TWI632203B - Photoelectric conversion element, optical sensor and image capture element - Google Patents

Abstract

An object of the present invention is to provide a photoelectric conversion element which is excellent in responsiveness and exhibits high photoelectric conversion efficiency, which can be produced by vapor deposition, a photosensor including the photoelectric conversion element, and an image pickup element. The photoelectric conversion element of the present invention includes, in order, a conductive film, a photoelectric conversion film containing a photoelectric conversion material, and a transparent conductive film, and the photoelectric conversion material contains the compound (A) and the n-type semiconductor represented by the following formula (1). .

Description

Photoelectric conversion element, photo sensor and imaging element

The present invention relates to a photoelectric conversion element, a photo sensor, and an image pickup element.

A conventional photosensor is an element in which a photodiode (PD) is formed in a semiconductor substrate such as bismuth (Si). For a solid-state imaging device, PD is widely used and is read by a circuit. A planar solid-state imaging element that emits signal charges generated by each PD.

In order to realize a color solid-state imaging device, a color filter that transmits light of a specific wavelength is disposed on the light incident surface side of the planar solid-state imaging device. At present, a single-plate solid-state imaging device is widely used in a digital camera or the like, and blue (B) light is regularly arranged on each of two PDs arranged two-dimensionally. , green (G) light, red (R) light through the color filter.

In addition, in recent years, development of a solid-state imaging device having a structure in which a photoelectric conversion film is formed on a signal reading substrate has been underway.

For such a solid-state imaging element or a photoelectric conversion element using a photoelectric conversion film In other words, responsiveness and photoelectric conversion efficiency are especially considered as topics.

For example, Patent Document 1 discloses a photoelectric conversion element containing a compound having a specific structure.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-40280

In the above, the inventors of the present invention produced a photoelectric conversion element using the compound used in the examples of Patent Document 1, and as a result, it was confirmed that the compound was decomposed by vapor deposition, and the element could not be produced.

Therefore, in view of the above circumstances, an object of the present invention is to provide a photoelectric conversion element which can be produced by vapor deposition, which is excellent in responsiveness and exhibits high photoelectric conversion efficiency.

Another object of the present invention is to provide a photo sensor and an image pickup element including the photoelectric conversion element.

In order to solve the problem, the present inventors have conducted intensive studies, and as a result, it has been found that the compound (A) and the n-type semiconductor represented by the formula (1) described below are used as a photoelectric conversion material, and excellent responsiveness is exhibited. The present invention has been completed by a photoelectric conversion element which can be produced by vapor deposition with high photoelectric conversion efficiency. That is, the inventors of the present invention have found that the above problems can be solved by the following configuration.

(1) A photoelectric conversion element comprising, in order, a conductive film, a photoelectric conversion film containing a photoelectric conversion material, and a transparent conductive film, wherein the photoelectric conversion material contains the compound (A) represented by the following formula (1) and N-type semiconductor,

(In the formula (1), R ¹ to R ⁶ each independently represent a hydrogen atom or a substituent; and R ¹ and R ² , R ³ and R ⁴ may be bonded to each other to form a ring; and Ar ¹ and Ar ² are each independently The aryl group which may have a substituent or the heteroaryl group which may have a substituent; Ar ¹ and Ar ² , Ar ¹ and R ¹ , and Ar ² and R ⁶ may be bonded to each other to form a ring; X represents a group of free oxygen atoms, sulfur atoms, >CR ^C1 R ^C2 , >NR ^N1 and >SiR ^Si1 R ^Si2 ; where R ^C1 , R ^C2 , R ^N1 , R ^Si1 and R ^Si2 are independent The ground represents a hydrogen atom or a substituent; A represents a group selected from the group consisting of an oxygen atom, a sulfur atom, =CR ^C3 R ^C4 and =NR ^N2 ; here, R ^C3 , R ^C4 and R ^N2 are independently A hydrogen atom or a substituent; R ^C3 and R ^C4 may be bonded to each other to form a ring; when A is =NR ^N2 , R ^N2 and R ⁴ may be bonded to each other to form a ring; A has no carboxyl group and Hydroxyl).

(2) The photoelectric conversion element according to the above (1), wherein the X is an oxygen atom.

(3) The photoelectric conversion element according to the above (1), wherein the R ³ and the R ⁴ are bonded to each other to form a benzene ring.

The photoelectric conversion element according to any one of the above-mentioned (1), wherein the compound (A) is a compound (a1) represented by the following formula (2),

(In the formula (2), R ¹ , R ² , R ⁵ and R ⁶ each independently represent a hydrogen atom or a substituent; and R ⁷ to R ²⁰ each independently represent a hydrogen atom or a substituent; R ¹ and R ² , R ¹ and R ¹⁶ , R ⁶ and R ⁷ , R ¹¹ and R ¹² may be bonded to each other to form a ring; A represents a group selected from the group consisting of an oxygen atom, a sulfur atom, =CR ^C3 R ^C4 and =NR ^N2 In the above, R ^C3 , R ^C4 and R ^N2 each independently represent a hydrogen atom or a substituent; R ^C3 and R ^C4 may be bonded to each other to form a ring; A does not have a carboxyl group or a hydroxyl group).

The photoelectric conversion element according to any one of the above-mentioned (1), wherein the A is an oxygen atom or a group represented by the following formula (Z1),

(In the formula (Z1), Z is a ring containing at least 2 carbon atoms, and represents a 5-membered ring, a 6-membered ring or a fused ring containing at least one of a 5-membered ring and a 6-membered ring; Z may have a substituent ; * indicates the bonding position; Z does not have a carboxyl group and a hydroxyl group).

(6) The photoelectric conversion element according to any one of (1) to (5) wherein the n-type semiconductor contains a fullerene selected from the group consisting of fullerenes and derivatives thereof class.

(7) The photoelectric conversion element according to the above (6), wherein the content of the fullerene relative to the total content of the compound (A) and the fullerene (= the fullerene The film thickness in a single layer conversion (the film thickness in a single layer of the compound (A) + the film thickness in the single layer of the fullerene) is 50% by volume or more .

The photoelectric conversion element according to any one of the above aspects of the present invention, wherein a charge blocking is disposed between the conductive film and the transparent conductive film Floor.

The photoelectric conversion element according to any one of the above-mentioned, wherein the light is incident on the photoelectric conversion film via the transparent conductive film.

The photoelectric conversion element according to any one of the above aspects, wherein the transparent conductive film contains a transparent conductive metal oxide.

(11) A photoelectric sensor comprising the photoelectric conversion element according to any one of (1) to (10) above.

(12) An image sensor comprising the photoelectric conversion element according to any one of (1) to (10) above.

As described below, according to the present invention, it is possible to provide a photoelectric conversion element which can be produced by vapor deposition, which is excellent in responsiveness and exhibits high photoelectric conversion efficiency.

Further, according to the present invention, a photosensor including the photoelectric conversion element and an image pickup element including the photoelectric conversion element can be provided.

10a, 10b‧‧‧ photoelectric conversion components

11‧‧‧lower electrode (conductive film)

12‧‧‧Photoelectric conversion film

15‧‧‧Upper electrode (transparent conductive film)

16A‧‧‧Electronic barrier

16B‧‧‧ hole barrier

100‧‧‧Photographic components

101‧‧‧Substrate

102‧‧‧Insulation

103‧‧‧Connecting electrode

104‧‧‧ pixel electrodes (lower electrode)

105‧‧‧Connecting Department

106‧‧‧Connecting Department

107‧‧‧Photoelectric conversion film

108‧‧‧ opposite electrode (upper electrode)

109‧‧‧buffer layer

110‧‧‧ Sealing layer

111‧‧‧Color Filter (CF)

112‧‧‧ partition wall

113‧‧‧Lighting layer

114‧‧‧Protective layer

115‧‧‧ Counter electrode voltage supply unit

116‧‧‧Readout circuit

1(a) and 1(b) are schematic cross-sectional views showing an embodiment of a photoelectric conversion element, respectively.

2 is a schematic cross-sectional view of a pixel of an image pickup element.

Figure 3 is a ¹ H-Nuclear Magnetic Resonance (NMR) spectrum of the compound of (3).

[Photoelectric Conversion Element]

The photoelectric conversion element of the present invention includes a conductive film, a photoelectric conversion film containing a photoelectric conversion material, and a transparent conductive film containing a compound (A) and an n-type semiconductor represented by the following formula (1).

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

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

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

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

Further, in the case of using the photoelectric conversion element 10a (10b), an electric field can be applied. In this case, it is preferable that the conductive film 11 and the transparent conductive film 15 form a pair of electrodes, and an electric field of 1 × 10 ^-5 V / cm to 1 × 10 ⁷ V / cm is applied between the pair of electrodes. More preferably, an electric field of 1 × 10 ^-4 V/cm to 1 × 10 ⁷ V/cm is applied. From the viewpoint of performance and power consumption, it is preferred to apply an electric field of 1 × 10 ^-4 V / cm to 1 × 10 ⁶ V / cm, more preferably 1 × 10 ^-3 V / cm - 5 × 10 ⁵ The electric field of V/cm.

