WO2014050764A1

WO2014050764A1 - Photoelectric conversion element, imaging element, optical sensor

Info

Publication number: WO2014050764A1
Application number: PCT/JP2013/075564
Authority: WO
Inventors: 伊勢　俊大; 知昭吉岡; 陽介山本; 大悟澤木
Original assignee: 富士フイルム株式会社
Priority date: 2012-09-26
Filing date: 2013-09-20
Publication date: 2014-04-03
Also published as: TW201428988A; TWI611594B; JP5890366B2; JP2014082473A; KR20150046785A; KR101635332B1

Abstract

The purpose of the present invention is to provide a photoelectric conversion element which is provided with a photoelectric conversion film exhibiting excellent heat resistance and excellent response, and an imaging element and an optical sensor containing said photoelectric conversion element. This photoelectric conversion element is formed by laminating a conductive film, a photoelectric conversion film containing a photoelectric conversion material, and a transparent conductive film, in that order, wherein the photoelectric conversion material contains at least one compound X selected from the group consisting of compounds represented by general formula (1), compounds represented by general formula (2), and compounds represented by general formula (3).

Description

Photoelectric conversion element, imaging element, optical sensor

The present invention relates to a photoelectric conversion element, an imaging element, and an optical sensor.

A conventional photosensor is an element in which a photodiode (PD) is formed in a semiconductor substrate such as silicon (Si), and as a solid-state imaging element, PDs are two-dimensionally arrayed and signal charges generated in each PD A flat-type solid-state image sensor which reads out the signal by a circuit is widely used.

In order to realize a color solid-state imaging device, a structure in which a color filter for transmitting light of a specific wavelength is disposed on the light incident surface side of the planar solid-state imaging device is generally used. Currently, color filters that transmit blue (B) light, green (G) light, and red (R) light are regularly arranged on each of the two-dimensionally arrayed PDs widely used in digital cameras etc. Single-plate solid-state imaging devices are well known.
In this single-plate solid-state imaging device, the light not transmitted through the color filter is not used and the light utilization efficiency is poor. In recent years, while the number of pixels has been increased, the pixel size has become smaller, and the reduction of the aperture ratio and the reduction of the light collection efficiency have become problems.

In order to solve these defects, a structure is known in which a photoelectric conversion film or a photoelectric conversion film of amorphous silicon is formed on a signal readout substrate.
There are several known examples of a photoelectric conversion element, an imaging element, and an optical sensor using a photoelectric conversion film.
For example, in Patent Document 1, a photoelectric conversion film including a compound (3) or the like represented by the following formula is disclosed in the Example column, and it is described that the photoelectric conversion efficiency is high. Further, Patent Documents 2 and 3 also disclose a photoelectric conversion element containing a diketopyrrolopyrrole compound.

Japanese Patent Application Publication No. 2006-339424 Unexamined-Japanese-Patent No. 2010-192782 Japanese Patent Application Publication No. 2003-346926

In recent years, with the demand for performance improvement of imaging devices, optical sensors and the like, improvements have also been required for various characteristics such as heat resistance and response speed required for photoelectric conversion films used for these. For example, when the photoelectric conversion element is applied to various applications such as an imaging element and a photoelectric cell, the photoelectric conversion element is required to exhibit high heat resistance from the viewpoint of process suitability. More specifically, as a process for forming an imaging device, there are many processes for applying heat treatment such as color filter installation, protective film installation, device soldering, etc. The photoelectric conversion device is excellent even through these processes It is required to show other characteristics (response speed, low dark current characteristics, etc.).
The present inventors prepared a photoelectric conversion film using a compound (for example, the above-mentioned compound 3) specifically disclosed in Patent Documents 1 to 3, and it was found that the heat resistance and the response speed were not necessarily obtained. It has been found that it has not reached the level required nowadays and further improvement is necessary.

An object of this invention is to provide the photoelectric conversion element provided with the photoelectric conversion film which shows the outstanding heat resistance and responsiveness in view of the said situation.
Another object of the present invention is to provide an imaging device and a photosensor including a photoelectric conversion device.

As a result of intensive studies on the above problems, the present inventors have found that a diketopyrrolopyrrole compound contained in a photoelectric conversion film or a compound in which an aromatic ring is further condensed between two pyrrole rings of diketopyrrolopyrrole. It has been found that the above-mentioned problems can be solved by introducing an aromatic ring-containing amine group at the position of, and the present invention has been completed.
That is, the above-mentioned subject can be solved by the means shown below.

(1) A photoelectric conversion element obtained by laminating a conductive film, a photoelectric conversion film containing a photoelectric conversion material, and a transparent conductive film in this order,
The photoelectric conversion material is selected from the group consisting of a compound represented by General Formula (1) described later, a compound represented by General Formula (2) described later, and a compound represented by General Formula (3) described later Photoelectric conversion element containing at least one compound X.
(2) The photoelectric conversion element as described in (1) whose compound X is a compound represented by General formula (4) mentioned later.
(3) Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , and at least one of R ¹³ and R ¹⁴ respectively bond to each other to form a ring The photoelectric conversion element as described in (1) or (2) which is forming.
(4) The photoelectric conversion device according to any one of (1) to (3), wherein X ¹ and X ² are O.
(5) The photoelectric conversion device according to any one of (1) to (4), wherein the photoelectric conversion film further contains an organic n-type compound.
(6) The photoelectric conversion device according to (5), wherein the organic n-type compound comprises fullerenes including fullerene and a derivative thereof.

(7) The photoelectric conversion element as described in (6) whose molar ratio (molar amount of fullerenes / molar amount of compound X) of compound X and fullerenes is 1.0 or more.
(8) The photoelectric conversion device according to any one of (1) to (7), wherein a charge blocking film is disposed between the conductive film and the transparent conductive film.
(9) An imaging device comprising the photoelectric conversion device according to any one of (1) to (8).
(10) An optical sensor comprising the photoelectric conversion device according to any one of (1) to (8).

ADVANTAGE OF THE INVENTION According to this invention, the photoelectric conversion element provided with the photoelectric conversion film which shows the outstanding heat resistance and responsiveness can be provided.
Further, according to the present invention, it is possible to provide an imaging device and a photosensor including the photoelectric conversion device.

FIG. 1A and FIG. 1B are schematic cross-sectional views showing one structural example of the photoelectric conversion element. It is a cross-sectional schematic diagram for one pixel of an image pick-up element.

Below, the preferable embodiment of the photoelectric conversion element of this invention is demonstrated.
First, the features of the present invention in comparison with the prior art will be described in detail.
As described above, in the present invention, a diketopyrrolopyrrole compound contained in the photoelectric conversion film or a compound obtained by condensing an aromatic ring between two pyrrole rings of diketopyrrolopyrrole is used to provide an aromatic at a predetermined position. It has been found that by introducing a group ring containing amine group, the desired effect can be obtained. By introducing such an aromatic ring-containing amine group, the molecular weight of the compound to be used is increased and the interaction between the compounds is appropriately increased, and the degree of freedom of the molecule is reduced by introducing a large number of ring structures. As a result, it is presumed that the heat resistance is improved. In addition, by introducing an aromatic ring-containing amine group, a skeleton capable of stably holding holes protrudes to the outside of the molecule, facilitating exchange of holes between molecules, resulting in improved response speed. It is guessed.

