Material for photoelectric conversion element for image sensor, photoelectric conversion element for image sensor, and compound

Abstract

To provide a material useful for fabricating a photoelectric conversion element for an image sensor that exhibits excellent dark current characteristics and responsiveness.SOLUTION: A material for a photoelectric conversion element for an image sensor comprises a compound represented by the formula (1) in the figure. (In the formula (1), Ar1 and Ar2 are the same and each represent a fused ring in which rings selected from among monocyclic rings and fused rings of up to three rings are fused, or an aryl group having 14 to 26 carbon atoms comprising a fused ring of up to three rings; Ar3 represents an aromatic hydrocarbon group having 6 to 40 carbon atoms and optionally having a substituent, or a heteroaryl group having 6 to 40 carbon atoms and optionally having a substituent.)SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a material for a photoelectric conversion element for an imaging device, a photoelectric conversion element for an imaging device, and a compound.

Background Art

[0002] The photoelectric conversion element for an imaging device is used in applications such as mobile phones and cameras, and its development is being actively carried out.

[0003] In recent years, the market requirements for photoelectric conversion elements for imaging devices have been increasing, and materials having excellent characteristics such as dark current and responsivity are required. As an organic photoelectric conversion element having a photoelectric conversion layer made of an organic material, a laminated structure having a charge transport layer such as a hole transport layer that transports holes generated in the photoelectric conversion layer to the first electrode and an electron transport layer that transports electrons generated in the photoelectric conversion layer to the second electrode is common (for example, see Patent Document 1). However, even with such a charge transport layer, the dark current characteristics and the responsivity are not sufficient, and a photoelectric conversion element having further excellent characteristics in these aspects is required.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a material contributing to the production of a photoelectric conversion element for an imaging device having excellent dark current characteristics and responsivity.

Means for Solving the Problems

[0006] The inventors of the present invention have found that by using a specific compound as a material for a photoelectric conversion element for an imaging device, the above problems can be solved, and thus the present invention has been completed.

[0007] Aspects of the present disclosure relate to the following materials for photoelectric conversion elements for imaging devices, photoelectric conversion elements for imaging devices, and compounds.

[0008] [1] A material for a photoelectric conversion element for an imaging device, containing a compound represented by the following formula (1). [Chemical formula] (In formula (1), Ar 1 and Ar 2 are the same and represent a linked ring in which any ring selected from a monocyclic ring and a condensed ring of 3 or less rings is linked, or an aryl group having 14 to 26 carbon atoms and consisting of a condensed ring of 3 or less rings. Ar 3 represents an aromatic hydrocarbon group having 6 to 40 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 40 carbon atoms which may have a substituent.)

[0009] [2] The material for a photoelectric conversion element for an imaging device according to [1], wherein the substituent is a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a deuterium atom, a cyano group, an aromatic hydrocarbon group having 6 to 25 carbon atoms, a heteroaryl group having 4 to 25 carbon atoms, or a group combining these.

[0010] [3] The material for a photoelectric conversion element for an imaging device according to [1] or [2], wherein the molecular weight of the compound represented by the formula (1) is 500 or more and 1000 or less.

[0011] [4] The material for a photoelectric conversion element for an imaging device according to any one of [1] to [3], wherein Ar 3 is an aromatic hydrocarbon ring which is a condensed ring of 3 or more rings, or a heteroaryl ring which is a condensed ring of 3 or more rings.

[0012] [5] The above Ar3 The material for a photoelectric conversion element for an image pickup device according to any one of [1] to [4], which is an aromatic hydrocarbon group composed of a condensed ring of 3 or more rings that may have a substituent, or a heteroaryl group composed of a condensed ring of 3 or more rings that may have a substituent.

[0013] [6] The Ar 1 and the Ar 2 in which the aryl group is formed from a 6-membered ring, the material for a photoelectric conversion element for an image pickup device according to any one of [1] to [5].

[0014] [7] The Ar 3 is an aromatic hydrocarbon group formed from a 5-membered ring, a 6-membered ring or both that may have a substituent, or a heteroaryl group composed of a condensed ring containing a carbazole ring that may have a substituent, the material for a photoelectric conversion element for an image pickup device according to [1] to [6].

[0015] [8] The glass transition point of the compound represented by the formula (1) is 140 °C or higher, the material for a photoelectric conversion element for an image pickup device according to [1] to [7].

[0016] [9] The material for a photoelectric conversion element for an image pickup device according to [1] to [8], which is a hole transport material for a photoelectric conversion element for an image pickup device.

[0017]

[10] An image pickup device photoelectric conversion element including the material for a photoelectric conversion element for an image pickup device according to any one of [1] to [9].

[0018]

[11] A compound represented by the following formula (2).

Chemical formula

[0019]

[12] The compound according to

[11] , wherein L is a phenylene group, a naphthylene group, a biphenylene group, a phenanthrenylene group, or a fluorenylene group.

[0020]

[13] The compound according to

[11] or

[12] , wherein n is 0.

[0021]

[14] The Ar 20 is an aromatic hydrocarbon group composed of a condensed ring containing a phenanthrene ring which may have a substituent, or a heteroaryl group composed of a condensed ring containing a carbazole ring which may have a substituent, and is the compound according to any one of

[11] to

[13] . [Advantages of the Invention]

[0022] According to the present disclosure, it is possible to provide a material useful for manufacturing a photoelectric conversion element for an image sensor, which has excellent dark current characteristics and responsiveness. [Brief Description of the Drawings]

[0023]

Figure 1

[0024] ≪Material for Photoelectric Conversion Element for Image Sensor≫ The material for a photoelectric conversion element for an image sensor contains a compound represented by the following formula (1).

[0025] [Compound Represented by Formula (1)]

Chem.

[0026] By having the above specific structure, the compound represented by formula (1) can provide a material useful for producing a photoelectric conversion element for an image sensor, which is excellent in dark current characteristics and responsiveness.

[0027] Preferred embodiments of the definitions in formula (1) are as follows.

[0028] 〔Ar 1 and Ar 2 〕 Ar 1 and Ar 2 Examples of the above aryl group as Ar 1 and Ar 2 include groups consisting of condensed rings such as an acenaphthylene group and an anthryl group; groups consisting of linked rings in which a single ring is linked such as a terphenyl group and a quaterphenyl group; groups consisting of linked rings in which condensed rings of 3 or fewer rings are linked such as a naphthylnaphthyl group; and groups consisting of linked rings in which a single ring and condensed rings of 3 or fewer rings are linked such as a naphthylphenyl group, a phenylnaphthyl group, a phenanthrylphenyl group, a phenylphenanthryl group, a naphthylphenanthryl group, and a diphenylfluorenyl group. As Ar 1 and Ar 2 groups consisting of linked rings in which a single ring is linked, groups consisting of linked rings in which condensed rings of 3 or fewer rings are linked, and groups consisting of linked rings in which a single ring and condensed rings of 3 or fewer rings are linked are preferred, and a terphenyl group, a quaterphenyl group, a naphthylnaphthyl group, a naphthylphenyl group, a phenanthrylphenyl group, and a phenylphenanthryl group are more preferred.