Further, in the voltage application method, in FIGS. 1(a) and 1(b), it is preferable to apply a voltage such that the electron blocking layer 16A side serves as a cathode and the photoelectric conversion film 12 side becomes an anode. In the case where the photoelectric conversion element 10a (10b) is used as the photo sensor, in the case of being incorporated into the image pickup element, the application of the voltage can be performed by the same method.

Hereinafter, the aspects of the respective layers (photoelectric conversion film, lower electrode, upper electrode, electron blocking layer, hole blocking layer, and the like) constituting the photoelectric conversion element will be described in detail.

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

[Photoelectric conversion film]

The photoelectric conversion film is a film containing a compound (A) represented by the following formula (1) and an n-type semiconductor as a photoelectric conversion material.

It is considered that the compound (A) and the n-type semiconductor described later are used as a photoelectric conversion material in combination with the photoelectric conversion element of the present invention, and thus can be produced by vapor deposition, and exhibit excellent responsiveness and high photoelectric conversion efficiency.

Although the reason is not clear, it can be roughly estimated as follows.

As will be described later, the compound (A) has a structure in which a ring having an aromatic amine moiety bonded to a group represented by the above-mentioned A and having at least a tricyclic ring is condensed. It is considered that the aromatic amine moiety exhibits electron donating property (donating property), and the ring of the base bond represented by A, which is condensed by at least three rings, exhibits electron acceptability (acceptability). Speculation Good charge separation occurs in the molecules of the compound by absorption of light. Here, it is considered that the photoelectric conversion material of the present invention has an aromatic amine moiety, and the inter-electrode holes can be rapidly transferred, and the responsiveness is improved. In addition, in the present invention, an n-type semiconductor is used as a photoelectric conversion material in combination, so that electron transfer after exciton formation between the compound (A) and the n-type semiconductor proceeds rapidly, and the photoelectric conversion efficiency is high. Further, the reason why the responsiveness is improved as follows is that the crystallization is suppressed by using the compound (A) and the n-type semiconductor in combination. Further, as described later, the group represented by A does not have a carboxyl group or a hydroxyl group, and decomposition at the time of vapor deposition is suppressed.

As a result, it is considered that the photoelectric conversion element of the present invention can be produced by vapor deposition, and exhibits excellent responsiveness and high photoelectric conversion efficiency. In some cases, it can be estimated from the case of the comparative example described later, that is, when A has a carboxyl group (Comparative Example 1), it is decomposed during vapor deposition, and it is impossible to produce an element; in the case where triarylamine is not contained (Comparative Example 5) When the photoelectric conversion material does not contain an n-type semiconductor (Comparative Example 3 and Comparative Example 4), responsiveness and/or photoelectric conversion efficiency are insufficient.

<compound (A)>

In the photoelectric conversion element of the present invention, the compound (A) contained in the photoelectric conversion material is represented by the following formula (1).

[Chemical 4]

In the formula (1), R ¹ to R ⁶ each independently represent a hydrogen atom or a substituent. Examples of the substituent include a substituent W and the like which will be described later.

For the reason that the responsiveness is more excellent, at least one of R ¹ to R ⁶ is preferably a halogen atom (particularly a chlorine atom), and further preferably R ⁵ is a halogen atom (particularly a chlorine atom).

R ¹ and R ² , R ³ and R ⁴ may be bonded to each other to form a ring. Examples of the ring to be formed include a ring R and the like which will be described later. Among them, a benzene ring is preferred. The ring formed may have a substituent. Examples of the substituent include a substituent W and the like which will be described later.

For the reason that the responsiveness is more excellent, it is preferred that R ¹ and R ^{2 are} not bonded to each other to form a ring.

For the reason that the responsiveness is more excellent, it is preferred that R ³ and R ⁴ are bonded to each other to form a ring (particularly a benzene ring).

In the formula (1), Ar ¹ and Ar ² each independently represent an aryl group which may have a substituent or a heteroaryl group which may have a substituent. Examples of the substituent include a substituent W and the like which will be described later.

In the case where Ar ¹ or Ar ² is an aryl group, an aryl group having 6 to 30 carbon atoms is preferred, and an aryl group having 6 to 20 carbon atoms is more preferred. Specific examples of the ring constituting the aryl group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, an anthracene ring, a triphenylene ring, a condensed tetraphenyl ring, and a biphenyl ring (two phenyl groups can be arbitrarily linked). Link), bistriphenyl ring (3 benzene rings can be linked by any connection).

In the case where Ar ¹ or Ar ² is a heteroaryl group, a heteroaryl group containing a ring of 5 members, 6 members or 7 members or a condensed ring thereof is preferred. Examples of the hetero atom contained in the heteroaryl group include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the ring constituting the heteroaryl group include a furan ring, a thiophene ring, a pyrrole ring, a pyrroline ring, a pyrrolidine ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, and an imidazoline. Ring, imidazolium ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazan ring, tetrazole ring, pyran ring, thiene ring, Pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring, triazine ring, benzofuran ring, isobenzofuran ring, benzene And thiophene ring, thiophene thiophene ring, anthracene ring, porphyrin ring, isoindole ring, benzoxazole ring, benzothiazole ring, indazole ring, benzimidazole ring, quinoline ring, isoquine Phytoline, cinnoline ring, pyridazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, dibenzothiophene ring, indazole ring, dibenzopyran ring, acridine ring , pyridine ring, phenanthroline ring, phenazine ring, phenoxazine ring, thianthrene ring, pyridazine ring, quinazoline ring, Quinuclidine ring, naphthyridine ring, anthracene ring, acridine ring and the like.

Ar ¹ and Ar ² preferably each independently have an alkyl group, an aryl group or a heteroaryl group as a substituent, and further preferably have an aryl group as a substituent for the purpose of further excellent responsiveness. Specific examples and preferred aspects of the aryl group and the heteroaryl group are as described above.

Ar ¹ and Ar ² , Ar ¹ and R ¹ , Ar ² and R ⁶ may be bonded to each other to form a ring. Examples of the ring to be formed include a ring R and the like which will be described later. The ring formed may have a substituent. Examples of the substituent include a substituent W and the like which will be described later.

For the reason that the responsiveness is more excellent, it is preferred that Ar ¹ and Ar ^{2 are} not bonded to each other to form a ring.

For the reason that the responsiveness is more excellent, it is preferred that at least one of Ar ¹ and R ¹ , and Ar ² and R ⁶ are bonded to each other to form a ring.

In the formula (1), X represents a group selected from the group consisting of an oxygen atom (-O-), a sulfur atom (-S-), >CR ^C1 R ^C2 , >NR ^N1 and >SiR ^Si1 R ^Si2 . base. Here, R ^C1 , R ^C2 , R ^N1 , R ^Si1 and R ^Si2 each independently represent a hydrogen atom or a substituent. Examples of the substituent include a substituent W and the like which will be described later. The substituent is preferably a hydrocarbon group.

The hydrocarbon group may, for example, be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and among them, an aliphatic hydrocarbon group is preferred.

The aliphatic hydrocarbon group may be any of a linear chain, a branched chain, and a cyclic group. Specific examples of the aliphatic hydrocarbon group include a linear or branched alkyl group (particularly, a carbon number of 1 to 20), a linear or branched alkenyl group (particularly, a carbon number of 2 to 20), and a straight Chain or branched alkynyl groups (especially carbon number 2 to 20).

Examples of the aromatic hydrocarbon group include an aryl group, a naphthyl group and the like. Examples of the aryl group include an aryl group having 6 to 18 carbon atoms such as a phenyl group, a tolyl group and a xylyl group.

In the reason that the photoelectric conversion efficiency is further increased, X is preferably an oxygen atom.

In the formula (1), A represents a group selected from the group consisting of an oxygen atom, a sulfur atom, =CR ^C3 R ^C4 and =NR ^N2 . Here, R ^C3 , R ^C4 and R ^N2 each independently represent a hydrogen atom or a substituent. Examples of the substituent include, for example, a substituent W (excluding a carboxyl group and a hydroxyl group, and a substituent having a carboxyl group or a hydroxyl group) which will be described later.

For the reason that the responsiveness is more excellent, A is preferably a group selected from the group consisting of an oxygen atom, a sulfur atom, and =CR ^C3 R ^C4 , more preferably an oxygen atom or =CR ^C3 R ^C4 .

R ^C3 and R ^C4 may also be bonded to each other to form a ring. In the case where A is =NR ^N2 , R ^N2 and R ⁴ may be bonded to each other to form a ring. Examples of the ring to be formed include a ring R and the like which will be described later. The ring formed may have a substituent. Examples of the substituent include, for example, a substituent W (excluding a carboxyl group and a hydroxyl group, and a substituent having a carboxyl group or a hydroxyl group) which will be described later.

A does not have a carboxyl group (-COOH) and a hydroxyl group (-OH). That is, A is not a carboxyl group or a hydroxyl group, and is not a group having a carboxyl group or a hydroxyl group as a substituent.

For the reason that the responsiveness is more excellent, A is preferably an oxygen atom or a group represented by the following formula (Z1), and more preferably a group represented by the following formula (Z1). Further, the group represented by the following formula (Z1) is one aspect of the aspect in which R ^C3 and R ^C4 are bonded to each other to form a ring in the above-mentioned =CR ^C3 R ^C4 .

