Photoelectric conversion element material, and photoelectric conversion element using same

Abstract

Provided are: a material that imparts increased sensitivity and resolution to photoelectric conversion elements for imaging; and a photoelectric conversion element for imaging using this material. A photoelectric conversion element material comprising a compound represented by general formula (1) is used. Ar1 to Ar3 each represent deuterium, a C1-20 alkyl group, a C12-36 aryl heteroaryl amino group, a C6-18 aromatic hydrocarbon group, or the like, with at least one of Ar1 to Ar3 being represented by general formulas (2) to (5); X is C(Ar4Ar5), O, S, or the like; and a and b are integers from 0 to 4. * represents the bonding site with general formula (1), and L1 and L2 each represent a direct bond, a C6-18 aromatic hydrocarbon group, a C3-18 aromatic heterocyclic group, or the like. Ar4 to Ar12 have the same definition as Ar1 to Ar3; c, e, and f represent integers from 0 to 3; and d represents an integer from 0 to 2.

Description

Material for photoelectric conversion element and photoelectric conversion element using the same

[0001] The present invention relates to a material for a photoelectric conversion element and a photoelectric conversion element using the same, and particularly to a material for a photoelectric conversion element that is useful for an imaging device.

[0002] In recent years, the development of organic electronics devices using thin films formed from organic semiconductors has progressed. Examples include electroluminescent elements, solar cells, transistor elements, and photoelectric conversion elements. In particular, the development of organic electroluminescent elements, which are electroluminescent elements made of organic materials, has progressed the most. As their application to smartphones, TVs, and the like progresses, development aimed at further increasing their functionality is also ongoing.

[0003] Meanwhile, the development and practical application of photoelectric conversion elements for imaging, which use PN junctions of inorganic semiconductors such as silicon, has been progressing. Studies are being conducted to improve the functionality of digital cameras and smartphone cameras, as well as for applications such as surveillance cameras and automotive sensors. However, challenges to meeting these various applications include increasing sensitivity and miniaturizing pixels (higher resolution). Conventional photoelectric conversion elements using inorganic semiconductors typically employ a method of placing color filters corresponding to the three primary colors of light, RGB, on the light-receiving section of the photoelectric conversion element to obtain color images. This method, which places the RGB color filters on a flat surface, poses challenges in terms of the efficiency of incident light utilization and resolution (Non-Patent Documents 1 and 2).

[0004] As one solution to these problems with photoelectric conversion elements, development is underway to use organic semiconductors instead of inorganic semiconductors (Non-Patent Documents 1 and 2). This takes advantage of the property of organic semiconductors, which allows them to selectively absorb only light in a specific wavelength range with high sensitivity, and it has been proposed to solve the problems of high sensitivity and high resolution by stacking photoelectric conversion elements made of organic semiconductors corresponding to the three primary colors of light. In addition, a device has been proposed in which a photoelectric conversion element made of an organic semiconductor and a photoelectric conversion element made of an inorganic semiconductor are stacked (Non-Patent Document 3).

[0005] Here, a photoelectric conversion element using an organic semiconductor is an element configured by having a photoelectric conversion layer made of a thin film of an organic semiconductor between two electrodes, with a hole-blocking layer and / or an electron-blocking layer disposed between the photoelectric conversion layer and the two electrodes as needed. In a photoelectric conversion element, excitons are generated by absorbing light of a desired wavelength in the photoelectric conversion layer, and then holes and electrons are generated by charge separation of the excitons. The holes and electrons then migrate to the respective electrodes, converting light into an electrical signal. To accelerate this process, a bias voltage is typically applied between the two electrodes, but reducing the leakage current from the two electrodes caused by the application of the bias voltage presents a challenge. For these reasons, controlling the movement of holes and electrons within the photoelectric conversion element is key to achieving the desired characteristics of the photoelectric conversion element.

[0006] Organic semiconductors used in each layer of a photoelectric conversion element can be roughly divided into P-type organic semiconductors and N-type organic semiconductors, with P-type organic semiconductors being used as hole transport materials and N-type organic semiconductors being used as electron transport materials. In order to control the movement of holes and electrons in a photoelectric conversion element, various organic semiconductors having appropriate physical properties, such as hole mobility, electron mobility, energy value of the highest occupied molecular orbital (HOMO), and energy value of the lowest unoccupied molecular orbital (LUMO), have been developed, but the current situation is such that they cannot be said to have sufficient properties.

[0007] Incidentally, various compounds have been disclosed that are excellent as hole transport materials or electron blocking materials for organic electroluminescent devices and organic solar cells, but these are not necessarily excellent as hole transport materials or electron blocking materials for imaging. Specifically, one of the important properties required of a hole transport material for an imaging photoelectric conversion element is, for example, to increase the difference between the current value when the shutter is closed and the current value when the shutter is open (light-dark ratio), so that a camera can capture clear images in a dark place. Therefore, a lower current value in a dark place is preferable, and a higher current value in a bright place is preferable. In other words, a "high light-dark ratio" is important.

[0008] On the other hand, in organic electroluminescent devices, the characteristics to be improved are the voltage required to pass a certain current, luminous efficiency, device life, etc., which are significantly different from the characteristics required for photoelectric conversion devices for imaging. Also, it is important for organic solar cells to generate a large amount of current in both dark and bright places, which is different from the characteristics required for photoelectric conversion devices for imaging, for which a low current value in dark places is preferable.