[0029] Ar 1 and Ar 2 The number of carbon atoms of the aryl group as described above is preferably 14 to 24, more preferably 16 to 20. Ar 1 and Ar 2 The above aryl group as described above is preferably formed from a 6-membered ring.

[0030] [Ar 3 Ar 3 Examples of the aromatic hydrocarbon group having 6 to 40 carbon atoms as Ar include a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a fluorenyl group, a fluoranthenyl group, an anthryl group, a phenanthryl group, a benzofluorenyl group, a triphenylenyl group, a dibenzofluorenyl group, a benzospirobifluorenyl group, an indenophenanthrenyl group, an indenotriphenylenyl group, an indenobenz[g]chrysenyl group, a benz[g]chrysenyl group, a dibenz[g,p]chrysenyl group, and a group formed by combining these. Among them, an aromatic hydrocarbon group formed from a 5-membered ring, a 6-membered ring or both is preferable, and an aromatic hydrocarbon group composed of a condensed ring of 3 or more rings (more preferably 3 to 8 rings) is preferable. As such aromatic hydrocarbon groups, a triphenylenyl group, a benzofluorenyl group, a dibenzofluorenyl group, an indenophenanthrenyl group, an indenotriphenylenyl group, a benz[g]chrysenyl group, and a dibenz[g,p]chrysenyl group are more preferable.

[0031] Ar 3 The number of carbon atoms of the above aromatic hydrocarbon group as Ar is preferably 6 to 30, more preferably 16 to 28, and even more preferably 18 to 26.

[0032] Ar 3 Examples of the substituent that the above aromatic hydrocarbon group as Ar may have include a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 6 carbon atoms, a deuterium atom, a cyano group, an aromatic hydrocarbon group having 6 to 25 carbon atoms, a heteroaryl group having 4 to 25 carbon atoms, and a group formed by combining these.​

[0033] Examples of the linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms as the above-mentioned substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, a cyclohexyl group, and the like.

[0034] Examples of the linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms as the above-mentioned substituent include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentyloxy group, an n-hexyloxy group, a cyclohexyloxy group, and the like.

[0035] Examples of the aromatic hydrocarbon group having 6 to 25 carbon atoms as the above-mentioned substituent include, for example, a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a fluoranthenyl group, an anthryl group, a phenanthryl group, a triphenylenyl group, a spirobifluorenyl group, a benzo[g]chrysenyl group, and the like.

[0036] Examples of the heteroaryl group having 4 to 25 carbon atoms as the above-mentioned substituent include a pyrrolyl group, a thienyl group, a furyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridyl group, a phenylpyridyl group, a pyridylphenyl group, a pyrimidyl group, a pyrazyl group, a 1,3,5-triazinyl group, a 1,3,5-triazinylphenyl group, a 1,3,5-triazinylbiphenylyl group, a 4,6-diphenyl-1,3,5-triazinyl group, an indolyl group, a benzothienyl group, a benzofuranyl group, a benzimidazolyl group, an indazolyl group, a benzothiazolyl group, a benzoisothiazolyl group, a 2,1,3-benzothiadiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a 2,1,3-benzoxadiazolyl group, a quinolyl group, an isoquinolyl group, a quinoxalyl group, a quinazolinyl group, a carbazolyl group, a dibenzothienyl group, a dibenzofuranyl group, a phenoxazinyl group, a phenothiazinyl group, a phenazinyl group, a thianthrenyl group, and the like.

[0037] Ar 3 Examples of the substituent that the aromatic hydrocarbon group as Ar may have include a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, a heteroaryl group having 4 to 25 carbon atoms, and a group formed by combining these, with a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms and an aromatic hydrocarbon group having 6 to 25 carbon atoms being more preferred, and a methyl group, a phenyl group, a biphenylyl group, a terphenylyl group, and a naphthyl group being even more preferred.

[0038] Ar 3Examples of the heteroaryl group having 6 to 40 carbon atoms include a pyrrolyl group, a thienyl group, a furyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridyl group, a phenylpyridyl group, a pyridylphenyl group, a pyrimidyl group, a pyrazyl group, a 1,3,5-triazolyl group, a 1,3,5-triazolylphenyl group, a 1,3,5-triazolylbiphenylyl group, a 4,6-diphenyl-1,3,5-triazolyl group, an indolyl group, a benzothienyl group, a benzofuranyl group, a benzimidazolyl group, an indazolyl group, a benzothiazolyl group, a benzisothiazolyl group, a 2,1,3-benzothiadiazolyl group, a benzoxazolyl group, a benzisoxazolyl group, a 2,1,3-benzoxadiazolyl group, a quinolyl group, an isoquinolyl group, a quinoxalyl group, a quinazolyl group, a carbazolyl group, a dibenzothienyl group, a dibenzofuranyl group, a phenoxazinyl group, a phenothiazinyl group, a phenazinyl group, a thianthrenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an indophenanthrenyl group, an indotriphenylenyl group, an indobenzo[g]chrysenyl group, an indodibenzo[g,p]chrysenyl group, an indenocarbazolyl group, a benzophenanthrothienyl group, a benzotriphenylenothienyl group, a benzo[g]chrysene benzothienyl group, a dibenzo[g,p]chrysene benzothienyl group, a benzophenanthrofuranyl group, a benzotriphenylenofuranyl group, a benzo[g]chrysene benzofuranyl group, a dibenzo[g,p]chrysene benzofuranyl group, etc. Among them, a heteroaryl group composed of a condensed ring having 3 or more rings (more preferably 3 to 8 rings) is preferable. As such a heteroaryl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an indophenanthrenyl group, an indotriphenylenyl group, an indobenzo[g]chrysenyl group, an indodibenzo[g,p]chrysenyl group, an indenocarbazolyl group, a benzophenanthrothienyl group, a benzotriphenylenothienyl group, a benzo[g]chrysene benzothienyl group, a dibenzo[g,p]chrysene benzothienyl group, a benzophenanthrofuranyl group, a benzotriphenylenofuranyl group, a benzo[g]chrysene benzofuranyl group, a dibenzo[g,p]chrysene benzofuranyl group are preferable.Also, a heteroaryl group composed of a condensed ring containing a carbazole ring is preferred.

[0039] Ar 3 The number of carbon atoms of the above heteroaryl group as [Ar] is preferably 6 to 30, more preferably 10 to 26, and even more preferably 12 to 24.