In the formula (Z1), Z is a ring containing at least two carbon atoms, and represents a 5-membered ring, a 6-membered ring, or a condensed ring containing at least one of a 5-membered ring and a 6-membered ring.

Such a ring is usually preferably used as an acid core in the merocyanine dye, and specific examples thereof include the following.

(a) a 1,3-dicarbonyl core: for example, a 1,3-decanedione core, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 1,3-dioxane-4,6-dione, and the like.

(b) Pyrazolinone core: for example, 1-phenyl-2-pyrazolin-5-one, 3-methyl-1-phenyl-2-pyrazolin-5-one, 1- (2-Benzothiazolyl)-3-methyl-2-pyrazoline-5-one and the like.

(c) Isoxazolinone nucleus: for example, 3-phenyl-2-isoxazolin-5-one, 3-methyl-2-isoxazolin-5-one, and the like.

(d) Hydroxamic nucleus: for example, 1-alkyl-2,3-dihydro-2-oxindole or the like.

(e) 2,4,6-Triketohexahydropyrimidine nucleus: for example, barbituric acid or 2-thiobarbituric acid and derivatives thereof. Examples of the derivative include 1-alkyl group such as 1-methyl group and 1-ethyl group, and 1,3-diyl group such as 1,3-dimethyl group, 1,3-diethyl group, and 1,3-dibutyl group. Alkyl, 1,3-diphenyl, 1,3-bis(p-chlorophenyl), 1,3-di(p-ethoxycarbonylphenyl), etc., 1,3-diaryl, 1-ethyl a 1-alkyl-1-aryl group such as -3-phenyl group, a 1,3-di-heterocyclic substituent such as 1,3-bis(2-pyridyl) or the like.

(f) 2-thio-2,4-tetrahydrothiazolidinedione core: for example, rhodamine and its derivatives. Examples of the derivative include 3-methyl rhodamine, 3-ethyl rhodamine, 3-allyl rhodamine, etc. 3-alkyl rhodamine, 3-phenyl rhodamine, etc. 3-aryl The base of the rhodamine, 3-(2-pyridyl)-rhodanine, etc., is substituted by rhodamine.

(g) 2-thio-2,4-oxazolidinedione (2-thio-2,4-(3H,5H)-oxazolidinedione) core: for example 3-ethyl-2-thio -2,4-oxazolidinedione and the like.

(h) Thianaphthenone core: for example, 3(2H)-thioxanthone-1,1-dioxide or the like.

(i) 2-thio-2,5-tetrahydrothiazolidinedione core: for example, 3-ethyl-2-thio-2,5-tetrahydrothiazolidinedione.

(j) 2,4-tetrahydrothiazolidinedione core: for example 2,4-tetrahydrothiazolidine, 3-ethyl-2,4-tetrahydrothiazolidine, 3-phenyl-2,4-tetra Hydrothiazole dione and the like.

(k) thiazolin-4-one core: for example, 4-thiazolinone, 2-ethyl-4-thiazolinone or the like.

(1) 2,4-imidazolidindione (ethylhydantoin) core: for example, 2,4-imidazolidinone, 3-ethyl-2,4-imidazolidinone, and the like.

(m) 2-thio-2,4-imidazolidindione (2-thioethyl carbazide) nucleus: for example 2-thio-2,4-imidazolidinone, 3-ethyl-2- Thio-2,4-imidazolidinone and the like.

(n) Imidazoline-5-ketone nucleus: for example, 2-propyl decyl-2-imidazolin-5-one or the like.

(o) 3,5-pyrazolidinedione core: for example, 1,2-diphenyl-3,5-pyrazolidinedione, 1,2-dimethyl-3,5-pyrazolidinedione Wait.

(p) Benzothiophen-3-one core: for example, benzothiophene-3-one, oxobenzothiophene-3-one, dioxobenzothiophen-3-one, and the like.

(q) indanone core: for example, 1-indanone, 3-phenyl-1-indanone, 3-methyl-1-indanone, 3,3-diphenyl-1 - Indoline, 3,3-dimethyl-1-indanone, and the like.

Z may have a substituent. Examples of the substituent include, for example, a substituent W (excluding a carboxyl group and a hydroxyl group, and a substituent having a carboxyl group or a hydroxyl group) which will be described later.

Z does not have a carboxyl group or a hydroxyl group. That is, Z is not a ring having a carboxyl group or a hydroxyl group as a substituent.

In the formula (Z1), * represents a bonding position.

The compound (A) is preferably a compound (a1) represented by the following formula (2), for the reason that the photoelectric conversion efficiency is further increased.

In the formula (2), R ¹ , R ² , R ⁵ and R ⁶ each independently represent a hydrogen atom or a substituent. Examples of the substituent include a substituent W and the like which will be described later.

It is more excellent responsiveness reason, it is preferably R ^1, R ^2, R ⁵ and R ⁶ at least one of a halogen atom (particularly chlorine atom), further R ⁵ is as good a halogen atom (particularly chlorine atom).

In the formula (2), R ⁷ to R ²⁰ each independently represent a hydrogen atom or a substituent. Examples of the substituent include a substituent W and the like which will be described later.

For the reason that the responsiveness is more excellent, it is preferred that R ⁷ to R ¹⁶ are each independently an aryl group or a heteroaryl group. Specific examples and preferred aspects of the aryl group and the heteroaryl group are as described above.

R ¹ and R ² , R ¹ and R ¹⁶ , R ⁶ and R ⁷ , and R ¹¹ and R ¹² may be bonded to each other to form a ring.

For the reason that the responsiveness is more excellent, it is preferred that R ¹ and R ^{2 are} not bonded to each other to form a ring.

In the case where the responsiveness is more excellent, it is preferred that R ¹¹ and R ^{12 are} not bonded to each other to form a ring.

For the reason that the responsiveness is more excellent, it is preferred that at least one of R ¹ and R ¹⁶ and R ⁶ and R ⁷ are bonded to each other to form a ring.

The definition, specific examples, and preferred aspects of A in the formula (2) are the same as those in the above formula (1).

(substituent W)

The substituent W of this specification is described.

Examples of the substituent W include a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group, a bicycloalkenyl group), an alkynyl group, an aryl group, and a heterocyclic group. (Also known as heterocyclic group), cyano group, hydroxy group, nitro group, carboxyl group, alkoxy group, aryloxy group, nonyloxy group, heterocyclic oxy group, decyloxy group, amine methyl methoxy group, alkoxy group A carbonyloxy group, an aryloxycarbonyloxy group, an amine group (including an anilino group), an ammonium group, a mercaptoamine group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an amine sulfonium group Alkylamino, alkylsulfonylamino or arylsulfonylamino, fluorenyl, alkylthio, arylthio, heterocyclic thio, sulfonyl, sulfo, alkylsulfinyl or Arylsulfinyl, alkylsulfonyl or arylsulfonyl, fluorenyl, aryloxycarbonyl, alkoxycarbonyl, aminemethanyl, arylazo or heterocyclic azo, hydrazine Imino, phosphino, phosphinyl, phosphinyloxy, phosphinylamino, phosphonium, decyl, decyl, ureido, boronic acid (-B(OH) ₂ ), phosphate (-OPO(OH) ₂ ), sulfonate (-OSO ₃ H), other well-known Dai Ke et al.

In addition, the details of the substituent are described in paragraph [0023] of JP-A-2007-234651.

(ring R)

The ring R of this specification is described.

Examples of the ring R include an aromatic hydrocarbon ring, an aromatic hetero ring, a non-aromatic hydrocarbon ring, a non-aromatic hetero ring, or a polycyclic condensed ring formed by combining these. More specifically, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, an anthracene ring, a triphenylene ring, a condensed tetraphenyl ring, a biphenyl ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, an oxazole ring, Thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, pyridazine ring, anthracene ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinoliz ring, quinoline ring, Pyridazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, indazole ring, pyridine ring, acridine ring, phenanthroline ring, thiophene ring, benzopyrazine Chromene ring, dibenzopyran ring, phenoxathiin ring, phenothiazine ring, phenazine ring, cyclopentane ring, cyclohexane ring, pyrrolidine ring, piperidine ring, tetrahydrofuran ring a tetrahydropyran ring, a tetrahydrothiophene ring, a tetrahydrothiopyran ring or the like.

Ring R may also have a substituent. Examples of the substituent include the substituent W and the like described above.

Compound (A) can be produced by carrying out according to a known method and locally changing. Specific examples of the compound (A) are shown below, but the present invention is not limited to these specific examples.

[化8]

The ionization potential (hereinafter sometimes abbreviated as IP) of the compound (A) is preferably 6.0 eV or less, more preferably 5.8 eV or less, and particularly preferably 5.6 eV or less. If it is this range, it is preferable to carry out electron-acceptance with this material with a small resistance in the case of an electrode and other materials. The IP can be obtained using AC-2 manufactured by Riken Instruments.

