JP2015032711A - Photoelectric conversion material, photoelectric conversion element, method for using the same, photosensor, and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide photoelectric conversion material excellent in vapor deposition stability, excellent in responsibility when making an element, and excellent in photoelectric conversion efficiency at a long wavelength region.SOLUTION: Photoelectric conversion material is a compound (A) represented by the following formula (1).

Description

  The present invention relates to a photoelectric conversion material, a photoelectric conversion element, a method for using the photoelectric conversion element, an optical sensor, and an imaging element.

  Conventional optical sensors are generally elements in which photodiodes (PDs) are formed in a semiconductor substrate such as silicon (Si). As solid-state image sensors, PDs are two-dimensionally arranged and generated in each PD. Flat-type solid-state imaging devices that read out the signal charges that have been used in a circuit are widely used.

  In order to realize a color solid-state imaging device, a structure in which a color filter that transmits light of a specific wavelength is arranged on the light incident surface side of the flat solid-state imaging device is generally used. Color filters that transmit blue (B) light, green (G) light, and red (R) light are regularly arranged on each two-dimensionally arranged PD that is currently widely used in digital cameras and the like. Single-plate solid-state imaging devices are well known.

In recent years, development of solid-state imaging devices having a structure in which an organic photoelectric conversion film is formed on a signal readout substrate has been advanced.
In solid-state imaging devices and photoelectric conversion devices using such an organic photoelectric conversion film, responsiveness and photoelectric conversion efficiency are particularly problematic.

  Under such circumstances, for example, Patent Document 1 and Patent Document 2 disclose a photoelectric conversion material having a specific structure and a photoelectric conversion element manufactured using the photoelectric conversion material.

JP 2011-119745 A JP 2012-77064 A

  In recent years, further improvement in responsiveness has been demanded for image sensors and optical sensors. Accordingly, further improvement in responsiveness has been demanded for the photoelectric conversion elements used for these. In particular, photoelectric conversion elements such as silicon photodiodes are required to have excellent photoelectric conversion efficiency in a long wave region (for example, a wavelength of 600 to 700 nm).

  Further, from the viewpoint of the manufacturing process, when the photoelectric conversion material is continuously deposited for a long time, it is required that the performance such as responsiveness does not easily change even when the latter batch is obtained. That is, the photoelectric conversion material is required to have excellent vapor deposition stability.

  Under these circumstances, when the present inventors produced a photoelectric conversion element using the photoelectric conversion material disclosed in Patent Document 1 and Patent Document 2, the level of responsiveness and photoelectric conversion efficiency in the long-wave region is recently required. It became clear that it did not meet. In addition, it became clear that the deposition stability does not meet the level required recently.

Then, in view of the said situation, this invention aims at providing the photoelectric conversion material which is excellent in vapor deposition stability, and is excellent in the responsiveness and photoelectric conversion efficiency in a long wave area | region when it is set as an element.
Another object of the present invention is to provide a photoelectric conversion element using the photoelectric conversion material, a method for using the photoelectric conversion element, and an optical sensor and an imaging element including the photoelectric conversion element.

  As a result of intensive studies on the above problems, the present inventors have found that the compound (A) represented by the formula (1), which will be described later, has excellent vapor deposition stability as a photoelectric conversion material. It was found that the photoelectric conversion efficiency in the region was excellent, and the present invention was completed. That is, the present inventors have found that the above problem can be solved by the following configuration.

(1) The photoelectric conversion material which is a compound (A) represented by following formula (1).

(In Formula (1), R < ¹ > -R < ⁸ > represents a hydrogen atom or a substituent each independently.
R ^{9 to} R ¹¹ each independently represents a hydrogen atom or a substituent. n represents an integer of 0 or more. R ⁹ and R ¹⁰ , R ⁹ and R ¹¹ may be bonded to each other to form a ring. When n is 2 or more, a plurality of R ^{9 s} and a plurality of R ^{10 s} may be bonded to each other to form a ring.
Ar ¹ and Ar ² each independently represents an aryl group or a heteroaryl group which may have a substituent. When Ar ¹ has a substituent, the substituent that Ar ¹ has must not be bonded to R ² or R ³ . When Ar ² has a substituent, the substituent that Ar ² has may be bonded to R ¹ or R ⁸ to form a ring.
La represents a group selected from the group consisting of> CR ^1a R ^1b ,> NR ^1c , an optionally substituted alkenylene group,> SiR ^1d R ^1e , —O—, and —S—. Here, R ^1a , R ^1b , R ^1c , R ^1d and R ^1e each independently represent a hydrogen atom or a substituent.
m represents 0 or 1.
Z ₁ represents a ring containing at least two carbon atoms and 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. )
(2) The photoelectric conversion material according to (1), wherein the compound (A) is a compound (a1) represented by the following formula (2).

(In Formula (2), R < ¹ > -R < ⁸ > represents a hydrogen atom or a substituent each independently.
R ^{9 to} R ¹¹ each independently represents a hydrogen atom or a substituent. n represents an integer of 0 or more. R ⁹ and R ¹⁰ , R ⁹ and R ¹¹ may be bonded to each other to form a ring. When n is 2 or more, a plurality of R ^{9 s} and a plurality of R ^{10 s} may be bonded to each other to form a ring.
Ar ¹ and Ar ² each independently represents an aryl group or a heteroaryl group which may have a substituent. When Ar ¹ has a substituent, the substituent that Ar ¹ has must not be bonded to R ² or R ³ . When Ar ² has a substituent, the substituent that Ar ² has may be bonded to R ¹ or R ⁸ to form a ring.
La represents a group selected from the group consisting of> CR ^1a R ^1b ,> NR ^1c , an optionally substituted alkenylene group,> SiR ^1d R ^1e , —O—, and —S—. Here, R ^1a , R ^1b , R ^1c , R ^1d and R ^1e each independently represent a hydrogen atom or a substituent.
Z ₁ represents a ring containing at least two carbon atoms and 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. )
(3) The photoelectric conversion material according to (1) or (2) above, wherein Z ₁ is a ring represented by the following formula (Z1).
(In the formula (Z1), Z ₂ represents a ring containing at least 3 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. * Represents the bonding position with the carbon atom to which R ¹¹ is bonded.)
(4) The photoelectric conversion material according to any one of (1) to (3), wherein n is 0.
(5) The photoelectric conversion material according to any one of (1) to (4), wherein Ar ¹ or Ar ² is an aryl group which may have a substituent.
(6) The above La is a group represented by> CR ^1a R ^1b (wherein R ^1a and R ^1b each independently represents a hydrogen atom or a hydrocarbon group). The photoelectric conversion material according to any one of 5).
(7) The photoelectric conversion material according to any one of (1) to (6), which does not contain an F atom.
(8) The photoelectric conversion material according to any one of (1) to (7), which does not contain a halogen atom.
(9) A photoelectric conversion element comprising a conductive film, a photoelectric conversion film containing the photoelectric conversion material according to any one of (1) to (8), and a transparent conductive film in this order.
(10) The photoelectric conversion element according to (9), wherein the photoelectric conversion film further contains an organic n-type semiconductor.
(11) The photoelectric conversion element according to (10), wherein the organic n-type semiconductor includes fullerenes selected from the group consisting of fullerenes and derivatives thereof.
(12) Content of the fullerenes relative to the total content of the photoelectric conversion material and the fullerenes (= film thickness in terms of a single layer of the fullerenes / (film thickness in terms of a single layer of the photoelectric conversion material) + The film thickness of the fullerenes in terms of a single layer)) is 50% by volume or more.
(13) The photoelectric conversion element according to any one of (9) to (12), wherein a charge blocking layer is disposed between the conductive film and the transparent conductive film.
(14) The photoelectric conversion element according to (13), wherein the charge blocking layer is an electron blocking layer, and an ionization potential of a compound forming the electron blocking layer is less than 5.5 eV.
(15) The photoelectric conversion element according to any one of (9) to (14), wherein the photoelectric conversion film is formed by a vacuum vapor deposition method.
(16) The photoelectric conversion element according to any one of (9) to (15), wherein light is incident on the photoelectric conversion film through the transparent conductive film.
(17) The photoelectric conversion element according to any one of (9) to (16), wherein the transparent conductive film is made of a transparent conductive metal oxide.
(18) An optical sensor including the photoelectric conversion element according to any one of (9) to (17).
(19) An imaging device including the photoelectric conversion device according to any one of (9) to (17).
(20) A method of using the photoelectric conversion element according to any one of (9) to (17) above,
The method for using a photoelectric conversion element, wherein the conductive film and the transparent conductive film are a pair of electrodes, and an electric field of 1 × 10 ⁻⁴ to 1 × 10 ⁷ V / cm is applied between the pair of electrodes.

