include the aforementioned ring R. The ring is preferably a benzene ring, a naphthalene ring, an anthracene ring, a pyridine ring, a pyrimidine ring, or the like.

Xc ₁ , Xc ₂ , and Xc ₃ each independently represent a single bond, an oxygen atom, a sulfur atom, an alkylene group, a silylene group, an alkenyl group, a cycloalkylene group, a cycloalkenyl group, an alkylene group, or a divalent group. Heterocyclyl, or imino. When Xc ₁ , Xc ₂ , and Xc ₃ represent an alkylene group, a silylene group, an alkylene group, a cycloalkylene group, a cycloalkenyl group, an alkylene group, a divalent heterocyclic group, or an imino group These may further have a substituent. Examples of the further substituent include the substituent W.

Xc ₁ , Xc ₂ , and Xc _{3 are} preferably a single bond, an alkylene group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an arylene group having 6 to 14 carbon atoms, and carbon. Heterocyclic groups of 4 to 13, oxygen atoms, sulfur atoms, imine groups (e.g., phenylimide, methyl) having a hydrocarbon group (preferably aryl or alkyl) of 1 to 12 carbons Imino, third butylimino), more preferably a single bond, 1 to 6 carbon alkylene (e.g., methylene, 1,2-ethylene, 1,1-dimethyl) Methylene), an alkenyl group having 2 carbon atoms (e.g. -CH ₂ = CH _2- ), and an arylene group having 6 to 10 carbon atoms (e.g. 1,2-phenylene, 2,3-phenylene) Naphthyl).

Z ₃₁ , Z ₄₁ , and Z ₅₁ each independently represent a cycloalkyl ring, an aromatic hydrocarbon ring, or an aromatic heterocyclic ring. In the general formulae (A-3) to (A-5), Z ₃₁ , Z ₄₁ , and Z _{51 are} condensed with a benzene ring. Considering the reason that the high heat resistance and high hole transmission ability of the photoelectric conversion element can be expected, it is preferable that Z ₃₁ , Z ₄₁ , and Z ₅₁ are aromatic hydrocarbon rings.

The electron blocking film may be composed of a plurality of films.

The electron blocking film may also use an inorganic material. In general, the dielectric constant of an inorganic material is larger than that of an organic material. Therefore, when it is used in an electron blocking film, a large amount of voltage is applied to the photoelectric conversion film, which can improve the photoelectric conversion efficiency. Materials that can be used as electron blocking films include calcium oxide, chromium oxide, chromium oxide copper, manganese oxide, cobalt oxide, nickel oxide, copper oxide, gallium copper oxide, copper strontium oxide, niobium oxide, molybdenum oxide, indium copper oxide, Indium silver oxide, iridium oxide, etc. When the electron blocking film is a single layer, the layer may be a layer including an inorganic material, or in the case of a plurality of layers, one or two or more layers may be a layer including an inorganic material.

(Hole blocking film)

Electron-accepting organic materials can be used in the hole blocking film.

Electron-accepting materials can be derived from oxadiazole derivatives such as 1,3-bis (4-third butylphenyl-1,3,4-oxadiazolyl) benzene (OXD-7), and anthraquinone dimethane Compounds, biphenylquinone derivatives, bathhoproproine, bathhophenanthroline, and their derivatives, triazole compounds, tris (8-hydroxyquinoline) aluminum complexes, bis (4 -Methyl-8-quinoline) aluminum complex, distyryl aromatic hydrocarbon derivative, silapentadiene (silole) compounds and the like. And, it ’s not just electron-accepting organic materials. Materials having sufficient electron-transport properties can also be used. A porphyrin-based compound or a styrene-based system such as DCM (4-dicyanomethylene-2-methyl-6- (4- (dimethylaminostyryl))-4H pyran) can be used Compound, 4H pyran compound. Specifically, compounds described in [0073] to [0078] of Japanese Patent Laid-Open No. 2008-72090 are preferable.