The compound (A) preferably has a maximum absorption in a range of 400 nm or more and less than 720 nm in an ultraviolet-visible absorption spectrum, and a peak wavelength (maximum absorption wavelength) of an absorption spectrum is obtained from the viewpoint of widely absorbing light in a visible range. It is preferably 450 nm or more and 700 nm or less, more preferably 480 nm or more and 700 nm or less, and further preferably 510 nm or more and 680 nm or less.

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

The compound (A) preferably has a maximum absorption in a range of 400 nm or more and less than 720 nm in an ultraviolet-visible absorption spectrum, and a molar absorption coefficient of a maximum absorption wavelength of 10,000 mol ^-1 . l. Cm ^-1 or more. In order to reduce the film thickness of the photoelectric conversion film, an element having high charge trapping efficiency and high sensitivity characteristics is preferable, and a material having a large molar absorption coefficient is preferable. The molar absorption coefficient of the compound (A) is preferably 10,000 mol ^-1 . l. More than cm ^{-1 ,} more preferably 30,000 mol ^-1 . l. More than cm ^-1 , especially preferably 50,000 mol ^-1 . l. Cm ^-1 or more. The molar absorption coefficient of the compound (A) is determined in a chloroform solution.

The larger the difference between the melting point of the compound (A) and the vapor deposition temperature (melting point-vapor deposition temperature), the more difficult it is to decompose during vapor deposition, and the higher the temperature can be applied to accelerate the vapor deposition rate. Further, the difference between the melting point and the vapor deposition temperature (melting point - vapor deposition temperature) is preferably 40 ° C or higher, more preferably 50 ° C or higher, and still more preferably 60 ° C or higher.

Further, the melting point of the compound (A) is preferably 240 ° C or higher, more preferably 280 ° C or higher, and still more preferably 300 ° C or higher. When the melting point is 300° C. or more, it is less likely to be melted before vapor deposition, and film formation can be stably performed, and a decomposition product of a compound is less likely to be generated, so that photoelectric conversion performance is not easily lowered, which is preferable.

The vapor deposition temperature of the compound is set to a temperature at a vacuum of 4 × 10 ^-4 Pa or less, and the vapor deposition rate is set to a temperature of 1.5 angstroms/s (1.5 × 10 ^-10 m/s).

The glass transition temperature (Tg) of the compound (A) is preferably 95 ° C or more. More preferably, it is 110 ° C or more, and further preferably 135 ° C or more, particularly preferably 150 ° C or more, and most preferably 160 ° C or more.

The molecular weight of the compound (A) is preferably from 300 to 1,500, more preferably from 400 to 1,000, still more preferably from 500 to 900. By lowering the molecular weight, the vapor deposition temperature can be lowered, so that thermal decomposition of the compound at the time of vapor deposition can be further prevented. In addition, the vapor deposition time can be shortened, and the energy necessary for vapor deposition can be suppressed. The vapor deposition temperature of the compound (A) is preferably 400 ° C or lower, more preferably 380 ° C or lower, further preferably 360 ° C or lower, and most preferably 340 ° C or lower.

The compound (A) is desirably purified by sublimation before the production of the photoelectric conversion element or the image pickup element. The impurities or residual solvent contained in the pre-sublimation can be removed by sublimation purification. As a result, the performance of the photoelectric conversion element or the image pickup element can be stabilized. In addition, it is easy to keep the vapor deposition rate constant.

The purity of the compound (A) before sublimation purification is preferably 99% or more, more preferably 99.5% or more, and still preferably 99.9% in High Performance Liquid Chromatography (HPLC). the above. Further, the content of the residual solvent such as the reaction solvent or the purification solvent used in the step of obtaining the compound (A) is preferably 3% or less, more preferably 1% or less, further preferably 0.5% or less, and particularly preferably a detection limit. the following. The content of the residual solvent (including moisture) can be measured by ¹ H-NMR measurement, gas chromatography, Karl-fischer measurement, or the like. By increasing the purity and reducing the residual solvent, thermal decomposition during sublimation purification can be suppressed.

Compound (A) as an imaging element, a photo sensor, or a photocell It is particularly useful as a material for a photoelectric conversion film. Further, the compound (A) usually functions as an organic p-type semiconductor (compound) in the photoelectric conversion film. Further, it can be used as a coloring material, a liquid crystal material, an organic semiconductor material, an organic light-emitting device material, a charge transport material, a medical material, a fluorescent diagnostic drug material, or the like as another use.

<n-type semiconductor>

In the photoelectric conversion element of the present invention, the n-type semiconductor (for example, an organic n-type semiconductor) contained in the photoelectric conversion material is an acceptor semiconductor, and mainly refers to a property typified by an electron-transporting compound and having electron-accepting properties. Compound. More specifically, it means a compound having a large electron affinity when the two compounds are brought into contact. Therefore, any compound can be used as long as the acceptor semiconductor is a compound having an electron accepting property. Preferred are a fullerene selected from the group consisting of fullerene and a derivative thereof, a metal complex having the following compound as a ligand, and the like: a condensed aromatic carbocyclic compound (naphthalene derivative, An anthracene derivative, a phenanthrene derivative, a thick tetraphenyl derivative, an anthracene derivative, an anthracene derivative, a 1,2-benzofluorene derivative, a heterocyclic compound containing a nitrogen atom, an oxygen atom, or a sulfur atom ( For example, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, pyridazine, porphyrin, isoquinoline, acridine, acridine, phenazine, phenanthroline, tetrazole, Pyrazole, imidazole, thiazole, oxazole, oxazole, benzimidazole, benzotriazole, benzoxazole, benzothiazole, oxazole, hydrazine, triazolopyridazine, triazolopyrimidine, tetraaza Anthracene, oxadiazole, imidazolium, pyrazine, pyrrolopyridine, thiadiazolopyridine, dibenzoazepine, tribenzoazepine, etc., poly-arylene compound, anthraquinone compound, cyclopentane Diene compound, 矽 An alkyl compound, a nitrogen-containing heterocyclic compound.

The n-type semiconductor is preferably a fullerene selected from the group consisting of fullerenes and derivatives thereof. Fullerene, means fullerene C ₆₀ , fullerene C ₇₀ , fullerene C ₇₆ , fullerene C ₇₈ , fullerene C ₈₀ , fullerene C ₈₂ , fullerene C ₈₄ , Fuller The olefin C ₉₀ , the fullerene C ₉₆ , the fullerene C ₂₄₀ , the fullerene C ₅₄₀ , and the mixed fullerene, the fullerene derivative is a compound obtained by adding a substituent to the fullerene. The substituent is preferably an alkyl group, an aryl group or a heterocyclic group. The fullerene derivative is preferably a compound described in JP-A-2007-123707.

The photoelectric conversion film preferably has a structure of a bulk hetero structure formed by mixing the compound (A) with a fullerene. The bulk heterostructure is a film in which the compound (A) and the n-type compound are mixed and dispersed in the photoelectric conversion film, and can be formed by any of a wet method and a dry method, and is preferably formed by a co-evaporation method. By the structure containing the heterojunction, the shortcoming of the carrier diffusion length of the photoelectric conversion film can be compensated for, and the photoelectric conversion efficiency of the photoelectric conversion film can be improved. In addition, the structure of the bulk heterojunction is described in detail in [0013] to [0014] of JP-A-2005-303266.

The content of the fullerene relative to the total content of the compound (A) and the fullerene (=the film thickness of the fullerene in a single layer conversion / (the compound (A) in a single layer The film thickness of the film thickness + fullerene in a single layer conversion) is preferably 50% by volume or more, more preferably 55% by volume or more, and still more preferably 65% by volume or more. The upper limit is not particularly limited, and is preferably 95% by volume or less, more preferably 90% by volume or less.

The photoelectric conversion film of the photoelectric conversion element of the present invention is a non-luminescent film, There are features different from organic electroluminescent elements (Organic Light-emitting Diodes (OLED)). The non-light-emitting film refers to a film having a light-emitting quantum efficiency of 1% or less, more preferably 0.5% or less, and still more preferably 0.1% or less.

<Other materials>

The photoelectric conversion film may further contain an organic p-type semiconductor other than the compound (A).

The organic p-type semiconductor is a donor organic semiconductor, and mainly refers to an organic compound represented by a hole-transporting organic compound and having a property of easily supplying electrons. More specifically, it means an organic compound having a small ionization potential when the two organic materials are brought into contact with each other. Therefore, as long as the donor organic compound is an organic compound having electron donating properties, any organic compound can be used. For example, a triarylamine compound, a benzidine compound, a pyrazoline compound, a styrylamine compound, an anthracene compound, a triphenylmethane compound, a carbazole compound, or the like can be used.

<film formation method>

The photoelectric conversion film 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 method such as a vacuum deposition method, a sputtering method, an ion plating method, or a molecular beam epitaxy (MBE) method, or a chemical gas such as plasma polymerization. Chemical Vapor Deposition (CVD) method. As the wet film formation method, a casting method, a spin coating method, a dipping method, a Langmuir-Blodgett (LB) method, or the like can be used. It is preferably a dry film forming method, more preferably a vacuum vapor deposition method. In the case where the film formation is performed by a vacuum deposition method, the production conditions such as the degree of vacuum and the vapor deposition temperature can be set in accordance with a usual method.