[0040] Ar 3 [Ar] preferably contains an aromatic hydrocarbon ring which is a condensed ring of 3 rings or more (more preferably 3 to 8 rings), or a heteroaryl ring which is a condensed ring of 3 rings or more (more preferably 3 to 8 rings). Examples of the aromatic hydrocarbon ring which is a condensed ring of 3 rings or more include a fluorene ring, a fluoranthene ring, an anthracene ring, a phenanthrene ring, a benzofluorene ring, a triphenylene ring, a dibenzofluorene ring, a spirobifluorene ring, an indenophenanthrene ring, an indenotriphenylene ring, an indenobenz[g]chrysene ring, a benz[g]chrysene ring, a dibenz[g,p]chrysene ring, etc. Among them, a triphenylene ring, a benzofluorene ring, a dibenzofluorene ring, an indenophenanthrene ring, an indenotriphenylene ring, a benz[g]chrysene ring, a dibenz[g,p]chrysene ring are preferred. Examples of the heteroaryl ring which is a condensed ring of three or more rings include a carbazole ring, a dibenzothiophene ring, a dibenzofuran ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a thianthrene ring, a benzocarbazole ring, a dibenzocarbazole ring, an indolophenanthrene ring, an indolotriphenylene ring, an indolobenzo[g]chrysene ring, an indolodibenzo[g,p]chrysene ring, an indenocarbazole ring, a benzophenanthrophene ring, a benzotriphenylenothiophene ring, a benzo[g]chrysenobenzothiophene ring, a dibenzo[g,p]chrysenobenzothiophene ring, a benzophenanthrofuran ring, a benzotriphenylenofuran ring, a benzo[g]chrysenobenzofuran ring, and a dibenzo[g,p]chrysenobenzofuran ring. Among these, a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, an indolophenanthrene ring, an indolotriphenylene ring, an indolobenzo[g]chrysene ring, an indolodibenzo[g,p]chrysene ring, an indenocarbazole ring, a benzophenanthrophene ring, a benzotriphenylenothiophene ring, a benzo[g]chrysenobenzothiophene ring, a dibenzo[g,p]chrysenobenzothiophene ring, a benzophenanthrofuran ring, a benzotriphenylenofuran ring, a benzo[g]chrysenobenzofuran ring, and a dibenzo[g,p]chrysenobenzofuran ring are preferred.

[0041] Ar 3 The substituents that the heteroaryl group may have include Ar 3 Examples of the substituents include the same groups as those that may be contained in the aromatic hydrocarbon group as described above. Among these, a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, a heteroaryl group having 4 to 25 carbon atoms, or a group combining these are preferred, a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, a heteroaryl group having 4 to 25 carbon atoms, or a group combining these are more preferred, and a methyl group, a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a carbazolyl group, or a group combining these are even more preferred.

[0042] Preferred embodiments of the compound represented by formula (1) include the compound represented by the following formula (2) and the compound represented by formula (3).

[0043] [Compound represented by formula (2)] [Chemical formula] (In formula (2), Ar 20 represents an aromatic hydrocarbon group formed from a 6-membered ring having 12 to 40 carbon atoms which may have a substituent, or a heteroaryl group containing a 5-membered ring having 12 to 40 carbon atoms which may have a substituent, L represents an aromatic hydrocarbon group having 6 to 25 carbon atoms, or an aromatic heterocyclic group having 6 to 25 carbon atoms, n represents 0 or 2, The substituent represents a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a deuterium atom, a cyano group, an aromatic hydrocarbon group having 6 to 15 carbon atoms, a heteroaryl group having 4 to 15 carbon atoms, or a group combining these.)

[0044] (Ar 20 ) Ar 20 Examples of the aromatic hydrocarbon group formed from a 6-membered ring having 12 to 40 carbon atoms as Ar include a biphenylyl group, a terphenylyl group, an anthryl group, a phenanthryl group, a triphenylenyl group, a dibenzofluorenyl group, a benzo[g]chrysenyl group, a dibenzo[g,p]chrysenyl group, etc. Among them, an aromatic hydrocarbon group composed of a condensed ring containing a phenanthrene ring is preferable, and a triphenylenyl group, a benzo[g]chrysenyl group, a dibenzo[g,p]chrysenyl group are more preferable.

[0045] Ar 20 The number of carbon atoms of the above aromatic hydrocarbon group as Ar is preferably 16 to 28, and more preferably 18 to 26.

[0046] Ar 20Examples of the heteroaryl group containing a 5-membered ring having 12 to 40 carbon atoms include a benzocarbazolyl group, a dibenzocarbazolyl group, an indophenanthrenyl group, an indotriphenylenyl group, an indobenzogchrysenyl group, an indodibenzogpchrysenyl group, an indenocarbazolyl group, a benzophenanthrothienyl group, a benzotriphenylenothienyl group, a benzogchrysenobenzothienyl group, a dibenzogpchrysenobenzothienyl group, a benzophenanthrofuranyl group, a benzotriphenylenofuranyl group, a benzogchrysenobenzofuranyl group, a dibenzogpchrysenobenzofuranyl group, and the like. Among them, a heteroaryl group composed of a condensed ring containing a carbazole ring is preferable.

[0047] Ar 20 The number of carbon atoms of the above heteroaryl group is preferably 16 to 26, more preferably 19 to 24.

[0048] Ar 20 In the substituent in Ar 3 Examples of the linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms and the linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms include the same groups as the alkyl group and the alkoxy group in the substituent that the above aromatic hydrocarbon group may have.

[0049] Ar 20 Examples of the aromatic hydrocarbon group having 6 to 15 carbon atoms in the substituent in Ar include a phenyl group, a biphenylyl group, a naphthyl group, a fluorenyl group, an anthryl group, a phenanthryl group, and the like. Among them, a phenyl group is preferable.

[0050] Ar 20 Examples of the heteroaryl group having 4 to 15 carbon atoms in the substituent in Ar 3 include those having 4 to 15 carbon atoms among those exemplified as the heteroaryl group as the substituent in Ar. Among them, a carbazolyl group is preferable.

[0051] (L and n) Examples of the aromatic hydrocarbon group having 6 to 25 carbon atoms as L include groups obtained by removing one hydrogen atom from a phenyl group, biphenylyl group, terphenylyl group, naphthyl group, fluorenyl group, fluoranthenyl group, anthryl group, phenanthryl group, benzofluorenyl group, triphenylenyl group, spirobifluorenyl group, diphenylfluorenyl group, benzo[g]chrysenyl group, etc. Among them, a phenylene group, naphthylene group, biphenylene group, phenanthrenylene group, and fluorenylene group are preferable.

[0052] Examples of the aromatic heterocyclic group having 6 to 25 carbon atoms as L include groups obtained by removing one hydrogen atom from a pyrrolyl group, thienyl group, furyl group, imidazolyl group, pyrazolyl group, thiazolyl group, isothiazolyl group, oxazolyl group, isoxazolyl group, pyridyl group, phenylpyridyl group, pyridylphenyl group, pyrimidyl group, pyrazyl group, 1,3,5-triazolyl group, 1,3,5-triazolylphenyl group, 1,3,5-triazolylbiphenylyl group, 4,6-diphenyl-1,3,5-triazolyl group, indolyl group, benzothienyl group, benzofuranyl group, benzimidazolyl group, indazolyl group, benzothiazolyl group, benzoisothiazolyl group, 2,1,3-benzothiadiazolyl group, benzoxazolyl group, benzoisoxazolyl group, 2,1,3-benzoxadiazolyl group, quinolyl group, isoquinolyl group, quinoxalyl group, quinazolinyl group, carbazolyl group, dibenzothienyl group, dibenzofuranyl group, phenoxazinyl group, phenothiazinyl group, phenazinyl group, thianthrenyl group, etc.

[0053] n is preferably 0.

[0054] [Compound represented by formula (3)] [Chemical formula] (In formula (3), Ar 31 ~Ar 41Each independently represents a substituent selected from the group consisting of a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a deuterium atom, a cyano group, an aromatic hydrocarbon group having 6 to 15 carbon atoms, a heteroaryl group having 4 to 16 carbon atoms, or a group combining these.)