Hereinafter, preferred embodiments of the photoelectric conversion element of the present invention will be described with reference to the drawings. In FIG. 1, the cross-sectional schematic diagram of one Embodiment of the photoelectric conversion element of this invention is shown.
The photoelectric conversion element 10a shown in FIG. 1A includes a conductive film (hereinafter also referred to as a lower electrode) 11 functioning as a lower electrode, an electron blocking film 16A formed on the lower electrode 11, and an electron blocking film 16A. The photoelectric conversion film 12 formed thereon and the transparent conductive film (hereinafter also referred to as an upper electrode) 15 which functions as an upper electrode have a configuration in which the photoelectric conversion film 12 is stacked in this order.
The structural example of another photoelectric conversion element is shown in FIG.1 (b). The photoelectric conversion element 10b shown in FIG. 1B has a configuration in which an electron blocking film 16A, a photoelectric conversion film 12, a hole blocking film 16B, and an upper electrode 15 are stacked in this order on the lower electrode 11. Have. The stacking order of the electron blocking film 16A, the photoelectric conversion film 12, and the hole blocking film 16B in FIGS. 1A and 1B may be reversed depending on the application and characteristics. For example, the positions of the electron blocking film 16A and the photoelectric conversion film 12 may be reversed.

In the configuration of the photoelectric conversion element 10 a (10 b), light is preferably incident on the photoelectric conversion film 12 through the transparent conductive film 15.
Moreover, when using photoelectric conversion element 10a (10b), an electric field can be applied. In this case, preferably, the conductive film 11 and the transparent conductive film 15 form a pair of electrodes, and an electric field of 1 × 10 ⁻⁵ to 1 × 10 ⁷ V / cm is applied between the pair of electrodes. From the viewpoint of performance and power consumption, an electric field of 1 × 10 ⁻⁴ to 1 × 10 ⁶ V / cm is preferable, and an electric field of 1 × 10 ⁻³ to 5 × 10 ⁵ V / cm is particularly preferable.
As for the voltage application method, in FIGS. 1A and 1B, it is preferable to apply so that the electron blocking film 16A side is a cathode and the photoelectric conversion film 12 side is an anode. When the photoelectric conversion element 10a (10b) is used as an optical sensor, and also when it is incorporated in an imaging element, voltage application can be performed by the same method.

Below, the aspect of each layer (The photoelectric conversion film 12, the electron blocking film 16A, the lower electrode 11, the upper electrode 15, the hole blocking film 16B etc.) which comprises the photoelectric conversion element 10a (10b) is explained in full detail.
First, the photoelectric conversion film 12 will be described in detail.

[Photoelectric conversion film]
The photoelectric conversion film 12 is a compound represented by General Formula (1) described later as a photoelectric conversion material, a compound represented by General Formula (2) described later, and a compound represented by General Formula (3) described later A membrane comprising at least one compound X selected from the group consisting of By using the compound X, a photoelectric conversion film exhibiting excellent heat resistance and fast response can be obtained.
First, the compounds represented by the general formulas (1) to (3) used in the photoelectric conversion film 12 will be described in detail.

In the general formulas (1) to (3), R ¹ and R ² each independently represent an alkyl group, an aryl group or a heteroaryl group. Among them, an alkyl group is preferable in that the synthesis is easy and the characteristics (heat resistance and response) of the photoelectric conversion film are more excellent.
The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 6, and still more preferably 1 to 3 in that the characteristics (heat resistance and response) of the photoelectric conversion film are more excellent. The alkyl group may have any of linear, branched and cyclic structures.
Preferred examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group and an n-hexyl group.

The number of carbon atoms in the aryl group is not particularly limited, but is preferably 6 to 30, and more preferably 6 to 18 in that the characteristics (heat resistance and responsiveness) of the photoelectric conversion film are more excellent. The aryl group may have a single ring structure or a condensed ring structure in which two or more rings are fused, and may have a substituent W described later.
Examples of the aryl group include phenyl group, naphthyl group, anthryl group, pyrenyl group, phenanthrenyl group, methylphenyl group, dimethylphenyl group, biphenyl group, fluorenyl group and the like, and phenyl group, naphthyl group or anthryl group is exemplified. preferable.

The number of carbon atoms in the heteroaryl group (monovalent aromatic heterocyclic group) is not particularly limited, but is preferably 3 to 30, and more preferably 3 to 18 in that the characteristics (heat resistance and response) of the photoelectric conversion film are more excellent. Is more preferred. The heteroaryl group may have a substituent W described later.
Heteroaryl groups include hetero atoms other than carbon atom and hydrogen atom, and as hetero atoms, for example, nitrogen atom, sulfur atom, oxygen atom, selenium atom, tellurium atom, phosphorus atom, phosphorus atom, silicon atom, or boron atom Preferably, a nitrogen atom, a sulfur atom or an oxygen atom is mentioned. The number of heteroatoms contained in the heteroaryl group is not particularly limited, and is usually about 1 to 10, preferably 1 to 4.
The number of ring members of the heteroaryl group is not particularly limited, but is preferably a 3- to 8-membered ring, more preferably a 5- to 7-membered ring, and particularly preferably a 5- to 6-membered ring.
Examples of the heteroaryl group include pyridyl group, quinolyl group, isoquinolyl group, acridinyl group, phenanthrizinyl group, pteridinyl group, pyrazinyl group, quinoxalinyl group, pyrimidinyl group, quinazolyl group, pyridazinyl group, cinnolinyl group, phthalazinyl group, and the like. Triazinyl group, oxazolyl group, benzoxazolyl group, thiazolyl group, benzothiazolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, indazolyl group, isoxazolyl group, benzisoxazolyl group, isothiazolyl group, benzisothiazolyl group, oxazolyazolyl group Group, thiadiazolyl group, triazolyl group, tetrazolyl group, furyl group, benzofuryl group, thienyl group, benzothienyl group, dibenzofuryl group, dibenzothienyl group, pyrrolyl group, indolyl Group, imidazopyridinyl group, and carbazolyl group.

The substituent W in the present specification is described.
As the substituent W, a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group and a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, an aryl group and a heterocyclic ring Group (may be referred to as hetero ring group), cyano group, hydroxy group, nitro group, carboxy group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxy carbonyloxy group , Aryloxycarbonyloxy group, amino group (including anilino group), ammonio group, acylamino group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamide Group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl Or heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyl oxy group, phosphinyl amino group, phosphono group, silyl group, hydrazino group, ureido group, boronic acid group (-B (OH) ₂ ) And phosphato groups (-OPO (OH) ₂ ), sulfato groups (-OSO ₃ H), and other known substituents.
The details of the substituent W are described in paragraph [0023] of JP-A-2007-234651.