The thickness of the photoelectric conversion film is preferably 10 nm or more and 1000 nm or less. More preferably, it is 50 nm or more and 800 nm or less, More preferably, it is 100 nm or more and 500 nm or less.

[electrode]

The electrode (the upper electrode (transparent conductive film) and the lower electrode (conductive film)) is made of a conductive material. As the conductive material, a metal, an alloy, a metal oxide, a conductive compound, a mixture of these, or the like can be used.

In the case where light is incident on the photoelectric conversion film via the transparent conductive film, it is preferred that the upper electrode is sufficiently transparent to the light to be detected. Specific examples thereof include conductive metal oxides such as tin oxide (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide (IZO) doped with antimony or fluorine, gold, and the like. a metal thin film such as silver, chromium or nickel, a mixture or laminate of the metal and the conductive metal oxide, an inorganic conductive material such as copper iodide or copper sulfide, or an organic conductive material such as polyaniline, polythiophene or polypyrrole. Materials, and these laminates with ITO, etc. Among them, a transparent conductive metal oxide is preferred in terms of high conductivity, transparency, and the like.

When a transparent conductive film such as Transparent Conductive Oxide (TCO) is used as the upper electrode, a direct current (DC) short circuit or a leakage current may increase. One of the reasons for this is considered to be that the fine crack introduced into the photoelectric conversion film is covered by a dense film such as TCO, and the conduction between the lower electrode on the opposite side is increased. Therefore, in the case of an electrode having a relatively poor film quality such as aluminum, an increase in leakage current is less likely to occur. By controlling the film thickness of the upper electrode with respect to the film thickness of the photoelectric conversion film (that is, the depth of the crack), the increase in leakage current can be greatly suppressed. Upper The thickness of the electrode is preferably set to be 1/5 or less, preferably 1/10 or less of the thickness of the photoelectric conversion film.

In general, when the conductive film is made thinner than a certain range, the rapid increase in the resistance value is caused. For the solid-state image sensor in which the photoelectric conversion element of the embodiment is incorporated, the sheet resistance is preferably 100 Ω/□. It is preferable that it is ~10000 Ω/□, and the degree of freedom of the film thickness of the film can be made large. Further, the thinner the thickness of the upper electrode (transparent conductive film), the smaller the amount of light absorbed, and the light transmittance generally increases. The increase in the light transmittance increases the light absorption in the photoelectric conversion film and increases the photoelectric conversion ability, which is very preferable. In consideration of suppression of leakage current due to thin film formation, increase in resistance value of the film, and increase in transmittance, the film thickness of the upper electrode is preferably 5 nm to 100 nm, more preferably 5 nm to 20 nm.

The lower electrode may have transparency in accordance with the use, and may be used in the case of using a material that does not have transparency and reflects light. Specific examples thereof include conductive metal oxides such as tin oxide (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide (IZO) doped with antimony or fluorine, gold, and the like. a conductive compound such as a metal such as silver, chromium, nickel, titanium, tungsten or aluminum, or an oxide or nitride of the metal (for example, titanium nitride (TiN)), and further, the metal and the conductive metal oxide The mixture or laminate, an inorganic conductive material such as copper iodide or copper sulfide, an organic conductive material such as polyaniline, polythiophene or polypyrrole, and a laminate of the same with ITO or titanium nitride.

The method of forming the electrode is not particularly limited, and may be appropriately selected in consideration of the suitability of the electrode material. Specifically, it can be formed by: printing method, A wet method such as a coating method, a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method, or a chemical method such as a CVD or plasma CVD method.

When the material of the electrode is ITO, methods such as electron beam method, sputtering method, resistance heating vapor deposition method, chemical reaction method (sol-gel method, etc.), and dispersion of indium tin oxide may be used. form. Further, a film produced using ITO may be subjected to UV-ozone treatment, plasma treatment, or the like. In the case where the material of the electrode is TiN, various methods typified by a reactive sputtering method, and further, UV-ozone treatment, plasma treatment, or the like can be used.

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

The photoelectric conversion element of the present invention may also have a charge blocking layer. By having this layer, the characteristics (photoelectric conversion efficiency, response speed, and the like) of the obtained photoelectric conversion element are more excellent. The charge blocking layer can be exemplified by an electron blocking layer and a hole blocking layer. Hereinafter, each layer will be described in detail.

[Electronic barrier layer]

In the electron blocking layer, an electron-donating organic material can be used. Specifically, N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD) or 4,4 can be used in the low molecular material. Aromatic diamine compounds such as '-bis[N-(naphthyl)-N-phenyl-amino]biphenyl (α-NPD), oxazole, oxadiazole, triazole, imidazole, imidazolidone, diphenyl Ethylene derivative, pyrazoline derivative, tetrahydroimidazole, polyarylalkane, butadiene, 4,4',4"-tris(N-(3-methylphenyl)N-phenylamino) Triphenylamine (m-MTDATA), porphyrin compound such as porphyrin, copper tetraphenylporphyrin, phthalocyanine, copper phthalocyanine, titanium oxide phthalocyanine, triazole derivative, oxadiazole derivative, imidazole derivative , polyarylalkane derivatives, pyrazoline derivatives, Pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amine-substituted chalcone derivatives, oxazole derivatives, styrylpurine derivatives, anthrone derivatives, anthracene derivatives, anthracene A nitrone derivative or the like; a polymer such as phenylacetylene, hydrazine, carbazole, hydrazine, hydrazine, pyrrole, picoline, thiophene, acetylene or diacetylene or a derivative thereof can be used as the polymer material. Even if it is not an electron-donating compound, it can be used as long as it is a compound which has sufficient hole-transportability. Specifically, the compounds described in [0050] to [0063] of JP-A-2008-72090, or [0050] to [0063] of JP-A-2011-176259, are preferred.

The electron blocking layer also preferably contains a compound represented by the formula (F-1). By using this compound, the resulting photoelectric conversion film is more excellent in response speed, and variation in response speed between the respective manufacturing lots can be further suppressed.

In (Formula (F-1), R " 11 ~ R" 18, R '11 ~ R' 18 each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, a hydroxyl group Or an amine group or a thiol group, which may further have a substituent; any one of R" ₁₅ to R" ₁₈ is bonded to any one of R' ₁₅ to R' ₁₈ to form a single bond; A ₁₁ and A ₁₂ each independently represent a group of the following formula (a-1) represented by a R _"11 ~ R" _14, and any one of R _{14 '11} ~ R' a substitution; the Y each independently represent a carbon atom, a nitrogen An atom, an oxygen atom, a sulfur atom or a helium atom, which may also have a substituent).

(In the formula (A-1), Ra ₁ to Ra ₈ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group or a heterocyclic group, and these may further have a substituent; * represents Bonding position; Xa represents a single bond, an oxygen atom, a sulfur atom, an alkylene group, an alkylene group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an extended aryl group, a divalent heterocyclic group or -NR _a - (R _a represents a hydrogen atom or a substituent (for example, the substituent W described above)), and these may further have a substituent; and S ₁₁ independently represents the following substituent (S ₁₁ ) as Ra Any one of ₁ to Ra ₈ is substituted; n' represents an integer of 0 to 4).

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

Formula (F-1) _{in, R "11 ~ R" 18} , R '11 ~ R' 18 each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, a hydroxyl group, Amino or anthracenyl, these may also have more substituents. Specific examples of the further substituent include the above-mentioned substituent W, preferably a halogen atom, an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, a hydroxyl group, an amine group or a fluorenyl group, more preferably a halogen atom. The alkyl group, the aryl group or the heterocyclic group is further preferably a fluorine atom, an alkyl group or an aryl group, more preferably an alkyl group or an aryl group, and most preferably an alkyl group.

R" ₁₁ to R" ₁₈ and R' ₁₁ to 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 or a carbon which may have a substituent. 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. Among them, it is preferred that the substituent represented by the formula (A-1) is independently substituted on R" ₁₂ and R' ₁₂ , and more preferably the substituent represented by the formula (A-1) is independently Substitution on R" ₁₂ and R' ₁₂ and R" ₁₁ , R" ₁₃ - R" ₁₈ , R' ₁₁ , R' ₁₃ - R' ₁₈ are a hydrogen atom, and the number of carbons which may have a substituent is 1-18. The alkyl group, particularly preferably the substituent represented by the formula (A-1), is independently substituted on R" ₁₂ and R' ₁₂ and 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 ruthenium 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 ruthenium atom. Preferably, it is -C(R' ₂₁ )(R' ₂₂ )-, -Si(R' ₂₃ )(R' ₂₄ )-, -N(R' ₂₀ )-, more preferably -C(R' ₂₁ (R' ₂₂ )-, -N(R' ₂₀ )-, and more preferably -C(R' ₂₁ )(R' ₂₂ )-.

R' ₂₀ to R' ₂₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aryl group, a heterocyclic group, a hydroxyl group, an amine group or a fluorenyl group. Specific examples of the further substituent include the substituent W described above. R' ₂₀ to R' _{24 is} preferably a hydrogen atom or an alkyl group, an aryl group or a heterocyclic group which may have a substituent, more preferably a hydrogen atom or a C 1-18 alkyl group which may have a substituent. An aryl group having 6 to 18 carbon atoms or a 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, and particularly preferably a carbon number of 1 to 18 Alkyl.