  As shown below, according to the present invention, the deposition stability is excellent, and when it is made into an element, responsiveness and photoelectric conversion efficiency in the long wave region (hereinafter referred to as “photoelectric conversion efficiency in the long wave region” are simply referred to as “photoelectric conversion efficiency”. Another object is to provide a photoelectric conversion material excellent in the above.

Fig.1 (a) and FIG.1 (b) are cross-sectional schematic diagrams which respectively show one embodiment of a photoelectric conversion element. FIG. 2 is a schematic cross-sectional view showing an embodiment of an image sensor (for one pixel).

[Photoelectric conversion material]
The photoelectric conversion material of this invention is a compound (A) represented by Formula (1) mentioned later. Since the photoelectric conversion material of the present invention has a specific structure represented by the formula (1) described later, it exhibits excellent vapor deposition stability, and also exhibits excellent responsiveness and photoelectric conversion efficiency when formed into an element. it is conceivable that.

The reason is not clear, but it is presumed that it is as follows.
The compound (A) is a compound having a structure in which a triarylamine and a ring represented by Z ₁ are linked, as can be seen from the formula (1) described later. Since the triarylamine exhibits an electron donating property (donor property) and the ring represented by Z ₁ exhibits an electron accepting property (acceptor property), good charge separation occurs in the molecule of the compound due to light absorption. .
Here, the compound (A) has a monovalent aryl group on the aryl of the triarylamine, as can be seen from the formula (1) described later. Triarylamine forms a ring (a ring containing La in formula (1) described later). Therefore, it is considered that the packing between molecules is appropriately formed through the triarylamine, and the deposition temperature can be suppressed while maintaining the decomposition temperature (melting point). As a result, it is considered that excellent vapor deposition stability is exhibited. This indicates that the triarylamine has a monovalent aryl group on the aryl of the triarylamine, but the triarylamine does not form a ring (a ring containing La in formula (1) described later), as shown in a comparative example described later. In the case (Comparative Example 1) and the triarylamine forms a ring, but the monovalent aryl group is not present on the aryl of the triarylamine (Comparative Example 2 and Comparative Example 3), the deposition stability is high. It is speculated that it will be insufficient.
In addition, since the compound (A) has the structure as described above, the conjugation of triarylamine is broadened, and the electron donating property of triarylamine is increased. It is considered that the photoelectric conversion efficiency is excellent. This indicates that, when the triarylamine does not form a ring (Comparative Example 1), the photoelectric conversion efficiency in the long wave region becomes insufficient or a monovalent aryl group can be used instead, as shown in Comparative Examples described later. In addition, when an alkyl group or a condensed ring structure is introduced into triarylamine (Comparative Example 2 and Comparative Example 3), it is presumed that the photoelectric conversion efficiency in the long wave region is excellent but the responsiveness becomes insufficient.

Hereinafter, the photoelectric conversion material of the present invention will be described in detail.
The photoelectric conversion material of the present invention is a compound (A) represented by the following formula (1).

In said formula (1), R < ¹ > -R < ⁸ > represents a hydrogen atom or a substituent each independently. Examples of the substituent include a substituent W described later. R ^{1 to} R ⁸ are preferably hydrogen atoms.

In said formula (1), R < ⁹ > -R < ¹¹ > represents a hydrogen atom or a substituent each independently. Examples of the substituent include a substituent W described later.
When R ⁹ or R ¹⁰ is a substituent, an alkyl group having 1 to 10 carbon atoms (particularly a methyl group, an ethyl group, a propyl group, an i-propyl group, or a t-butyl group), an alkenyl group having 2 to 10 carbon atoms (In particular, a vinyl group or an allyl group), an alkoxy group having 1 to 10 carbon atoms, or an alkylthio group having 1 to 10 carbon atoms is preferable.
R ¹¹ is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (particularly a methyl group or an ethyl group).
In the above formula (1), n represents an integer of 0 or more. Especially, it is preferable that it is 0-3, and it is more preferable that it is 0.
R ⁹ and R ¹⁰ , R ⁹ and R ¹¹ may be bonded to each other to form a ring. When n is 2 or more, a plurality of R ^{9 s} and a plurality of R ^{10 s} may be bonded to each other to form a ring. Examples of the ring formed include a ring R described later.

In the above formula (1), Ar ¹ and Ar ² each independently represents an aryl group or heteroaryl group which may have a substituent. Examples of the substituent include a substituent W described later. Ar ¹ or Ar ² is preferably an aryl group which may have a substituent.
Ar ¹ and Ar ² are preferably those that do not have a substituent because they are more excellent in vapor deposition stability and more responsive when made into an element.

When Ar ¹ or Ar ² is an aryl group, the aryl group is preferably an aryl group having 6 to 30 carbon atoms, and more preferably an aryl group having 6 to 20 carbon atoms. Specific examples of the ring constituting the aryl group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a triphenylene ring, a naphthacene ring, and a biphenyl ring. And a terphenyl ring (the three benzene rings may be connected in any connection manner).

When Ar ¹ or Ar ² is a heteroaryl group, it is preferably a heteroaryl group consisting of a 5-membered, 6-membered or 7-membered ring or a condensed ring thereof. 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, an imidazoline ring, and an imidazolidine. Ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, thiine 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, benzothiophene ring, thienothiophene ring, indole ring, indoline ring, isoindole ring, benzoxazole ring, benzothiazole ring, indazole ring, benzimidazole Quinoline ring, isoquinoline ring, cinnoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, xanthene ring, acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, phenoxazine ring, Examples include thianthrene ring, indolizine ring, quinolidine ring, quinuclidine ring, naphthyridine ring, purine ring, pteridine ring and the like.

When Ar ¹ has a substituent, the substituent that Ar ¹ has must not be bonded to R ² or R ³ .
When Ar ² has a substituent, the substituent that Ar ² has may be bonded to R ¹ or R ⁸ to form a ring. Examples of the ring formed include a ring R described later.

In the above formula (1), La is> CR ^1a R ^1b ,> NR ^1c , an ^optionally substituted alkenylene group,> SiR ^1d R ^1e , —O—, and —S—. Represents a selected group. Here, R ^1a , R ^1b , R ^1c , R ^1d and R ^1e each independently represent a hydrogen atom or a substituent. Examples of the substituent include a substituent W described later. Especially, it is preferable that it is a C1-C10 alkyl group (especially methyl group, ethyl group).
La is preferably a group represented by> CR ^1a R ^1b (wherein R ^1a and R ^1b each independently represents a hydrogen atom or a hydrocarbon group).
Specific examples in the case where R ^1a or R ^1b is a hydrocarbon group include an aliphatic hydrocarbon group and an aromatic hydrocarbon group. Among them, an aliphatic hydrocarbon group is preferable.
The aliphatic hydrocarbon group may be linear, branched or cyclic. Specific examples of the aliphatic hydrocarbon group include a linear or branched alkyl group (particularly having 1 to 20 carbon atoms), a linear or branched alkenyl group (particularly having 2 to 20 carbon atoms), Examples thereof include a linear or branched alkynyl group (particularly, having 2 to 20 carbon atoms).
Examples of the aromatic hydrocarbon group include an aryl group and a naphthyl group. As said aryl group, C6-C18 aryl groups, such as a phenyl group, a tolyl group, a xylyl group, etc. are mentioned, for example.

  In the above formula (1), m represents 0 or 1. Among these, 1 is preferable.

  When m = 1, the above formula (1) is the following formula (2).

  When m = 0, the above formula (1) is the following formula (3).

In the above formula (1), Z ₁ represents 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. .
As such a ring, what is normally used as an acidic nucleus with a merocyanine dye is preferable, and specific examples thereof include the following.

(A) 1,3-dicarbonyl nucleus: For example, 1,3-indandione nucleus, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 1,3-dioxane-4,6 -Dione etc.
(B) pyrazolinone nucleus: for example, 1-phenyl-2-pyrazolin-5-one, 3-methyl-1-phenyl-2-pyrazolin-5-one, 1- (2-benzothiazoyl) -3-methyl- 2-pyrazolin-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) Oxindole nucleus: For example, 1-alkyl-2,3-dihydro-2-oxindole and the like.
(E) 2,4,6-triketohexahydropyrimidine nucleus: for example, barbituric acid or 2-thiobarbituric acid and its derivatives. Examples of the derivatives include 1-alkyl compounds such as 1-methyl and 1-ethyl, 1,3-dialkyl compounds such as 1,3-dimethyl, 1,3-diethyl and 1,3-dibutyl, 1,3-diaryls such as diphenyl, 1,3-di (p-chlorophenyl), 1,3-di (p-ethoxycarbonylphenyl), 1-alkyl-1-aryls such as 1-ethyl-3-phenyl And 1,3-diheterocyclic substituents such as 1,3-di (2-pyridyl) and the like.
(F) 2-thio-2,4-thiazolidinedione nucleus: for example, rhodanine and derivatives thereof. Examples of the derivatives include 3-alkylrhodanine such as 3-methylrhodanine, 3-ethylrhodanine and 3-allylrhodanine, 3-arylrhodanine such as 3-phenylrhodanine, and 3- (2-pyridyl). ) 3-position heterocyclic substituted rhodanine such as rhodanine.

