Photoelectric conversion element for imaging element, and compound

Abstract

The purpose of the present invention is to achieve an imaging element having excellent response, high external quantum efficiency, and reduced dark current, and provide a photoelectric conversion element for the imaging element having high thermal stability. This photoelectric conversion element for an imaging element comprises a first electrode, a photoelectric conversion layer, an electron blocking layer, and a second electrode in this order, wherein the electron blocking layer contains a compound represented by formula (1). In formula (1), Ar1 is selected from hydrogen, an aromatic hydrocarbon group having 6 to 30 carbon atoms, and an oxygen-containing or sulfur-containing heteroaryl group having 3 to 30 carbon atoms; L1 and L4 are selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms and an oxygen-containing or sulfur-containing heteroaryl group having 3 to 30 carbon atoms; Ar2, Ar3, L2, and L3 are selected from an aromatic hydrocarbon group containing a monocyclic ring or a condensed ring having three or fewer rings, and an oxygen-containing or sulfur-containing heteroaryl group having 3-30 carbon atoms and containing a monocyclic ring or a condensed ring having three or fewer rings; n1 to n4 are each represented by an integer of 0-3; and Ar1 to Ar3 and L1 to L4 may be substituted by at least one substituent.

Description

Photoelectric conversion element for image sensor, and compound

[0001] The present invention relates to a photoelectric conversion element for an image sensor and a compound.

[0002] Photoelectric conversion elements are widely used in solar cells, light sensors, image sensors, and the like. Their applications and market are expanding, and development is being actively pursued.

[0003] For example, Patent Documents 1 to 3 disclose photoelectric conversion elements for image sensors that include a mono(triphenylene)amine derivative in the electron blocking layer.

[0004] For example, Patent Document 4 discloses a photoelectric conversion element for an image sensor that includes a bis(triphenylene)amine derivative in its electron blocking layer.

[0005] International Publication No. 2020 / 218264, International Publication No. 2022 / 071444, International Publication No. 2023 / 286817, International Publication No. 2023 / 286816

[0006] In photoelectric conversion elements used in applications such as image sensors, improvements in external quantum efficiency are desired to increase sensitivity, dark current is reduced to reduce noise, and responsiveness is improved to reduce afterimages. Furthermore, in some applications, such as automotive applications, extremely high heat resistance is required, and materials with high glass transition temperatures (T) are desirable. ｇ They are being asked to do so.

[0007] One aspect of the present invention aims to realize a novel compound that can obtain an image sensor with excellent responsiveness, high external quantum efficiency, and reduced dark current, and a photoelectric conversion element material for an image sensor with excellent responsiveness, high external quantum efficiency, and reduced dark current, and that also has extremely high heat resistance.

[0008] To solve the above problems, a photoelectric conversion element for an image sensor according to one aspect of the present invention is a photoelectric conversion element for an image sensor comprising a first electrode, a photoelectric conversion layer, an electron blocking layer, and a second electrode in this order, wherein the photoelectric conversion layer comprises at least two types of organic materials, and the electron blocking layer comprises a compound represented by the following formula (1); In the above formula (1), Ar１ is selected from hydrogen, an aromatic hydrocarbon group having 6 to 30 carbon atoms, and a heteroaryl group containing oxygen or sulfur and having 3 to 30 carbon atoms, and L １ and L ４ are each independently selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms and a heteroaryl group containing oxygen or sulfur and having 3 to 30 carbon atoms, and Ar ２ and Ar ３ as well as L ２ and L ３ are each independently selected from an aromatic hydrocarbon group containing a single ring or a condensed ring of 3 rings or less, and a heteroaryl group containing oxygen or sulfur and having 3 to 30 carbon atoms and containing a single ring or a condensed ring of 3 rings or less, and n １ to n ４ are each independently represented by an integer of 0 to 3, and n １ to n ４ When each is independently 0, L １ to L ４ represent a single bond, and Ar １ to Ar ３ , and L<00​​​​​​​​​​​​​Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linking, and fused rings, and is substituted or unsubstituted. １ ~R １５ Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linking, and fused rings, and is substituted or unsubstituted. ５ and Ar ６ And R １ ~R １５ These may be linked to each other to form a six-membered aromatic ring, and Ar ５ ~Ar ６ If R is a hydrogen atom, １ ~R ８ Any two of these locations, and any two of R9 to R15, are linked to each other to form a six-membered aromatic ring.

[0010] According to one aspect of the present invention, it is possible to obtain an image sensor with excellent responsiveness, high external quantum efficiency, and reduced dark current, and a photoelectric conversion element material for an image sensor with excellent responsiveness, high external quantum efficiency, and reduced dark current, and to realize a novel compound having extremely high heat resistance.

[0011] This is a schematic cross-sectional view showing a laminated structure of a photoelectric conversion element for an image sensor, including a material for a photoelectric conversion element for an image sensor according to one aspect of the present invention.

[0012] The following describes in detail the photoelectric conversion element material for an image sensor included in a layer of a photoelectric conversion element according to one aspect of the present invention.

[0013] A "photoelectric conversion element" comprising a layer containing photoelectric conversion element materials, such as photoelectric conversion element materials for image sensors, refers to a light-receiving element that utilizes the photoelectric effect or photovoltaic effect. Examples of light-receiving elements include photodiodes, phototransistors, image sensors (image sensors), and solar cells, with image sensors being preferred. Typically, a light-receiving element is an element that converts irradiated light into an electric current. In such cases, the light-receiving element operates on a different operating principle than a light-emitting element that converts applied electric current into light. Therefore, "photoelectric conversion element materials" used in "photoelectric conversion elements" refer to "photoelectric conversion element materials" used in "light-receiving elements," while "photoelectric conversion element materials" used in image sensors are referred to as "photoelectric conversion element materials for image sensors."

[0014] The definitions of each group in the formulas described below, and their preferred specific examples, are as follows. In this specification, functional groups such as aromatic hydrocarbon groups, heteroaryl groups, and cyclic aliphatic hydrocarbon groups are described without distinction according to their valency. For example, "phenyl group" described in the context of monovalent to trivalent aromatic hydrocarbon groups includes not only monovalent benzene rings (i.e., phenyl groups in the narrow sense), but also divalent benzene rings (i.e., phenylene groups) and trivalent benzene rings (i.e., benzenetriyl groups). Also, "pyridyl group" includes "pyridylene groups" and "pyridinetriyl groups."

[0015] <Material for photoelectric conversion element for image sensor> An image sensor according to one aspect of the present invention is an image sensor comprising a layer containing a material for a photoelectric conversion element for an image sensor, wherein the layer contains a material for a photoelectric conversion element for an image sensor that is a compound represented by the following formula (1).