R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent an alkyl group, an aryl group or a heteroaryl group. In addition, at least one of R ¹¹ and R ¹² and at least one of R ¹³ and R ¹⁴ represent an aryl group or a heteroaryl group. Among them, in that the characteristics of the photoelectric conversion layer (heat resistance and responsiveness) more excellent, it is preferable R ^11, R ^12, R ¹³ and R ¹⁴ are aryl groups.
The definitions and preferred embodiments of the alkyl group, aryl group and heteroaryl group represented by R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are the same as the alkyl group, aryl group and heteroaryl group represented by R ¹ and R ² above. Are the same as the definition and preferred embodiment of

Ar ¹ and Ar ² each independently represent an arylene group or a heteroarylene group. Among them, Ar ¹ and Ar ² are preferably arylene groups in that the characteristics (heat resistance and responsiveness) of the photoelectric conversion film are more excellent.
The number of carbon atoms in the arylene group is not particularly limited, but is preferably 6 to 30, and more preferably 6 to 20 in that the characteristics (heat resistance and response) of the photoelectric conversion film are more excellent.
As the arylene group, for example, phenylene group, biphenylene group, terphenylene group, naphthylene group, anthrylene group, phenanthrylene group, pyranediyl group, perylenediyl group, fluorenediyl group, chrysendiyl group, triphenylenediyl group, benzoanthracenediyl group, benzo And phenanthrenediyl groups.

The number of carbon atoms in the heteroarylene group is not particularly limited, but is preferably 1 to 20 and more preferably 2 to 12 in that the characteristics (heat resistance and response) of the photoelectric conversion film are more excellent.
Examples of the heteroarylene group include pyridylene group, quinolylene group, isoquinolylene group, acridine diyl group, phenanthridine diyl group, pyrazine diyl group, quinoxaline diyl group, pyrimidine diyl group, triazine diyl group, imidazole diyl group, pyrazole diyl group, Examples include oxadiazole diyl group, triazole diyl group, furylene group, thienylene group, pyrrol diyl group, indole diyl group, carbazole diyl group and the like.

X ¹ and X ² are each independently, O (oxygen atom), S (sulfur atom), or an NR ^A. Among them, O (oxygen atom) or S (sulfur atom) is preferable, and O (oxygen atom) is more preferable, in that the characteristics (heat resistance and responsiveness) of the photoelectric conversion film are more excellent.
R ^A represents an alkyl group, an aryl group or a heteroaryl group. Especially, an alkyl group is preferable at the point which the characteristic (heat resistance and responsiveness) of a photoelectric conversion film is more excellent.
The definitions and the preferred embodiments of the alkyl group, the aryl group and the heteroaryl group represented by R ^A are the same as the definitions and the preferred embodiment of the alkyl group, the aryl group and the heteroaryl group represented by R ¹ and R ² above. .

Q represents a group represented by formula (A), a group represented by formula (B), a group represented by formula (C), a group represented by formula (D), and It is any one group selected from the group consisting of a group represented by formula (E).

In formulas (A) to (E), each of R ^Q1 to R ^Q22 independently represents a hydrogen atom or a substituent. Examples of the substituent include the above-mentioned substituent W, and examples include an alkyl group, an alkoxy group, a halogen atom and the like. Among them, it is preferable that R ^Q1 to R ^{Q22 be} a hydrogen atom in that the characteristics (heat resistance or response) of the photoelectric conversion element are more excellent.
The carbon atoms represented by * 1 to * 4 in the general formulas (A) to (E) are represented by * 1 to * 4 in the general formulas (1) to (3), respectively. Corresponds to a carbon atom. More specifically, examples of structural formulas when groups represented by general formulas (A) to (E) below are introduced into Q in general formulas (1) to (3) Indicates

In the general formulas (1) to (3), Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , R ¹³ and R ¹⁴ respectively represent You may combine with each other to form a ring. At the time of bonding, Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and R ¹⁴ are each directly or via a linking group. It is preferable to form a ring by forming a ring, and it is more preferable to form a ring by forming a ring directly from the viewpoint that the characteristics (heat resistance and responsiveness) of the photoelectric conversion film are more excellent.
By the formation of the ring structure, the heat resistance of the compounds represented by the general formulas (1) to (3) is improved, and the photoelectric conversion element can be produced at a high deposition rate under high temperature conditions. And the responsiveness is further improved.
The structure of the linking group is not particularly limited, and examples thereof include oxygen atom, sulfur atom, alkylene group, silylene group, alkenylene group, cycloalkylene group, cycloalkenylene group, arylene group, divalent heterocyclic group, imino group, and the like. Or the group which combined these is mentioned, These may have a substituent further. Preferred are an alkylene group, a silylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group and the like.
The structure of the ring formed is not particularly limited, and examples thereof include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, Oxazole ring, Thiazole ring, Pyridine ring, Pyrazine ring, Pyrimidine ring, Pyridazine ring, Indolizine ring, Indole ring, Indole ring, Benzofuran ring, Benzothiophene ring, Isobenzofuran ring, Quinolizine ring, Quinoline ring, Phthalazine ring, Naphthiridine ring, Quinoxaline ring , Quinoxazoline ring, isoquinoline ring, carbazole ring, phenanthridine ring, acridine ring, phenanthroline ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, phenazine ring, cyclopenta Ring, cyclohexane ring, pyrrolidine ring, piperidine ring, a tetrahydrofuran ring, tetrahydropyran ring, a tetrahydrothiophene ring, a tetrahydrothiopyran ring.

Note that at least one of Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , and R ¹¹ and R ¹² combine with each other to form a ring, and Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R Preferably, at least one of ¹³ and R ¹⁴ is bonded to each other to form a ring. With such an embodiment, the heat resistance and response of the photoelectric conversion film are further improved.

n represents 0 or 1; Among them, n is preferably 0 in terms of more excellent characteristics (heat resistance or response) of the photoelectric conversion element.
When n is 1, the compounds represented by the above general formulas (1A) to (3E) are exemplified.
When n is 0, the carbon atom shown by * 1 and the carbon atom shown by * 3 are the same carbon atom, and the carbon atom shown by * 2 and the carbon atom shown by * 4 are the same. It becomes a carbon element. That is, in the general formula (1) to the general formula (3), when n = 0, the compounds represented by the following general formula (4) to the general formula (6) are represented.
The definition of each group in the general formulas (4) to (6) is as described above.

Especially, the compound represented by General formula (4) is especially preferable at the point which the effect of this invention is more excellent. The compound represented by the general formula (4) is a so-called diketopyrrolopyrrole compound.
The compounds represented by the general formulas (1) to (3) are exemplified below.