(G) 2-thio-2,4-oxazolidinedione (2-thio-2,4- (3H, 5H) -oxazoledione nucleus: for example, 3-ethyl-2-thio-2,4-oxazolidinedione and the like.
(H) Tianaphthenone nucleus: For example, 3 (2H) -thianaphthenone-1,1-dioxide and the like.
(I) 2-thio-2,5-thiazolidinedione nucleus: For example, 3-ethyl-2-thio-2,5-thiazolidinedione and the like.
(J) 2,4-thiazolidinedione nucleus: For example, 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, 3-phenyl-2,4-thiazolidinedione and the like.
(K) Thiazolin-4-one nucleus: For example, 4-thiazolinone, 2-ethyl-4-thiazolinone and the like.
(L) 2,4-imidazolidinedione (hydantoin) nucleus: for example, 2,4-imidazolidinedione, 3-ethyl-2,4-imidazolidinedione, etc.
(M) 2-thio-2,4-imidazolidinedione (2-thiohydantoin) nucleus: for example, 2-thio-2,4-imidazolidinedione, 3-ethyl-2-thio-2,4-imidazolidine Zeon etc.
(N) Imidazolin-5-one nucleus: For example, 2-propylmercapto-2-imidazolin-5-one and the like.
(O) 3,5-pyrazolidinedione nucleus: for example, 1,2-diphenyl-3,5-pyrazolidinedione, 1,2-dimethyl-3,5-pyrazolidinedione and the like.
(P) Benzothiophen-3-one nucleus: for example, benzothiophen-3-one, oxobenzothiophen-3-one, dioxobenzothiophen-3-one and the like.
(Q) Indanone nucleus: For example, 1-indanone, 3-phenyl-1-indanone, 3-methyl-1-indanone, 3,3-diphenyl-1-indanone, 3,3-dimethyl-1-indanone and the like.

Z ₁ may have a substituent. Examples of the substituent include a substituent W described later.

Z ₁ is preferably a group represented by the following formula (Z1) for reasons of excellent sensitivity.

In formula (Z1), Z ₂ represents a ring containing at least 3 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.
In formula (Z1), * represents a bonding position with the carbon atom to which R ¹¹ is bonded.

The compound (A) is preferably the compound (a1) represented by the above formula (2).
The compound (A) preferably does not contain F atoms (fluorine atoms), and more preferably does not contain a halogen atom, because the photoelectric conversion efficiency is more excellent when formed into an element.

(Substituent W)
It describes about the substituent W in this specification.
Examples of the substituent W include a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, an aryl group, Heterocyclic group (may be referred to as heterocyclic group), cyano group, hydroxy group, nitro group, carboxy group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyl Oxy group, aryloxycarbonyloxy group, amino group (including anilino group), ammonio group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfo Ruamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, Aryl or heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, phosphono group, silyl group, hydrazino group, ureido group, boronic acid group (-B (OH) ₂ ), A phosphato group (—OPO (OH) ₂ ), a sulfato group (—OSO ₃ H), and other known substituents.
Details of the substituent are described in paragraph [0023] of JP-A-2007-234651.

(Ring R)
It describes about the ring R in this specification.
Examples of the ring R include an aromatic hydrocarbon ring, an aromatic heterocycle, a non-aromatic hydrocarbon ring, a non-aromatic heterocycle, or a polycyclic fused ring formed by combining these. More specifically, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring , Pyrazine ring, pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole Ring, phenanthridine ring, acridine ring, phenanthroline ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, phenazine ring, cyclopentane ring, cyclohexane ring, pyro Jin ring, piperidine ring, a tetrahydrofuran ring, tetrahydropyran ring, a tetrahydrothiophene ring, a tetrahydrothiopyran ring.
The ring R may have the substituent W.

  Compound (A) can be produced by carrying out a partial modification according to a known method. Although the specific example of a compound (A) is shown below, this invention is not limited to these.

  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, when an electrode and another material exist, it is preferable in order to perform transfer of the electron with the material with small electrical resistance. IP can be obtained using AC-2 manufactured by Riken Keiki Co., Ltd.

The compound (A) preferably has an absorption maximum at 400 nm or more and less than 720 nm in the UV-visible absorption spectrum, and the peak wavelength (absorption maximum wavelength) of the absorption spectrum is 450 nm or more and 700 nm from the viewpoint of broadly absorbing light in the visible region. The following is preferable, 480 nm to 700 nm is more preferable, and 510 nm to 680 nm is further preferable.
The absorption maximum wavelength of the compound (A) can be measured using a chloroform solution of the compound (A) using, for example, UV-2550 manufactured by Shimadzu Corporation. The concentration of the chloroform solution is preferably 5 × 10 ⁻⁵ to 1 × 10 ⁻⁷ mol / l, more preferably 3 × 10 ⁻⁵ to 2 × 10 ⁻⁶ mol / l, and 2 × 10 ^{−5 to} 5 × 10 ^{−. 6} mol / l is particularly preferred.

The compound (A) preferably has an absorption maximum at 400 nm or more and less than 720 nm in the ultraviolet-visible absorption spectrum, and the molar extinction coefficient at the absorption maximum wavelength is 10,000 mol ⁻¹ · l · cm ⁻¹ or more. In order to reduce the film thickness of the photoelectric conversion film and to obtain an element having high charge collection efficiency and high sensitivity characteristics, a material having a large molar extinction coefficient is preferable. Preferably 10000mol ^-1 · l · cm ^-1 or more molar extinction coefficient of the compound (A), more preferably 30000mol ^-1 · l · cm ^-1 or more, 50000mol ^-1 · l · cm ^-1 or more is particularly preferred . The molar extinction coefficient of compound (A) is measured with a chloroform solution.

The compound (A) is preferable because the difference between the melting point and the vapor deposition temperature (melting point−vapor deposition temperature) is larger, so that the compound (A) is less likely to be decomposed during vapor deposition, and the vapor deposition rate can be increased by applying a higher temperature. The difference between the melting point and the deposition temperature (melting point−deposition temperature) is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, and still more preferably 60 ° C. or higher.
Moreover, 240 degreeC or more is preferable, as for melting | fusing point of a compound (A), 280 degreeC or more is more preferable, and 300 degreeC or more is further more preferable. A melting point of 300 ° C. or higher is preferable because it hardly melts before vapor deposition and can form a stable film, and a decomposition product of the compound is relatively unlikely to be generated, so that the photoelectric conversion performance is hardly lowered.
The vapor deposition temperature of the compound is such that the crucible is heated at a vacuum of 4 × 10 ⁻⁴ Pa or less and the vapor deposition rate reaches 2.6 Å / s (2.6 × ^{10 −10} m / s).

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

  The molecular weight of the compound (A) is preferably 300 to 1500, more preferably 400 to 1000, and particularly preferably 500 to 900.

  The compound (A) is particularly useful as a material for a photoelectric conversion film used for an image sensor, an optical sensor, or a photovoltaic cell. In general, the compound (A) functions as an organic p-type semiconductor (compound) in the photoelectric conversion film. As other applications, it can also 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 pharmaceutical material, a fluorescent diagnostic material, and the like.

[Photoelectric conversion element]
The photoelectric conversion element of this invention is equipped with a conductive film, the photoelectric conversion film containing the photoelectric conversion material (compound (A)) of this invention mentioned above, and a transparent conductive film in this order.

In FIG. 1, the cross-sectional schematic diagram of one embodiment of the photoelectric conversion element of this invention is shown.
A photoelectric conversion element 10a shown in FIG. 1A includes a conductive film (hereinafter also referred to as a lower electrode) 11 that functions as a lower electrode, an electron blocking layer 16A formed on the lower electrode 11, and an electron blocking layer 16A. The photoelectric conversion film 12 formed above and a transparent conductive film (hereinafter also referred to as an upper electrode) 15 functioning as an upper electrode are stacked in this order.
FIG. 1B shows a configuration example of another photoelectric conversion element. The photoelectric conversion element 10b shown in FIG. 1B 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 stacked in this order on a lower electrode 11. Have. Note that the stacking order of the electron blocking layer 16A, the photoelectric conversion film 12, and the hole blocking layer 16B in FIGS. 1A and 1B may be reversed depending on the application and characteristics.