[0009] As described above, the hole transport materials and electron blocking materials for organic electroluminescent devices and organic solar cells differ in the properties required for the hole transport materials and electron blocking materials for image-capturing photoelectric conversion elements. Therefore, it is unclear until confirmation by experiment whether a material that is excellent as a hole transport material and electron blocking material for organic electroluminescent devices and organic solar cells is also excellent as a hole transport material and electron blocking material for image-capturing photoelectric conversion elements.

[0010] Here, Patent Document 1 proposes a device that uses quinacridone as a P-type organic semiconductor in a photoelectric conversion layer, subphthalocyanine chloride as an N-type organic semiconductor, and an indolocarbazole derivative in a first buffer layer disposed between the photoelectric conversion layer and an electrode.

[0011] Furthermore, Patent Document 2 proposes a device in which a chrysenodithiophene derivative is used as a P-type organic semiconductor in a photoelectric conversion layer, and a fullerene or a subphthalocyanine derivative is used as an N-type organic semiconductor.

[0012] Furthermore, Patent Documents 3 and 4 propose elements using a carbazole derivative in an electron blocking layer disposed between a photoelectric conversion layer and an electrode, and Patent Document 5 proposes elements using a pyrene derivative or a triphenylene derivative in an electron blocking layer disposed between a photoelectric conversion layer and an electrode.

[0013] Japanese Patent Application Publication No. 2018-85427 Japanese Patent Application Publication No. 2019-54228 Japanese Patent Application Publication No. 2011-228614 Japanese Patent Application Publication No. 2021-77888 Japanese Patent Application Publication No. 2015-153910

[0014] NHK Giken R&D No.132, pp.4-11 (2012.3) NHK Giken R&D No.174, pp.4-17 (2019.3) 2019 IEEE International Electron Devices Meeting (IEDM), pp.16.6.1-16.6.4 (2019)

[0015] Further improvements in sensitivity and resolution are required for imaging photoelectric conversion elements to improve the functionality of digital cameras and smartphone cameras, and to be applied to surveillance cameras, automotive sensors, etc. In light of this current situation, the present invention aims to provide a material that achieves high sensitivity and high resolution in imaging photoelectric conversion elements, and an imaging photoelectric conversion element using the same.

[0016] As a result of extensive research, the present inventors have found that the process of generating holes and electrons due to charge separation of excitons in a photoelectric conversion layer, and the process of moving holes and electrons within a photoelectric conversion element, can be efficiently carried out by using a specific compound, and have thus completed the present invention.

[0017] The present invention provides a material for a photoelectric conversion device, comprising a compound represented by the following general formula (1): In the general formula (1), Ar １ ~Ar ３are each independently deuterium, a cyano group, a halogen, a nitro group, an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 38 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an acyl group having 2 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkoxycarbonyloxy group having 2 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, a dialkylamino group having 2 to 20 carbon atoms, a substituted or unsubstituted alkyl group having 7 to 20 carbon atoms, and Ar represents a substituted or unsubstituted alkylarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted diarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted arylheteroarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted diheteroarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 10 of these aromatic hydrocarbon groups and aromatic groups of the aromatic heterocyclic group, １ ~Ar ３ At least one of Ar is represented by any one of the following general formulas (2) to (8). １ ~Ar ３ When X is a group having a hydrogen atom, the hydrogen atom may be substituted with a deuterium atom or a halogen atom. ４ Ar ５ ), NAr ６ , O, or S. a and b represent the number of substitutions, and each independently represents an integer of 0 to 4.

[0018]

[0019] In the general formulas (2) to (8), * represents the point of attachment to the general formula (1). １ and L ２ each independently represents a direct bond, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 3 of these aromatic rings. ４ ~Ar １２ are each independently Ar １ ~Ar３ Similar to that described above, but Ar ４ ~Ar １２ When Ar represents a linking aromatic group, it represents a substituted or unsubstituted linking aromatic group in which 2 to 3 aromatic rings are linked together. ４ , Ar ５ may be bonded to each other to form a ring structure. c to f represent the number of substitutions, c, e, and f each independently represent an integer of 0 to 3, and d represents an integer of 0 to 2.

[0020] The general formula (1) is preferably represented by any one of the following general formulas (9) to (12): The general formula (1) is more preferably represented by any one of the following general formulas (9), (11), and (12), and even more preferably represented by any one of the following general formulas (11) and (12). In the general formulas (9) to (12), Ar １ ~Ar ６ , and a and b are the same as those described in the general formula (1).

[0021] Ar in the general formula (1) １ ~Ar ３ At least one of the above is preferably represented by any one of the general formulae (2) to (8), and more preferably represented by any one of the general formulae (2), (3), (5), (7), and (8).

[0022] In addition, L in the general formulas (2) to (8) １ is preferably a single bond.

[0023] The photoelectric conversion element material preferably has a highest occupied molecular orbital (HOMO) energy level of −4.0 eV or less, and a lowest unoccupied molecular orbital (LUMO) energy level of −2.5 eV or more, as determined by a geometry optimization calculation using density functional theory calculation B3LYP / 6-31G(d).

[0024] The material for the photoelectric conversion element is 1×10 －６ cm ２ It is preferable that the material for a photoelectric conversion element has a hole mobility of 1 / Vs or more. In addition, it is preferable that the material for a photoelectric conversion element is amorphous.

[0025] The material for a photoelectric conversion element can be used as a hole transport material.

[0026] The present invention also relates to a photoelectric conversion element for imaging, which has a photoelectric conversion layer and an electron blocking layer between two electrodes, and is characterized in that at least one of the photoelectric conversion layer and the electron blocking layer contains the above-mentioned material for photoelectric conversion elements.

[0027] The photoelectric conversion element of the present invention may contain the above-mentioned material for a photoelectric conversion element in the electron blocking layer, and may contain an electron transporting material such as a fullerene derivative in the photoelectric conversion layer.