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

Preferably, 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, more preferably hydrogen. The atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 14 carbon atoms is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms. The alkyl group may also have a branch.

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

Further, it is particularly preferable that Ra ₃ and Ra ₆ are a hydrogen atom or an alkyl group 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, an alkylene group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an extended aryl group, a divalent heterocyclic group or -NR _a -(R _a Represents a hydrogen atom or a substituent (for example, the substituent W described above), which may also have a more substituent.

Xa is preferably a single bond, an alkylene group having 1 to 13 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an extended aryl group having 6 to 14 carbon atoms, a heterocyclic group having 4 to 13 carbon atoms, an oxygen atom, a sulfur atom or an alkylene group, more preferably a single bond, an oxygen atom, or an alkylene group having 1 to 6 carbon atoms (for example, methylene, 1,2-extended ethyl, 1,1-dimethylmethylene) a carbon number 2 alkenyl group (for example, -CH ₂ =CH ₂ -), a carbon number of 6 to 10 aryl group (for example, 1,2-phenylene, 2,3-naphthyl), or decane Further, it is preferably a single bond, an oxygen atom, or an alkylene group having 1 to 6 carbon atoms (for example, a methylene group, a 1,2-extended ethyl group, a 1,1-dimethylmethylene group). These substituents may also have the substituent W described above.

Specific examples of the group represented by the formula (A-1) include the groups exemplified below for N1 to N11. Among them, it is not limited to these. The group represented by the formula (A-1) is preferably N-1 to N-7, more preferably N-1 to N-6, further preferably N-1 to N-3, and particularly preferably N-1. ~N-2, the best is N-1.

[化12]

In the substituent (S ₁₁ ), R' ₁ represents a hydrogen atom or an alkyl group. R' _{1 is} preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group or a tert-butyl group, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group or a t-butyl group. It is preferably a methyl group, an ethyl group, an isopropyl group or a tert-butyl group, and more preferably a methyl group, an ethyl group or a tert-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 tert-butyl group, and more preferably a hydrogen atom, a methyl group, an ethyl group or a propyl group, more preferably a hydrogen atom. Methyl, especially methyl.

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

Further, 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 is preferably a 5-member ring or a 6-member ring, and more preferably a 6-member ring.

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

The substituent (S ₁₁ ) is preferably exemplified by the following (a) to (x), more preferably (a) to (j), and further preferably (a) to (h), and more preferably (a) to (() f), and more preferably (a) to (d), and most preferably (a).

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

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

(In the general formula (A-3) to the general formula (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 or an alkyl group, which may further have a substituent; * represents 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, an alkylene group; An alkenyl group, a cycloalkyl group, a cycloalkenyl group, an extended aryl group, a divalent heterocyclic group or -NR _a - (R _a represents a hydrogen atom or a substituent (for example, the substituent W described above) Further, these may further have a substituent; Z ₃₁ , Z ₄₁ and Z ₅₁ each independently represent a cycloalkyl ring, an aromatic hydrocarbon ring or an aromatic hetero 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. In the case where the substituent having a low polarity is advantageous for hole transport, a hydrogen atom or an alkyl group is preferred, and a hydrogen atom is more preferred.

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

In the general formulae (A-3) to (A-5), adjacent ones of Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , and Ra ₅₅ to Ra ₅₈ may be mutually adjacent to each other. Bonding to form a ring. The ring may exemplify the ring R described above. 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, an alkylene group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an extended aryl group, a divalent group. A ring group or -NR _a - (R _a represents a hydrogen atom or a substituent (for example, the substituent W described above)). When Xc ₁ , Xc ₂ and Xc ₃ represent an alkylene group, an alkylene group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an extended aryl group, a divalent heterocyclic group or -NR _a -, These may also have more substituents. The further substituent may be exemplified by the substituent W described above.

Xc ₁ , Xc ₂ and Xc _{3 are} preferably a single bond, an alkylene group having 1 to 12 carbon atoms, an extended alkenyl group having 2 to 12 carbon atoms, an extended aryl group having 6 to 14 carbon atoms, and a carbon number of 4 to 13 a heterocyclic group, an oxygen atom, a sulfur atom, and more preferably a single bond, an alkylene group having 1 to 6 carbon atoms (for example, a methylene group, a 1,2-extended ethyl group, a 1,1-dimethylmethylene group) An alkenyl group having a carbon number of 2 (e.g., -CH ₂ =CH ₂ -) or an extended aryl group having 6 to 10 carbon atoms (e.g., 1,2-phenylene, 2,3-naphthyl).

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

The electron blocking layer is also preferably a compound represented by the following formula (F-2).

Definition of R (F-2) in the formula _'11 ~ R' _14, and specific examples and preferred aspects are of the general formula R (F-1) in the above _'11 ~ R' ₁₄ the same.

Definition of R (F-2) in the formula _"11 ~ R" _14, and specific examples and preferred aspects are of the general formula R (F-1) in the above _"11 ~ R" ₁₄ the same.

Definitions, specific examples and preferred aspects of Xa in the formula (F-2) and the above Xa in the general formula (A-1) is the same.

In the formula (F-2), A ₁₁ and A ₁₂ each independently represent a group represented by the above formula (A-1) as R" ₁₁ - R" ₁₄ and R' ₁₁ ~, respectively. Any of R' ₁₄ is substituted.

In the formula (F-2), Rf ₂₁ represents a hydrogen atom or a substituent. Examples of the substituent include the substituent W and the like described above. Rf _{21 is} preferably an aryl group which may have a substituent.

Furthermore, the electron blocking layer may also be composed of a plurality of layers.

An inorganic material can also be used for the electron blocking layer. In general, the inorganic material has a dielectric constant larger than that of the organic material, so that when it is used in the case of the electron blocking layer, more voltage is applied to the photoelectric conversion film, and the photoelectric conversion efficiency can be improved. The material that can be used as the electron blocking layer is calcium oxide, chromium oxide, chromium oxide copper, manganese oxide, cobalt oxide, nickel oxide, copper oxide, copper oxide copper, copper beryllium oxide, cerium oxide, molybdenum oxide, indium copper oxide, indium oxide. Silver, cerium oxide, etc. In the case where the electron blocking layer is a single layer, the layer may be set to a layer containing an inorganic material, or in the case of a plurality of layers, one or two or more layers may be set as a layer containing an inorganic material.

<hole blocking layer>

In the hole blocking layer, an electron-accepting organic material can be used.

Electron-accepting materials: oxadiazole derivatives such as 1,3-bis(4-tert-butylphenyl-1,3,4-oxadiazolyl)benzene (OXD-7), and quinodimethane Derivative, diphenyl hydrazine derivative, 2,9-dimethyl-4,7-biphenyl-1,10-morpholine (bathocuproin), 4,7-diphenyl-1,10-morpholine (bathophenanthroline) And derivatives thereof, triazole compounds, tris(8-hydroxyquinoline)aluminum complex, bis(4-methyl-8-quinoline)aluminum complex, stilbene A aryl derivative, a fluorene heterocyclic pentadiene compound, or the like. Further, even if it is not an electron-accepting organic material, it can be used as long as it has a sufficient electron transporting property. A porphyrin compound such as a porphyrin compound or DCM (4-dicyanomethylidene-2-methyl-6-(4-(dimethylaminostyryl))-4H-pyran) can be used. 4H pyran compound. Specifically, the compound described in [0073] to [0078] of JP-A-2008-72090 is preferably used.

The method for producing the charge blocking layer 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 either physical vapor deposition (PVD) or chemical vapor deposition (CVD), and physical vapor deposition such as vacuum vapor deposition is preferred. The wet film formation method can be carried out by using an inkjet method, a spray method, a nozzle printing method, a spin coating method, a dip coating method, a casting method, a die coating method, a roll coating method, a bar coating method, a gravure coating method, or the like. From the viewpoint of precision patterning, an inkjet method is preferred.

The thickness of the charge blocking layer (electron blocking layer and hole blocking layer) is preferably 10 nm to 200 nm, more preferably 20 nm to 150 nm, and particularly preferably 30 nm to 50 nm. This is because if the thickness is too thin, the effect of suppressing dark current is lowered, and if it is too thick, the photoelectric conversion efficiency is lowered.

[substrate]

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

Further, the position of the substrate is not particularly limited, and a conductive film, a photoelectric conversion film, and a transparent conductive film are usually laminated on the substrate in this order.

[sealing layer]

The photoelectric conversion element of the present invention may further contain a sealing layer. Photoelectric conversion materials are sometimes degraded by the presence of degradation factors such as water molecules, so that dense metal oxides do not allow water molecules to penetrate. Metal nitride. When a ceramic or a sealing layer such as a diamond-like carbon (DLC) such as a metal oxynitride coats the entire photoelectric conversion film and seals it, the deterioration can be prevented.

Further, regarding the sealing layer, the selection and manufacture of materials can be carried out in accordance with the description of paragraphs [0210] to [0215] of JP-A-2011-082508.