[0016] By having a mono(triphenyleneamine) as a substructure in the photoelectric conversion element material for the image sensor, as specifically shown in formula (1) below, it is possible to obtain an image sensor with excellent responsiveness, high external quantum efficiency, and reduced dark current, and to impart high heat resistance to the photoelectric conversion element material for the image sensor.

[0017] Below, Ar as shown in formula (1) above １ ~Ar ３ , and L １ ~L ４ , and also, n １ ~n ４ Each of these will be explained in detail.

[0018] [Ar １ ~Ar ３ , L １ ~L ４ , n １ ~n ４ In the above formula (1), Ar １ L is selected from hydrogen, aromatic hydrocarbon groups having 6 to 30 carbon atoms, and oxygen-containing or sulfur-containing heteroaryl groups having 3 to 30 carbon atoms. １ and L ４ Each of these is independently selected from aromatic hydrocarbon groups having 6 to 30 carbon atoms and oxygen-containing or sulfur-containing heteroaryl groups having 3 to 30 carbon atoms.

[0019] Ar １ , L １ and L ４ Because the number of carbon atoms constituting the fused ring is larger, the thermal stability of the layer in the photoelectric conversion element for the image sensor can be improved. Also, Ar １ , L １ and L ４ This is because the smaller number of carbon atoms constituting the fused ring can improve the solubility of the photoelectric conversion element material for image sensors, thereby increasing the ease of manufacturing the photoelectric conversion element material for image sensors.

[0020] Also, Ar ２ and Ar ３ and L ２ and L ３Each of these is independently selected from an aromatic hydrocarbon group containing a monocyclic or fused ring of three or fewer rings, and an oxygen-containing or sulfur-containing heteroaryl group having 3 to 30 carbon atoms containing a monocyclic or fused ring of three or fewer rings. This makes it possible to increase the solubility of the photoelectric conversion element material for image sensors while not impairing the thermal stability provided by the substructure of the mono(triphenylene)amine represented by formula (1). Thus, the ease of manufacturing the photoelectric conversion element material for image sensors can be increased.

[0021] Ar １ , L １ and L ４ When is an aromatic hydrocarbon group, it is preferably selected from aromatic hydrocarbon groups having 6 to 30 carbon atoms, and is preferably selected from a monocyclic ring with 6 members or a fused ring with 10 to 15 carbon atoms. The monocyclic aromatic hydrocarbon group is a phenyl group, which is a 6-membered ring, and examples of fused rings with 10 to 15 carbon atoms include fused rings with three or fewer rings. Examples of fused rings with two rings include a naphthyl group, and examples of fused rings with three rings include a phenanthryl group, anthryl group, phenalenyl group, fluorenyl group, and dimethylfluorenyl group. These monocyclic rings, or fused rings with two or three rings, are Ar １ , L １ and L ４ Similarly, Ar ２ and Ar ３ and L ２ and L ３ It is also preferably selected in Ar ２ and Ar ３ and L ２ and L ３ In this case, it is more preferable that it be a single ring or a fused ring of two rings.

[0022] Other, Ar １ , L １ and L ４ When the group is an aromatic hydrocarbon group having 16 to 30 carbon atoms, examples include triphenylenyl group, pyrenyl group, tetracenyl group, chrysenyl group, fluoranthenyl group, benzofluorenyl group, perilenyl group, picenyl group, benzotriphenylenyl group, and so on.

[0023] Ar １ , L１ and L ４ When L is an oxygen - or sulfur - containing heteroaryl group having 3 to 30 carbon atoms, thesaid heteroaryl group includes, ２ there is, for example, Arand Ar ３ and L ２ and L ３ oxygen - or sulfur - containing heteroaryl groups represented by them.

[0024] Ar ２ and Ar ３ and L ２ and L ３ When Ar, L, and L are aromatic hydrocarbon groups, the aromatic hydrocarbon group is an aromatic hydrocarbon group containing a monocyclic or a condensed ring of 3 rings or less, and is selected from the monocyclic 6 - membered ring, the bicyclic condensed ring, and the tricyclic condensed ring similar to the aromatic hydrocarbon groups exemplified for Ar, １ L １ and L ４ above.

[0025] Ar [[ID= and Ar ２ ３ and L ２ and L ３ The oxygen - or sulfur - containing heteroaryl group represented by them is not particularly limited and may be, for example, a monocyclic, or a linked or condensed ring containing a plurality of rings. In the heteroaryl group, the heteroatoms contained in the aromatic ring may be one or two or more. When there are two or more heteroatoms contained in the aromatic ring, the heteroatoms may be the same as or different from each other.

[0026] Examples of the oxygen - containing heteroaryl group include, for monocyclic rings, a furyl group, a dioxanyl group, etc., for bicyclic condensed rings, a benzofuryl group, a benzodioxanyl group, etc., and for tricyclic condensed rings, a dibenzofuryl group, a xanthenyl group, a fluorenonyl group, etc.

[0027] Examples of the sulfur - containing heteroaryl group include, for monocyclic rings, a thienyl group, for bicyclic condensed rings, a benzothienyl group, and for tricyclic condensed rings, a thianthrenyl group, a dibenzothienyl group, a thioxanthenyl group, etc.

[0028] n １ ~ n ４ are each independently represented by an integer from 0 to 3, and n １ and n ４ are more preferably each independently represented by 0 or 1, and n ２ and n ３ are more preferably each independently represented by an integer from 0 to 2. When n １ ~ n ４ is represented by 0, L １ ~ L ４ each represents a single bond.

[0029] Ar １ ~ Ar ３ , and L １ ~ L ４ may each independently be substituted with at least one substituent selected from the group consisting of a nitro group, a halogen atom, a halogenated alkyl group, an acyl group, a sulfonyl group, a phosphoryl group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, a tricycloalkyl group having 5 to 20 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms.

[0030] Examples of the halogenated alkyl group include perfluoroalkyl groups such as a trifluoromethyl group, examples of the acyl group include an acetyl group and a benzoyl group, and examples of the sulfonyl group include a mesyl group and a tosyl group.

[0031] The C1-C20 alkyl group may be a linear alkyl group or a branched alkyl group. Examples of C1-C20 alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, and the like. In the alkyl group, the number of carbon atoms is preferably 1 to 10, and preferably 1 to 6.