The method for manufacturing the charge blocking film is not particularly limited, and a film can be formed by a dry film formation method or a wet film formation method. As the dry film formation method, a vapor deposition method, a sputtering method, or the like can be used. The vapor deposition may be any one of physical vapor deposition (PVD) and chemical vapor deposition (CVD). Physical vapor deposition such as vacuum vapor deposition is preferred. The wet film forming method can be inkjet method, spray method, nozzle printing method, spin coating method, dip coating method, casting method, die coating method, roll coating method, bar coating method, gravure printing coating method, etc. From the viewpoint of precision patterning, the inkjet method is preferred.

The thickness of the charge blocking film (electron blocking film and hole blocking film) is preferably 10 nm to 200 nm, more preferably 30 nm to 150 nm, and particularly preferably 50 nm to 100 nm. The reason is that if the thickness is too thin, the dark current suppression effect is reduced; if it is too thick, the photoelectric conversion efficiency is reduced.

[Substrate]

The photoelectric conversion element may further include a substrate. The type of the substrate used is not particularly limited, and a semiconductor substrate, a glass substrate, or a plastic substrate can be used.

In addition, the position of the substrate is not particularly limited, and generally a conductive film, a photoelectric conversion film, and a transparent conductive film are sequentially laminated on the substrate.

[Sealing layer]

The photoelectric conversion element may further include a sealing layer. The photoelectric conversion material has a phenomenon that significantly deteriorates its performance due to the presence of degradation factors such as water molecules, which can be prevented by the following methods: dense metal oxides, metal nitrides, and metal oxynitrides that are impermeable to water molecules A sealing layer such as ceramic or diamond-like carbon (DLC) covers the entire photoelectric conversion film and seals it.

The sealing layer can be selected and manufactured in accordance with the description in paragraphs [0210] to [0215] of Japanese Patent Laid-Open No. 2011-082508.

[Light sensor]

The use of the photoelectric conversion element includes, for example, a photovoltaic cell and a light sensor. The photoelectric conversion element of the present invention is preferably used as a light sensor. The light sensor may be a light sensor using the above-mentioned photoelectric conversion element alone. Preferably, the above-mentioned photoelectric conversion element is configured as a linear line sensor or a two-dimensional sensor arranged on a plane. Morphological light sensor. In the on-line sensor of the photoelectric conversion element of the present invention, the optical system and the driving unit are used to convert the optical image information into an electric signal, such as a scanner, and function as a photographic element. In a two-dimensional sensor, Like a photographing module, an optical system forms an image on a sensor, and converts light image information into an electrical signal to function as a photographing element.

Since a photovoltaic cell is a power generation device, the efficiency of converting light energy into electrical energy becomes an important performance, but as a current in a dark place, that is, a dark current, there is no functional problem. In addition, it is not necessary to provide a subsequent heating step such as a color filter. As a light sensor, it is important to convert light and dark signals into electrical signals with high accuracy. The efficiency of conversion to current is also an important performance. If a signal is output in a dark place, it becomes noise, so a low dark current is required. In addition, tolerance to subsequent steps is also important.

[Photographic element]

Next, a configuration example of a photographing element including the photoelectric conversion element 10a will be described.

In addition, in the configuration examples described below, descriptions of components having a structure equivalent to or equivalent to the components already described and functions are simplified or omitted by attaching the same or equivalent symbols to the drawings.

The so-called photographic element is an element that converts the optical information of an image into an electrical signal. It means that a plurality of photoelectric conversion elements are arranged on the matrix in the same plane. The optical signals can be converted into electrical signals in each photoelectric conversion element (pixel). , And output the electric signal to the elements outside the photographing element successively for each pixel. Therefore, each pixel contains one photoelectric conversion element and one or more transistors.

FIG. 2 is a schematic cross-sectional view illustrating a schematic configuration of an imaging element according to an embodiment of the present invention. This photographing element can be used by being mounted in photographing devices such as digital cameras and digital video recorders, photographing modules such as electronic endoscopes and mobile phones.

This photographic element includes a plurality of photoelectric conversion elements having a structure as shown in FIG. 1 (a) and FIG. 1 (b), and a reading circuit formed in the photoelectric conversion film of the reading circuit and each photoelectric conversion element. (The signal corresponding to the generated electric charge) circuit board, on the same surface above the circuit board, a plurality of photoelectric conversion elements are arranged in one dimension Shape or two-dimensional shape.