[0055] (Ar 31 ~Ar 41 ) Ar 31 ~Ar 41 Examples of the linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms and the linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms as Ar 3 include the same groups as the alkyl group and alkoxy group in the substituent that the above aromatic hydrocarbon group as Ar

[0056] Ar 31 ~Ar 41 Examples of the aromatic hydrocarbon group having 6 to 15 carbon atoms and the heteroaryl group having 4 to 16 carbon atoms as Ar 20 include the same groups as the aromatic hydrocarbon group and heteroaryl group in the substituent that the above aromatic hydrocarbon group and the above heteroaryl group may have.)

[0057] Ar 31 ~Ar 41 is preferably a hydrogen atom or an aromatic hydrocarbon group having 6 to 15 carbon atoms.)

[0058] [Preferred specific examples of the compound represented by formula (1)] Hereinafter, preferred compounds of the compound represented by formula (1) are exemplified, but the compounds are not limited thereto.)

[0059]

Chemical formula

[0060]

Chemical formula

[0061]

Chem.

[0062]

Chem.

[0063]

Chem.

[0064]

Chem.

[0065]

Chem.

[0066] (Physical properties of the compound represented by formula (1)) The preferable physical properties of the compound represented by formula (1) are described below.

[0067] (Molecular weight) The molecular weight of the compound represented by formula (1) is not particularly limited, but from the viewpoints such as heat resistance stability during sublimation, it is preferably 500 or more and 1500 or less, more preferably 500 or more and 1000 or less, and even more preferably 500 or more and 910 or less.

[0068] (Glass transition point) The glass transition point (Tg) of the compound represented by formula (1) is not particularly limited, but from the viewpoint of compatibility with the photoelectric conversion element for the imaging device, it is preferably 130 °C or more, and more preferably 140 °C or more. Note that this glass transition point is a value obtained from differential scanning calorimetry.

[0069] 〔Novel compound〕 As novel compounds included in the compound represented by formula (1), the compound represented by the above formula (2) and the compound represented by the above formula (3) are provided. Preferred embodiments of these compounds are as described above.

[0070] <Use of the material for the photoelectric conversion element of the imaging device> As the material for the photoelectric conversion element of the imaging device, for example, a charge transport material for the photoelectric conversion element of the imaging device or a charge blocking material for the photoelectric conversion element of the imaging device is preferable. As the charge transport material for the photoelectric conversion element of the imaging device, for example, a hole transport material for the photoelectric conversion element of the imaging device is preferable. As the charge blocking material for the photoelectric conversion element of the imaging device, for example, an electron blocking material for the photoelectric conversion element of the imaging device is preferable.

[0071] ≪Photoelectric conversion element for imaging device≫ The photoelectric conversion element for the imaging device includes the material for the photoelectric conversion element for the imaging device described above. The configuration of the photoelectric conversion element for the imaging device is not particularly limited, and examples thereof include the configurations (i) to (v) shown below.

[0072] (i) First electrode / Photoelectric conversion layer / Second electrode (ii) First electrode / Electron transport layer (hole blocking layer) / Photoelectric conversion layer / Second electrode (iii) First electrode / Photoelectric conversion layer / Hole transport layer (electron blocking layer) / Second electrode (iv) First electrode / Electron transport layer (hole blocking layer) / Photoelectric conversion layer / Hole transport layer (electron blocking layer) / Second electrode (v) First electrode / Electron transport layer (hole blocking layer) / Photoelectric conversion layer / Hole transport layer (electron blocking layer) / Buffer layer / Second electrode

[0073] Note that the buffer layer may be replaced with a layer having another name or function as necessary. Examples of the layer having another name or function include a hole injection layer, a work function adjustment layer, and the like. The photoelectric conversion element for an imaging element may contain a material for a photoelectric conversion element for an imaging element in at least one layer selected from the group consisting of an electron transport layer (hole blocking layer), a photoelectric conversion layer, a hole transport layer (electron blocking layer), and a buffer layer. Further, it is preferable that the photoelectric conversion element for an imaging element contains a material for a photoelectric conversion element for an imaging element in the photoelectric conversion layer and / or the hole transport layer (electron blocking layer), and it is more preferable that the hole transport layer (electron blocking layer) contains a material for a photoelectric conversion element for an imaging element. Note that the material for a photoelectric conversion element for an imaging element may be contained in a plurality of layers included in the photoelectric conversion element for an imaging element.

[0074] Hereinafter, the photoelectric conversion element for an imaging element will be described in more detail with reference to FIG. 1 by taking the configuration of (v) above as an example. FIG. 1 is a schematic cross-sectional view showing an example of a stacked structure of a photoelectric conversion element for an imaging element containing a material for a photoelectric conversion element for an imaging element.

[0075] The photoelectric conversion element 100 for an imaging element shown in FIG. 1 includes a substrate 1, a first electrode 2, an electron transport layer (hole blocking layer) 3, a photoelectric conversion layer 4, a hole transport layer (electron blocking layer) 5, a buffer layer 6, and a second electrode 7 in this order. Note that the photoelectric conversion element for an imaging element may have a configuration in which FIG. 1 is upside down, some of these layers may be omitted, and other layers may be added.

[0076] In the photoelectric conversion element 100 for an imaging element, light is incident from the transparent first electrode 2 or second electrode 7. Further, a voltage is applied to the photoelectric conversion element 100 so that among the charges (holes and electrons) generated in the photoelectric conversion layer 4, electrons move to the first partial electrode 2 and holes move to the second electrode 7. That is, the photoelectric conversion element 100 uses the first electrode 2 as an electron collection electrode and the second electrode 7 as a hole collection electrode.

[0077] [Layer containing material for photoelectric conversion element for imaging element] The photoelectric conversion element 100 for an imaging element contains a material for a photoelectric conversion element for an imaging element in at least one layer selected from the group consisting of an electron transport layer (hole blocking layer) 3, a photoelectric conversion layer 4, a hole transport layer (electron blocking layer) 5, and a buffer layer 6. The photoelectric conversion element 100 for an imaging element preferably contains a material for a photoelectric conversion element for an imaging element in the photoelectric conversion layer 4 and / or the hole transport layer (electron blocking layer) 5, and more preferably contains a material for a photoelectric conversion element for an imaging element in the hole transport layer (electron blocking layer) 5. Note that the material for a photoelectric conversion element for an imaging element may be contained in a plurality of layers included in the photoelectric conversion element 100 for an imaging element.

[0078] Hereinafter, the photoelectric conversion element 100 for an imaging element in which the hole transport layer (electron blocking layer) 5 contains a material for a photoelectric conversion element for an imaging element will be described.

[0079] [Substrate 1] The substrate is not particularly limited, and examples thereof include a glass plate, a quartz plate, and a plastic plate. In the case of a configuration in which light is incident from the substrate 1 side, the substrate 1 preferably has high transmittance (for example, a transmittance of 80% or more, preferably 90% or more) with respect to the wavelength of light.

[0080] [First electrode 2] The first electrode 2 is provided on the substrate 1. In the case of a photoelectric conversion element for an imaging element having a configuration in which light passes through the first electrode 2 and is incident on the photoelectric conversion layer, the first electrode 2 preferably has high transmittance (for example, a transmittance of 80% or more, preferably 90% or more) with respect to the wavelength of the incident light.