The compounds represented by the general formulas (1) to (3) preferably have an absorption maximum at 400 nm or more and less than 720 nm in the UV-visible absorption spectrum. The peak wavelength (absorption maximum wavelength) of the absorption spectrum is preferably 450 nm or more and 700 nm or less, more preferably 480 nm or more and 700 nm or less, and preferably 510 nm or more and 680 nm or less from the viewpoint of wide absorption of light in the visible range. Particularly preferred.
The absorption maximum wavelength of the compound can be measured using a chloroform solution of the compound using UV-2550 manufactured by Shimadzu Corporation. Concentration of the chloroform solution is preferably from ^{5 × 10 -5 ~ 1 × 10} -7 mol / l, more preferably ^{3 × 10 -5 ~ 2 × 10} -6 mol / l, 2 × 10 -5 ~ 5 × 10 - ⁶ mol / l is particularly preferred.

The compounds represented by the general formula (1) to the general formula (3) have an absorption maximum at 400 nm or more and less than 720 nm in the UV-visible absorption spectrum, and the molar absorption coefficient of the absorption maximum wavelength is 10000 mol ⁻¹ · l · cm It is preferably ^-1 or more. In order to make the film thickness of the photoelectric conversion film thin and to make it an element having high charge collection efficiency, high-speed response, and high sensitivity characteristics, a material having a large molar absorption coefficient is preferable. More preferably 30000mol ^{^-1} · l · cm ^-1 or more as a molar extinction coefficient of the formulas (1) to (3), compounds represented by a further preferred 50000mol ^{^-1} · l · cm ^-1 or more. The molar absorption coefficients of the compounds represented by the general formulas (1) to (3) are those measured in a chloroform solution.

The compounds represented by the general formulas (1) to (3) are more difficult to be decomposed during deposition as the difference between the melting point and the deposition temperature (melting point-deposition temperature) increases, and the deposition rate increases with an increase in temperature. can do. The difference between the melting point and the vapor deposition temperature (melting point-vapor deposition temperature) is preferably 40 ° C. or more, more preferably 50 ° C. or more, still more preferably 60 ° C. or more, and particularly preferably 80 ° C. or more.

The molecular weight of the compound represented by the general formula (1) to the general formula (3) is preferably 300 to 1,500, more preferably 500 to 1000, and particularly preferably 500 to 900. If the molecular weight of the compound is 1,500 or less, the deposition temperature does not increase, and decomposition of the compound does not easily occur. If the molecular weight of the compound is 300 or more, the glass transition point of the deposited film does not decrease, and the heat resistance of the device does not easily decrease.

95 degreeC or more is preferable, as for the glass transition point (Tg) of the compound represented by General formula (1)-General formula (3), 110 degreeC or more is more preferable, 135 degreeC or more is more preferable, and 150 degreeC or more is especially preferable Preferably, 160 ° C. or more is the most preferable. It is preferable that the glass transition point becomes high because the heat resistance of the element is improved.

The compounds represented by the general formula (1) to the general formula (3) are particularly useful as a material of a photoelectric conversion film used for an imaging device, an optical sensor, or a photovoltaic cell. In addition, normally, the compound represented by General formula (1) functions as an organic p-type compound in a photoelectric conversion film. Moreover, it can also be used as a coloring material, a liquid-crystal material, an organic-semiconductor material, an organic light emitting element material, a charge transport material, a pharmaceutical material, a fluorescence diagnostic agent material etc. as another use.

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

The organic n-type semiconductor (compound) is an acceptor-type organic semiconductor, mainly represented by an electron-transporting organic compound, and refers to an organic compound having a property of easily accepting an electron. More specifically, when the two organic compounds are brought into contact with each other and used, the organic compound having higher electron affinity is used. Therefore, as the acceptor-type organic semiconductor, any organic compound can be used as long as it is an electron-accepting organic compound. Preferably, a fullerene or a fullerene derivative, a fused aromatic carbocyclic compound (naphthalene derivative, anthracene derivative, phenanthrene derivative, tetracene derivative, pyrene derivative, perylene derivative, fluoranthene derivative), a nitrogen atom, an oxygen atom or a sulfur atom is contained 5 to 7-membered heterocyclic compounds (eg, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, quintalin, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole , Benzimidazole, benzotriazole, benzoxazole, benzothiazole, carbazole, purine, triazolopyridazine, tria Lopyrimidin, tetrazaindene, oxadiazole, imidazopyridine, pyraridine, pyrrolopyridine, thiadiazolopyridine, dibenzoazepine, dibenzoazepine, etc., polyarylene compounds, fluorene compounds, cyclopentadiene compounds, silyl compounds, nitrogen-containing heterocyclic rings The metal complex etc. which have a compound as a ligand are mentioned.

The organic n-type compound is preferably a fullerene selected from the group consisting of a fullerene and a fullerene derivative. With fullerenes, fullerene C ₆₀ , fullerene C ₇₀ , fullerene C ₇₆ , fullerene C ₇₈ , fullerene C ₈₀ , fullerene C ₈₂ , fullerene C ₈₄ , fullerene C ₉₀ , fullerene C ₉₆ , fullerene C ₂₄₀ , fullerene C ₂₄₀ , fullerene C ₅₄₀ , mixed Represents a fullerene, and a fullerene derivative represents a compound to which a substituent is added. As a substituent, an alkyl group, an aryl group or a heterocyclic group is preferable. As the fullerene derivative, compounds described in JP-A-2007-123707 are preferable.

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

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

The photoelectric conversion film containing the compound X and the organic n-type compound of the present invention is a non-luminescent film, and has different characteristics from the organic electroluminescent device (OLED). The non-luminescent film is a film having a light emission quantum efficiency of 1% or less, more preferably 0.5% or less, and still more preferably 0.1% or less.

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

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

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

Usually, making the conductive film thinner than a certain range causes a sharp increase in resistance value, but in the solid-state imaging device incorporating the photoelectric conversion device according to this embodiment, the sheet resistance is preferably 100 to 10000 Ω / □. The degree of freedom in the range of film thickness that can be made thin is large. In addition, as the thickness of the upper electrode (transparent conductive film) 15 decreases, the amount of light absorbed decreases, and the light transmittance generally increases. An increase in light transmittance is very preferable because it increases the light absorption in the photoelectric conversion film 12 and the photoelectric conversion capability. The thickness of the upper electrode 15 is preferably 5 to 100 nm, more preferably 5 to 20 nm, in consideration of suppression of leakage current, increase in resistance of the thin film, and increase in transmittance as the film thickness decreases. Is desirable.

The lower electrode 11 may be made transparent or may be made of a material that does not have transparency and reflects light depending on the application. Specifically, conductive metal oxides such as tin oxide (ATO, FTO) doped with antimony or fluorine, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), zinc indium oxide (IZO), etc. Metals such as gold, silver, chromium, nickel, titanium, tungsten, and aluminum, and conductive compounds such as oxides and nitrides of these metals (for example, titanium nitride (TiN) is mentioned), and these metals and conductive properties Mixtures or laminates with metal oxides, inorganic conductive materials such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene and polypyrrole, and laminates of these with ITO or titanium nitride .