The imaging element 100 shown in FIG. 2 includes a substrate 101, an insulating layer 102, a connection electrode 103, a pixel electrode (lower electrode) 104, a connection portion 105, a connection portion 106, a photoelectric conversion film 107, and a counter electrode (upper electrode). 108, a buffer layer 109, a sealing layer 110, a color filter (CF) 111, a separator 112, a light shielding layer 113, a protective layer 114, a counter electrode voltage supply unit 115, and a readout circuit 116.

The pixel electrode 104 has the same function as the lower electrode 11 of the photoelectric conversion element 10a shown in FIGS. 1 (a) and 1 (b). The counter electrode 108 has the same function as the upper electrode 15 of the photoelectric conversion element 10 a shown in FIGS. 1 (a) and 1 (b). The structure of the photoelectric conversion film 107 is the same as the layer provided between the lower electrode 11 and the upper electrode 15 of the photoelectric conversion element 10a shown in FIGS. 1 (a) and 1 (b).

The substrate 101 is a semiconductor substrate such as a glass substrate or Si. An insulating layer 102 is formed on the substrate 101. A plurality of pixel electrodes 104 and a plurality of connection electrodes 103 are formed on the surface of the insulating layer 102.

The photoelectric conversion film 107 is a layer common to all the photoelectric conversion elements provided on the plurality of pixel electrodes 104 and covering them.

The counter electrode 108 is one electrode common to all photoelectric conversion elements provided on the photoelectric conversion film 107. The counter electrode 108 is formed on the connection electrode 103 disposed outside the photoelectric conversion film 107 and is electrically connected to the connection electrode 103.

The connection portion 106 is a plug or the like buried in the insulating layer 102 and used to electrically connect the connection electrode 103 and the counter electrode voltage supply portion 115. Counter electrode The voltage supply section 115 is formed on the substrate 101 and applies a predetermined voltage to the counter electrode 108 via the connection section 106 and the connection electrode 103. When the voltage to be applied to the counter electrode 108 is higher than the power supply voltage of the imaging element, the power supply voltage is boosted by a booster circuit such as a charge pump to supply the predetermined voltage.

The readout circuit 116 is provided on the substrate 101 in correspondence with each of the plurality of pixel electrodes 104, and reads out a signal corresponding to the electric charge captured by the corresponding pixel electrode 104. The readout circuit 116 includes, for example, a Charge Coupled Device (CCD), a Complementary Metal Oxide Semiconductor (CMOS) circuit, or a Thin-Film Transistor (TFT) circuit. A light shielding layer (not shown) arranged in the layer 102 blocks light. The readout circuit 116 is electrically connected to the corresponding pixel electrode 104 through the connection portion 105.

The buffer layer 109 covers the counter electrode 108 and is formed on the counter electrode 108. The sealing layer 110 covers the buffer layer 109 and is formed on the buffer layer 109. The color filter 111 is formed at a position opposed to each pixel electrode 104 on the sealing layer 110. The spacer 112 is provided between the color filters 111 to improve the light transmission efficiency of the color filters 111.

The light shielding layer 113 is formed on a region other than the region where the color filter 111 and the spacer 112 are provided on the sealing layer 110, and prevents light from entering the photoelectric conversion film 107 formed outside the effective pixel region. The protective layer 114 is formed on the color filter 111, the spacer 112, and the light-shielding layer 113, and protects the entire imaging element 100.

In the imaging element 100 configured as described above, when light is incident, Light is incident on the photoelectric conversion film 107, and charges are generated there. The hole in the generated electric charge is captured by the pixel electrode 104, and a voltage signal corresponding to the amount of the hole is output by the readout circuit 116 to the outside of the imaging element 100.

The manufacturing method of the imaging element 100 is as follows.

A connection portion 105, a connection portion 106, a plurality of connection electrodes 103, a plurality of pixel electrodes 104, and an insulating layer 102 are formed on a circuit substrate on which a counter electrode voltage supply portion 115 and a readout circuit 116 are formed. The plurality of pixel electrodes 104 are arranged on the surface of the insulating layer 102 in a square grid shape, for example.