[0028] The photoelectric conversion element material of the present invention can be applied to photoelectric conversion elements for imaging, but can also be applied to other sensors that convert light information into signals, solar cells, etc. When the photoelectric conversion element material of the present invention is applied to a photoelectric conversion element for imaging, appropriate movement of holes and electrons can be achieved, thereby making it possible to reduce the leakage current that occurs when a bias voltage is applied when light is converted into electrical energy. As a result, it is believed that a photoelectric conversion element that achieves a low dark current value and a high light-dark ratio can be obtained. Therefore, the material of the present invention is useful as a material for photoelectric conversion elements in photoelectric conversion film stacked imaging devices.

[0029] 1 is a cross-sectional view showing a structural example of a photoelectric conversion element used in the present invention.

[0030] The photoelectric conversion element of the present invention has at least one organic layer between two electrodes and converts light into electrical energy. The organic layer contains a material for photoelectric conversion elements comprising a compound represented by the general formula (1). Specifically, in an imaging photoelectric conversion element having a photoelectric conversion layer and an electron blocking layer between two electrodes, the material for photoelectric conversion elements represented by the general formula (1) is contained in at least one of the photoelectric conversion layer and the electron blocking layer. Hereinafter, the material for photoelectric conversion elements comprising the compound represented by the general formula (1) will be simply referred to as a material for photoelectric conversion elements. It may also be referred to as the material of the present invention or the compound represented by the general formula (1).

[0031] The compound represented by the above general formula (1) will be explained below.

[0032] Preferred forms of the general formula (1) are represented by the general formulas (9) to (12), and are preferably represented by the general formula (9), (11), or (12), and more preferably represented by the general formula (11) or (12).

[0033] In the general formulas (9) to (12), Ar １ ~Ar ６ , and a and b are the same as those described in the general formula (1).

[0034] In the above general formula (1), Ar １ ~Ar ３ At least one of the above is represented by any one of the general formulas (2) to (8), and Ar １ is preferably represented by any one of general formulas (2) to (8).

[0035] In the above general formula (1), Ar １ ~Ar ３ At least one of the above is represented by any one of the general formulae (2) to (8), but is preferably represented by any one of the general formulae (2), (3), (5), (7), or (8), and more preferably represented by any one of the general formulae (2), (5), or (8).

[0036] In the general formulae (2) to (8), * represents the point of attachment to the general formula (1), and L １ , L ２ , Ar ４ ~Ar １２ , c to f are the same as those described in the general formulae (2) to (8).

[0037] Ar １ ~Ar ３are each independently deuterium, a cyano group, a halogen, a nitro group, an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 38 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an acyl group having 2 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkoxycarbonyloxy group having 2 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, a dialkylamino group having 2 to 20 carbon atoms, a substituted or unsubstituted alkyl group having 7 carbon atoms, It represents an alkylarylamino group having 12 to 28 carbon atoms, a substituted or unsubstituted diarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted arylheteroarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted diheteroarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 10 aromatic groups from these aromatic hydrocarbon groups and aromatic heterocyclic groups. Among these, preferred are substituted or unsubstituted aromatic hydrocarbon groups having 6 to 18 carbon atoms, substituted or unsubstituted aromatic heterocyclic groups having 6 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 10 aromatic groups from these aromatic hydrocarbon groups and aromatic heterocyclic groups. １ ~Ar ３ In the case where these groups have a hydrogen atom, the hydrogen atom may be substituted with a deuterium atom or a halogen atom. １ ~Ar ３ At least one of the above is represented by any one of the general formulas (2) to (8).

[0038] Ar １ ~Ar ３Among these, the alkyl group having 1 to 20 carbon atoms may be any of a linear, branched, or cyclic alkyl group, and is preferably a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Specific examples thereof include linear saturated hydrocarbon groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-dodecyl, n-tetradecyl, and n-octadecyl groups; branched saturated hydrocarbon groups such as isopropyl, isobutyl, neopentyl, 2-ethylhexyl, and 2-hexyloctyl groups; and saturated alicyclic hydrocarbon groups such as cyclopentyl, cyclohexyl, cyclooctyl, and 4-butylcyclohexyl groups.

[0039] Specific examples of aralkyl groups having 7 to 38 carbon atoms include benzyl, phenethyl, phenylpropyl, phenylbutyl, naphthylmethyl, and triphenylenylmethyl. Specific examples of alkenyl groups having 2 to 20 carbon atoms include ethylene, propylene, butylene, pentene, cyclopentene, hexene, cyclohexene, and octene. Specific examples of alkynyl groups having 2 to 20 carbon atoms include acetylene, propyne, butyne, and pentyne. Specific examples of acyl groups having 2 to 20 carbon atoms include formyl, acetyl, propionyl, and benzoyl. Specific examples of acyloxy groups having 2 to 20 carbon atoms include methanoyl, ethanoyl, propanoyl, butanoyl, benzoyl, propenoyl, and butenoyl. Specific examples of alkoxy groups having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Specific examples of alkoxycarbonyl groups having 2 to 20 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, and a pentoxycarbonyl group. Specific examples of alkoxycarbonyloxy groups having 2 to 20 carbon atoms include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, a propoxycarbonyloxy group, a butoxycarbonyloxy group, and a pentoxycarbonyloxy group. Specific examples of alkylsulfonyl groups having 1 to 20 carbon atoms include methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, and pentylsulfonyl.