The method of forming the electrode is not particularly limited, and can be appropriately selected according to the electrode material. Specifically, it can be formed by a printing method, a wet method such as a coating method, a physical method such as a vacuum evaporation method, a sputtering method, an ion plating method, or a chemical method such as CVD or plasma CVD.
When the material of the electrode is ITO, it can be formed by an electron beam method, a sputtering method, a resistance heating evaporation method, a chemical reaction method (sol-gel method etc.), application of a dispersion of indium tin oxide, or the like. Furthermore, UV-ozone treatment, plasma treatment, and the like can be performed on a film manufactured using ITO. When the material of the electrode is TiN, various methods such as reactive sputtering can be used, and further, UV-ozone treatment, plasma treatment, etc. can be performed.

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

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

The electron blocking film preferably also contains a compound represented by Formula (F-1). By using the compound, the response speed of the obtained photoelectric conversion film is more excellent, and the variation in the response speed among the production rods is further suppressed.

(In the general formula (F-1), R " 11 ~ R" 18, R a _'11 ~ R' ₁₈ are each independently a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amino group , or represents a mercapto group, these are further any one in good .R _"15 ~ R" ₁₈ may have a substituent, R linked to any one in the _'15 ~ R' ₁₈ , .A ₁₁ and a ₁₂ form a single bond represents a group each represented independently by the following general formula (a-1), R " 11 ~ R" 14, and R _'11 ~ R' in ₁₄ And Y is independently substituted by Y. Each Y independently represents a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom, and these may further have a substituent.

(In the general formula (A-1), each of Ra ₁ to Ra ₈ independently represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group or a heterocyclic group, and these further have a substituent * Represents a bonding position, and Xa represents a single bond, oxygen atom, sulfur atom, alkylene group, silylene group, alkenylene group, cycloalkylene group, cycloalkenylene group, arylene group, divalent heterocyclic group, or an imino group, which further indicates which may have a substituent .S ₁₁ each independently represent the following substituents (S _11), .n substituting as any one of in Ra ₁ ~ Ra ₈ ' Represents an integer of 0 to 4)

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

In formula (F-1), R a _{_{"11 ~ R" 18, R}} '11 ~ R' 18 are each independently a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amino group, Or a mercapto group, which may further have a substituent. Specific examples of the further substituent include the above-mentioned substituent W, preferably a halogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxyl group, an amino group or a mercapto group, more preferably a halogen atom, an alkyl It is a group, an aryl group or a heterocyclic group, more preferably a fluorine atom, an alkyl group or an aryl group, particularly preferably an alkyl group or an aryl group, and most preferably an alkyl group.
Preferred as _{_{R "11 ~ R" 18,}} R '11 ~ R' 18, a hydrogen atom, an optionally substituted alkyl group, an aryl group or a heterocyclic group, more preferably a hydrogen atom And an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heterocyclic group having 4 to 16 carbon atoms which may have a substituent. Among them, the substituent represented by general formula (A-1) is preferably independently substituted to R ′ ′ ₁₂ and R ′ ₁₂ respectively, and the substituent represented by general formula (A-1) is R ′ ′ ₁₂ and 'replaced independently to _{_{12, R "11, R"}} 13 ~ R "18, R' R 11, R '13 ~ R' 18 is hydrogen atom, optionally 1 carbon atoms which may ~ have a substituent more preferably 18 alkyl group, particularly preferably a substituent represented by the general formula (a-1) is "substituted independently on ₁₂ and _{_{R '12, R" R 11}} , R "13 ~ R ′ ′ ₁₈ , R ′ _{11 and} R ′ ₁₃ to R ′ ₁₈ are hydrogen atoms.

Y each independently represents a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom, and these may further have a substituent. That is, Y represents a divalent linking group consisting of carbon atom, nitrogen atom, oxygen atom, sulfur atom, or silicon atom. Among _{-C (R '21) (R} ' 22) -, - Si (R '23) (R' 24) -, - N (R '20) -, preferably, -C (R' ₂₁₎ ( R ′ ₂₂ ) —, —N (R ′ ₂₀ ) —, is more preferable, and —C (R ′ ₂₁ ) (R ′ ₂₂ ) — is particularly preferable.
R ′ ₂₀ to R ′ ₂₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aryl group, a heterocyclic group, a hydroxyl group, an amino group or a mercapto group. Specific examples of the further substituent include the substituent W. R ′ ₂₀ to R ′ ₂₄ are preferably a hydrogen atom, an alkyl group which may have a substituent, an aryl group, or a heterocyclic group, and more preferably a hydrogen atom or a substituent. A good alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heterocyclic group having 4 to 16 carbon atoms, and more preferably a hydrogen atom or a carbon number which may have a substituent It is an alkyl group of 1 to 18, particularly preferably an alkyl group having 1 to 18 carbon atoms.

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

Each of Ra ₁ to Ra ₈ is preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heterocyclic group having 4 to 16 carbon atoms. An alkyl group of 1 to 12 or an aryl group having 6 to 14 carbon atoms is more preferable, and a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms is more preferable. The alkyl group may be branched.
Preferred specific examples include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group, a phenyl group or a naphthyl group.
It is particularly preferable that Ra ₃ and Ra _{6 each} be a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and each of Ra ₁ , Ra ₂ , Ra ₄ , Ra ₅ , Ra ₇ and Ra ₈ be a hydrogen atom. .

Xa represents a single bond, an oxygen atom, a sulfur atom, an alkylene group, a silylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, a divalent heterocyclic group, or an imino group, which are further substituted May be included.
Xa is a single bond, an alkylene group having 1 to 12 carbon atoms, an alkenylene group having 2 to 12 carbon atoms, an arylene group having 6 to 14 carbon atoms, a heterocyclic group having 4 to 13 carbon atoms, an oxygen atom, a sulfur atom, carbon An imino group (for example, a phenylimino group, a methylimino group, a t-butylimino group) having a hydrocarbon group (preferably an aryl group or an alkyl group) of 1 to 12 or a silylene group is preferable, and a single bond, an oxygen atom, or a carbon number 1 to 6 alkylene group (for example, methylene group, 1,2-ethylene group, 1,1-dimethylmethylene group), alkenylene group having 2 carbon atoms (for example, -CH ₂ = CH _2- ), 6 to 10 carbon atoms An arylene group (for example, 1,2-phenylene group, 2,3-naphthylene group) or a silylene group is more preferable, and a single bond, an oxygen atom, an alkylene group having 1 to 6 carbon atoms (for example, methyl group) Down group, 1,2-ethylene group, 1,1-dimethylmethylene group) is more preferred. These substituents may further have a substituent W.
Specific examples of the group represented by formula (A-1) include groups exemplified by the following N1 to N11. However, it is not limited to these. The group represented by formula (A-1) is preferably N-1 to N-7, more preferably N-1 to N-6, more preferably N-1 to N-3, and N-1 -N-2 is particularly preferred, and N-1 is most preferred.