In the configuration of the photoelectric conversion element 10 a (10 b), it is preferable that light is incident on the photoelectric conversion film 12 through the transparent conductive film 15.
Moreover, when 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 ⁻³ to 1 × 10 ⁷ V / cm is applied between the pair of electrodes, It is more preferable to apply an electric field of 1 × 10 ⁻⁴ to 1 × 10 ⁷ V / cm. From the viewpoint of performance and power consumption, an electric field of 1 × 10 ⁻⁴ to 1 × 10 ⁶ V / cm is preferably applied, and an electric field of 1 × 10 ^{−5 to} 5 × 10 ⁵ V / cm is preferably applied. More preferred.
In addition, about the voltage application method, in FIG. 1 (a) and (b), it is preferable to apply so that the electron blocking layer 16A side may become a cathode and the photoelectric converting film 12 side may become an anode. When the photoelectric conversion element 10a (10b) is used as an optical sensor, or when it is incorporated into an image sensor, voltage can be applied by the same method.

Below, the aspect of each layer (a photoelectric conversion film, a lower electrode, an upper electrode, an electron blocking layer, a hole blocking layer, etc.) which comprises the photoelectric conversion element 10a (10b) is explained in full detail.
First, the photoelectric conversion film will be described in detail.

<Photoelectric conversion film>
The photoelectric conversion film contains the above-described photoelectric conversion material (compound (A)) of the present invention.
The compound (A) is as described above.

(Other materials)
The photoelectric conversion film may further contain an organic p-type semiconductor (compound) or an organic n-type semiconductor (compound) photoelectric conversion material.
The organic p-type semiconductor (compound) is a donor-type organic semiconductor (compound), which is mainly represented by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound. For example, a triarylamine compound, a benzidine compound, a pyrazoline compound, a styrylamine compound, a hydrazone compound, a triphenylmethane compound, a carbazole compound, or the like can be used.

  An organic n-type semiconductor (compound) is an acceptor organic semiconductor, and is mainly represented by an electron-transporting organic compound and means an organic compound having a property of easily accepting electrons. More specifically, the organic compound having the higher electron affinity when two organic compounds are used in contact with each other. Therefore, any organic compound can be used as the acceptor organic semiconductor as long as it is an organic compound having an electron accepting property. Preferably, fullerene or fullerene derivatives, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives), heterocycles containing nitrogen atoms, oxygen atoms, sulfur atoms Compounds (e.g. pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole, benzimidazole, benzo Triazole, benzoxazole, benzothiazole, carbazole, purine, triazolopyridazine, triazolopyrimimi , Tetrazaindene, oxadiazole, imidazopyridine, pyralidine, pyrrolopyridine, thiadiazolopyridine, dibenzazepine, tribenzazepine) And a metal complex having as a ligand.

As the organic n-type semiconductor (compound), fullerenes selected from the group consisting of fullerenes and derivatives thereof are preferable. The fullerene, fullerene C _60, fullerene C _70, fullerene C _76, fullerene C _78, fullerene C _80, fullerene C _82, fullerene C _84, fullerene C _90, fullerene C _96, fullerene C _240, fullerene C _540, mixed Fullerene is represented, and its derivative (fullerene derivative) represents a compound having a substituent added thereto. As the substituent, an alkyl group, an aryl group, or a heterocyclic group is preferable. As a fullerene derivative, the compound as described in Unexamined-Japanese-Patent No. 2007-123707 is preferable.

  The photoelectric conversion film preferably has a bulk heterostructure formed by mixing the compound (A) and fullerene or a fullerene derivative. A bulk heterostructure is a film in which an organic p-type compound (for example, compound (A)) and an organic n-type compound are mixed and dispersed in a photoelectric conversion film, and can be formed by either a wet method or a dry method. Those formed by vapor deposition are preferred. By including the heterojunction structure, it is possible to make up for the disadvantage that the carrier diffusion length of the photoelectric conversion film is short, and to improve the photoelectric conversion efficiency of the photoelectric conversion film. The bulk heterojunction structure is described in detail in JP-A-2005-303266, [0013] to [0014].

  From the viewpoint of the sensitivity of the photoelectric conversion element, the content of fullerenes with respect to the total content of the photoelectric conversion material (compound (A)) and fullerenes of the present invention (= film thickness in terms of a single layer of fullerenes / (this The photoelectric conversion material of the invention (film thickness in terms of a single layer of compound (A) + film thickness in terms of a single layer of fullerenes)) is preferably 50% by volume or more, and 60% by volume or more. It is more preferable that The upper limit is not particularly limited, but is preferably 90% by volume or less, and more preferably 80% by volume or less.

  The photoelectric conversion film (in which an organic n-type compound may be mixed) containing the compound (A) of the present invention is a non-light-emitting film and has characteristics different from those of an organic electroluminescent element (OLED). The non-light-emitting film is a film having an emission quantum efficiency of 1% or less, more preferably 0.5% or less, and still more preferably 0.1% or less.

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

  The thickness of the photoelectric conversion film 12 is preferably 10 nm to 1000 nm, more preferably 50 nm to 800 nm, and particularly preferably 100 nm to 500 nm. By setting the thickness to 10 nm or more, a suitable dark current suppressing effect can be obtained, and by setting the thickness to 1000 nm or less, more preferable photoelectric conversion efficiency can be obtained.

<Electrode>
The electrodes (upper electrode (transparent conductive film) 15 and lower electrode (conductive film) 11) are made of a conductive material. As the conductive material, a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used.
Since light is incident from the upper electrode 15, the upper electrode 15 needs to be sufficiently transparent to the light to be detected. Specifically, conductive metal oxides such as tin oxide (ATO, FTO) doped with antimony or fluorine, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), Metal thin films such as gold, silver, chromium, nickel, etc., and mixtures or laminates of these metals and conductive metal oxides, inorganic conductive materials such as copper iodide and copper sulfide, organics such as polyaniline, polythiophene, and polypyrrole Examples thereof include conductive materials and laminates of these with ITO. Among these, a transparent conductive metal oxide is preferable from the viewpoint of high conductivity and transparency.

  When a transparent conductive film such as TCO is used as the upper electrode 15, a DC short circuit or an increase in leakage current may occur. One reason for this is considered to be that fine cracks introduced into the photoelectric conversion film 12 are covered by a dense film such as TCO, and conduction with the lower electrode 11 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 unlikely to occur. By controlling the film thickness of the upper electrode 15 with respect to the film thickness of the photoelectric conversion film 12 (that is, the crack depth), an increase in leakage current can be largely suppressed. The thickness of the upper electrode 15 is desirably 1/5 or less, preferably 1/10 or less of the thickness of the photoelectric conversion film 12.

  Usually, when the conductive film is made thinner than a certain range, a rapid increase in resistance value is caused. However, in the solid-state imaging device incorporating the photoelectric conversion element according to the present embodiment, the sheet resistance is preferably 100 to 10,000 Ω / □. Well, there is a large degree of freedom in the range of film thickness that can be made thin. Further, as the thickness of the upper electrode (transparent conductive film) 15 decreases, the amount of light absorbed decreases, and the light transmittance generally increases. An increase in light transmittance is very preferable because it increases the light absorption in the photoelectric conversion film 12 and increases the photoelectric conversion ability. Considering the suppression of leakage current, the increase in the resistance value of the thin film, and the increase in transmittance due to the thinning, the thickness of the upper electrode 15 is preferably 5 to 100 nm, more preferably 5 to 20 nm. It is desirable.

  Depending on the application, the lower electrode 11 may have transparency, or conversely, may use a material that does not have transparency and reflects light. Specifically, conductive metal oxides such as tin oxide (ATO, FTO) doped with antimony or fluorine, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), Metals such as gold, silver, chromium, nickel, titanium, tungsten, and aluminum, and conductive compounds such as oxides and nitrides of these metals (for example, titanium nitride (TiN)), and these metals and conductivity Examples include mixtures or laminates with metal oxides, inorganic conductive materials such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO or titanium nitride. .

The method for forming the electrode is not particularly limited, and can be appropriately selected in consideration of suitability with the electrode material. Specifically, it can be formed by a wet method such as a printing method or 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 CVD or plasma CVD method.
When the material of the electrode is ITO, it can be formed by a method such as an electron beam method, a sputtering method, a resistance heating vapor deposition method, a chemical reaction method (such as a sol-gel method), or a dispersion of indium tin oxide. Furthermore, UV-ozone treatment, plasma treatment, or the like can be performed on a film formed using ITO. When the electrode material is TiN, various methods including a reactive sputtering method can be used, and further UV-ozone treatment, plasma treatment, and the like can be performed.