[Photo sensor]

Examples of the use of the photoelectric conversion element include a photovoltaic cell and a photo sensor, and the photoelectric conversion element of the present invention is preferably used as a photo sensor. The photosensor may be a single user of the photoelectric conversion element, preferably a line sensor in which the photoelectric conversion element is linearly arranged, or a two-dimensional sensor disposed on a plane. Shape. The photoelectric conversion element of the present invention converts optical image information into an electrical signal using an optical system and a driving unit in a line sensor, such as a scanner, in a two-dimensional sensor, such as a camera module. The optical image is imaged on the sensor by an optical system and converted into an electrical signal, thereby functioning as an imaging element.

The photovoltaic cell is a power generation device, so the efficiency of converting light energy into electrical energy becomes an important performance, but the dark current, that is, the dark current, is not functionally problematic. Further, the heating step in the subsequent stage such as the color filter setting is not required. It is an important performance for the photo sensor to convert the bright and dark signals into electrical signals with high precision. Therefore, the efficiency of converting the amount of light into current is also an important performance. However, if the signal is output in the dark, it becomes a noise, so the requirement is low. Dark current. Furthermore, the tolerance to the steps in the later stages is also important.

[image sensor]

Next, a configuration example of an image pickup element including a photoelectric conversion element will be described.

Further, in the configuration examples described below, the configuration is equivalent to the member described above. The components and the like that are the same are denoted by the same reference numerals or the corresponding symbols in the drawings, thereby simplifying or omitting the description.

The imaging element is an element that converts optical information of an image into an electrical signal, and means that a plurality of photoelectric conversion elements are arranged in a same plane on a matrix, and optical signals are converted into photoelectric conversion elements (pixels) into The electrical signal, and the electrical signal can be sequentially output to the outside of the imaging element according to the pixel. Therefore, each pixel is composed of one photoelectric conversion element and one or more transistors.

FIG. 2 is a schematic cross-sectional view showing a schematic configuration of an image pickup element according to an embodiment of the present invention. The imaging device is used in an imaging device such as a digital camera or a digital camera, an imaging module such as an electronic endoscope or a mobile phone, or the like.

The image pickup device has a configuration in which a plurality of photoelectric conversion elements having a configuration as shown in FIGS. 1(a) and 1(b) and a circuit board on which the readout and each photoelectric conversion element are formed A readout circuit for a signal corresponding to the charge generated in the photoelectric conversion film, and a plurality of photoelectric conversion elements are arranged in a one-dimensional or two-dimensional shape on the same surface above the circuit substrate.

The image sensor 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. , buffer layer 109, sealing layer 110, color filter (CF) 111, partition wall 112, light shielding layer 113, Bao The protective layer 114, the counter electrode voltage supply unit 115, and the readout circuit 116.

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

The substrate 101 is a glass substrate or a semiconductor substrate such as 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 of the photoelectric conversion elements provided on the plurality of pixel electrodes 104 so as to cover the pixel electrodes 104.

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

The connection portion 106 is embedded in the insulating layer 102 and is a plug or the like for electrically connecting the connection electrode 103 and the counter electrode voltage supply unit 115. The counter electrode voltage supply unit 115 is formed on the substrate 101, and a predetermined voltage is applied to the counter electrode 108 via the connection portion 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 image pickup element, the booster circuit such as a charge pump raises the power supply voltage to supply the predetermined voltage.

The readout circuit 116 is provided corresponding to each of the plurality of pixel electrodes 104 On the substrate 101, a signal corresponding to the charge trapped in the corresponding pixel electrode 104 is read. The readout circuit 116 is composed of, for example, a Charge Coupled Device (CCD), a Complementary Metal-Oxide-Semiconductor (CMOS) circuit, or a Thin Film Transistor (TFT) circuit. The light shielding layer (not shown) disposed in the insulating layer 102 is shielded from light. The readout circuit 116 is electrically connected to the pixel electrode 104 corresponding thereto via the connection portion 105.

The buffer layer 109 is formed by covering the counter electrode 108 with the counter electrode 108. The sealing layer 110 is formed by covering the buffer layer 109 with the buffer layer 109. The color filter 111 is a position opposed to each of the pixel electrodes 104 formed on the sealing layer 110. The partition wall 112 is disposed between the color filters 111 to improve the light transmission efficiency of the color filter 111.

The light shielding layer 113 is formed on the sealing layer 110 except for a region where the color filter 111 and the partition wall 112 are provided, 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 partition wall 112, and the light shielding layer 113 to protect the entire image pickup element 100.

In the imaging element 100 configured as described above, when light is incident, the light is incident on the photoelectric conversion film 107, and electric charges are generated therein. The holes in the generated charges are trapped by the pixel electrodes 104, and the voltage signals corresponding to the amounts are outputted to the outside of the image pickup device 100 by the readout circuit 116.

The manufacturing method of the image pickup element 100 is as follows.

The circuit base on which the counter electrode voltage supply unit 115 and the readout circuit 116 are formed 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 the board. The plurality of pixel electrodes 104 are disposed on the surface of the insulating layer 102 in a square lattice shape, for example.

Then, the photoelectric conversion film 107 is formed on the plurality of pixel electrodes 104 by, for example, vacuum heating evaporation. Then, the counter electrode 108 is formed on the photoelectric conversion film 107 by vacuum sputtering, for example. Then, the buffer layer 109 and the sealing layer 110 are sequentially formed on the counter electrode 108 by, for example, vacuum heating evaporation. Then, after the color filter 111, the partition wall 112, and the light shielding layer 113 are formed, the protective layer 114 is formed, and the image sensor 100 is completed.

In the method of manufacturing the image sensor 100, even in the step of forming the photoelectric conversion film 107 and the step of forming the sealing layer 110, a step of placing the image sensor 100 in the middle of production under a vacuum is added, and a plurality of photovoltaics can be prevented. The performance of the conversion element is degraded. By adding this step, deterioration in performance of the image pickup element 100 can be prevented, and manufacturing cost can be suppressed.

[Examples]

The embodiments are shown below, but the invention is not limited to the embodiments.

<Example 1>

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

Specifically, amorphous indium tin oxide (ITO) is formed on the glass substrate by sputtering to form a lower electrode 11 (thickness: 30 nm). Further, the following compound (EB-1) was formed on the lower electrode 11 by a vacuum heating deposition method to form an electron blocking layer 16A (thickness: 100 nm).

Further, in the state where the temperature of the substrate is controlled to 25 ° C, the following compound (1) and fullerene (C ₆₀ ) are each 133 nm in a single layer by vacuum heating deposition on the electron blocking layer 16A. The film was formed by co-evaporation at 267 nm to form a photoelectric conversion film 12. Here, the vapor deposition is carried out by heating the crucible to which the compound (1) described below is added under vacuum (a vacuum of 4 × 10 ^-4 Pa or less). Further, vapor deposition was carried out so that the vapor deposition rate of the compound (1) below was 1.5 Å (Å) / sec (1.5 × 10 ^-10 m / sec).

Further, 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 an 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. , making photoelectric conversion components.

<Example 2 to Example 15 and Comparative Example 1 to Comparative Example 5>

The compound shown in Table 1 was used instead of the compound (1), and the amount of vapor deposition of the compound and fullerene (C ₆₀ ) was as shown in Table 1 "Compound (nm): C ₆₀ (nm)". A photoelectric conversion element was produced in the same manner as in Example 1 except that co-deposition was performed.

The following compounds (1) to (15) correspond to the compound (A) represented by the above formula (1), and the compounds of the following comparative compounds (1) to (2) are not equivalent to the formula (1). ) the compound (A) represented. Further, the following comparative compound (1) is a compound described in JP-A-2010-40280. In addition, the compound (2) described below is a compound described in JP-A-H07-211457.

[化17]

The compounds (1) to (15) are synthesized by a known method. The identification of the compound was carried out by mass spectrometry (MS) measurement and ¹ H-NMR measurement.

The specific synthetic scheme for the compound (3) is shown below. Further, a ¹ H-NMR spectrum chart of the compound (3) is shown in Fig. 3 .

[化18]

<Component driver confirmation>

It is confirmed whether or not each of the obtained photoelectric conversion elements functions as a photoelectric conversion element. Specifically, a voltage was applied to the lower electrode and the upper electrode of the obtained photoelectric conversion element so as to have an electric field intensity of 2.0 × 10 ⁵ V/cm, and the current values in the dark and the bright places were measured. As a result, a dark current of 100 nA/cm ² or less was displayed in a dark place in any of the photoelectric conversion elements, and a current of 10 μA/cm ² or more was displayed in a bright place, and it was confirmed that it functions as a photoelectric conversion element.

<Responsive evaluation>

The responsiveness of each of the obtained photoelectric conversion elements was evaluated.

Specifically, in a state where an electric field of 2.0 × 10 ⁵ V/cm is applied to each of the obtained photoelectric conversion elements, light is irradiated from the side of the upper electrode (transparent conductive film), and a signal from 0 to 98% at this time is obtained. The rise time of the intensity. Table 1 shows the relative value in which the rise time of the first embodiment is 10 (">200" indicates that the relative value exceeds 200). Further, the method of determining the relative value is as follows.