In the substituent (S ₁₁ ), R ′ ₁ represents a hydrogen atom or an alkyl group. R ′ ₁ is preferably a methyl group, an ethyl group, a propyl group, an iso-propyl group, a butyl group or a tert-butyl group, and more preferably a methyl group, an ethyl group, a propyl group, an iso-propyl group or It is a tert-butyl group, more preferably a methyl group, an ethyl group, an iso-propyl group or a tert-butyl group, and particularly preferably a methyl group, an ethyl group or a tert-butyl group.

R ′ ₂ represents a hydrogen atom or an alkyl group. R ′ ₂ is preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, an iso-propyl group, a butyl group or a tert-butyl group, and more preferably a hydrogen atom, a methyl group, an ethyl group or a propyl group And more preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

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

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

S ₁₁ represents the above-mentioned substituent (S ₁₁ ), which is substituted as any one of Ra ₁ to Ra ₈ . It is preferable that any one of Ra ₃ and Ra ₆ in the general formula (A-1) independently represents the above-mentioned substituent (S ₁₁ ).
Preferable examples of the substituent (S ₁₁ ) include the following (a) to (x), (a) to (j) are more preferable, (a) to (h) are more preferable, and (a) to (h) Particularly preferred is f), more preferably (a) to (c), and most preferably (a).

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

As the above general formula (A-1), a group represented by the following general formula (A-3), a group represented by the following general formula (A-4), or a table represented by the following general formula (A-5) It may be a substituted group.

(In the general formulas (A-3) to (A-5), each of Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , and Ra ₅₅ to Ra ₅₈ independently represents a hydrogen atom , A halogen atom, or an alkyl group, which may further have a substituent, * represents a bonding position, and Xc ₁ , Xc ₂ , and Xc ₃ are each independently a single bond, an oxygen atom, Represents a sulfur atom, an alkylene group, a silylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, a divalent heterocyclic group, or an imino group, which may further have a substituent Z ₃₁ , Z ₄₁ and Z ₅₁ each independently represent a cycloalkyl ring, an aromatic hydrocarbon ring or an aromatic heterocyclic ring, which may further have a substituent.

In the general formulas (A-3) to (A-5), each of Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , and Ra ₅₅ to Ra ₅₈ independently represents a hydrogen atom or It represents a halogen atom (preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom) or an alkyl group. It is preferable that it is a hydrogen atom or an alkyl group from the viewpoint that it is advantageous to transport of a hole that the substituent is a low polarity substituent, and a hydrogen atom is more preferable.
When Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , and Ra ₅₅ to Ra ₅₈ each represent an alkyl group, the alkyl group is preferably an alkyl group having 1 to 18 carbon atoms, An alkyl group having 1 to 12 carbon atoms is more preferable, and an alkyl group having 1 to 6 carbon atoms is more preferable. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group or a cyclohexyl group is preferable.
In the general formulas (A-3) to (A-5), adjacent ones of Ra ₃₃ to Ra ₃₈ , Ra ₄₁ , Ra ₄₄ to Ra ₄₈ , Ra ₅₁ , Ra ₅₂ , and Ra ₅₅ to Ra ₅₈ are mutually bonded To form a ring. The ring includes the aforementioned ring R. The ring is preferably a benzene ring, a naphthalene ring, an anthracene ring, a pyridine ring, a pyrimidine ring and the like.

Xc ₁ , Xc ₂ and Xc ₃ each independently represent a single bond, an oxygen atom, a sulfur atom, an alkylene group, a silylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, a divalent heterocyclic group Or an imino group. When Xc ₁ , Xc ₂ and Xc _{3 each} represent an alkylene group, a silylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, a divalent heterocyclic group or an imino group, these further have a substituent You may have. The additional substituent includes a substituent W.

Xc ₁ , Xc ₂ and Xc _{3 each} represents a single bond, an alkylene group having 1 to 12 carbon atoms, an alkenylene group having 2 to 12 carbon atoms, an arylene group having 6 to 14 carbon atoms, or a heterocyclic group having 4 to 13 carbon atoms And an imino group (eg, phenylimino group, methylimino group, t-butylimino group) having an oxygen atom, a sulfur atom, or a hydrocarbon group having 1 to 12 carbon atoms (preferably an aryl group or an alkyl group) is preferable, a single bond, An alkylene group having 1 to 6 carbon atoms (eg, methylene group, 1,2-ethylene group, 1,1-dimethyl methylene group), an alkenylene group having 2 carbon atoms (eg, -CH ₂ CHCH _2- ), a carbon number An arylene group of 6 to 10 (eg, a 1,2-phenylene group, a 2,3-naphthylene group) is more preferable.

Z ₃₁ , Z ₄₁ and Z ₅₁ each independently represent a cycloalkyl ring, an aromatic hydrocarbon ring or an aromatic heterocyclic ring. In the general formulas (A-3) to (A-5), Z ₃₁ , Z ₄₁ and Z ₅₁ are fused to a benzene ring. Z ₃₁ , Z ₄₁ and Z ₅₁ are preferably aromatic hydrocarbon rings from the viewpoint that high heat resistance and high hole transportability of the photoelectric conversion element can be expected.

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

(Hole blocking film)
An electron accepting organic material can be used for the hole blocking film.
As the electron accepting material, oxadiazole derivatives such as 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7), anthraquinodimethane derivatives, diphenylquinone derivatives , Vasocuproin, vasophenanthroline, and derivatives thereof, triazole compounds, tris (8-hydroxyquinolinate) aluminum complexes, bis (4-methyl-8-quinolinate) aluminum complexes, distyrylarylene derivatives, silole compounds, etc. Can. Moreover, even if it is not an electron-accepting organic material, it is possible to use any material having a sufficient electron-transporting property. Porphyrin compounds, styryl compounds such as DCM (4-dicyanomethylene-2-methyl-6- (4- (dimethylaminostyryl))-4H pyran), 4H pyran compounds can be used. Specifically, compounds described in paragraphs [0073] to [0078] of JP-A-2008-72090 are preferable.

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

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

[substrate]
The photoelectric conversion element may further include a substrate. The type of substrate used is not particularly limited, and a semiconductor substrate, a glass substrate, or a plastic substrate can be used.
Although the position of the substrate is not particularly limited, in general, the conductive film, the photoelectric conversion film, and the transparent conductive film are stacked in this order on the substrate.
[Sealing layer]
The photoelectric conversion element may further include a sealing layer. Photoelectric conversion materials may deteriorate their performance significantly due to the presence of deterioration factors such as water molecules, and such as dense metal oxides, metal nitrides, metal nitride oxides, etc. that do not allow water molecules to permeate, and diamond-like The above deterioration can be prevented by covering and sealing the entire photoelectric conversion film with a sealing layer of carbon (DLC) or the like.
In addition, as the sealing layer, materials may be selected and manufactured according to the description in paragraphs [0210] to [0215] of JP-A-2011-082508.