<Charge blocking layer: electron blocking layer, hole blocking layer>
The photoelectric conversion element of the present invention may have a charge blocking layer. By having this layer, the characteristics (photoelectric conversion efficiency, response speed, etc.) of the obtained photoelectric conversion element are more excellent. The charge blocking layer is preferably disposed between the conductive film and the transparent conductive film.
Examples of the charge blocking layer include an electron blocking layer and a hole blocking layer. Below, each layer is explained in full detail.

(Electronic blocking layer)
An electron donating organic material can be used for the electron blocking layer. Specifically, for low molecular weight materials, N, N′-bis (3-methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (TPD) or 4,4′-bis [N Aromatic diamine compounds such as-(naphthyl) -N-phenyl-amino] biphenyl (α-NPD), oxazole, oxadiazole, triazole, imidazole, imidazolone, stilbene derivative, pyrazoline derivative, tetrahydroimidazole, polyarylalkane, butadiene 4,4 ′, 4 ″ tris (N- (3-methylphenyl) N-phenylamino) triphenylamine (m-MTDATA), porphyrin, tetraphenylporphyrin copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, etc. Compounds, triazole derivatives, oxazizazole derivatives, Midazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, etc. can be used. As the molecular material, polymers such as phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, diacetylene, and derivatives thereof can be used. Any compound having transportability can be used, and specifically, compounds described in [0083] to [0089] of JP-A-2008-72090 are preferred.

  As a suitable aspect of the compound which forms an electron blocking layer, the compound represented by the following general formula (F-1) is mentioned, for example. By using this compound, the response speed of the obtained photoelectric conversion film is more excellent, and variations in the response speed between the manufacturing rods are further suppressed.

(In General Formula (F-1), R ″ _{11 to} R ″ ₁₈ and R ′ _{11 to} R ′ ₁₈ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, or a hydroxyl group. , An amino group, or a mercapto group, which may further have a substituent. Any one of R ″ _{15 to} R ″ ₁₈ is any one of R ′ _{15 to} R ′ _18. A ₁₁ and A ₁₂ each independently represents a group represented by the following general formula (A-1), R ″ _{11 to} R ″ ₁₄ , and R ′ _{11 to} R ′. _And substituted as any one of _14. Each Y independently represents a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom, and these may further have a substituent.

(In general formula (A-1), Ra _{1 to} Ra ₈ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, or a heterocyclic group, and these further have a substituent. * Represents a bonding position, and Xa is a single bond, oxygen atom, sulfur atom, alkylene group, silylene group, alkenylene group, cycloalkylene group, cycloalkenylene group, arylene group, divalent heterocyclic ring. A group, or an imino group, which may further have a substituent, each of S ₁₁ independently represents the following substituent (S ₁₁ ), and is substituted as any one of Ra _{1 to} Ra ₈ ; N ′ represents an integer of 0 to 4.)

(R ′ _{1 to} R ′ ₃ each independently represents a hydrogen atom or an alkyl group.)

In general formula (F-1), R ″ _{11 to} R ″ ₁₈ and R ′ _{11 to} R ′ ₁₈ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, a hydroxyl group, It represents an amino group or a mercapto group, and these may further have a substituent. Specific examples of the further substituent include the substituent W described above, preferably a halogen atom, an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, a hydroxyl group, an amino group, or a mercapto group, more preferably a halogen atom. An atom, an alkyl group, an aryl group, or a heterocyclic group, more preferably a fluorine atom, an alkyl group, or an aryl group, particularly preferably an alkyl group or an aryl group, and most preferably an alkyl group.
R ″ _{11 to} R ″ ₁₈ and R ′ _{11 to} R ′ ₁₈ are preferably a hydrogen atom, an alkyl group which may have a substituent, an aryl group, or a heterocyclic group, more preferably a hydrogen atom. , An optionally substituted 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 preferable that the substituent represented by the general formula (A-1) is independently substituted with R ″ ₁₂ and R ′ ₁₂ , and the substituent represented by the general formula (A-1) is R ″ ₁₂ and R ′ ₁₂ is each independently substituted, and R ″ _11, R ″ _{13 to} R ″ ₁₈ , R ′ _{11, and} R ′ _{13 to} R ′ _{18 each} have a hydrogen atom and optionally have 1 to 1 carbon atoms. More preferably, the substituent represented by formula (A-1) is each independently substituted with R ″ ₁₂ and R ′ ₁₂ , and R ″ _11, R ″ _13- R ″ ₁₈ , R ′ _{11 and} R ′ _{13 to} R ′ ₁₈ are hydrogen atoms.

Y independently represents a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom, and these may further have a substituent. That is, Y represents a divalent linking group composed of a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom. Among _{-C (R '21) (R} ' 22) -, - Si (R '23) (R' 24) -, - N (R '20) -, preferably, -C (R' ₂₁₎ ( R ′ ₂₂ ) — and —N (R ′ ₂₀ ) — are more preferable, and —C (R ′ ₂₁ ) (R ′ ₂₂ ) — is particularly preferable.
R ′ _{20 to} R ′ ₂₄ each independently represents a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amino group, or a mercapto group. Specific examples of the further substituent include the substituent W described above. R ′ _{20 to} R ′ ₂₄ are preferably a hydrogen atom, an alkyl group which may have a substituent, an aryl group, or a heterocyclic group, more preferably a hydrogen atom or a substituent. A good 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 a hydrogen atom or an optionally substituted carbon number. It is a C1-C18 alkyl group, Most preferably, it is a C1-C18 alkyl group.

Ra _{1 to} Ra ₈ in the general formula (A-1) are each independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amino group, or Represents a mercapto group. Specific examples of the further substituent include the substituent W described above. In addition, a plurality of these substituents may be bonded to each other to form a ring.

Ra _{1 to} Ra ₈ are preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heterocyclic group having 4 to 16 carbon atoms, and preferably a hydrogen atom or carbon number. An alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms is more preferable, and a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms is still more preferable. The alkyl group may be branched.
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 a hydrogen atom. .

Xa represents a single bond, an oxygen atom, a sulfur atom, an alkylene group, a silylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, a divalent heterocyclic group, or an imino group, and these further represent a substituent. You may have.
Xa is a single bond, an alkylene group having 1 to 13 carbon atoms, an alkenylene group having 2 to 12 carbon atoms, an arylene group having 6 to 14 carbon atoms, a heterocyclic group having 4 to 13 carbon atoms, an oxygen atom, a sulfur atom, carbon An imino group (for example, phenylimino group, methylimino group, t-butylimino group) having 1 to 12 hydrocarbon groups (preferably an aryl group or an alkyl group) or a silylene group is preferable, and a single bond, an oxygen atom, or a carbon number 1 to 6 alkylene groups (for example, methylene group, 1,2-ethylene group, 1,1-dimethylmethylene group), alkenylene groups having 2 carbon atoms (for example, —CH ₂ ═CH ₂ —), 6 to 10 carbon atoms An arylene group (for example, 1,2-phenylene group, 2,3-naphthylene group) or a silylene group is more preferable, and a single bond, an oxygen atom, or an alkylene group having 1 to 6 carbon atoms (for example, a methyl group). Down group, 1,2-ethylene group, 1,1-dimethylmethylene group) is more preferred. These substituents may further have the above-described substituent W.
Specific examples of the group represented by the general formula (A-1) include groups exemplified by the following N1 to N11. However, it is not limited to these. The group represented by formula (A-1) is preferably N-1 to N-7, more preferably N-1 to N-6, more preferably N-1 to N-3, and N-1 -N-2 is particularly preferred, and N-1 is most preferred.

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 iso-propyl group, a butyl group, or a tert-butyl group, more preferably a methyl group, an ethyl group, a propyl group, an iso-propyl group, or A tert-butyl group, more preferably a methyl group, an ethyl group, an iso-propyl group, or a tert-butyl group, and particularly 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, methyl group, ethyl group, propyl group, iso-propyl group, butyl group, or tert-butyl group, more preferably a hydrogen atom, methyl group, ethyl group, or propyl group. More preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

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.

R ′ _{1 to} R ′ ₃ may be bonded to each other to form a ring. When forming a ring, the number of ring members is not particularly limited, but is preferably a 5- or 6-membered ring, more preferably a 6-membered ring.

S ₁₁ represents the above substituent (S ₁₁ ) and is substituted as any one of Ra _{1 to} Ra ₈ . It is preferable that at least one of Ra ₃ and Ra ₆ in the general formula (A-1) independently represents the substituent (S ₁₁ ).
Preferred examples of the substituent (S ₁₁ ) include the following (a) to (x), (a) to (j) are more preferable, (a) to (h) are more preferable, and (a) to ( f) is particularly preferable, (a) to (d) are more preferable, and (a) is most preferable.