[0081] The transparent material used for the first electrode 2 is not particularly limited. From the viewpoint of excellent light transmittance, the material constituting the first electrode 2 is, for example, indium-tin oxide (ITO; Indium Tin Oxide), indium-zinc oxide (IZO; Indium Zinc Oxide), tin oxide, aluminum-doped tin oxide, magnesium-indium oxide, nickel-tungsten oxide, other metal oxides, metal nitrides such as gallium nitride, metal selenides such as zinc selenide, metal sulfides such as zinc sulfide, and the like.

[0082] In the case of a photoelectric conversion element for an image pickup device configured such that light enters the photoelectric conversion layer only from the second electrode 7 side, the transmission characteristics of the first electrode 2 are not important. Therefore, as an example of the material used for the first electrode 2 in this case, sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, silver, gold, magnesium / silver mixture, aluminum, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al2O3) mixture, indium, lithium / aluminum mixture, iridium, molybdenum, palladium, platinum, rare earth metals, and the like may be used.

[0083] [Electron transport layer (hole blocking layer) 3] An electron transport layer (hole blocking layer) 3 is provided between the first electrode 2 and the photoelectric conversion layer 4.

[0084] The electron transport layer (hole blocking layer) 3 has a role of transporting electrons generated in the photoelectric conversion layer 4 to the first electrode 2 and a role of blocking the holes generated in the photoelectric conversion layer 4 from moving to the first electrode 2.

[0085] The electron transport layer (hole blocking layer) 3 may have a single-layer structure composed of one or more materials, or may have a laminated structure composed of a plurality of layers of the same composition or different compositions. The electron transport layer (hole blocking layer) 3 may be, for example, a two-layer structure including a layer adjacent to the photoelectric conversion layer 4 made of a material specialized for hole blocking property and a layer adjacent to the first electrode 2 made of a material specialized for electron transport property.

[0086] The electron transport layer (hole blocking layer) 3 may be a layer containing a conventionally known electron transport material. Examples of the conventionally known electron transport materials include manganese bis(8-hydroxyquinolinate), aluminum tris(8-hydroxyquinolinate), aluminum tris(2-methyl-8-hydroxyquinolinate), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), BAlq (bis(2-methyl-8-quinolinolate)-4-(phenylphenolate)aluminum), 4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-methylpyrimidine, N,N'-diphenyl-1,4,5,8-naphthalenetetracarboxylic diimide, and N,N'-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic diimide.

[0087] [Photoelectric conversion layer 4] A photoelectric conversion layer 4 is provided between the electron transport layer (hole blocking layer) 3 and the hole transport layer (electron blocking layer) 5 described later. The photoelectric conversion layer 4 contains a material having a photoelectric conversion function.

[0088] The photoelectric conversion layer 4 may be an organic material or an inorganic material, as long as it can generate signal charges corresponding to the amount of received light. When the photoelectric conversion layer 4 is composed of an organic material, the photoelectric conversion layer 4 may have a single-layer structure composed of one or more materials, or may have a laminated structure composed of a plurality of layers of the same composition or different compositions. As materials used for the photoelectric conversion layer 4, there are n-type semiconductors and p-type semiconductors. The n-type semiconductor is an acceptor-type organic semiconductor, which easily accepts electrons, and a compound with high electron transportability is used. The p-type semiconductor is a donor-type organic semiconductor, which easily donates electrons, and a compound with high hole transportability is used. When a plurality of materials are used for the photoelectric conversion layer 4, examples of the combination include an n-type semiconductor and a p-type semiconductor, an n-type semiconductor and a compound with lower acceptor properties than the n-type semiconductor, a p-type semiconductor and a compound with lower donor properties than the p-type semiconductor, and the like. Each material may be one type, or two or more types of materials may be used. The photoelectric conversion layer 4 may contain a dye compound excellent in absorption of specific light. The dye compound may be a compound with lower acceptor properties than the n-type semiconductor, or a compound with lower donor properties than the p-type semiconductor. From the viewpoint of enhancing the photoelectric conversion efficiency, it is desirable that the photoelectric conversion layer 4 further contains a dye compound in addition to the n-type semiconductor and the p-type semiconductor. Examples of the compounds contained in the photoelectric conversion layer 4 include coumarin and its derivatives, quinacridone and its derivatives, phthalocyanine and its derivatives, fullerene and its derivatives, azole derivatives such as imidazole, thiazole, thiadiazole, oxazole, oxadiazole, and triazole, naphthalene tetracarboxylic acid diimide, hole transport materials, and the like. Among these, phthalocyanine and its derivatives, and fullerene and its derivatives are preferable. The photoelectric conversion layer 4 made of these materials may be formed, for example, by vapor deposition using a mixed powder obtained by mixing powders of each material, or may be formed by co-vapor deposition of each material at an arbitrary ratio.

[0089] Specific examples of the coumarin derivative include coumarin 6, coumarin 30, and the like. Specific examples of the quinacridone derivative include N,N-dimethylquinacridone and the like. Specific examples of the phthalocyanine derivative include boron subphthalocyanine chloride, boron subnaphthalocyanine chloride (SubNC), F6-SubPC-OC6F5, Cl6-SubPC-OC6, and the like. Specific examples of fullerenes and their derivatives include

[60] fullerene,

[70] fullerene, [6,6]-phenyl-C61-butyric acid methyl ester (

[60] PCBM), and the like. The hole transport material may be a known hole transport material. Examples of the hole transport material include, for example, aromatic tertiary amine compounds, naphthalene compounds, anthracene compounds, tetracene compounds, pentacene compounds, phenanthrene compounds, pyrene compounds, perylene compounds, fluorene compounds, carbazole compounds, indole compounds, pyrrole compounds, picene compounds, thiophene compounds, benzotrifuran compounds, benzotrithiophene compounds, naphthodithiophene compounds, naphthothienothiophene compounds, benzodifuran compounds, benzodithiophene compounds, benzothiophene compounds, naphthobisbenzothiophene compounds, chrysenedithiophene compounds, benzothienobenzothiophene compounds, indolocarbazole compounds, and the like. Among these, fluorene compounds, naphthodithiophene compounds, naphthothienothiophene compounds, benzodifuran compounds, benzothiophene compounds, naphthobisbenzothiophene compounds, chrysenedithiophene compounds, benzothienobenzothiophene compounds, indolocarbazole compounds, and the like are preferable, and fluorene compounds, chrysenedithiophene compounds, benzothienobenzothiophene compounds, indolocarbazole compounds are more preferable.

[0090] Specific examples of the hole transport material include 9,9'-(9,9'-spirobi[9H-fluorene]-2,7'-diyl)bis[9H-carbazole], 2,7-diphenyl[1]benzothieno[3,2-b][1]benzothiophene (DiPh-BTBT), benzo[1,2-b:3,4-b':5,6-b'']trifuran compounds, benzo[1,2-b:3,4-b':5,6-b'']trithiophene compounds, naphtho[1,2-b:5,6-b']dithiophene, naphtho[2,3-b]naphtho[2',3':4,5]thieno[2,3-d]thiophene, benzo[1,2-b:4,5-b']difuran, benzo[1,2-b:4,5-b']dithiophene, benzo[1,2-b:4,5-b']bis[1]benzothiophene, naphtho[1,2-b:5,6-b']bis[1]benzothiophene, chryseno[1,2-b:8,7-b']dithiophene, [1]benzothieno[3,2-b][1]benzothiophene, the compound represented by the following formula (ic-1), the compound represented by the following formula (ic-2), and the like.