[0040] Ar １ ~Ar ３represents an amino group, it represents a dialkylamino group having 2 to 20 carbon atoms, a substituted or unsubstituted alkylarylamino group having 7 to 28 carbon atoms, a substituted or unsubstituted diarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted arylheteroarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted diheteroarylamino group having 12 to 36 carbon atoms, etc. Specific examples of the alkyl group include linear saturated hydrocarbon groups such as methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, and n-octyl group, branched saturated hydrocarbon groups such as isopropyl group, isobutyl group, neopentyl group, and 2-ethylhexyl group, and saturated alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cyclooctyl group, and 4-butylcyclohexyl group. Specific examples of the aryl group include a phenyl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a naphthyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a fluorenyl group, a spirobifluorenyl group, etc. Specific examples of the heteroaryl group include pyrrole, pyrrolopyrrole, indole, pyrroloindole, benzoindole, naphthopyrrole, isoindole, pyrroloisoindole, benzoisoindole, naphthoisopyrrole, carbazole, phenoxazine, phenothiazine, acridine, phenazine, benzocarbazole, indoloindole, indolocarbazole, carbazolocarbazole, benzofurocarbazole, benzothienocarbazole, carboline, thiophene, benzothiophene, and naphthothiophene. , dibenzothiophene, benzothienonaphthalene, benzothienobenzothiophene, benzothienodibenzothiophene, dinaphthothiophene, dinaphthothienothiophene, naphthobenzothiophene, furan, benzofuran, naphthofuran, dibenzofuran, benzofuronaphthalene, benzofurobenzofuran, benzofurodibenzofuran, dinaphthofuran, dinaphthofuranofuran, naphthobenzofuran, pyridine, pyrimidine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, and the like.Specific examples of dialkylamino groups include groups derived from a dimethylamino group, a methylethylamino group, a diethylamino group, a dipropylamino group, a di-n-butylamino group, a di-t-butylamino group, a dipentylamino group, a dihexylamino group, a dicyclohexylamino group, a diheptylamino group, a dioctylamino group, a dinonylamino group, a didecylamino group, etc. Specific examples of alkylarylamino groups include groups derived from a methylphenylamino group, an ethylphenylamino group, a propylphenylamino group, a butylphenylamino group, a cyclohexylphenylamino group, a cyclohexylnaphthylamino group, a cyclohexylfluorenylamino group, a cyclohexylphenanthrenylamino group, a cyclohexylfluoranthenylamino group, a cyclohexyltriphenylenylamino group, etc. Specific examples of diarylamino groups include groups derived from a diphenylamino group, a phenylnaphthylamino group, a dinaphthylamino group, a phenylanthracenylamino group, a phenylfluorenylamino group, a phenylphenanthrenylamino group, a phenylfluoranthenylamino group, a phenyltriphenylenylamino group, a difluorenylamino group, a naphthyltriphenylenylamino group, a ditriphenylenylamino group, etc. Specific examples of arylheteroarylamino groups include groups derived from a phenylpyridylamino group, a phenylindolyl group, a phenyldibenzofuranylamino group, a phenyldibenzothiophenylamino group, etc. Specific examples of diheteroarylamino groups include groups derived from a bis-dibenzofuranylamino group, a bis-dibenzothiophenylamino group, a bis-carbazolylamino group, a dibenzofuranylcarbazolylamino group, a dibenzofuranyldibenzothiophenylamino group, a dibenzothiophenylcarbazolylamino group, etc.

[0041] Also, Ar １ ~Ar ３In the formula (I), examples of the unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms include groups obtained by removing one hydrogen atom from a known aromatic hydrocarbon. Examples of such aromatic hydrocarbon groups include groups derived from monocyclic aromatic hydrocarbons such as benzene, bicyclic aromatic hydrocarbons such as naphthalene, tricyclic aromatic hydrocarbons such as indacene, biphenylene, phenalene, anthracene, phenanthrene, and fluorene, and tetracyclic aromatic hydrocarbons such as fluoranthene, acephenanthrylene, aceanthrylene, triphenylene, pyrene, chrysene, tetraphene, tetracene, and pleiadene. Preferred are groups derived from benzene, naphthalene, anthracene, phenanthrene, triphenylene, or pyrene.

[0042] Also, Ar １ ~Ar ３In the above, examples of the unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic heterocyclic group. Examples of such aromatic heterocyclic groups include nitrogen-containing aromatic compounds having a pyrrole ring such as pyrrole, pyrrolopyrrole, indole, pyrroloindole, benzoindole, naphthopyrrole, isoindole, pyrroloisoindole, benzisoindole, naphthoisopyrrole, carbazole, benzocarbazole, indoloindole, carbazolocarbazole, indolocarbazole, and carboline; thiophene, benzothiophene, naphthothiophene, phenothiazine, dibenzothiophene, benzothienonaphthalene, benzothienobenzothiophene, and benzothienodibenzothiophene. Examples include sulfur-containing aromatic compounds having a thiophene ring such as dinaphthothiophene, dinaphthothienothiophene, naphthobenzothiophene, and benzothienocarbazole, oxygen-containing aromatic compounds having a furan ring such as furan, benzofuran, naphthofuran, phenoxazine, dibenzofuran, benzofuronaphthalene, benzofurobenzofuran, benzofurodibenzofuran, dinaphthofuranofuran, naphthobenzofuran, and benzofurocarbazole, pyridine, pyrimidine, triazine, quinoline, isoquinoline, quinazoline, and quinoxaline. Preferred are groups derived from dibenzofuran, dibenzothiophene, carbazole, phenoxazine, phenothiazine, benzothienodibenzothiophene, benzofurodibenzofuran, benzofurocarbazole, or benzothienocarbazole.