[0032] The C2-C20 alkenyl group may be a linear alkenyl group, a branched alkenyl group, or a cyclic alkenyl group. Examples of C2-C20 alkenyl groups include vinyl, allyl, propenyl, isopropenyl, butenyl, isobutenyl, pentenyl, isopentenyl, hexenyl, isohexenyl, heptenyl, octenyl, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptanyl, and cyclooctenyl groups. In the alkenyl group, the number of carbon atoms is preferably 1-10, and preferably 1-6.

[0033] Examples of the cycloalkyl groups having 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl groups. In these cycloalkyl groups, the number of carbon atoms is preferably 3 to 10, and preferably 3 to 6.

[0034] Examples of the bicycloalkyl groups having 4 to 20 carbon atoms include bicyclobutyl group, bicyclopentyl group, bicyclohexyl group, bicycloheptyl group, bicyclooctyl group, bicyclononyl group, and bicyclodecyl group. In the bicycloalkyl groups, the number of carbon atoms is preferably 4 to 15, and preferably 4 to 10.

[0035] Examples of the tricycloalkyl group having 5 to 20 carbon atoms include the adamantyl group. In the tricycloalkyl group, the number of carbon atoms is preferably 5 to 15, and preferably 10 to 15.

[0036] The alkoxy group having 1 to 10 carbon atoms may be a linear alkoxy group, a branched alkoxy group, or a cyclic alkoxy group. Examples of alkoxy groups having 1 to 10 carbon atoms include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, n-nonyloxy group, n-decyloxy group, cyclopropyloxy group, cyclobutyloxy group, cyclopentyloxy group, cyclohexyloxy group, cycloheptyloxy group, cyclooctyloxy group, cyclononyloxy group, and cyclodecyloxy group. In the alkoxy group, the number of carbon atoms is preferably 1 to 8, and preferably 1 to 6.

[0037] <Compound (2)> In one embodiment of the present invention, the above-described material (1) for the photoelectric conversion element for the image sensor may be a compound represented by the following formula (2). The compound represented by formula (2) is also within the scope of the present invention. Ar ４ Ar is selected from a phenyl group, a naphthyl group, and a biphenyl group. ５ and Ar ６ Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linking, and fused rings, and is substituted or unsubstituted. １ ~R １５ Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linking, and fused rings, and is substituted or unsubstituted. ５ and Ar ６ And R １ ~R １５These may be linked to each other to form a six-membered aromatic ring, and Ar ５ ~Ar ６ If R is a hydrogen atom, １ ~R ８ Any two locations, and R ９ ~R １５ Any two of these points are linked to each other to form a six-membered aromatic ring.

[0038] Ar ５ and Ar ６ When the alkyl group has 1 to 10 carbon atoms, it may be a linear alkyl group or a branched alkyl group. Examples of alkyl groups having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, etc. In the alkyl group, the number of carbon atoms is preferably 1 to 10, and preferably 1 to 6.

[0039] Ar ５ and Ar ６ When is an aromatic hydrocarbon group, the aromatic hydrocarbon group has 6 to 15 carbon atoms and is selected from monocyclic, linking, and fused rings. Examples include phenyl, biphenyl, naphthyl, phenanthryl, anthryl, phenalenyl, fluorenyl, and dimethylfluorenyl groups, with phenyl, biphenyl, naphthyl, and phenanthryl groups being more preferred.

[0040] R １ ~R １５ Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linked, and fused rings, and all atoms except the hydrogen atom are Ar ５ and Ar ６ Since the alkyl groups having 1 to 10 carbon atoms and aromatic hydrocarbon groups selected in the above are the same groups, an explanation is omitted.

[0041] Ar ５ and Ar ６ And R １~R １５ However, when they are linked to each other to form a six-membered aromatic ring, R １ ~R ８ Any two locations, and R ９ ~R １５ Any two of these groups may be linked to each other to form a six-membered aromatic ring, and examples of aromatic rings include naphthylene groups and phenantrenyl groups.

[0042] Ar ５ and Ar ６ And R １ ~R １５ Ar may be substituted with a substituent. In other words, Ar ５ and Ar ６ And R １ ~R １５ If each of the substituents is present, they may be independently substituted with substituents selected from the group consisting of a nitro group, a halogen atom, an alkyl halide, an acyl group, a sulfonyl group, a phosphoryl group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, a tricycloalkyl group having 5 to 20 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. The substituents are the same as those that the compound represented by formula (1) may have, so their explanation is omitted.

[0043] Preferred specific examples of compounds represented by formulas (1) and (2) are shown below, but are not limited to these.

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] Furthermore, the photoelectric element material (1) for an image sensor and the compound (2) which is a photoelectric element material for an image sensor according to one aspect of the present invention can be synthesized by appropriately combining known reactions (for example, the Suzuki-Miyaura cross-coupling reaction).

[0054] <Materials for photoelectric conversion elements for image sensors, hole transport materials for image sensors> A material for a photoelectric conversion element for an image sensor according to one aspect of the present invention consists of or includes a compound represented by formula (1) (for example, a compound represented by formula (2)). The applications of the material for an image sensor according to one aspect of the present invention will be described below. As described above, the material for a photoelectric conversion element for an image sensor can be suitably used in layers of an image sensor, such as the photoelectric conversion layer and the electron block layer, due to the balance between response speed and external quantum efficiency.

[0055] Furthermore, the material for the photoelectric conversion element for an image sensor according to one aspect of the present invention has high T ｇ By having this property, changes in the film state, such as crystallization caused by annealing during the manufacturing of the photoelectric conversion element, are prevented. As a result, a decrease in the external quantum efficiency in an image sensor formed from the photoelectric conversion element material for image sensors according to one aspect of the present invention is prevented, and the dark current is reduced. Therefore, the photoelectric conversion element material for image sensors according to one aspect of the present invention can be suitably used as a photoelectric conversion element material and an electron blocking layer for image sensors, where resistance to annealing after the formation of the photoelectric conversion layer is required.

[0056] A photoelectric conversion element material for an image sensor according to one aspect of the present invention can be used, for example, as an electronic block material, which is a material for the photoelectric conversion layer or an electronic block layer in an image sensor.

[0057] A photoelectric element material for an image sensor according to one aspect of the present invention includes a framework represented by the above formula (1). The photoelectric element material for an image sensor and the electronic block material including the framework represented by the formula (1) contribute to the fabrication of a photoelectric element material for an image sensor that has excellent response speed and external quantum efficiency characteristics.