[0091] [Chemical formula]

[0092] Note that the material having the above-described photoelectric conversion function may be contained only in the photoelectric conversion layer 4, or may also be contained in layers other than the photoelectric conversion layer 4. For example, the layers adjacent to the photoelectric conversion layer 4 (electron transport layer (hole blocking layer) 3, hole transport layer (electron blocking layer) 5) may contain a material having a photoelectric conversion function.

[0093] [Hole transport layer (electron blocking layer) 5] A hole transport layer (electron blocking layer) 5 is provided between the photoelectric conversion layer 4 and the buffer layer 6 described later.

[0094] The hole transport layer (electron blocking layer) 5 has the role of transporting the holes generated in the photoelectric conversion layer 4 to the second electrode 7 side and the role of blocking the electrons generated in the photoelectric conversion layer 4 from moving to the second electrode 7 side. The hole transport layer (electron blocking layer) 5 preferably contains the above-described material for the photoelectric conversion element for the imaging device.

[0095] The hole transport layer (electron blocking layer) 5 may have a single-layer structure composed of one or more than two kinds of materials, or may have a laminated structure composed of a plurality of layers of the same composition or different compositions. The hole transport layer (electron blocking layer) 5 may be, for example, a two-layer structure including a layer adjacent to the photoelectric conversion layer 4 made of a material specialized in electron blocking property and a layer adjacent to the buffer layer 6 made of a material specialized in hole transport property.

[0096] In addition to the above-described material for the photoelectric conversion element for the imaging device, the hole transport layer (electron blocking layer) 5 may further contain a conventionally known hole transport material. Preferred compounds and specific examples of the conventionally known hole transport material include the same ones as the hole transport materials described in the item of the photoelectric conversion layer 4.

[0097] [Buffer layer 6] A buffer layer 6 is provided between the hole transport layer (electron blocking layer) 5 and the second electrode 7 described later. When the second electrode 7 is formed by a sputtering method, the buffer layer 6 has the role of reducing the damage to the organic layer (for example, the hole transport layer (electron blocking layer) 5) during sputtering. Also, by adjusting the work function of the buffer layer 6, it also has the role of efficiently accepting holes from the hole transport layer (electron blocking layer) 5 or accepting electrons from the second electrode 7, and is also called a hole injection layer or a work function adjustment layer.

[0098] The material constituting the buffer layer 6 may be a known material, and for example, naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN), etc. may be used.

[0099] [Second electrode 7] A second electrode 7 is provided on the buffer layer 6. The material of the second electrode 7 is not particularly limited, and may be, for example, sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, silver, gold, magnesium / silver mixture, aluminum, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al2O3) mixture, indium, lithium / aluminum mixture, iridium, molybdenum, palladium, platinum, rare earth metals, etc. In the case of a photoelectric conversion element for an imaging device configured such that light enters the photoelectric conversion layer from the second electrode 7 side, the material constituting the second electrode 7 may be, for example, indium-tin oxide (ITO; Indium Tin Oxide), indium-zinc oxide (IZO; Indium Zinc Oxide), tin oxide, aluminum-doped tin oxide, magnesium-indium oxide, nickel-tungsten oxide, other metal oxides, metal nitrides such as gallium nitride, metal selenides such as zinc selenide, metal sulfides such as zinc sulfide, etc.

[0100] [Formation method of each layer] Each layer other than the first electrode 2 and the second electrode 7 can be formed by thinning the material of each layer (materials such as a binder resin and a solvent as necessary) by a known method such as vacuum evaporation, spin coating, casting, LB (Langmuir-Blodgett method), etc. The thickness of each layer other than the first electrode 2 and the second electrode 7 is not particularly limited and can be appropriately selected according to the situation. The thickness of each layer other than the first electrode 2 and the second electrode 7 is usually in the range of 5 nm or more and 5 μm or less.

[0101] The first electrode 2 and the second electrode 7 can be formed by thinning the electrode material by a method such as evaporation or sputtering. When the first electrode 2 and the second electrode 7 have patterns, for example, the patterns can be formed through a mask having a desired shape. Also, after forming a thin film by vapor deposition, sputtering, or the like, a pattern having a desired shape may be formed by photolithography.

[0102] The film thicknesses of the first electrode 2 and the second electrode 7 may be 1 μm or less, and are preferably 10 nm or more and 200 nm or less.

[0103] The imaging device including the photoelectric conversion element according to this embodiment can be applied to, for example, imaging devices such as digital cameras and digital video cameras, and imaging devices incorporated in mobile phones and the like. As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to the above embodiments.

Example

[0104] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not to be construed as being limited in any way by these examples.

[0105] [Synthesis Example 1]

Chemical formula

[0106] [Synthesis Example 2] [Chemical Formula] It was synthesized in the same manner as in Synthesis Example 1, except that Compound X2 was used instead of Compound X1 in Synthesis Example 1, and a white powder was obtained in a yield of 87%. 1H-NMR (DMSO-d 6 ) δ (ppm) = 8.28 (d, J = 9.5 Hz, 1H), 8.22 (d, J = 7.1 Hz, 1H), 8.00 - 7.96 (m, 4H), 7.93 (d, J = 8.9 Hz, 2H), 7.89 (d, J = 8.8 Hz, 2H), 7.85 - 7.73 (m, 8H), 7.58 - 7.39 (m, 17H), 7.34 - 7.30 (m, 5H), 7.24 (s, 1H), 7.21 (d, J = 8.3 Hz, 1H).

[0107] [Synthesis Example 3] [Chemical Formula] It was synthesized in the same manner as in Synthesis Example 1, except that Compound X3 was used instead of Compound X1 and twice the amount of Compound Y2 was used instead of Compound Y1 in Synthesis Example 1, and a white powder was obtained in a yield of 75%. 1H-NMR (DMSO-d 6 ) δ (ppm) = 8.88 - 7.79 (m, 4H), 8.68 (d, J = 10.5 Hz, 1H), 8.63 (d, J = 9.1 Hz, 1H), 8.29 (d, J = 8.4 Hz, 1H), 8.13 (s, 1H), 7.84 - 7.62 (m, 21H), 7.55 - 7.33 (m, 12H).