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

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

(In the general formulas (A-3) to (A-5), Ra _{33 to} Ra ₃₈ , Ra ₄₁ , Ra _{44 to} Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , Ra _{55 to} Ra ₅₈ are each independently 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 are each independently a single bond, an oxygen atom, sulfur atom, an alkylene group, a silylene group, an alkenylene group, cycloalkylene group, cycloalkenylene group, an arylene group, divalent heterocyclic group or an imino group, and these may have a substituent .Z ₃₁ , Z ₄₁ , and Z ₅₁ each independently represents a cycloalkyl ring, an aromatic hydrocarbon ring, or an aromatic heterocyclic ring, which may further have a substituent.

In the general formulas (A-3) to (A-5), Ra _{33 to} Ra ₃₈ , Ra ₄₁ , Ra _{44 to} Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , Ra _{55 to} Ra ₅₈ are each independently a hydrogen atom, A halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom) or an alkyl group is represented. A hydrogen atom or an alkyl group is preferable and a hydrogen atom is more preferable because a substituent having a low polarity is advantageous for hole transport.
When Ra _{33 to} Ra ₃₈ , Ra ₄₁ , Ra _{44 to} Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , Ra _{55 to} Ra ₅₈ represent an alkyl group, the alkyl group is preferably an alkyl group having 1 to 18 carbon atoms, A C1-C12 alkyl group is more preferable, and a C1-C6 alkyl group is still more preferable. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, or a cyclohexyl group is preferable.
In the general formulas (A-3) to (A-5), adjacent ones of Ra _{33 to} Ra ₃₈ , Ra ₄₁ , Ra _{44 to} Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , Ra _{55 to} Ra ₅₈ are bonded to each other. To form a ring. The ring R mentioned above is mentioned as a ring. The ring is preferably a benzene ring, naphthalene ring, anthracene ring, pyridine ring, pyrimidine ring or the like.

Xc ₁ , Xc ₂ , and Xc ₃ are each independently a single bond, an oxygen atom, a sulfur atom, an alkylene group, a silylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, or a divalent heterocyclic group. Or an imino group. When Xc ₁ , Xc ₂ , and Xc ₃ represent an alkylene group, a silylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, a divalent heterocyclic group, or an imino group, these further represent a substituent. You may have. Examples of the further substituent include the substituent W described above.

Xc _1, Xc _2, and Xc ₃ is a single bond, an alkylene group having 1 to 12 carbon atoms, an alkenylene group having 2 to 12 carbon atoms, an arylene group having 6 to 14 carbon atoms, heterocyclic group of 4 to 13 carbon atoms , An oxygen atom, a sulfur atom, an imino group having a hydrocarbon group having 1 to 12 carbon atoms (preferably an aryl group or an alkyl group) (for example, phenylimino group, methylimino group, t-butylimino group) is preferable, An alkylene group having 1 to 6 carbon atoms (for example, methylene group, 1,2-ethylene group, 1,1-dimethylmethylene group), an alkenylene group having 2 carbon atoms (for example, —CH ₂ ═CH ₂ —), carbon number 6 to 10 arylene groups (for example, 1,2-phenylene group and 2,3-naphthylene group) are more preferable.

Z ₃₁ , Z ₄₁ , and Z ₅₁ each independently represent a cycloalkyl ring, an aromatic hydrocarbon ring, or an aromatic heterocyclic ring. In the general formulas (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 because the photoelectric conversion element can be expected to have high heat resistance and high hole transport ability.

  The ionization potential of the compound that forms the electron blocking layer is not particularly limited, but is preferably less than 5.5 eV, and preferably less than 5.50 eV, because the response and photoelectric conversion efficiency when the device is made are more excellent. Is more preferable. The ionization potential of the compound can be determined using AC-2 manufactured by Riken Keiki Co., Ltd.

  Although it does not restrict | limit especially as a compound in which the ionization potential which forms an electron blocking layer is less than 5.50 eV, As a suitable aspect, the compound represented by a following formula (F-2) is mentioned, for example.

Definition of R _'11 ~R' ₁₄ in the formula (F-2), specific examples and preferred embodiments, respectively, the same as R _'11 ~R' ₁₄ in the above-mentioned general formula (F-1) is there.
Definition of R _"11 ~R" ₁₄ in the formula (F-2), specific examples and preferred embodiments, respectively, the same as R _"11 ~R" ₁₄ in the above-mentioned general formula (F-1) is there.
The definition, specific examples and preferred embodiments of Xa in the above formula (F-2) are the same as Xa in the above general formula (A-1).
In Formula (F-2), A ₁₁ and A ₁₂ each independently represent a group represented by General Formula (A-1) described above, and R ″ _{11 to} R ″ ₁₄ and R ′ ₁₁ , respectively. to R 'substituted as any one of _14.
In the above formula (F-2), Rf ₂₁ represents a hydrogen atom or a substituent. Examples of the substituent include the substituent W described above. Rf ₂₁ is preferably an aryl group which may have a substituent.

The electron blocking layer may be composed of a plurality of layers.
An inorganic material can also be used as the electron blocking layer. In general, since an inorganic material has a dielectric constant larger than that of an organic material, when used in an electron blocking layer, a large voltage is applied to the photoelectric conversion film, and the photoelectric conversion efficiency can be increased. Materials that can be used as an electron blocking layer include calcium oxide, chromium oxide, chromium oxide copper, manganese oxide, cobalt oxide, nickel oxide, copper oxide, gallium copper oxide, strontium copper oxide, niobium oxide, molybdenum oxide, indium copper oxide, and oxide. Examples include indium silver and iridium oxide. In the case where the electron blocking layer is a single layer, the layer can be a layer made of an inorganic material, or in the case of a plurality of layers, one or more layers can be a layer made of an inorganic material. .

(Hole blocking layer)
An electron-accepting organic material can be used for the hole blocking layer.
Examples of electron accepting materials include 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7) and other oxadiazole derivatives, anthraquinodimethane derivatives, and diphenylquinone derivatives. , Bathocuproine, bathophenanthroline, and derivatives thereof, triazole compounds, tris (8-hydroxyquinolinato) aluminum complexes, bis (4-methyl-8-quinolinato) aluminum complexes, distyrylarylene derivatives, silole compounds, etc. Can do. Moreover, even if it is not an electron-accepting organic material, it can be used if it is a material which has sufficient electron transport property. A porphyrin compound, a styryl compound such as DCM (4-dicyanomethylene-2-methyl-6- (4- (dimethylaminostyryl))-4H pyran), or a 4H pyran compound can be used. Specifically, compounds described in JP-A-2008-72090, [0073] to [0078] are preferable.

  The method for producing the charge blocking layer is not particularly limited, and can be formed by a dry film forming method or a wet film forming method. As a dry film forming 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), but physical vapor deposition such as vacuum vapor deposition is preferred. As the wet film forming method, 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, etc. can be used. From the viewpoint of high-precision patterning, the inkjet method is preferable.

  The thickness of the charge blocking layer (electron blocking layer and hole blocking layer) is preferably 10 to 200 nm, more preferably 20 to 150 nm, and particularly preferably 30 to 100 nm. This is because if the thickness is too thin, the dark current suppressing effect is lowered, and if it is too thick, the photoelectric conversion efficiency is lowered.

<Board>
The photoelectric conversion element of the present invention may further include a substrate. The type of the substrate used is not particularly limited, and a semiconductor substrate, a glass substrate, or a plastic substrate can be used.
The position of the substrate is not particularly limited, but usually a conductive film, a photoelectric conversion film, and a transparent conductive film are laminated on the substrate in this order.

<Sealing layer>
The photoelectric conversion element of the present invention may further include a sealing layer. The performance of photoelectric conversion materials may deteriorate significantly due to the presence of degradation factors such as water molecules. Ceramics such as dense metal oxides, metal nitrides, and metal nitride oxides that do not penetrate water molecules and diamond-like materials Covering and sealing the entire photoelectric conversion film with a sealing layer such as carbon (DLC) can prevent the deterioration.
In addition, as a sealing layer, you may select and manufacture a material according to description of Paragraph [0210]-[0215] of Unexamined-Japanese-Patent No. 2011-082508.