[0043] Furthermore, in this specification, an unsubstituted linked aromatic group in which aromatic groups of an aromatic hydrocarbon group and an aromatic heterocyclic group are linked refers to an aromatic group in which two or more aromatic groups are linked by single bonds. These linked aromatic groups may be linear or branched. The linking position when benzene rings are linked may be ortho, meta, or para, but para- or meta-linking is preferred. The aromatic group may be an aromatic hydrocarbon group or an aromatic heterocyclic group, and the multiple aromatic groups may be the same or different.

[0044] Here, Ar １~Ar ３ When Ar represents a linking aromatic group, the number of links is 2 to 10, preferably 2 to 8, and more preferably 2 to 6. １ ~Ar ３ When L represents a linking aromatic group, the number of linking groups is two carbazole (CBZ) groups, L １ , L ２ , and Ar ６ ~Ar １２ is the total number of aromatic hydrocarbon groups and aromatic heterocyclic groups connected thereto.

[0045] In the general formula (1) and the general formulae (9) to (12), a and b represent the number of substitutions, and each independently represents an integer of 0 to 4, preferably 0 to 2, and more preferably 0.

[0046] In addition, in the general formulas (2) to (8), L １ and L ２ L each independently represents a direct bond, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 3 of these aromatic rings. １ is preferably a direct bond or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, and more preferably a direct bond. ２ is preferably a direct bond or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, and more preferably a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. １ and L ２ In the above, specific examples of the unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms and the unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms include groups obtained by removing two hydrogen atoms from an aromatic hydrocarbon, such as Ar １ ~Ar ３ It is the same as that explained in L １ , and L ２is a linking aromatic group, the two carbazole (CBZ) groups described in formulas (2) to (8) and formula (1) may be bonded via either an aromatic hydrocarbon group or an aromatic heterocyclic group contained in the linking aromatic group, and may be bonded at both ends or in a branched manner.

[0047] c to f represent the number of substitutions, and c, e, and f each independently represent an integer of 0 to 3, preferably 0 to 1. d represents an integer of 0 to 2, preferably 0.

[0048] Ar ４ ~Ar １２ are each independently Ar １ ~Ar ３ Similar to that described above, but Ar ４ ~Ar １２ When Ar represents a linking aromatic group, it represents a substituted or unsubstituted linking aromatic group in which 2 to 3 aromatic rings are linked together. ４ , Ar ５ may be bonded to each other to form a ring structure.

[0049] Ar １ ~Ar １２When is an alkylarylamino group having 7 to 28 carbon atoms, a diarylamino group having 12 to 36 carbon atoms, an arylheteroarylamino group having 12 to 36 carbon atoms, a diheteroarylamino group having 12 to 36 carbon atoms, an aromatic hydrocarbon group, an aromatic heterocyclic group, or a linked aromatic group, these may have a substituent. Examples of the substituent include deuterium, an alkyl group having 1 to 20 carbon atoms, a cyano group, and an alkylsilyl group. The alkyl group having 1 to 20 carbon atoms may be any of a linear, branched, or cyclic alkyl group. The substituent is preferably deuterium, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, or a cyano group. Specific examples include linear saturated hydrocarbon groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-dodecyl, n-tetradecyl, and n-octadecyl groups, branched saturated hydrocarbon groups such as isopropyl, isobutyl, neopentyl, 2-ethylhexyl, and 2-hexyloctyl groups, and saturated alicyclic hydrocarbon groups such as cyclopentyl, cyclohexyl, cyclooctyl, 4-butylcyclohexyl, and 4-dodecylcyclohexyl groups. In the present invention, the substituent is substituted on the aromatic ring.

[0050] Preferred specific examples of the compound represented by formula (1) which is the material for the photoelectric conversion element of the present invention are shown below, but the invention is not limited to these.

[0051]

[0052] The compound represented by general formula (1) of the present invention can be obtained by synthesis using various organic synthesis reaction methods established in the field of organic synthetic chemistry, including coupling reactions such as Suzuki coupling, Stille coupling, Grignard coupling, Ullmann coupling, Buchwald-Hartwig reaction, and Heck reaction, using commercially available reagents as raw materials, followed by purification using known methods such as recrystallization, column chromatography, and sublimation purification, but is not limited to these methods.

[0053] The material for photoelectric conversion elements of the present invention preferably has an energy level of the highest occupied molecular orbital (HOMO) obtained by a geometry optimization calculation using density functional theory calculation B3LYP / 6-31G(D) of −4.0 eV or less, more preferably in the range of −6.0 eV to −4.3 eV, and even more preferably in the range of −4.9 eV to −4.4 eV.

[0054] The material for photoelectric conversion elements of the present invention preferably has an energy level of the lowest unoccupied molecular orbital (LUMO) obtained by a structure optimization calculation using density functional theory calculation B3LYP / 6-31G(D) of −2.5 eV or higher, more preferably in the range of −2.0 eV to −0.5 eV, and even more preferably in the range of −1.5 eV to −1.0 eV.

[0055] In the material for photoelectric conversion elements of the present invention, the difference (absolute value) between the HOMO energy level and the LUMO energy level is preferably in the range of 2.0 eV to 5.0 eV, more preferably in the range of 2.5 eV to 4.5 eV, and even more preferably in the range of 3.5 eV to 4.5 eV.

[0056] The material for a photoelectric conversion element of the present invention has a viscosity of 1×10 －６ cm ２ / Vs or more, and preferably 1×10 －５ cm ２ / Vs~1cm ２ / Vs, and more preferably 1.0×10 －４ cm ２ / Vs~1×10 －２ cm ２ The hole mobility can be evaluated by known methods such as a method using a FET transistor element, a time-of-flight method, or an SCLC method.