Next, a photoelectric conversion film 107 is formed on the plurality of pixel electrodes 104 by, for example, a vacuum heating evaporation method. Next, the counter electrode 108 is formed on the photoelectric conversion film 107 under a vacuum by, for example, a sputtering method. Next, a buffer layer 109 and a sealing layer 110 are sequentially formed on the counter electrode 108 by, for example, a vacuum heating evaporation method. Next, after forming the color filter 111, the spacer 112, and the light-shielding layer 113, a protective layer 114 is formed to complete the imaging device 100.

In the manufacturing method of the photographic element 100, a step of placing the photographic element 100 in the process of production under a non-vacuum may be added between the step of forming the photoelectric conversion film 107 and the step of forming the sealing layer 110 to prevent multiple photoelectric conversions. The performance of the component is deteriorated. By adding this step, it is possible to prevent performance degradation of the imaging element 100 and suppress manufacturing costs.

[Example]

Examples are shown below, but the present invention is not limited to these examples.

(Synthesis of Compound D3)

In a 100 mL three-neck round bottom flask, 5.46 g (30 mmol) of p-bromobenzonitrile, 20 mL of tertiary pentanol, and 5.05 g (45 mmol) of potassium tert-butoxide were added, and heated to 95 ° C. while stirring. To this mixture, a solution in which 2.73 g (13.5 mmol) of diisopropyl succinate was dissolved in 3 mL of third pentanol was added dropwise over 25 minutes. After the dropwise addition, the reaction mixture was heated under reflux for 4 hours, followed by cooling to 50 ° C. 15 mL of water and 15 mL of methanol were added to the mixture, and the mixture was stirred for 30 minutes, and the precipitate was collected by filtration. The obtained red powder was washed with 50% aqueous methanol and water, and vacuum-dried at 80 ° C to obtain 3.0 g (yield 50%) of Compound 1 as a red powder.

A 200 mL three-necked round-bottom flask was charged with Compound 1 (1.0 g, 2.24 mmol), potassium carbonate 1.24 g (8.97 mmol), and 35 mL of N-methylpyrrolidone, and the mixture was stirred at room temperature for 30 minutes under a nitrogen atmosphere. Next, 4.07 g (28.7 mmol) of methyl iodide was added and the mixture was stirred at room temperature for 1 hour. Further, 3.18 g (22.4 mmol) of methyl iodide was added, and the mixture was heated to 55 ° C. and stirred for 5 hours. cool down After reaching room temperature, 100 mL of water was added, and the obtained solid was collected by filtration. Purification was performed by silica gel column chromatography to obtain 319 mg (yield 30%) of Compound 2 as an orange powder.

In a 100 mL three-necked round-bottomed flask, compound 2 (0.3 g, 0.63 mmol), Pd ₂ (dba) ₃ 50 mg, 1,1'-bis (diphenylphosphine) ferrocene (1,1'-Bis (diphenylphosphino) ) ferrocene (DPPF) 30 mg, xylene 15 mL, and stirred under a nitrogen environment at room temperature for 15 minutes. Diphenylamine 0.32 g (1.89 mmol) and sodium tert-butoxide 0.9 g (9.45 mmol) were added, and the mixture was stirred at 100 ° C. for 7 hours, and then cooled to room temperature. Water and ethyl acetate were added to the reaction mixture, the organic layer was extracted, and the solvent was distilled off. Purification by silica gel column chromatography gave 0.26 g (64% yield) of D3 as a reddish brown powder.

In addition, the compounds D1 to D2 and D4 to D14 to be described later can be synthesized by referring to the method for synthesizing the compound D3 and a known method.

The compounds (D1 to D14, RD1 to RD4) used in the examples and comparative examples are collectively shown below.

[Chemical 31]

[Chemical 32]

<Production of photoelectric conversion element>

A photoelectric conversion element in the form of FIG. 1 (a) was produced. Here, the photoelectric conversion element It includes a lower electrode 11, an electron blocking film 16A, a photoelectric conversion film 12, and an upper electrode 15.