[0108] [Synthesis Example 4]

Chemical Formula

[0109] [Synthesis Example 5]

Chemical Formula

[0110] [Synthesis Example 6] [Chemical Formula] It was synthesized in the same manner as in Synthesis Example 1, except that Compound X6 was used instead of Compound X1 and Compound Y2 was used instead of Compound Y1, and a white powder was obtained in a yield of 89%. 1H-NMR (DMSO-d 6 ) δ (ppm) = 8.90 (dd, J = 9.2 Hz, 5.3 Hz, 2H), 8.84 (dd, J = 6.9 Hz, 5.6 Hz, 2H), 8.50 (d, J = 2.3 Hz, 1H), 8.45 (d, J = 9.3 Hz, 1H), 8.11 (d, J = 9.3 Hz, 1H), 8.06 (d, J = 9.8 Hz, 1H), 7.82 - 7.67 (m, 20H), 7.54 (dd, J = 8.9 Hz, 2.3 Hz, 1H), 7.49 (t, J = 8.0 Hz, 4H), 7.38 (tt, J = 7.2 Hz, 2H), 7.31 (d, J = 8.7 Hz, 4H)

[0111] [Synthesis Example 7] [Chemical Formula] It was synthesized in the same manner as in Synthesis Example 1, except that Compound X3 was used instead of Compound X1 and twice the amount of Compound Y3 was used instead of Compound Y1, and a white powder was obtained in a yield of 69%. 1H-NMR (DMSO-d 6 ) δ (ppm) = 8.95 (d, J = 8.7 Hz, 2H), 8.93 - 8.82 (m, 6H), 8.72 (d, J = 9.4 Hz, 1H), 8.68 (d, J = 8.3 Hz, 1H), 8.40 (d, J = 2.0 Hz, 2H), 8.37 (d, J = 8.3 Hz, 1H), 8.22 (d, J = 2.3 Hz, 1H), 8.11 (dd, J = 7.6 Hz, 2.0 Hz, 2H), 8.06 - 7.98 (m, 8H), 7.94 - 7.92 (m, 2H), 7.82 - 7.68 (m, 8H), 7.66 (t, J = 7.5 Hz, 1H), 7.61 (dd, J = 8.8 Hz, 2.1 Hz, 1H), 7.50 (t, J = 7.7 Hz, 1H), 7.44 (t, J = 8.9 Hz, 4H).

[0112] [Synthesis Example 8] [Chemical Formula] In Synthesis Example 1, it was synthesized in the same manner as in Synthesis Example 1, except that 2-fold amounts of Compound X3 were used instead of Compound X1 and Compound Y4 was used instead of Compound Y1, and a white powder was obtained in a yield of 79%. 1H-NMR(DMSO-d 6 )δ(ppm)=8.91(d,J=9.1Hz,1H),8.88~8.83(m,2H),8.77(d,J=8.2Hz,1H),8.72(dd,J=6.4Hz,3.6Hz,1H),8.67(d,J=8.6Hz,1H),8.45(d,J=4.9Hz,4H),8.33(d,J=8.3Hz,1H),8.24(d,J=2.3Hz,1H),8.15(d,J=8.7Hz,2H),8.12~7.97(m,12H),7.81~7.77(m,5H),7.72(t,J=7.0Hz,1H),7.63~7.53(m,8H),8.14(t,J=7.7Hz,1H).

[0113] [Synthesis Example 9] [Chemical Formula] In Synthesis Example 1, it was synthesized in the same manner as in Synthesis Example 1, except that Compound X7 was used instead of Compound X1, and a white powder was obtained in a yield of 80%. 1H-NMR(DMSO-d 6 )δ(ppm)=8.85-8.68(m,5H),8.34(s,1H),8.03~7.99(m,6H),7.78-7.73(m,4H),7.71(t,J=8.0Hz、1H),7.68-7.52(m,10H),7.42(d,J=9.2Hz,1H),7.31(t,J=7.2Hz,4H),7.26(d,J=9.2Hz,1H),7.10-6.97(m,7H)

[0114] [Comparative Examples 1 to 4] As Comparative Examples 1 to 4, Compounds Ref1 to Ref4 represented by the following formulas were used respectively. [Chemical formula]

[0115] (Glass transition temperature) Measurement was carried out using DSC7020 manufactured by Hitachi High-Technologies Corporation. The results are shown in Table 1.

[0116] [Table 1]

[0117] (Element Example 1: Fabrication of a photoelectric conversion element for an imaging device using Compound A023) As shown in Fig. 1, a photoelectric conversion element 100 for an imaging device having a stacked structure composed of a substrate 1 / a first electrode 2 / an electron transport layer (hole blocking layer) 3 / a photoelectric conversion layer 4 / a hole transport layer (electron blocking layer) 5 / a buffer layer 6 / a second electrode 7 was fabricated and its characteristics were evaluated.

[0118] (Preparation of Substrate 1 and First Electrode 2) As a substrate having a first electrode on its surface, a glass substrate with an ITO transparent electrode in which a 2 mm-wide indium tin oxide (ITO) film (film thickness: 110 nm) was patterned in a stripe shape was prepared. Then, this substrate was washed with isopropyl alcohol and then surface-treated by ozone ultraviolet cleaning.

[0119] (Vacuum Evaporation) Each layer was laminated on the substrate subjected to the surface treatment after washing by vacuum evaporation. Specifically, a glass substrate with an ITO transparent electrode was introduced into a vacuum evaporation chamber and the pressure was reduced to 7.0×10 -5 Pa. Then, each layer was fabricated in the following order. (1) Fabrication of Electron Transport Layer (Hole Blocking Layer) 3) Sublimation-purified 4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-methylpyrimidine was deposited at a rate of 0.10 nm / second to form a 10-nm film, thereby fabricating the electron transport layer (hole blocking layer) 3. (2) Fabrication of Photoelectric Conversion Layer 4 2-Ph-BTBT, F6-SubPc-OC6F5, and fullerene (C60) were co-evaporated at a deposition rate ratio of 4:4:2 to form a 200-nm-thick photoactive layer 4. The deposition rate was 0.15 nm / sec. (3) Fabrication of the hole transport layer (electron blocking layer) 5 The sublimation-purified compound A023 was deposited at a rate of 0.10 nm / sec to form a 10-nm-thick hole transport layer 5. (4) Fabrication of the buffer layer 6 The sublimation-purified 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN) was deposited at a rate of 0.10 nm / sec to form a 10-nm-thick buffer layer 6.

[0120] (5) Fabrication of the second electrode 7 A metal mask was placed perpendicular to the ITO stripes on the substrate, and the second electrode 7 was deposited. The second electrode was formed by depositing 80 nm of gold. The deposition rate of gold was 0.1 nm / sec.

[0121] Using the above method, a photoelectric conversion element for an imaging device with an area of 4 mm 2 was fabricated. The thickness of each layer was measured using a stylus profilometer (DEKTAK, manufactured by Bruker). The fabricated device was sealed in a nitrogen atmosphere glove box with an oxygen and moisture concentration of 1 ppm or less. The sealing was performed using a glass sealing cap and bisphenol F type epoxy resin (manufactured by Nagase ChemteX).

[0122] (Device Example 2) A photoelectric conversion element for an imaging device of Device Example 2 was fabricated in the same manner as Device Example 1, except that compound A022 was used instead of compound A023 in the fabrication of the hole transport layer 5 of Device Example 1.

[0123] (Device Example 3) A photoelectric conversion element for an imaging device of Device Example 3 was fabricated in the same manner as Device Example 1, except that compound A026 was used instead of compound A023 in the fabrication of the hole transport layer 5 of Device Example 1.

[0124] (Element Comparative Example 1) In the production of the hole transport layer 5 of Element Example 1, a photoelectric conversion element for an imaging device of Element Comparative Example 1 was produced in the same manner as in Element Example 1, except that Ref1 was used instead of Compound A023.