[0057] The material for a photoelectric conversion element of the present invention is preferably amorphous. The amorphous nature of the material can be confirmed by various methods, for example, by the absence of a peak detected by XRD or the absence of an endothermic peak detected by DSC.

[0058] Next, an imaging photoelectric conversion element using the material for a photoelectric conversion element of the present invention will be described, but the structure of the imaging photoelectric conversion element of the present invention is not limited thereto.

[0059] Figure 1 is a cross-sectional view schematically showing an example of the structure of an imaging photoelectric conversion element of the present invention, in which 1 represents an electrode, 2 represents a hole blocking layer, 3 represents a photoelectric conversion layer, 4 represents an electron blocking layer, 5 represents an electrode, and 6 represents a substrate. Note that the configuration excluding the substrate may be reversed from that shown in Figure 1, i.e., 1 represents an electrode, 2 represents an electron blocking layer, 3 represents a photoelectric conversion layer, 4 represents a hole blocking layer, 5 represents an electrode, and 6 represents a substrate. The structure is not limited to that shown in Figure 1, and layers can be added or omitted as necessary.

[0060] - Electrode - The electrode used in an imaging photoelectric conversion element using the imaging photoelectric conversion element material of the present invention has the function of collecting holes and electrons generated in the photoelectric conversion layer. It also needs to have the function of allowing light to enter the photoelectric conversion layer. Therefore, it is desirable that at least one of the two electrodes is transparent or semi-transparent. In addition, the material used as the electrode is not particularly limited as long as it is conductive, but examples thereof include ITO, IZO, SnO ２ , ATO (antimony-doped tin oxide), ZnO, AZO (Al-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO ２ Examples of the conductive material include transparent conductive materials such as fluorine-containing tetrahydrofuran (FTO), metals such as gold, silver, platinum, chromium, aluminum, iron, cobalt, nickel, and tungsten, inorganic conductive materials such as copper iodide and copper sulfide, and conductive polymers such as polythiophene, polypyrrole, and polyaniline. A mixture of these materials may be used as needed. Two or more layers may also be laminated.

[0061] Photoelectric Conversion Layer: The photoelectric conversion layer is a layer in which holes and electrons are generated by charge separation of excitons generated by incident light. It may be formed of a single photoelectric conversion material, or may be formed in combination with a P-type organic semiconductor material, which is a hole-transporting material, or an N-type organic semiconductor material, which is an electron-transporting material. Two or more P-type organic semiconductors may be used, or two or more N-type organic semiconductors may be used. It is desirable that one or more of these P-type organic semiconductors and / or N-type organic semiconductors be a dye material capable of absorbing light of a desired wavelength in the visible range. The compound represented by general formula (1) of the present invention can be used as the P-type organic semiconductor material, which is a hole-transporting material.

[0062] The P-type organic semiconductor material may be any material having hole transport properties, and is preferably a material represented by general formula (1). However, other P-type organic semiconductor materials may also be used. Two or more materials represented by general formula (1) may be mixed and used. Furthermore, a compound represented by general formula (1) may be mixed with other P-type organic semiconductor materials.

[0063] Other p-type organic semiconductor materials may be any material having hole transport properties, and examples thereof include compounds having a condensed polycyclic aromatic group such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene; compounds having a π-excess aromatic group such as cyclopentadiene derivatives, furan derivatives, thiophene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, dinaphthothienothiophene derivatives, indole derivatives, pyrazoline derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, and indolocarbazole derivatives; aromatic amine derivatives, styrylamine derivatives, benzidine derivatives, porphyrin derivatives, phthalocyanine derivatives, and quinacridone derivatives.

[0064] Examples of polymer-type p-type organic semiconductor materials include polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives. Two or more selected from the compound represented by general formula (1), p-type organic semiconductor materials, and polymer-type p-type organic semiconductor materials may be mixed and used.

[0065] The N-type organic semiconductor material may be any material having electron transport properties, such as naphthalene tetracarboxylic acid diimide, perylene tetracarboxylic acid diimide, fullerenes, and azole derivatives such as imidazole, thiazole, thiadiazole, oxazole, oxadiazole, and triazole. Two or more N-type organic semiconductor materials may be mixed and used.

[0066] -Electron Blocking Layer- The electron blocking layer is provided to suppress dark current generated by electron injection from one electrode into the photoelectric conversion layer when a bias voltage is applied between two electrodes. It also functions as a hole transport layer, transporting holes generated by charge separation in the photoelectric conversion layer to the electrode. A single layer or multiple layers can be arranged as needed. The electron blocking layer can be made of a P-type organic semiconductor material, which is a hole transport material. Any material with hole transport properties can be used as the P-type organic semiconductor material. The compound represented by general formula (1) is preferably used, but other P-type organic semiconductor materials may also be used. Furthermore, a mixture of the compound represented by general formula (1) and other P-type organic semiconductor materials may also be used. Other p-type organic semiconductor materials may be any material having hole transport properties, and examples thereof include compounds having a condensed polycyclic aromatic group such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene; compounds having a π-excess aromatic group such as cyclopentadiene derivatives, furan derivatives, thiophene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, dinaphthothienothiophene derivatives, indole derivatives, pyrazoline derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, and carbazole derivatives; aromatic amine derivatives, styrylamine derivatives, benzidine derivatives, porphyrin derivatives, phthalocyanine derivatives, and quinacridone derivatives.