Specifically, the lower electrode 11 (thickness: 30 nm) was formed by forming an amorphous ITO film on a glass substrate by a sputtering method, and the following compound was further formed on the lower electrode 11 by a vacuum heating evaporation method ( EB-1) to form an electron blocking film 16A (thickness: 100 nm). In a state where the substrate temperature was controlled to 25 ° C, the above compounds (D1 to D14, RD1 to RD4) and fullerene (C ₆₀ ) were converted to 100 nm on a single-layer basis on the electron blocking film 16A. At 300 nm, a film was formed by co-evaporation by vacuum heating vapor deposition, and a photoelectric conversion film 12 was formed. Further, an amorphous ITO was formed on the photoelectric conversion film 12 by a sputtering method to form an upper electrode 15 (transparent conductive film) (thickness: 10 nm). After forming a SiO film as a sealing layer on the upper electrode 15 by heating evaporation, an aluminum oxide (Al ₂ O ₃ ) layer is formed thereon by an atomic layer chemical vapor deposition (ALCVD) method. Production of photoelectric conversion elements.

<Element heat resistance>

The obtained elements were thermally annealed in a nitrogen atmosphere on a 150 ° C hot plate for 20 minutes, and the dark current was measured after returning to room temperature. The increase rate of the dark current from before the annealing was [{(after annealing) Dark current value-Dark current value before annealing) / Dark current value before annealing} × 100 (%)] When the value is less than 5%, it is regarded as "A", and when it is 5% or more and less than 10%, it is regarded as "B", Cases exceeding 10% are described as "C" in the "Heat resistance" column of Table 1. In addition, it must be A or B practically.

<Evaluation of response speed (98% signal rise time)>

The relative response speed (rising time from 0 to 98% signal intensity) when an electric field of 2 × 10 ⁵ V / cm was applied to the photoelectric conversion element in the obtained solid-state imaging element was measured, and Example 1 was set to 1 to obtain The relative value is described in the "Response speed (relative value)" column in Table 1. When measuring the photoelectric conversion performance of each element, light was incident from the upper electrode (transparent conductive film) side. The method of obtaining the relative value is shown below.

(Set Example 1 to a relative value of 1.)

= [Rise time from 0 to 98% signal strength in Example (or Comparative Example) X] / [Rise time from 0 to 98% signal strength in Example 1]

In addition, practically, it is preferably within 20, and more preferably within 5.

As shown in Table 1 above, it was confirmed that the photoelectric conversion element of the present invention exhibits excellent heat resistance and responsiveness.

For example, it can be seen from the comparison of Examples 1 to 14 that if Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and When at least one of R ¹⁴ is bonded to each other to form a ring, the heat resistance is more excellent.

Further, it is known from the comparison between Example 1 and Example 5 that at least one of Ar ¹ and R ¹¹ , Ar ¹ and R ^12, and R ¹¹ and R ¹² in the general formulae (1) to (3) was confirmed. When a ring is bonded to each other, at least one of Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and R ¹⁴ is bonded to each other to form a ring (equivalent to Example 1), and the response is more excellent. .

Furthermore, it can be seen from the comparison between Example 4 and Example 6 that Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and R were confirmed. ^In the case where ¹⁴ is directly bonded without a linking group (corresponding to Example 6), the responsiveness is more excellent.

Further, it is known from the comparison between Example 3 and Example 7 that when X ¹ and X ² are O (oxygen atom) (corresponding to Example 3), the response speed and heat resistance are more excellent.

Further, it is found from a comparison between Example 1 and Example 8 that when Ar ¹ and Ar ² are arylene groups (equivalent to Example 1), the response is more excellent.

On the other hand, when the RD1 used in the Example column of Patent Document 1 was used (compared to Comparative Example 1), it was confirmed that the heat resistance and responsiveness were poor.

Furthermore, when using RD2 in which R ¹ and R ² in the general formulae (1) to (3) were hydrogen atoms (corresponding to Comparative Example 2), it was confirmed that the response was poor.

In addition, when using RD3 in which R ¹¹ to R ¹⁴ in the general formulae (1) to (3) were alkyl groups (corresponding to Comparative Example 3), the response was poor.

Moreover, when RD4 which does not have an amine group is used (equivalent to the comparative example 4), a compound is decomposed during vapor deposition, and a photoelectric conversion film cannot be manufactured at all.