[Optical sensor]
Examples of the use of the photoelectric conversion element include a photovoltaic cell and an optical sensor, but the photoelectric conversion element of the present invention is preferably used as an optical sensor. As an optical sensor, the photoelectric conversion element used alone may be used, or a line sensor in which the photoelectric conversion elements are linearly arranged or a two-dimensional sensor arranged on a plane is preferable. The photoelectric conversion element of the present invention converts optical image information into an electrical signal using an optical system and a drive unit like a scanner in a line sensor, and optically converts optical image information like an imaging module in a two-dimensional sensor. The system functions as an image sensor by forming an image on a sensor and converting it into an electrical signal.
Since the photovoltaic cell is a power generation device, the efficiency of converting light energy into electrical energy is an important performance, but dark current, which is a current in a dark place, is not a functional problem. Further, a subsequent heating step such as installation of a color filter is not necessary. Since it is important to convert light and dark signals into electrical signals with high accuracy, the efficiency of converting light intensity into current is also important for optical sensors. Low dark current is required. In addition, resistance to subsequent processes is also important.

[Image sensor]
Next, a configuration example of an image sensor including a photoelectric conversion element will be described.
In the configuration examples described below, members having the same configuration / action as those already described are denoted by the same or corresponding reference numerals in the drawings, and the description is simplified or omitted.
An image sensor is an element that converts optical information of an image into an electric signal. A plurality of photoelectric conversion elements are arranged on a matrix in the same plane, and an optical signal is converted into an electric signal in each photoelectric conversion element (pixel). That can be output to the outside of the imaging device for each pixel sequentially. Therefore, one 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 sensor for explaining an embodiment of the present invention. This imaging device is used by being mounted on an imaging device such as a digital camera or a digital video camera, an imaging module such as an electronic endoscope or a mobile phone, or the like.
This imaging element has a plurality of photoelectric conversion elements having the configuration shown in FIG. 1 and a circuit board on which a readout circuit for reading a signal corresponding to the charge generated in the photoelectric conversion film of each photoelectric conversion element is formed. A plurality of photoelectric conversion elements are arranged one-dimensionally or two-dimensionally on the same surface above the circuit board.

  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 112, light shielding layer 113, protective layer 114, counter electrode voltage supply 115, and readout circuit 116.

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

  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 the photoelectric conversion elements provided on the plurality of pixel electrodes 104 so as to cover them.

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

  The connection part 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 part 115. The counter electrode voltage supply unit 115 is formed on the substrate 101 and applies a predetermined voltage to the counter electrode 108 via the connection unit 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 sensor, the power supply voltage is boosted by a booster circuit such as a charge pump to supply the predetermined voltage.

  The readout circuit 116 is provided on the substrate 101 corresponding to each of the plurality of pixel electrodes 104, and reads out a signal corresponding to the charge collected by the corresponding pixel electrode 104. The readout circuit 116 is configured by, for example, a CCD, a CMOS circuit, a TFT circuit, or the like, and is shielded by a light shielding layer (not shown) disposed in the insulating layer 102. The readout circuit 116 is electrically connected to the corresponding pixel electrode 104 via the connection unit 105.

  The buffer layer 109 is formed on the counter electrode 108 so as to cover the counter electrode 108. The sealing layer 110 is formed on the buffer layer 109 so as to cover the buffer layer 109. The color filter 111 is formed at a position facing each pixel electrode 104 on the sealing layer 110. The partition wall 112 is provided between the color filters 111 and is for improving the light transmission efficiency of the color filter 111.

  The light shielding layer 113 is formed in a region other than the region where the color filter 111 and the partition 112 on the sealing layer 110 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 112, and the light shielding layer 113, and protects the entire image sensor 100.

  In the imaging device 100 configured as described above, when light is incident, the light is incident on the photoelectric conversion film 107, and charges are generated here. Holes in the generated charges are collected by the pixel electrode 104, and a voltage signal corresponding to the amount is output to the outside of the image sensor 100 by the readout circuit 116.

The manufacturing method of the image sensor 100 is as follows.
On the circuit board on which the common electrode voltage supply unit 115 and the readout circuit 116 are formed, the connection units 105 and 106, the plurality of connection electrodes 103, the plurality of pixel electrodes 104, and the insulating layer 102 are formed. The plurality of pixel electrodes 104 are arranged on the surface of the insulating layer 102 in a square lattice pattern, for example.

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

  Even in the method of manufacturing the image sensor 100, a plurality of processes can be performed even when a step of placing the image sensor 100 being manufactured under non-vacuum is added between the process of forming the photoelectric conversion film 107 and the process of forming the sealing layer 110. The performance deterioration of the photoelectric conversion element can be prevented. By adding this step, it is possible to suppress the manufacturing cost while preventing the performance degradation of the image sensor 100.

  Examples are shown below, but the present invention is not limited thereto.

<Example 1>
The following compound (1) (photoelectric conversion material of Example 1) was synthesized according to the following synthesis scheme.

(Preparation of photoelectric conversion element)
Using the obtained compound (1), a photoelectric conversion element having the form of FIG. Here, the photoelectric conversion element includes the lower electrode 11, the electron blocking layer 16 </ b> A, the photoelectric conversion film 12, and the upper electrode 15.
Specifically, an amorphous ITO film is formed on a glass substrate by sputtering to form a lower electrode 11 (thickness: 30 nm), and the following compound (EB-1) (ionization) is formed on the lower electrode 11. An electron blocking layer 16A (thickness: 100 nm) was formed by forming a film with a potential of 5.45 eV) by a vacuum heating vapor deposition method.
Further, in a state where the substrate temperature is controlled at 25 ° C., the compound (1) and fullerene (C ₆₀ ) on the electron blocking layer 16A are co-distributed by vacuum heating deposition so as to be 120 nm and 280 nm, respectively, in terms of a single layer. A photoelectric conversion film 12 was formed by vapor deposition. Here, vapor deposition was performed so that the vapor deposition rate was 2.6 （(angstrom) / second (2.6 × 10 ⁻¹⁰ m / second).
Further, an amorphous ITO film was formed on the photoelectric conversion film 12 by sputtering to form an upper electrode 15 (transparent conductive film) (thickness: 10 nm). An SiO film was formed as a sealing layer on the upper electrode 15 by heating vapor deposition, and then an aluminum oxide (Al ₂ O ₃ ) layer was formed thereon by ALCVD to produce a photoelectric conversion element.

<Examples 2-6, Comparative Examples 1-3>
By using a known method, the following compounds (2) to (6) (photoelectric conversion materials of Examples 2 to 6) and the following comparative compounds (1) to (3) (Comparative Examples 1 to 3) Photoelectric conversion material) was synthesized. The compound was identified by MS measurement and ¹ H-NMR measurement.
Moreover, the photoelectric conversion element was produced according to the procedure similar to Example 1 except using the compound shown in Table 1 instead of the compound of (1).
In addition, the compounds of the following (1) to (6) correspond to the compound (A) represented by the above formula (1).

<Confirmation of driving (measurement of dark current)>
About each obtained photoelectric conversion element, it was confirmed whether it functions as a photoelectric conversion element. Specifically, a voltage was applied to the lower electrode and the upper electrode of the photoelectric conversion element so that the electric field strength was 2.5 × 10 ⁵ V / cm, and current values in a dark place and a bright place were measured. As a result, each photoelectric conversion element showed a dark current of 100 nA / cm ² or less in the dark place, but showed a current of 10 μA / cm ² or more in the bright place, and it was confirmed that the photoelectric conversion element functions as a photoelectric conversion element.

<Evaluation of photoelectric conversion efficiency (external quantum efficiency)>
The photoelectric conversion efficiency in a long wave area | region was evaluated about each obtained photoelectric conversion element. Specifically, the evaluation was as follows.
First, a voltage was applied to the photoelectric conversion element so that the electric field strength was 2.0 × 10 ⁵ V / cm. Then, the external quantum efficiency in 640 nm was measured by irradiating light from the upper electrode (transparent conductive film) side. The external quantum efficiency was measured using an Optel constant energy quantum efficiency measuring device. The amount of light irradiated was 50 uW / cm ² . The results are shown in Table 1.
When the external quantum efficiency of Example 1 is 1, the relative value is 0.9 or more is “A”, the one less than 0.9 is 0.8 or more and “B” is less than 0.8. Those with 6 or more were designated as “C”, and those with less than 0.6 were designated as “D”. Practically, it is preferably “A” or “B”, and more preferably “A”.

<Evaluation of responsiveness>
Responsiveness was evaluated for each obtained photoelectric conversion element. Specifically, the evaluation was as follows.
First, a voltage was applied to the photoelectric conversion element so that the electric field strength was 2.0 × 10 ⁵ V / cm. Thereafter, the LED was turned on instantaneously, light was irradiated from the upper electrode (transparent conductive film) side, the photocurrent at that time was measured with an oscilloscope, and the rise time from 0 to 98% signal intensity was obtained. . The results are shown in Table 1.
In addition, when the rise time in Example 1 is 1, the relative value is less than 1.2, “A”, the value of 1.2 to 2.0 is “B”, and the value of 2.0 to 3.0 Less than "C" and 3.0 or more are "D". Practically, it is preferably “A” or “B”, and more preferably “A”.