[0125] (Element Comparative Example 2) In the production of the hole transport layer 5 of Element Example 1, a photoelectric conversion element for an imaging device of Element Comparative Example 2 was produced in the same manner as in Element Example 1, except that Ref2 was used instead of Compound A023.

[0126] (Element Example 4) In the production of the hole transport layer 5 of Element Example 1, a photoelectric conversion element for an imaging device of Element Example 4 was produced in the same manner as in Element Example 1, except that A017 was used instead of Compound A023.

[0127] (Element Example 5) In the production of the hole transport layer 5 of Element Example 1, a photoelectric conversion element for an imaging device of Element Example 5 was produced in the same manner as in Element Example 1, except that A040 was used instead of Compound A023.

[0128] (Element Example 6) In the production of the hole transport layer 5 of Element Example 1, a photoelectric conversion element for an imaging device of Element Example 6 was produced in the same manner as in Element Example 1, except that A042 was used instead of Compound A023.

[0129] (Element Example 7) In the production of the hole transport layer 5 of Element Example 1, a photoelectric conversion element for an imaging device of Element Example 7 was produced in the same manner as in Element Example 1, except that A015 was used instead of Compound A023.

[0130] (Element Example 8) In the production of the hole transport layer 5 of Device Example 1, a photoelectric conversion element for an imaging device of Device Example 8 was produced in the same manner as in Device Example 1, except that A057 was used instead of compound A023.

[0131] (Device Example 9) In the production of the hole transport layer 5 of Device Example 1, a photoelectric conversion element for an imaging device of Device Example 9 was produced in the same manner as in Device Example 1, except that A093 was used instead of compound A023.

[0132] (Device Comparative Example 3) In the production of the hole transport layer 5 of Device Example 1, a photoelectric conversion element for an imaging device of Device Comparative Example 3 was produced in the same manner as in Device Example 1, except that Ref3 was used instead of compound A023.

[0133] (Device Comparative Example 4) In the production of the hole transport layer 5 of Device Example 1, a photoelectric conversion element for an imaging device of Device Comparative Example 4 was produced in the same manner as in Device Example 1, except that Ref4 was used instead of compound A023.

[0134] (Measurement of Dark Current and Response Time) When a voltage of 2.5 V as an absolute value was applied to the photoelectric conversion element for an imaging device produced as described above so that electrons were transported to the first electrode 2 side and holes were transported to the second electrode 7 side, the current in the dark (dark current) and the response time were evaluated. The dark current was evaluated using a source measure unit 2636B manufactured by Keithley Instruments, Inc. The response time was measured by irradiating a light pulse and measuring the time until the current value returned to the value before irradiation.

[0135] The results are shown in Tables 2 and 3. The results shown in Table 2 are relative values with the results in Device Comparative Example 2 as the reference value (1.0), and the results shown in Table 3 are relative values with the results in Device Comparative Example 3 as the reference value (1.0). A lower numerical value of the dark current indicates better dark current characteristics, and a shorter response time indicates better responsiveness.

[0136]

Table 2

[0137]

Table 3

[0138] As shown in Table 2 and Table 3, the elements of the examples using the materials for the photoelectric conversion elements for specific imaging elements had suppressed dark current and excellent responsiveness as compared with the elements of the comparative examples.

Explanation of Signs

[0139] 1 Substrate 2 First electrode 3 Electron transport layer (hole blocking layer) 4 Photoelectric conversion layer 5 Hole transport layer (electron blocking layer) 6 Buffer layer 7 Second electrode 100 Photoelectric conversion element for imaging element

Claims

1. A material for a photoelectric conversion element for an imaging device, containing a compound represented by the following formula (1). 【Chemical 1】 (In formula (1), Ar １ and Ar ２ are the same and represent a linked ring in which any ring selected from a monocyclic ring and a condensed ring having 3 or fewer rings is linked, or an aryl group having 14 to 26 carbon atoms and consisting of a condensed ring having 3 or fewer rings. Ar ３ represents an aromatic hydrocarbon group having 6 to 40 carbon atoms which may have a substituent, or a heteroaryl group having 6 to 40 carbon atoms which may have a substituent.)

2. The material for a photoelectric conversion element for an imaging device according to claim 1, wherein the substituent is a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a deuterium atom, a cyano group, an aromatic hydrocarbon group having 6 to 25 carbon atoms, a heteroaryl group having 4 to 25 carbon atoms, or a group combining these.)

3. The material for a photoelectric conversion element for an imaging device according to claim 1, wherein the molecular weight of the compound represented by the formula (1) is 500 or more and 1000 or less.

4. The above-mentioned Ar ３ The material for a photoelectric conversion element for an imaging device according to claim 1, wherein Ar contains an aromatic hydrocarbon ring which is a condensed ring of three or more rings or a heteroaryl ring which is a condensed ring of three or more rings.

5. Said Ar ３ is an aromatic hydrocarbon group composed of a condensed ring of 3 or more rings which may have a substituent, or a heteroaryl group composed of a condensed ring of 3 or more rings which may have a substituent, the material for a photoelectric conversion element for an imaging device according to claim 1.

6. Said Ar １ and said Ar ２ The material for a photoelectric conversion element for an imaging device according to claim 1, wherein the aryl group in is formed from a 6-membered ring.

7. The above-mentioned Ar ３ is an aromatic hydrocarbon group formed from a 5-membered ring, a 6-membered ring, or both, which may have a substituent, or a heteroaryl group composed of a condensed ring including a carbazole ring, which may have a substituent. The material for a photoelectric conversion element for an imaging device according to claim 1.

8. The material for a photoelectric conversion element for an imaging device according to claim 1, wherein the glass transition point of the compound represented by the formula (1) is 140°C or higher.

9. The material for a photoelectric conversion element for an imaging device according to claim 1, which is a hole transport material for a photoelectric conversion element for an imaging device.

10. An imaging device photoelectric conversion element, comprising the material for an imaging device photoelectric conversion element according to any one of claims 1 to 9.

11. A compound represented by the following formula (2). [Chemical Formula 2] (In formula (2), Ar ２０ represents an aromatic hydrocarbon group formed from a 6-membered ring having 12 to 40 carbon atoms which may have a substituent, or a heteroaryl group containing a 5-membered ring having 12 to 40 carbon atoms which may have a substituent, L represents an aromatic hydrocarbon group having 6 to 25 carbon atoms or an aromatic heterocyclic group having 6 to 25 carbon atoms, n represents 0 or 2, and the substituent represents a group selected from the group consisting of a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a deuterium atom, a cyano group, an aromatic hydrocarbon group having 6 to 15 carbon atoms, a heteroaryl group having 4 to 15 carbon atoms, or a group combining these.)

12. The compound according to claim 11, wherein L is a phenylene group, a naphthylene group, a biphenylene group, a phenanthrenylene group, or a fluorenylene group.

13. The compound according to claim 11, wherein n is 0.

14. Said Ar ２０ is an aromatic hydrocarbon group consisting of a condensed ring containing a phenanthrene ring, which may have a substituent, or a heteroaryl group consisting of a condensed ring containing a carbazole ring, which may have a substituent, and the compound according to claim 11.

Images