[0067] Examples of polymer-type P-type organic semiconductor materials include polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives. Two or more selected from the compound represented by general formula (1) of the present invention, P-type organic semiconductor materials, and polymer-type P-type organic semiconductor materials may be mixed and used.

[0068] -Hole Blocking Layer- The hole blocking layer is provided to suppress dark current generated by holes being injected from one electrode into the photoelectric conversion layer when a bias voltage is applied between the two electrodes. It also functions as an electron transport layer, transporting electrons generated by charge separation in the photoelectric conversion layer to the electrode, and a single layer or multiple layers may be disposed as needed. An N-type organic semiconductor having electron transport properties may be used for the hole blocking layer. The N-type organic semiconductor material may be any material having electron transport properties, and examples thereof include polycyclic aromatic polycarboxylic acid anhydrides and imidized products thereof, such as naphthalene tetracarboxylic acid diimide and perylene tetracarboxylic acid diimide, fullerenes such as C60 and C70, azole derivatives such as imidazole, thiazole, thiadiazole, oxazole, oxadiazole, and triazole, tris(8-quinolinolato)aluminum(III) derivatives, phosphine oxide derivatives, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, bipyridine derivatives, quinoline derivatives, and indolocarbazole derivatives. Two or more of these N-type organic semiconductor materials may also be used in combination.

[0069] As described above, the hydrogen in the material of the present invention may be deuterium. That is, in addition to the hydrogen on the aromatic ring in general formula (1) or general formulas (2) to (8), some or all of the hydrogen in the substituent may be deuterium. Furthermore, some or all of the hydrogen in the compounds used as the N-type organic semiconductor material and the P-type organic semiconductor material may be deuterium.

[0070] When producing the imaging photoelectric conversion element of the present invention, the method for forming each layer is not particularly limited, and the layer may be produced by either a dry process or a wet process. The organic layer containing the material for a photoelectric conversion element of the present invention may be a multi-layer layer, if necessary.

[0071] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0072] Calculation Example: Calculation of HOMO and LUMO The HOMO, LUMO, and energy difference between HOMO and LUMO of the above compounds A4, C13, D61, E42, E45, E58, E126, F42, and F125 were calculated. The calculation was performed using density functional theory (DFT), Gaussian as the calculation program, and structural optimization calculation using density functional calculation B3LYP / 6-31G(d). The results are shown in Table 1. It can be said that all of the materials for photoelectric conversion elements of the present invention have preferable HOMO and LUMO values.

[0073] The HOMO, LUMO, and energy difference between the HOMO and LUMO of the comparative compounds H1, H2, and H3 were calculated in the same manner. The results are shown in Table 1.

[0074]

[0075] The synthesis of compound E42 is shown below as a representative example. Other compounds were also synthesized in a similar manner.

[0076] Synthesis Example 1 (Synthesis of Intermediate R3) R1 (19.0 mmol), R2 (19.9 mmol), copper iodide (0.4 mmol), and tripotassium phosphate (56.9 mmol) were placed in a degassed, nitrogen-purged 500 ml three-neck flask. 70 ml of anhydrous dioxane was added, followed by stirring at 120°C for 3 hours. After cooling to room temperature, inorganic materials were removed by filtration. 200 ml of water and 200 ml of dichloromethane were added to the filtrate, which was then transferred to a separatory funnel and fractionated into an organic layer and an aqueous layer. The organic layer was washed three times with 200 ml of water. The resulting organic layer was dehydrated over magnesium sulfate and then concentrated under reduced pressure. The resulting residue was purified by column chromatography to give R3 (a pale yellow solid). Yield: 7.5 g, 81.3%.

[0077] Synthesis Example 2 (Synthesis of E42) A 300 ml three-neck flask was degassed and purged with nitrogen and charged with R3 (10.3 mmol), R4 (13.3 mmol), trisdibenzylideneacetonedipalladium (0.5 mmol), tri-tert-butylphosphine (2.1 mmol), sodium tert-butoxide (30.8 mmol), and 50 ml of dehydrated xylene, followed by stirring at 120°C for 2 hours. After cooling to room temperature, the inorganic matter was removed by filtration. 200 ml of water and 200 ml of dichloromethane were added to the filtrate, which was then transferred to a separatory funnel and fractionated into an organic layer and an aqueous layer. The organic layer was washed three times with 200 ml of water, dehydrated over magnesium sulfate, and then concentrated under reduced pressure. The resulting residue was purified by column chromatography to give E42 (a pale yellow solid). Yield: 4.2 g, 69.4%. The obtained solid was evaluated by XRD, but no peak was detected, indicating that the compound was amorphous.

[0078] On a glass substrate having a transparent electrode made of ITO with a thickness of 110 nm, Compound E42 was formed as an organic layer by vacuum deposition under conditions of a thickness of about 3 μm. Then, using a device having an electrode made of aluminum (Al) with a thickness of 70 nm, charge mobility was measured by the time-of-flight method. As a result, the hole mobility was 1.4 × 10 －４ cm ２ / Vs.

[0079] The hole mobility was evaluated in the same manner except that compound E42 was replaced with A04, C13, E45, E126, F125, H1, H2, or H3. The results are shown in Table 2.