In addition, RD2 and RD3 correspond to the exemplified compound (19) and the exemplified compound (71) disclosed in Japanese Patent Laid-Open No. 2010-192782, and RD4 corresponds to that described in Example 6 of Japanese Patent Laid-Open No. 2003-346926. Used compounds.

<Production of Photographic Elements>

An imaging element having the same configuration as that shown in FIG. 2 was produced. That is, by sputtering After forming an amorphous TiN film on the CMOS substrate at 30 nm, the photodiode method was used to pattern the photodiodes (PD) on the CMOS substrate in such a manner that there is one pixel each to form a lower portion. The electrodes were produced in the same manner as in Examples 1 to 14 and Comparative Examples 1 to 4 after the formation of the electron blocking material. The evaluation was performed in the same manner, and the same results as in Table 1 were obtained. It was found that the imaging element is suitable for manufacturing and exhibits excellent performance.

10a‧‧‧photoelectric conversion element

11‧‧‧Lower electrode (conductive film)

12‧‧‧photoelectric conversion film

15‧‧‧upper electrode (transparent conductive film)

16A‧‧‧Electronic blocking film

Claims (8)

A photoelectric conversion element is a photoelectric conversion element in which a conductive film, a photoelectric conversion film including a photoelectric conversion material, and a transparent conductive film are sequentially laminated, and the photoelectric conversion material includes a component selected from the group consisting of the formula (1) At least one compound X of the group consisting of a compound, a compound represented by general formula (2), and a compound represented by general formula (3); and the photoelectric conversion film further includes an organic n-type compound;

In the general formulae (1) to (3), R ¹ and R ² each independently represent an alkyl group, an aryl group, or a heteroaryl group; R ¹¹ , R ¹² , R ^13, and R ¹⁴ each independently represent an alkyl group. , Aryl or heteroaryl; Ar ¹ and Ar ² each independently represent an aryl or heteroaryl; and at least one of R ¹¹ and R ¹² and at least one of R ¹³ and R ¹⁴ represent an aryl or Heteroaryl; X ¹ and X ² each independently represent O, S, or NR ^A ; R ^A represents an alkyl group, an aryl group, or a heteroaryl group; Q represents a group selected from the group consisting of the general formula (A) to the general formula (E) R ^Q1 ~ R ^Q22 each independently represent a hydrogen atom or a substituent; n represents 0 or 1; In addition, Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , At least one of Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and R ¹⁴ are bonded to each other to form a ring;

The photoelectric conversion element according to item 1 of the scope of patent application, wherein the compound X is a compound represented by the general formula (4);

In the general formula (4), R ¹ and R ² each independently represent an alkyl group, an aryl group, or a heteroaryl group; R ¹¹ , R ¹² , R ^13, and R ¹⁴ each independently represent an alkyl group, an aryl group, or a heteroaryl group. Ar ¹ and Ar ² each independently represent an aryl or heteroaryl group; and at least one of R ¹¹ and R ¹² and at least one of R ¹³ and R ¹⁴ each represent an aryl group or a heteroaryl group; X ¹ And X ² each independently represent O, S, or NR ^A ; R ^A represents an alkyl group, an aryl group, or a heteroaryl group; In addition, Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar At least one of ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and R ¹⁴ are bonded to each other to form a ring. The photoelectric conversion element according to item 1 or item 2 of the scope of patent application, wherein X ¹ and X ² are O. The photoelectric conversion element according to item 1 of the scope of patent application, wherein the organic n-type compound includes fullerenes, and the fullerenes are selected from the group consisting of fullerenes and derivatives thereof. The photoelectric conversion element according to item 4 of the scope of patent application, wherein the molar ratio of the compound X to the fullerenes (the molar amount of the fullerenes / the molar amount of the compound X) is 1.0. the above. The photoelectric conversion element according to claim 1 or claim 2, wherein a charge blocking film is disposed between the conductive film and the transparent conductive film. A photographic element includes the photoelectric conversion element according to any one of claims 1 to 6 of the scope of patent application. A light sensor includes the photoelectric conversion element according to any one of claims 1 to 6 of the scope of patent application.