[0058] <Regarding HOMO Levels> For photoelectric conversion elements used in image sensors, it may be necessary to rapidly transfer the charge generated in the photoelectric conversion layer in order to improve dark current and response speed. For rapid charge transfer, it is preferable that the HOMO levels of the p-type semiconductor material in the photoelectric conversion layer and the material used in the electron block layer are close. The HOMO level of the electron block layer, as a quantum calculation value obtained by density functional theory (DFT) as described later, is preferably -5.5 eV or higher, and more preferably -4.0 eV or lower. More preferably -5.00 eV or higher and -4.5 eV or lower. The LUMO level of the electron block layer is not limited, but it may be -2.0 eV or higher, and preferably -1.6 eV or higher.

[0059] The HOMO level of a photoelectric conversion element material containing either the compound represented by formula (1) or (2) is not particularly limited, but from the viewpoint of compatibility with the image sensor, a HOMO level of -5.5 eV or higher is preferred, and -5.0 eV or higher is more preferred.

[0060] In an image sensor according to one aspect of the present invention, the HOMO level of the photoelectric conversion element material for the image sensor is a numerical value calculated by quantum chemical calculations, and the optimization of the molecular structure and the calculation of the HOMO level can be obtained using density functional theory (DFT) with the calculation conditions of the B3LYP functional and the 6-31G(d) basis function using a Gaussian program.

[0061] <Regarding the glass transition temperature> The photoelectric element material for image sensors used to form the layer of an image sensor according to one aspect of the present invention is the photoelectric element material for image sensors represented by formula (1). The glass transition temperature of these photoelectric element materials for image sensors represented by formula (1) is not particularly limited, but from the viewpoint of suitability to an image sensor, that is, a photoelectric element for an image sensor, it is preferable that the glass transition temperature is 130°C or higher, more preferably 140°C or higher, even more preferably 145°C or higher, and most preferably 150°C or higher. Note that this glass transition temperature is a value obtained from differential scanning calorimetry.

[0062] The differential scanning calorimeter and test conditions are as follows: Differential scanning calorimeter model: Hitachi High-Tech DSC7020; Operating conditions: The glass transition temperature was determined from the peak obtained after two scans under the conditions of heating rate of 10°C / min and temperature range of 40°C to 400°C.

[0063] <Regarding Amorphous Properties> In one aspect of the present invention, the material for a photoelectric conversion element used as an image sensor, or the material for a photoelectric conversion element for an image sensor represented by formula (1), preferably has a vapor-deposited film that forms an amorphous layer. If the vapor-deposited film is a crystalline layer, the interface with adjacent layers will not be uniform, which can lead to defects in the element.

[0064] There are no particular limitations on the method for confirming whether or not a deposited film is an amorphous layer, but it can be confirmed by methods commonly used by those skilled in the art, such as visual inspection to determine the presence or absence of crystallization, or by XRD measurement of the deposited film, where no sharp diffraction peaks are observed.

[0065] <Image Sensor> An image sensor according to one aspect of the present invention, comprising a layer containing a material for a photoelectric conversion element for an image sensor according to one aspect of the present invention.

[0066] The configuration of the image sensor is not particularly limited, but for example, the following configurations (i) to (vi) can be cited.

[0067] (i) First electrode / photoelectric conversion layer / second electrode (ii) First electrode / hole blocking layer / photoelectric conversion layer / second electrode (iii) First electrode / photoelectric conversion layer / electron blocking layer / second electrode (iv) First electrode / hole blocking layer / photoelectric conversion layer / electron blocking layer / second electrode (v) First electrode / hole blocking layer / photoelectric conversion layer / electron blocking layer / hole transport enhancement layer / second electrode (vi) First electrode / auxiliary layer / hole blocking layer / photoelectric conversion layer / electron blocking layer / hole transport enhancement layer / second electrode

[0068] Hereinafter, an image sensor according to one aspect of the present invention will be described in more detail with reference to Figure 1, using the configuration of (v) above as an example. Figure 1 is a schematic cross-sectional view showing an example of a stacked configuration of an image sensor comprising a layer containing a photoelectric conversion element material for an image sensor according to one aspect of the present invention.

[0069] The image sensor 100 comprises a first electrode 1, a hole blocking layer 2, a photoelectric conversion layer 3, an electron blocking layer 4, a hole transport enhancement layer 5, and a second electrode 6 in this order. However, some of these layers may be omitted, or other layers may be added. Of the above layers, the hole blocking layer 2, the photoelectric conversion layer 3, the electron blocking layer 4, and the hole transport enhancement layer 5 constitute an organic layer 10 consisting of multiple layers.

[0070] The image sensor 100 shown in Figure 1 may specifically be an imaging photoelectric conversion element. Light enters the image sensor 100 from below the transparent first electrode 1 and is received by the photoelectric conversion layer 3, which is a light-receiving layer. The direction of light incidence is not particularly limited; the second electrode 6 may be transparent, and light may be incident from the second electrode 6.

[0071] The image sensor 100, due to the difference in carrier density in each layer and the internal electric field resulting from the difference in work function between the first electrode 1 and the second electrode 6, causes electrons to move to the first electrode 1 and holes to move to the second electrode 6 from the charge (holes and electrons) generated by light reception in the photoelectric conversion layer 3. Furthermore, charge can also be moved by applying a voltage between the first electrode 1 and the second electrode 6. Thus, the first electrode 1 acts as an electron collecting electrode, and the second electrode 6 acts as a hole collecting electrode.

[0072] Furthermore, each of the multiple layers may be replaced with a layer having a different name or function, as needed. Examples of layers with different names or functions include, for example, a hole transport layer as an alternative name for the electron block layer, and a hole transport enhancement layer, which is a layer known as a form of the hole transport layer, and other names for it include a hole injection layer, a work function adjustment layer, and so on.

[0073] Note that in Figure 1, the substrate provided on the lower surface of the first electrode 1 is omitted. There are no particular limitations on the substrate here; for example, a glass plate, quartz plate, or plastic plate can be used. Also, in a configuration where light is incident from the substrate side, the substrate is transparent to the wavelength of light. Note that the substrate may be provided on the side of the second electrode 6. The above layers will be described below.

[0074] [Layer containing photoelectric conversion element material for image sensor] An image sensor, which is one embodiment of a photoelectric conversion element, may contain a compound represented by formula (1) or (2) above as a photoelectric conversion element material for the image sensor in one or more layers selected from the group consisting of a photoelectric conversion layer and a layer between the photoelectric conversion layer and a second electrode. In the example configuration shown in Figure 1, the image sensor 100 contains a photoelectric conversion element material for the image sensor in at least one layer selected from the group consisting of an electron block layer 4 and a photoelectric conversion layer 3. In an image sensor according to one embodiment of the present invention, it is preferable that the electron block layer 4 contains a photoelectric conversion element material for the image sensor. This has the effect of rapidly moving the necessary charge while controlling the reverse movement of electrons.