[Light sensor]
As a use of a photoelectric conversion element, although a photovoltaic cell and an optical sensor are mentioned, for example, it is preferred to use a photoelectric conversion element of the present invention as an optical sensor. As an optical sensor, what was used by the said photoelectric conversion element independently may be used, and what has a form of the line sensor which distribute | arranged the said photoelectric conversion element linearly, and what has a form of the two-dimensional sensor arranged on plane is preferable. The photoelectric conversion element of the present invention converts optical image information into an electrical signal using an optical system and a driving unit such as a scanner in a line sensor, and the two-dimensional sensor converts optical image information into an optical signal as an imaging module. The system functions as an imaging element by forming an image on a sensor and converting it into an electric signal.
Since a photovoltaic cell is a power generation device, the efficiency of converting light energy into electrical energy is an important performance, but the dark current, which is the current in a dark place, does not pose a functional problem. Furthermore, there is no need for a subsequent heating process such as color filter installation. Since it is important that the light sensor convert light and dark signals into electrical signals with high accuracy, the efficiency of converting the amount of light into current is also an important performance, but outputting a signal in a dark place causes noise, Low dark current is required. Furthermore, resistance to the subsequent steps is also important.

[Image sensor]
Next, a configuration example of an imaging device provided with the photoelectric conversion device 10a will be described.
In the configuration example described below, the description of the members or the like having the same configuration and action as the members and the like already described is simplified or omitted by attaching the same reference numerals or the corresponding reference numerals in the drawings.
An imaging element is an element that converts light information of an image into an electrical signal, and a plurality of photoelectric conversion elements are arranged on a matrix in the same plane, and an optical signal is converted into an electrical signal in each photoelectric conversion element (pixel). And the electric signal can be sequentially output to the outside of the imaging device for each pixel. Therefore, one photoelectric conversion element and one or more transistors are provided per pixel.
FIG. 2 is a schematic cross-sectional view showing a schematic configuration of an imaging device for describing an embodiment of the present invention. The image pickup device is used by being mounted on an image pickup apparatus such as a digital camera or a digital video camera, an image pickup module such as an electronic endoscope, or a mobile phone.
This imaging device has a plurality of photoelectric conversion devices configured as shown in FIG. 1 and a circuit board on which a readout circuit for reading out a signal corresponding to the charge generated in the photoelectric conversion film of each photoelectric conversion device is formed. A plurality of photoelectric conversion elements are arranged in a one-dimensional or two-dimensional manner on the same plane above the circuit board.

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

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

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

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

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

The connection portion 106 is embedded in the insulating layer 102 and is a plug or the like for electrically connecting the connection electrode 103 and the counter electrode voltage supply portion 115. The counter electrode voltage supply unit 115 is formed on the substrate 101, and applies a predetermined voltage to the counter electrode 108 through the connection portion 106 and the connection electrode 103. When the voltage to be applied to the counter electrode 108 is higher than the power supply voltage of the imaging device, the power supply voltage is boosted by a charge pump or other booster circuit to supply the predetermined voltage.

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

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

The light shielding layer 113 is formed on the sealing layer 110 except the area where the color filter 111 and the partition wall 112 are provided, and prevents light from entering the photoelectric conversion film 107 formed in areas other than the effective pixel area. The protective layer 114 is formed on the color filter 111, the partition wall 112, and the light shielding layer 113, and protects the entire imaging element 100.

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

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

connection portions

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

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

Even in the method of manufacturing the imaging device 100, even if a process of placing the imaging device 100 in the middle of production under non-vacuum is added between the process of forming the photoelectric conversion film 107 and the process of forming the sealing layer 110, Performance degradation of the photoelectric conversion element can be prevented. By adding this process, it is possible to suppress the manufacturing cost while preventing the performance deterioration of the imaging device 100.

Although an example is shown below, the present invention is not limited to these.

(Synthesis of Compound D3)

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

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

Compound 2 (0.3 g, 0.63 mmol), 50 mg of Pd ₂ (dba) ₃ , ₃₀ mg of DPPF, and 15 mL of xylene were added to a 100 mL three-necked round bottom flask, and stirred at room temperature for 15 minutes under a nitrogen atmosphere. 0.32 g (1.89 mmol) of diphenylamine and 0.9 g (9.45 mmol) of sodium t-butoxide were added, and the mixture was stirred at 100 ° C. for 7 hours and then cooled to room temperature. Water and ethyl acetate were added to the reaction mixture, the organic layer was extracted, and the solvent was evaporated. The residue was purified by silica gel column chromatography to obtain 0.26 g (yield 64%) of D3 as a reddish brown powder.

The compounds D1 to D2 and D4 to D14 described later were synthesized with reference to the synthesis method of the compound D3 and a known method.
The compounds (D1 to D14, RD1 to RD4) used in this example and the comparative example are collectively shown below.

<Fabrication of photoelectric conversion element>
The photoelectric conversion element of the form of Fig.1 (a) was produced. Here, the photoelectric conversion element includes the lower electrode 11, the electron blocking film 16 A, the photoelectric conversion film 12, and the upper electrode 15.
Specifically, amorphous ITO is deposited on a glass substrate by sputtering to form the lower electrode 11 (thickness: 30 nm), and the following compound (EB-1) is vacuum-heated on the lower electrode 11 The film was formed by vapor deposition to form an electron blocking film 16A (thickness: 100 nm). Furthermore, with the substrate temperature controlled at 25 ° C., the above compounds (D1 to D14, RD1 to RD4) and fullerene (C ₆₀ ) become 100 nm and 300 nm in single layer conversion, respectively, on the electron blocking film 16A. As described above, the film was co-deposited by vacuum heating deposition to form a film, and the photoelectric conversion film 12 was formed. Furthermore, amorphous ITO was formed into a film on the photoelectric conversion film 12 by a sputtering method to form an upper electrode 15 (transparent conductive film) (thickness: 10 nm). After forming a SiO film as a sealing layer by heating vapor deposition on the upper electrode 15, an aluminum oxide (Al ₂ O ₃ ) layer was formed thereon by an ALCVD method, and a photoelectric conversion element was produced.

<Element heat resistance>
Each element thus obtained is thermally annealed by holding it on a hot plate at 150 ° C. for 20 minutes in a nitrogen atmosphere, returning it to room temperature and then measuring the dark current to increase the dark current from before annealing [{ (A dark current after annealing-dark current before annealing) / dark current before annealing} × 100 (%)] was less than 5%, "A" was 5% or more and less than 10% What was "B" and what was more than 10% was described in the "heat resistance" column of Table 1 as "C". In practice, it is necessary to be A or B.

<Evaluation of response speed (98% signal rise time)>
The relative response speed (rise time to a signal intensity of 0 to 98%) was measured when an electric field of 2 × 10 ⁵ V / cm was applied to the photoelectric conversion element in the obtained solid-state imaging device. It calculated | required as a relative value and was described in the "response speed (relative value)" column of Table 1. In addition, in the case of the measurement of the photoelectric conversion performance of each element, light was injected from the upper electrode (transparent conductive film) side. The following shows how to determine relative values.
(Relative value where Example 1 is 1)
= [Rise time from 0 to 98% signal strength in the embodiment (or comparative example) X] / [rise time from 0 to 98% signal strength in the embodiment 1]
In practice, it is preferably 20 or less, and more preferably 5 or less.