<Evaluation of deposition stability (decrease in responsiveness after continuous deposition for 8 hours)>
In order to compare the vapor deposition stability of each obtained photoelectric conversion material, the decrease in the responsiveness after 8 hours continuous vapor deposition was investigated using each photoelectric conversion material. Specifically, the evaluation was as follows.
First, continuous vapor deposition is performed with the vapor deposition rate fixed at 2.6 Å / sec, and the photoelectric conversion element is produced immediately after “deposition start” and “after 8 hours from the start of vapor deposition” according to the same procedure as the production of the photoelectric conversion element described above. Was made. Then, the rise time from 0 to 98% signal intensity is evaluated according to the same procedure as the evaluation of responsiveness described above for each of the “elements produced immediately after the start of vapor deposition” and “elements produced after 8 hours from the start of vapor deposition”. The decrease in responsiveness was examined as follows.
Decrease in responsiveness = (rise time of an element produced 8 hours after the start of vapor deposition) / (rise time of an element produced immediately after the start of vapor deposition)
The results are shown in Table 1. In addition, the above responsiveness drop is less than 1.1 "A", 1.1 to less than 1.5 "B", 1.5 to less than 3.0 "C", The thing of 3.0 or more was made into "D". The results are shown in Table 1. Practically, it is preferably “A” or “B”, and more preferably “A”.

As can be seen from Table 1, all of the examples of the present compound (A) were excellent in vapor deposition stability and exhibited excellent responsiveness and photoelectric conversion efficiency when formed into an element. Among these, in Examples 1 to 5 in which m in the above formula (1) is 1 than in Example 6 in which m in the above formula (1) is 0, deposition stability, responsiveness, and photoelectricity are improved. At least one of the conversion efficiencies was better. Among them, Examples 1 to 3 which do not contain a halogen atom showed more excellent photoelectric conversion efficiency. Among them, the deposition stability of Example 1 having no substituent in Ar ¹ and Ar ² is more stable than Examples 2 and 3 having a substituent in Ar ¹ or Ar ² in the above formula (1). Or better response.

  On the other hand, Comparative Example 1 having a monovalent aryl group on the aryl of the triarylamine but the triarylamine does not form a ring has insufficient vapor deposition stability, and has a photoelectric conversion efficiency when formed into an element. It was insufficient. Moreover, although triarylamine forms a ring but does not have a monovalent aryl group on the aryl of triarylamine (has an alkyl group), Comparative Example 2 or triarylamine forms a ring. In Comparative Example 3 having no monovalent aryl group on the aryl (having a condensed ring structure), the vapor deposition stability was insufficient, and the response when the device was formed was insufficient.

10a, 10b Photoelectric conversion element 11 Lower electrode (conductive film)
12 Photoelectric conversion film 15 Upper electrode (transparent conductive film)
16A Electron blocking layer 16B Hole blocking layer 100 Image sensor 101 Substrate 102 Insulating layer 103 Connection electrode 104 Pixel electrode (lower electrode)
105 connecting portion 106 connecting portion 107 photoelectric conversion film 108 counter electrode (upper electrode)
109 Buffer layer 110 Sealing layer 111 Color filter (CF)
112 partition wall 113 light shielding layer 114 protective layer 115 counter electrode voltage supply unit 116 readout circuit

Claims (20)

The photoelectric conversion material which is a compound (A) represented by following formula (1).

(In Formula (1), R < ¹ > -R < ⁸ > represents a hydrogen atom or a substituent each independently.
R ^{9 to} R ¹¹ each independently represents a hydrogen atom or a substituent. n represents an integer of 0 or more. R ⁹ and R ¹⁰ , R ⁹ and R ¹¹ may be bonded to each other to form a ring. When n is 2 or more, a plurality of R ^{9 s} and a plurality of R ^{10 s} may be bonded to each other to form a ring.
Ar ¹ and Ar ² each independently represents an aryl group or a heteroaryl group which may have a substituent. When Ar ¹ has a substituent, the substituent that Ar ¹ has must not be bonded to R ² or R ³ . When Ar ² has a substituent, the substituent that Ar ² has may be bonded to R ¹ or R ⁸ to form a ring.
La represents a group selected from the group consisting of> CR ^1a R ^1b ,> NR ^1c , an optionally substituted alkenylene group,> SiR ^1d R ^1e , —O—, and —S—. Here, R ^1a , R ^1b , R ^1c , R ^1d and R ^1e each independently represent a hydrogen atom or a substituent.
m represents 0 or 1.
Z ₁ represents a ring containing at least two carbon atoms and 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. ) The photoelectric conversion material according to claim 1, wherein the compound (A) is a compound (a1) represented by the following formula (2).

(In Formula (2), R < ¹ > -R < ⁸ > represents a hydrogen atom or a substituent each independently.
R ^{9 to} R ¹¹ each independently represents a hydrogen atom or a substituent. n represents an integer of 0 or more. R ⁹ and R ¹⁰ , R ⁹ and R ¹¹ may be bonded to each other to form a ring. When n is 2 or more, a plurality of R ^{9 s} and a plurality of R ^{10 s} may be bonded to each other to form a ring.
Ar ¹ and Ar ² each independently represents an aryl group or a heteroaryl group which may have a substituent. When Ar ¹ has a substituent, the substituent that Ar ¹ has must not be bonded to R ² or R ³ . When Ar ² has a substituent, the substituent that Ar ² has may be bonded to R ¹ or R ⁸ to form a ring.
La represents a group selected from the group consisting of> CR ^1a R ^1b ,> NR ^1c , an optionally substituted alkenylene group,> SiR ^1d R ^1e , —O—, and —S—. Here, R ^1a , R ^1b , R ^1c , R ^1d and R ^1e each independently represent a hydrogen atom or a substituent.
Z ₁ represents a ring containing at least two carbon atoms and 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. ) The photoelectric conversion material according to claim 1, wherein Z ₁ is a ring represented by the following formula (Z1).
(In the formula (Z1), Z ₂ represents a ring containing at least 3 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. * Represents the bonding position with the carbon atom to which R ¹¹ is bonded.)   The photoelectric conversion material according to claim 1, wherein n is 0. The photoelectric conversion material according to claim 1, wherein Ar ¹ or Ar ² is an aryl group which may have a substituent. The La is a group represented by> CR ^1a R ^1b (wherein R ^1a and R ^1b each independently represents a hydrogen atom or a hydrocarbon group). The photoelectric conversion material according to item.   The photoelectric conversion material of any one of Claims 1-6 which does not contain F atom.   The photoelectric conversion material according to claim 1, which does not contain a halogen atom.   A photoelectric conversion element provided with a conductive film, the photoelectric conversion film containing the photoelectric conversion material of any one of Claims 1-8, and a transparent conductive film in this order.   The photoelectric conversion element according to claim 9, wherein the photoelectric conversion film further contains an organic n-type semiconductor.   The photoelectric conversion element of Claim 10 in which the said organic n-type semiconductor contains fullerene selected from the group which consists of fullerene and its derivative (s).   Content of the fullerenes with respect to the total content of the photoelectric conversion material and the fullerenes (= film thickness in terms of a single layer of the fullerenes / (film thickness in terms of a single layer of the photoelectric conversion material + the fullerene The photoelectric conversion element according to claim 11, wherein the film thickness in terms of a single layer)) is 50% by volume or more.   The photoelectric conversion element according to claim 9, wherein a charge blocking layer is disposed between the conductive film and the transparent conductive film.   The photoelectric conversion element according to claim 13, wherein the charge blocking layer is an electron blocking layer, and an ionization potential of a compound forming the electron blocking layer is less than 5.5 eV.   The photoelectric conversion element of any one of Claims 9-14 whose said photoelectric conversion film is formed into a film by the vacuum evaporation method.   The photoelectric conversion element of any one of Claims 9-15 in which light injects into the said photoelectric converting film through the said transparent conductive film.   The photoelectric conversion element of any one of Claims 9-16 in which the said transparent conductive film consists of a transparent conductive metal oxide.   The optical sensor containing the photoelectric conversion element of any one of Claims 9-17.   The image pick-up element containing the photoelectric conversion element of any one of Claims 9-17. It is a usage method of the photoelectric conversion element of any one of Claims 9-17,
The method for using a photoelectric conversion element, wherein the conductive film and the transparent conductive film are a pair of electrodes, and an electric field of 1 × 10 ⁻⁴ to 1 × 10 ⁷ V / cm is applied between the pair of electrodes.