[0075] Furthermore, the photoelectric conversion element material for the image sensor, which is a compound represented by formulas (1) and (2) above, may be included in any one or more of the layers provided between the first electrode and the second electrode in the image sensor exemplified in (i) to (vi) above. For example, if a hole transport layer or an auxiliary layer is provided, the hole transport layer or auxiliary layer may also contain the photoelectric conversion element material for the image sensor. Here, the auxiliary layer is a layer provided between the first electrode and the hole block layer described later, and is a layer that assists in the transport of electrons from the hole block layer to the first electrode.

[0076] The following describes an imaging photoelectric conversion element 100 in which the electron block layer 4 contains a material for photoelectric conversion elements.

[0077] [First electrode 1] A first electrode 1 is provided on the substrate.

[0078] In the case of an image sensor configured such that light passes through a first electrode and is incident on a photoelectric conversion layer 3, the first electrode 1 may be formed of a transparent material that allows the light to pass through or substantially allows the light to pass through.

[0079] The transparent material used for the lower electrode, which is the first electrode 1, is not particularly limited, but examples include indium tin oxide (ITO), indium zinc oxide (IZO), 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, and metal sulfides such as zinc sulfide.

[0080] Furthermore, if the image sensor 100 is configured such that light enters the photoelectric conversion layer 3 only from the second electrode 6 side, the light transmission characteristics of the first electrode 1 are not important. Therefore, examples of materials that can be used for the first electrode 1 in this case include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, silver, gold, magnesium / silver mixture, aluminum, magnesium / aluminum mixture, magnesium / indium mixture, and aluminum / aluminum oxide (Al ２ O ３ Examples include mixtures, lithium / aluminum mixtures, iridium, molybdenum, palladium, and platinum, as well as rare earth metals.

[0081] [Hole Blocking Layer 2] A hole blocking layer 2 is provided between the first electrode 1 and the photoelectric conversion layer 3, which is a light-receiving layer and will be described later.

[0082] The hole blocking layer 2 has the role of transporting electrons generated in the photoelectric conversion layer 3 to the first electrode 1, and blocking the movement of holes from the photoelectric conversion layer 3 to the first electrode 1, which is the destination for electron transport. Depending on the application, it may also have the role of blocking hole injection from the first electrode 1.

[0083] The material may contain conventionally known hole-blocking materials (electron-transporting materials). Examples of conventionally known hole-blocking materials (electron-transporting materials) include bis(8-hydroxyquinolinate)manganese, tris(8-hydroxyquinolinate)aluminum, tris(2-methyl-8-hydroxyquinolinate)aluminum, 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(pyridine-4-yl)phenyl)-2-methylpyrimidine, N,N'-diphenyl-1,4,5,8-naphthalenetetracarboxylic acid diimide, and N,N'-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide.

[0084] The hole blocking layer 2 may be a single-layer structure made of one or more materials, or a laminated structure made of multiple layers of the same or different compositions. The hole blocking layer 2 may be a two-layer structure, in which one of the two layers may be, for example, a layer made of a material specialized for hole blocking adjacent to the photoelectric conversion layer 3, and the other remaining layer may be a layer adjacent to the first electrode 1 made of a material specialized for electron transport to the first electrode 1.

[0085] [Photoelectric Conversion Layer 3] A photoelectric conversion layer 3, which is a light-receiving layer, is provided between the hole blocking layer 2 and the electron blocking layer 4, which will be described later. The material for the photoelectric conversion layer 3 is a material that has a photoelectric conversion function.

[0086] The photoelectric conversion layer 3 may be a single-layer structure made of one or more materials, or a laminated structure made of multiple layers with the same or different compositions. In particular, in order to increase the photoelectric conversion efficiency, it is preferable that the photoelectric conversion layer 3 consists of layers containing at least two materials (organic materials which are organic components).

[0087] The photoelectric conversion layer 3 preferably contains at least three materials, and more preferably two of the three materials are organic materials. Examples of such organic materials include a dye compound and either an n-type semiconductor or a p-type semiconductor, and more preferably the two organic materials are either a dye compound and an n-type semiconductor, or a dye compound and a p-type semiconductor.

[0088] Organic materials used in the photoelectric conversion layer 3 include n-type semiconductors and p-type semiconductors. N-type semiconductors are acceptor-type organic semiconductors, and compounds that readily accept electrons and have high electron transport properties are used. P-type semiconductors are donor-type organic semiconductors, and compounds that readily donate electrons and have high hole transport properties are used. When multiple materials are used in the photoelectric conversion layer 3, possible combinations include, for example, 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, or a p-type semiconductor and a compound with lower donor properties than the p-type semiconductor. Each material may be used individually, or two or more materials may be used. The photoelectric conversion layer 3 may also contain a dye compound that is excellent at absorbing 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. In terms of increasing photoelectric conversion efficiency, it is desirable that the photoelectric conversion layer 3 contains a dye compound in addition to the n-type semiconductor and p-type semiconductor. Examples of compounds included in the photoelectric conversion layer 3 include organic materials such as coumarin and its derivatives, quinacridone and its derivatives, phthalocyanine and its derivatives, azole derivatives such as imidazole, thiazole, thiadiazole, oxazole, oxadiazole, and triazole, and dye compounds such as naphthalenetetracarboxylic acid diimide, as well as organic materials such as hole transport materials and fullerene and its derivatives. Among these, the organic material included in the photoelectric conversion layer 3 is preferably an organic material selected from phthalocyanine and its derivatives and hole transport materials, and more preferably contains fullerene or its derivatives. It is even more preferable that the photoelectric conversion layer 3 contains three materials, comprising two organic materials containing phthalocyanine derivatives and hole transport materials, and a material further containing fullerene or its derivatives. The photoelectric conversion layer 3 made of these materials may be formed by pre-mixing the powders and then depositing them, or by co-depositing them in any proportion.

[0089] Specific examples of coumarin derivatives, which are organic materials, include coumarin 6 and coumarin 30. Specific examples of quinacridone derivatives include N,N-dimethylquinacridone. Specific examples of phthalocyanine derivatives include boron subphthalocyanine chloride, boron subnaphthalocyanine chloride (SubNC), F6-SubPC-OC6F5, and Cl6-SubPC-OC6.

[0090] Specific examples of fullerenes and their derivatives, which are materials (also called carbon materials), include

[60] fullerene,

[70] fullerene, and [6,6]-phenyl-C61-methyl butyrate (

[60] PCBM).