As shown in the said Table 1, in the photoelectric conversion element of this invention, it was confirmed that the outstanding heat resistance and responsiveness are shown.
For example, as can be seen from the comparison of Examples 1-14, Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and R ¹⁴ It has been confirmed that the heat resistance is more excellent if at least one of them is bonded to each other to form a ring.
Also, as can be seen from the comparison between Example 1 and Example 5, at least one of Ar ¹ and R ¹¹ , Ar ¹ and R ^12, and R ¹¹ and R ¹² in the general formulas (1) to (3) When two are bonded to each other to form a ring, and at least one of Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ and R ¹⁴ are bonded to each other to form a ring (corresponding to Example 1) It was confirmed that the responsiveness is better.
Also, as can be seen from the comparison between Example 4 and Example 6, Ar ¹ and R ¹¹ , Ar ¹ and R ¹² , R ¹¹ and R ¹² , Ar ² and R ¹³ , Ar ² and R ¹⁴ , and R ¹³ It was confirmed that the response is more excellent when R ¹⁴ is directly bonded without a linking group (corresponding to Example 6).
Further, as can be seen from the comparison between Example 3 and Example 7, when X ¹ and X ² are O (oxygen atom) (corresponding to Example 3), it is confirmed that the response speed and the heat resistance are more excellent. The
Moreover, as Ar ¹ and Ar ² are arylene groups (it corresponds to Example 1), it turned out that a response is more excellent so that comparison with Example 1 and Example 8 may show.

On the other hand, when RD1 used by the Example column of patent document 1 was used (it corresponds to the comparative example 1), it was confirmed that it is inferior to heat resistance and responsiveness.
In addition, when RD2 in which R ¹ and R ² in the general formulas (1) to (3) are hydrogen atoms is used (corresponding to Comparative Example 2), it is confirmed that the responsiveness is inferior.
Moreover, the general formula (1) (corresponding to Comparative Example 3) were If used R ¹¹ - R ¹⁴ of ~ the general formula (3) is a RD3 is an alkyl group, it was confirmed that the poor responsiveness.
Moreover, when RD4 which does not have an amino group is used (it corresponds to the comparative example 4), the compound decomposed | disassembled at the time of vapor deposition from the first, and the photoelectric conversion film was not able to be manufactured.
RD2 and RD3 correspond to the exemplified compounds (19) and (71) exemplified in JP-A-2010-192782, and RD4 is used in Example 6 of JP-A-2003-346926. It corresponds to a compound.

<Fabrication of imaging device>
An imaging device similar to that shown in FIG. 2 was produced. That is, after depositing amorphous TiN 30 nm on a CMOS substrate by sputtering, it is patterned by photolithography so that one pixel exists on each of the photodiodes (PD) on the CMOS substrate to form a lower electrode. After the film formation of the electron blocking material, it was manufactured in the same manner as in Examples 1 to 14 and Comparative Examples 1 to 4. The evaluation was also conducted similarly, and the same results as in Table 1 were obtained, and it was found that the imaging device is also suitable for production and shows excellent performance.

10a, 10b photoelectric conversion element 11 lower electrode (conductive film)
12 photoelectric conversion film 15 upper electrode (transparent conductive film)
16A electron blocking film 16B hole blocking film 100 imaging device 101 substrate 102 insulating layer 103 connection electrode 104 pixel electrode (lower electrode)
105 connection portion 106 connection portion 107 photoelectric conversion film 108 counter electrode (upper electrode)
109 buffer layer 110 sealing layer 111 color filter (CF)
112 partition wall 113 light shielding layer 114 protective layer 115 counter electrode voltage supply unit 116 readout circuit

Claims

It is a photoelectric conversion element formed by laminating a conductive film, a photoelectric conversion film containing a photoelectric conversion material, and a transparent conductive film in this order,
The photoelectric conversion material is at least one selected from the group consisting of a compound represented by the general formula (1), a compound represented by the general formula (2), and a compound represented by the general formula (3) The photoelectric conversion element containing the compound X.

(In the general formulas (1) to (3), R 1 and R 2 each independently represent an alkyl group, an aryl group or a heteroaryl group. R 11 , R 12 , R 13 and R 14 each represent Each independently represents an aryl group or a heteroaryl group Ar 1 and Ar 2 each independently represent an alkyl group, an arylene group or a heteroarylene group, and at least one of R 11 and R 12 , and R 13 and at least one of R 14 is, .X 1 and X 2 represents an aryl group or heteroaryl group, each independently, O, S or .R a representative of the NR a, an alkyl group, an aryl group, or, And Q represents a group selected from the group consisting of general formula (A) to general formula (E) R 01 to R 022 each independently represent a hydrogen atom or a substituent The To .n represents 0 or 1.
Ar 1 and R 11 , Ar 1 and R 12 , R 11 and R 12 , Ar 2 and R 13 , Ar 2 and R 14 , or R 13 and R 14 respectively bond to each other to form a ring. It is also good. )
The photoelectric conversion element of Claim 1 whose said compound X is a compound represented by General formula (4).

(In the general formula (4), R 1 and R 2 each independently represent an alkyl group, an aryl group or a heteroaryl group. R 11 , R 12 , R 13 and R 14 are each independently. Ar 1 and Ar 2 each independently represent an alkyl group, an arylene group or a heteroarylene group, and at least one of R 11 and R 12 and R 13 and R 14 each independently represent an aryl group or a heteroaryl group. At least one represents an aryl group or a heteroaryl group X 1 and X 2 each independently represent O, S, or NRA A. R A represents an alkyl group, an aryl group or a heteroaryl group Represent.
Ar 1 and R 11 , Ar 1 and R 12 , R 11 and R 12 , Ar 2 and R 13 , Ar 2 and R 14 , or R 13 and R 14 respectively bond to each other to form a ring. It is also good. )
Ar 1 and R 11 , Ar 1 and R 12 , R 11 and R 12 , Ar 2 and R 13 , Ar 2 and R 14 , and at least one of R 13 and R 14 respectively combine with each other to form a ring The photoelectric conversion element according to claim 1 or 2.
The photoelectric conversion device according to any one of claims 1 to 3, wherein X 1 and X 2 are O.
The photoelectric conversion device according to any one of claims 1 to 4, wherein the photoelectric conversion film further contains an organic n-type compound.
The photoelectric conversion device according to claim 5, wherein the organic n-type compound contains fullerenes selected from the group consisting of fullerenes and derivatives thereof.
The photoelectric conversion element according to claim 6, wherein a molar ratio of the compound X to the fullerenes (molar amount of the fullerenes / molar amount of the compound X) is 1.0 or more.
The photoelectric conversion element according to any one of claims 1 to 7, wherein a charge blocking film is disposed between the conductive film and the transparent conductive film.
An imaging device comprising the photoelectric conversion device according to any one of claims 1 to 8.
An optical sensor comprising the photoelectric conversion element according to any one of claims 1 to 8.