(relative value) = 10 × (from 0 to 98% signal strength of each of the examples and comparative examples) Rise time) / (the rise time from 0 to 98% of the signal strength of Example 1)

The smaller the relative value, the shorter the rise time and the more excellent the responsiveness. Practically, the relative value is preferably 20 or less, more preferably 5 or less.

<Evaluation of photoelectric conversion efficiency (external quantum efficiency)>

The photoelectric conversion efficiency was evaluated for each of the obtained photoelectric conversion elements.

Specifically, a voltage is applied to the lower electrode and the upper electrode of each of the obtained photoelectric conversion elements so as to have an electric field intensity of 2.0 × 10 ⁵ V/cm, and the maximum wavelength of each compound (photoelectric conversion material) at the voltage is measured. External quantum efficiency. As a result, when the external quantum efficiency of Example 1 was 1 or the relative value was 0.8 or more, it was evaluated as "A", and when it was less than 0.8 and 0.6 or more, it was evaluated as "B", and when it was less than 0.6, it was evaluated as "C". The results are shown in Table 1. Practically, it is preferably "A" or "B", and more preferably "A".

In Table 1, "compound (nm)" in "compound (nm): C ₆₀ (nm)" represents the vapor deposition amount of the compound in a single layer conversion. In addition, "Compound _{(nm): C 60 (nm} ) " in "C ₆₀ (nm)" represents the amount in terms of a single layer deposited fullerene (C ₆₀₎ a.

[Table 1]

As is known from Table 1, the photoelectric conversion material does not contain the compound (A) represented by the formula (1), and the comparative compound (1) having a carboxyl group of A in the formula (1) is used as a photoelectric conversion material. In Comparative Example 1, it was decomposed during vapor deposition, and it was impossible to produce an element. In addition, the photoelectric conversion material does not contain the compound (A) represented by the formula (1), and the comparative compound (2) which does not have an aromatic amine moiety is used as the photoelectric conversion material, and can be deposited by evaporation. To make components, but the responsiveness is not enough.

In addition, Comparative Example 3 and Comparative Example 4 in which the photoelectric conversion material contained the compound (A) represented by the formula (1) but did not contain the n-type semiconductor were insufficient in responsiveness and photoelectric conversion efficiency.

On the other hand, the photoelectric conversion material containing the compound (A) represented by the formula (1) and the n-type semiconductor can be produced by vapor deposition, and the obtained elements all exhibit excellent response. Sexual and high photoelectric conversion efficiency. Among them, Examples 1 to 14 in which A in the formula (1) is an oxygen atom or =CR ^C3 R ^C4 exhibit more excellent responsiveness. Among them, Examples 1 to 10 in which the compound (A) is the compound (a1) represented by the formula (2) showed higher photoelectric conversion efficiency.

According to the comparison between Example 1 and Example 13, Example 1 in which R ³ and R ⁴ are bonded to each other to form a benzene ring shows more excellent responsiveness and higher photoelectric conversion efficiency.

According to the comparison between Example 1 and Example 2, Example 1 in which R ¹ and R ^{2 are} not bonded to each other to form a ring shows more excellent responsiveness.

According to the comparison between Example 1 and Example 3, Example 3 in which at least one of R ¹ to R ⁶ is a halogen atom showed more excellent responsiveness.

According to the comparison of Example 3 with Example 4, Example 4 in which Ar ¹ or Ar ² has an aryl group or a heteroaryl group as a substituent exhibits more excellent responsiveness.

According to the comparison of Example 1, Example 11, and Example 12, Example 1 in which X is an oxygen atom showed higher photoelectric conversion efficiency.

According to the comparison of Example 1, Example 7, and Example 8 to Example 10, A in the formula (1) or the formula (2) is an oxygen atom or a group represented by the formula (Z1). Example 1 and Examples 8 to 10 showed more excellent responsiveness.

According to Embodiment 1, Embodiment 7, Embodiment 8 to Embodiment 10, and Embodiment 13, In the comparison of Example 14, Examples 8 to 10 and Example 14 in which the formula (1) or the formula (2) is a group represented by the formula (Z1) shows that it is more excellent. Responsive.

According to the comparison between Example 9 and Example 10, Example 9 in which Ar ¹ and Ar ^{2 were} not bonded to each other to form a ring showed more excellent responsiveness.

According to the comparison between Example 1 and Example 6, Example 6 in which Ar ¹ and R ¹ and at least one of Ar ² and R ⁶ are bonded to each other to form a ring exhibits superiority. Responsiveness.

<Production of imaging element>

An image pickup element of the same shape as that shown in Fig. 2 was produced. That is, after the amorphous TiN is formed into a film by sputtering on a CMOS substrate for 30 nm, the photolithography is used to pattern each of the photodiodes (PD) on the CMOS substrate. After the lower electrode was formed to form an electron blocking layer, an image pickup element was produced in the same order as in the first to fifth embodiments and the comparative example 1 to the comparative example 5. The evaluation was carried out in the same manner. As a result, the same results as in Table 1 were obtained, and it was found that even when the photoelectric conversion element of the present invention is used as an image pickup element, it can be produced by vapor deposition, and the obtained element display is performed. Excellent responsiveness and high photoelectric conversion efficiency.

Claims (12)

A photoelectric conversion element comprising, in order, a conductive film, a photoelectric conversion film containing a photoelectric conversion material, and a transparent conductive film, the photoelectric conversion material containing the compound (A) and the n-type semiconductor represented by the following formula (1) , (In the formula (1), R ¹ to R ⁶ each independently represent a hydrogen atom or a substituent; and R ¹ and R ² , R ³ and R ⁴ may be bonded to each other to form a ring; and Ar ¹ and Ar ² are each independently The aryl group which may have a substituent or the heteroaryl group which may have a substituent; Ar ¹ and Ar ² , Ar ¹ and R ¹ , and Ar ² and R ⁶ may be bonded to each other to form a ring; X represents a group of free oxygen atoms, sulfur atoms, >CR ^C1 R ^C2 , >NR ^N1 and >SiR ^Si1 R ^Si2 ; where R ^C1 , R ^C2 , R ^N1 , R ^Si1 and R ^Si2 are independent The ground represents a hydrogen atom or a substituent; A represents a group selected from the group consisting of an oxygen atom, a sulfur atom, =CR ^C3 R ^C4 and =NR ^N2 ; here, R ^C3 , R ^C4 and R ^N2 are independently A hydrogen atom or a substituent; R ^C3 and R ^C4 may be bonded to each other to form a ring; when A is =NR ^N2 , R ^N2 and R ⁴ may be bonded to each other to form a ring; A has no carboxyl group and Hydroxyl). The photoelectric conversion element according to claim 1, wherein the X is an oxygen atom. The photoelectric conversion element according to claim 1 or 2, wherein the R ³ and the R ⁴ are bonded to each other to form a benzene ring. The photoelectric conversion element according to the above aspect, wherein the compound (A) is a compound (a1) represented by the following formula (2), (In the formula (2), R ¹ , R ² , R ⁵ and R ⁶ each independently represent a hydrogen atom or a substituent; and R ⁷ to R ²⁰ each independently represent a hydrogen atom or a substituent; R ¹ and R ² , R ¹ and R ¹⁶ , R ⁶ and R ⁷ , R ¹¹ and R ¹² may be bonded to each other to form a ring; A represents a group selected from the group consisting of an oxygen atom, a sulfur atom, =CR ^C3 R ^C4 and =NR ^N2 In the above, R ^C3 , R ^C4 and R ^N2 each independently represent a hydrogen atom or a substituent; R ^C3 and R ^C4 may be bonded to each other to form a ring; A does not have a carboxyl group or a hydroxyl group). The photoelectric conversion element according to claim 1 or 2, wherein the A is an oxygen atom or a group represented by the following formula (Z1), (In the formula (Z1), Z is a ring containing at least 2 carbon atoms, and represents a 5-membered ring, a 6-membered ring or a fused ring containing at least one of a 5-membered ring and a 6-membered ring; Z may have a substituent ; * indicates the bonding position; Z does not have a carboxyl group and a hydroxyl group). The photoelectric conversion element according to claim 1 or 2, wherein the n-type semiconductor contains a fullerene selected from the group consisting of fullerenes and derivatives thereof. The photoelectric conversion element according to claim 6, wherein the content of the fullerene relative to the total content of the compound (A) and the fullerene (=the fullerene) The film thickness in the single layer conversion (the film thickness in the single layer of the compound (A) + the film thickness in the single layer of the fullerene) is 50% by volume or more. The photoelectric conversion element according to claim 1 or 2, wherein a charge blocking layer is disposed between the conductive film and the transparent conductive film. The photoelectric conversion element according to claim 1 or 2, wherein light is incident into the photoelectric conversion film via the transparent conductive film. The photoelectric conversion element according to claim 1 or 2, wherein the transparent conductive film contains a transparent conductive metal oxide. A photosensor comprising the photoelectric conversion element according to any one of claims 1 to 10. An image pickup element comprising the photoelectric conversion element according to any one of claims 1 to 10.