[0091] The hole transport material may be any known hole transport material. Examples of hole transport materials include 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, naphthiothiophene compounds, benzodithiophene compounds, benzothiophene compounds, naphthobisbenzothiophene compounds, crisenodithiophene compounds, benzothienobenzothiophene compounds, indolocarbazole compounds, and the like. Among these, fluorene compounds, naphthodithiophene compounds, naphthothienothiophene compounds, benzodifuran compounds, benzothiophene compounds, naphthobisbenzothiophene compounds, crisenodithiophene compounds, benzothienobenzothiophene compounds, and indolocarbazole compounds are preferred, and organic materials such as fluorene compounds, crisenodithiophene compounds, benzothienobenzothiophene compounds, or indolocarbazole compounds are more preferred.

[0092] Specific examples of organic materials that act as hole transporters 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, and naphtho[2,3-b]naphtho Examples include [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, criseno[1,2-b:8,7-b']dithiophene, [1]benzothieno[3,2-b][1]benzothiophene, and the following compounds (ic-1), (ic-2), and (ic-3).

[0093]

[0094] Furthermore, the photoelectric conversion element material (compound) for the image sensor represented by formulas (1) and (2) may be contained only in the photoelectric conversion layer. However, it is not limited to this, and the photoelectric conversion element material for the image sensor represented by formulas (1) and (2) may also be contained in, for example, a layer adjacent to the photoelectric conversion layer 3 (electron block layer 4).

[0095] [Electron Blocking Layer 4] An electron blocking layer 4 is provided between the photoelectric conversion layer 3 and the hole transport enhancement layer 5.

[0096] The electron blocking layer 4 has the role of transporting holes generated in the photoelectric conversion layer 3 from the photoelectric conversion layer 3 to the second electrode 6, and blocking the movement of electrons generated in the photoelectric conversion layer 3 towards the second electrode 6. Depending on the application, it may also have the role of blocking electron injection from the second electrode 6.

[0097] The electron blocking layer 4 may be a single-layer structure made of one or more materials, or it may be a laminated structure made of multiple layers of the same or different compositions. For example, it may be a two-layer structure including a layer adjacent to the photoelectric conversion layer 3 made of a material specialized for electron blocking, and a layer adjacent to the hole transport promotion layer 5 made of a material specialized for hole transport.

[0098] The electron blocking layer 4 uses a compound represented by formula (1) or (2) described above. In addition, it may also contain a conventionally known hole transport material. Preferred compounds and specific examples of conventionally known hole transport materials are the same as those described in the section on the photoelectric conversion layer 3.

[0099] [Hole Transport Promotion Layer 5] A hole transport promotion layer 5 is provided between the electron blocking layer 4 and the second electrode 6, which will be described later. The hole transport promotion layer 5 is provided to promote hole transport from the electron blocking layer 4 to the second electrode 6. The promotion of hole transport is brought about by the hole transport material changing the internal electric field through interaction with the surrounding material. In addition, when the second electrode 6 is formed by the sputtering method, the hole transport promotion layer 5 plays a role in reducing damage to the organic layer (e.g., the electron blocking layer 4) during sputtering.

[0100] The promotion of hole transport by the hole transport-promoting layer 5 depends on its interaction with the hole transport material, and varies depending on the strength of the interaction between the two materials. The compound represented by formulas (1) and (2) above is expected to have a stronger interaction with the highly acceptor compound used in the hole transport-promoting layer as its conjugation length increases, thereby promoting carrier transfer between the electron blocking layer and the hole transport-promoting layer. From this viewpoint, it is preferable that the hole transport-promoting layer 5 contains an acceptor organic material, and it is more preferable that the acceptor organic material is an acceptor compound having a cyano group.

[0101] Furthermore, the acceptor-like organic material contained in the hole transport-promoting layer 5 preferably has a lowest unoccupied orbital (LUMO) energy level of -2.7 eV or lower, more preferably -3.0 eV or lower, obtained by structural optimization calculations using density functional theory B3LYP / 6-31G(d). This is expected to promote carrier transfer between the electron blocking layer and the hole transport-promoting layer. From this viewpoint, it is preferable to make the LUMO level in the hole transport-promoting layer 5 deeper than the LUMO level in the electron blocking layer 4 by using the acceptor-like organic material.

[0102] The organic material contained in the hole transport-promoting layer 5 is preferably an acceptor-type organic material whose lowest unoccupied orbital (LUMO) energy level is -2.7 eV or less. For example, naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA) and its derivatives, aromatic compounds having a cyano group such as 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN), 4,4',4"-(cyclopropane-1,2,3-trilidentris(cyanomethanylylidene))tris(2,3,5,6-tetrafluorobenzonitrile), and imide compounds such as 1,8:4,5-naphthalenetetracarboxydiimide are more preferably acceptor-type compounds.

[0103] The hole transport-promoting layer 5 may be a single-layer structure made of one or more materials, or a multilayer structure of two or more layers, with the number of layers in the multilayer structure preferably being two to four, more preferably two or three, and even more preferably two. The hole transport-promoting layer 5 may, for example, have the above materials and a conventionally known hole transport material. Examples include conventionally known hole transport materials, and further, the same as those used in the photoelectric conversion layer 3 described above.

[0104] [Second electrode 6] A second electrode 6 is provided on the hole transport promoting layer 5.

[0105] The materials for the second electrode 6 include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, aluminum, magnesium / aluminum mixture, magnesium / indium mixture, and aluminum / aluminum oxide (Al ２ O ３ Examples include mixtures, indium, lithium / aluminum mixtures, silver, gold, palladium, platinum, and rare earth metals. In the case of a photoelectric conversion element for an image sensor in which light is incident on the photoelectric conversion layer from the second electrode 6 side, the material constituting the second electrode 6 may be, for example, indium tin oxide (ITO), indium zinc oxide (IZO), 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.

[0106] [Method for forming each layer] Each layer, excluding the first electrode 1 and the second electrode 6 described above, can be formed by thinning the material of each layer (along with binder resin and other materials and solvents as needed) using known methods such as vacuum deposition, spin coating, casting, or the LB (Langmuir-Blodgett method).

[0107] There are no particular restrictions on the thickness of each layer formed in this way, and it can be selected as appropriate depending on the situation, but it is usually in the range of 5 nm to 5 μm.

[0108] The first electrode 1, which is the lower electrode, and the second electrode 6, which is the upper electrode, can be formed by thinning the electrode material using methods such as vapor deposition or sputtering. A pattern may be formed through a mask of a desired shape during vapor deposition or sputtering, or a pattern of a desired shape may be formed by photolithography after the thin film has been formed by vapor deposition or sputtering.