[0080]

[0081] Example 1 A vacuum chamber was placed on an electrode made of ITO with a thickness of 70 nm formed on a glass substrate. －５Compound E42 was deposited as an electron blocking layer to a thickness of 10 nm at 200 Pa. Next, 2Ph-BTBT, F6-SubPc-OC6F5, and fullerene (C60) were co-deposited at a deposition rate ratio of 4:4:2 to form a 200 nm thick photoelectric conversion layer. Subsequently, dpy-NDI was deposited to a thickness of 10 nm to form a hole blocking layer. Finally, aluminum was deposited as an electrode to a thickness of 70 nm to prepare a photoelectric conversion element. When a voltage of 2.6 V was applied using ITO and aluminum as electrodes, the current in the dark (dark current) was 5.1 × 10 －１０ A / cm ２ When a voltage of 2.6 V was applied and the ITO electrode side was irradiated with light from a height of 10 cm using an LED adjusted to 1.6 μW and a wavelength of 500 nm, the current (light current) was 3.7×10 －７ A / cm ２ The light-dark ratio when a voltage of 2.6 V was applied was 7.3 × 10 ２ These results are shown in Table 3.

[0082] Examples 2 to 6 Photoelectric conversion elements were prepared in the same manner as in Example 1, except that the compounds shown in Table 3 were used for the electron blocking layer.

[0083] Comparative Examples 1 to 3 Photoelectric conversion elements were prepared in the same manner as in Example 1, except that the compounds shown in Table 3 were used for the electron blocking layer. The results of Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 3.

[0084] The compounds used in the examples and comparative examples are listed below.

[0085]

[0086] REFERENCE SIGNS LIST 1 Electrode 2 Hole blocking layer 3 Photoelectric conversion layer 4 Electron blocking layer 5 Electrode 6 Substrate

Claims

1. A material for a photoelectric conversion element, comprising a compound represented by the following general formula (1), characterized in that the energy level of the lowest unoccupied molecular orbital (LUMO) obtained by a structure optimization calculation using density functional calculation B3LYP / 6-31G(d) is -2.5 eV or more. 【Chemistry 1】 In general formula (1), Ar １ ~Ar ３ each independently represents deuterium, a cyano group, a halogen, a nitro group, an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 38 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an acyl group having 2 to 20 carbon atoms, an acyloxy group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, an alkoxycarbonyloxy group having 2 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, a dialkylamino group having 2 to 20 carbon atoms, a substituted or unsubstituted alkyl group having 7 to 2 Ar represents a substituted or unsubstituted alkylarylamino group having 12 to 38 carbon atoms, a substituted or unsubstituted diarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted arylheteroarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted diheteroarylamino group having 12 to 36 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 10 of these aromatic hydrocarbon groups and aromatic groups of the aromatic heterocyclic group, １ ~Ar ３ At least one of Ar is represented by any one of the following general formulas (2) to (8). １ ~Ar ３ When represents a group having a hydrogen atom, the hydrogen atom may be substituted with deuterium or halogen. X is C(Ar ４ Ar ５ ), NAr ６ , O, or S. a and b each independently represent the number of substitutions and are an integer of 0 to 4. 【Chemistry 2】 【Chemistry 3】 In the general formulas (2) to (8), * represents the point of attachment to the general formula (1), L １ and L ２ each independently represents a direct bond, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 18 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by linking 2 to 3 of these aromatic rings. Ar ４ ~Ar １２ are each independently Ar １ ~Ar ３ Similar to that described in , but Ar ４ ~Ar １２ When Ar represents a linking aromatic group, it represents a substituted or unsubstituted linking aromatic group in which 2 to 3 aromatic rings are linked together. ４ , Ar ５ may be bonded to each other to form a ring structure. c to f represent the number of substitutions, c, e, and f each independently represent an integer of 0 to 3, and d represents an integer of 0 to 2.

2. The material for photoelectric conversion elements according to claim 1, wherein the general formula (1) is represented by any one of the following general formulas (9) to (12): 【Chemistry 4】 In the general formulas (9) to (12), Ar １ ~Ar ６ and a and b are the same as those described in the general formula (1).

3. The material for a photoelectric conversion element according to claim 2 , wherein the general formula (1) is represented by any one of the general formulas (11) and (12).

4. In the general formula (1), Ar １ ~Ar ３ 2. The material for photoelectric conversion elements according to claim 1, wherein at least one of the above is represented by any one of general formulas (2), (3), (5), (7), and (8).

5. In the general formula (1), Ar １ The material for photoelectric conversion elements according to claim 1 , wherein is represented by any one of general formulas (2), (3), (5), (7), and (8).

6. L １ The material for a photoelectric conversion element according to claim 1, wherein is a single bond.

7. 2. The material for photoelectric conversion elements according to claim 1, characterized in that the energy level of the highest occupied molecular orbital (HOMO) obtained by a structure optimization calculation using density functional calculation B3LYP / 6-31G(d) is −4.0 eV or less.

8. 1x10 －６ cm ２ 2. The material for a photoelectric conversion element according to claim 1, which has a hole mobility of at least 1.0 V.

9. 2. The material for a photoelectric conversion element according to claim 1, which is amorphous.

10. 2. The material for a photoelectric conversion element according to claim 1, which is used as a hole transport material in a photoelectric conversion element for imaging.

11. A photoelectric conversion element for imaging, comprising a photoelectric conversion layer and an electron blocking layer between two electrodes, the photoelectric conversion layer and at least one of the electron blocking layer containing the material for photoelectric conversion elements according to any one of claims 1 to 10.

12. 12. The photoelectric conversion element for imaging according to claim 11, wherein the electron blocking layer contains the material for photoelectric conversion elements according to claim 1.

13. 12. The image pickup photoelectric conversion element according to claim 11, wherein the photoelectric conversion layer contains an electron transporting material.

14. 12. The photoelectric conversion element for imaging according to claim 11, wherein the electron blocking layer contains the material for a photoelectric conversion element according to claim 1, and the photoelectric conversion layer contains a fullerene derivative.

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