[0109] The film thickness of the first electrode 1 and the second electrode 6 is preferably 1 μm or less, and more preferably 10 nm to 200 nm.

[0110] [Summary] A photoelectric conversion element for an image sensor according to aspect [1] of the present disclosure is a photoelectric conversion element for an image sensor comprising a first electrode, a photoelectric conversion layer, an electron blocking layer, and a second electrode in this order, wherein the photoelectric conversion layer comprises at least two types of organic materials, and the electron blocking layer comprises a compound represented by the following formula (1); In the above formula (1), Ar １ L is selected from hydrogen, aromatic hydrocarbon groups having 6 to 30 carbon atoms, and oxygen-containing or sulfur-containing heteroaryl groups having 3 to 30 carbon atoms. １ and L ４ Each is independently selected from aromatic hydrocarbon groups having 6 to 30 carbon atoms and oxygen-containing or sulfur-containing heteroaryl groups having 3 to 30 carbon atoms, Ar ２ and Ar ３ and L ２ and L ３ Each is independently selected from an aromatic hydrocarbon group containing a monocyclic or fused ring of three or fewer rings, and an oxygen-containing or sulfur-containing heteroaryl group having 3 to 30 carbon atoms containing a monocyclic or fused ring of three or fewer rings, n １ ~n ４ Each of these can be represented independently by an integer between 0 and 3, and n １ ~n ４ If L is 0, １ ~L ４ Ar represents a single bond. １ ~Ar ３ , and L １ ~L ４ Each of these is independently substituted with or unsubstituted with at least one substituent selected from the group consisting of a nitro group, a halogen atom, an alkyl halide, an acyl group, a sulfonyl group, a phosphoryl group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, a tricycloalkyl group having 5 to 20 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; a photoelectric conversion element for an image sensor.

[0111] A photoelectric conversion element for an image sensor according to aspect [2] of the present disclosure, in aspect [1], in formula (1), n １ is represented by an integer of 0 or 1, Ar １ However, it is selected from aromatic hydrocarbon groups including hydrogen atoms, six-membered monocyclic rings, and fused rings with 10 to 15 carbon atoms, L １ However, it is more preferable that the aromatic hydrocarbon group be selected from a single bond, a six-membered monoring, and a fused ring having 10 to 15 carbon atoms.

[0112] A photoelectric conversion element for an image sensor according to aspect [3] of the present disclosure, in aspect [1] or [2], in formula (1), n ４ is represented by an integer of 0 or 1, L ４ However, it is more preferable that the aromatic hydrocarbon group be selected from a single bond, a six-membered monoring, or a fused ring having 10 to 15 carbon atoms.

[0113] A photoelectric conversion element for an image sensor according to aspect [4] of the present disclosure, in any of aspects [1] to [3], in formula (1), L ４ It is more preferable that the monoring in the above is a phenylene group and the fused ring is a naphthylene group.

[0114] A photoelectric conversion element for an image sensor according to aspect [5] of the present disclosure, in any of aspects [1] to [4], in formula (1), n ２ and n ３ However, each is independently represented by an integer between 0 and 2, Ar ２ and Ar ３ and L ２ and L ３ It is more preferable that at least one of these is selected from the three or fewer fused rings.

[0115] A photoelectric conversion element for an image sensor according to aspect [6] of the present disclosure, in aspect [5], in formula (1), Ar ２ and L ２ The combination includes at least one of the three or fewer fused rings, Ar ３ and L ３ It is more preferable that the combination is the aforementioned single ring combination.

[0116] A photoelectric conversion element for an image sensor according to aspect [7] of the present disclosure, in any of aspects [1] to [6], in formula (1), n ２ and n ３ However, each is represented independently by 1 to 2, Ar ２ and L ２ , and Ar ３ and L ３ It is more preferable that each of these be selected from the single rings or from the three or fewer fused rings.

[0117] In the photoelectric conversion element for an image sensor according to embodiment [8] of the present disclosure, in embodiment [7], it is more preferable that the three or fewer fused rings in formula (1) are two fused rings.

[0118] In the photoelectric conversion element for an image sensor according to embodiment [9] of the present disclosure, in any of embodiments [1] to [8], it is more preferable that the glass transition temperature of the compound represented by formula (1) is 150°C or higher.

[0119] In any of the embodiments [1] to [9] of the present disclosure, the photoelectric conversion element for an image sensor according to embodiment

[10] is more preferably such that the photoelectric conversion layer contains at least three materials.

[0120] In any of the embodiments [1] to

[10] of the present disclosure, the photoelectric conversion element for an image sensor is more preferably characterized in that the photoelectric conversion layer contains fullerene.

[0121] A photoelectric conversion element for an image sensor according to embodiment

[12] of the present disclosure comprises, in any of embodiments [1] to

[11] , a first electrode, a photoelectric conversion layer, an electron blocking layer, a hole transport promoting layer, and a second electrode in this order, wherein the hole transport promoting layer more preferably contains an acceptor organic material.

[0122] In the photoelectric conversion element for an image sensor according to embodiment

[13] of the present disclosure, in embodiment

[12] , it is more preferable that the acceptor organic material has an energy level of the lowest unoccupied orbital (LUMO) obtained by structural optimization calculation by density functional calculation B3LYP / 6-31G(d) of -2.7 eV or less.

[0123] In the photoelectric conversion element for an image sensor according to embodiment

[14] of the present disclosure, it is more preferable that the acceptor organic material in embodiment

[12] or

[13] is a compound having a cyano group.

[0124] In any of the embodiments [1] to

[14] of the present disclosure, the photoelectric conversion element for an image sensor according to embodiment

[15] is more preferably such that the first electrode is an electron collecting electrode and the second electrode is a hole collecting electrode.

[0125] A photoelectric element material for an image sensor according to an aspect [1'] of the present disclosure is a photoelectric element material for an image sensor comprising a compound represented by the following formula (1): In the above formula (1), Ar １ L is selected from hydrogen, aromatic hydrocarbon groups having 6 to 30 carbon atoms, and oxygen-containing or sulfur-containing heteroaryl groups having 3 to 30 carbon atoms. １ and L ４ Each is independently selected from aromatic hydrocarbon groups having 6 to 30 carbon atoms and oxygen-containing or sulfur-containing heteroaryl groups having 3 to 30 carbon atoms, Ar ２ and Ar ３ and L ２ and L ３ Each is independently selected from an aromatic hydrocarbon group containing a monocyclic or fused ring of three or fewer rings, and an oxygen-containing or sulfur-containing heteroaryl group having 3 to 30 carbon atoms containing a monocyclic or fused ring of three or fewer rings, n １ ~n ４ Each of these can be represented independently by an integer between 0 and 3, and n １ ~n ４ If L is 0, １ ~L ４ Ar represents a single bond. １ ~Ar ３ , and L １ ~L４ Each of these atoms is independently substituted with or unsubstituted with at least one substituent selected from the group consisting of a nitro group, a halogen atom, an alkyl halide, an acyl group, a sulfonyl group, a phosphoryl group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, a tricycloalkyl group having 5 to 20 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0126] Furthermore, the photoelectric conversion element material for an image sensor according to embodiment [2'] of the present disclosure is, in embodiment [1'], n １ is represented by an integer of 0 or 1, and Ar １ However, it is selected from aromatic hydrocarbon groups including hydrogen atoms, six-membered monocyclic rings, and fused rings with 10 to 15 carbon atoms, L １ However, it is more preferable that the aromatic hydrocarbon group be selected from a single bond, a six-membered monoring, and a fused ring having 10 to 15 carbon atoms.

[0127] Furthermore, the photoelectric conversion element material for an image sensor according to embodiment [3'] of this disclosure is, in embodiment [1'] or [2'], n ４ is represented by an integer of 0 or 1, L ４ However, it is more preferable that the aromatic hydrocarbon group be selected from a single bond, a six-membered monoring, or a fused ring having 10 to 15 carbon atoms.

[0128] Furthermore, the photoelectric conversion element material for an image sensor according to embodiment [4'] of the present disclosure is L ４ It is more preferable that the monoring in the above is a phenylene group and the fused ring is a naphthylene group.

[0129] Furthermore, the photoelectric conversion element material for an image sensor according to embodiment [5'] of the present disclosure is, in any of embodiments [1'] to [4'], n ２ and n ３ However, each is independently represented by an integer between 0 and 2, Ar ２ and Ar ３ and L ２ and L ３ It is more preferable that at least one of these is selected from the three or fewer fused rings.

[0130] Furthermore, the material for the photoelectric conversion element for the image sensor according to embodiment [6'] of the present disclosure is, in embodiment [5'], Ar ２ and L ２ The combination includes at least one of the three or fewer fused rings, Ar ３ and L ３ It is more preferable that the combination is the aforementioned single ring combination.

[0131] Furthermore, the photoelectric conversion element material for an image sensor according to embodiment [7'] of the present disclosure is, in any of embodiments [1'] to [4'], n ２ and n ３ However, each is independently represented by 1 to 2, Ar ２ and L ２ , and Ar ３ and L ３ It is more preferable that each of these be selected from the single rings or from the three or fewer fused rings.

[0132] Furthermore, in the photoelectric conversion element material for an image sensor according to embodiment [8'] of the present disclosure, it is more preferable that the three or fewer fused rings are two-ring fused rings in embodiment [7'].

[0133] Furthermore, the photoelectric conversion element material for an image sensor according to embodiment [9'] of the present disclosure may be a hole transport material in any of embodiments [1'] to [8'].

[0134] Furthermore, the photoelectric conversion element for an image sensor according to embodiment [10'] of the present disclosure comprises a layer containing a photoelectric conversion element material for an image sensor according to any of embodiments [1'] to [9'].

[0135] Furthermore, in the embodiment [11'] of the present disclosure, the photoelectric conversion element for an image sensor comprises an electrode, a photoelectric conversion layer, and an electron blocking layer, wherein the electron blocking layer contains a material for the photoelectric conversion element for the image sensor, and more preferably the electron blocking layer contains a fullerene.

[0136] Furthermore, the compounds relating to aspects [12'] or

[16] of this disclosure are compounds represented by the following formula (2): In the above formula (2), Ar ４Ar is selected from a phenyl group, a naphthyl group, and a biphenyl group. ５ and Ar ６ Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linking, and fused rings, and is substituted or unsubstituted. １ ~R １５ Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linking, and fused rings, and is substituted or unsubstituted. ５ and Ar ６ And R １ ~R １５ These may be linked to each other to form a six-membered aromatic ring, and Ar ５ ~Ar ６ If R is a hydrogen atom, １ ~R ８ Any two locations, and R ９ ~R １５ Any two of these points are linked to each other to form a six-membered aromatic ring.

[0137] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0138] The present invention will be described in more detail below based on examples, but the present invention is not to be limited in any way by these examples.

[0139] <Synthesis Example 1> [Synthesis Example 1] Synthesis of Compound (A004)

[0140]

[0141] Under an argon stream, add bis(2-phenantrenyl)amine (0.90 g, 2.44 mmol), 2-bromotriphenylene (0.75 g, 2.44 mmol), and NaO to a 200 mL two-necked flask. ｔBu (0.31 g, 3.22 mmol), palladium acetate (10.9 mg, 48.6 μmol), t-Bu ３ P (18.5 mg, 91.4 μmol) and xylene (26 mL) were added and the mixture was heated and stirred at 140°C for 4 hours. After cooling to room temperature, the mixture was quenched with water, and then hexane was added to crystallize and the solid was recovered. The obtained solid was dissolved in a chlorobenzene solution at 140°C, activated carbon was added and stirred, and then the activated carbon was removed using Celite. After concentrating the filtrate, recrystallization was performed in a mixed solvent of chlorobenzene and ethanol to obtain 1.40 g (2.35 mmol, yield 96%) of a pale yellow solid of compound (A004). The sublimation temperature of compound (A004) was 340°C, and it was confirmed that the sublimated compound (A004) was glassy. The identification of the compound was １ This was performed using H-NMR measurement.

[0142] １ H-NMR (CDCl ３ ) δ (ppm): 8.65-8.58 (m, 8H), 8.50 (d, J = 2.4Hz, 1H), 8.26 (d, J = 7.6Hz, 1H), 7.87 (d, J=6.8Hz, 2H), 7.71-7.53 (m, 16H), 7.45 (d, J=7.2Hz, 1H).

[0143] <Synthesis Example 2> [Synthesis Example 2] Synthesis of compound (A026)

[0144]

[0145] Under an argon stream, in a 200 mL two-necked flask, add 4-(triphenylene-2-yl)aniline (1.28 g, 4.00 mmol), 2-bromophenanthrene (2.26 g, 8.80 mmol), and NaO2. ｔ ​Bu (1.15 g, 12.0 mmol), palladium acetate (26.9 mg, 120 μmol), SPhos (98.5 mg, 240 μmol), and xylene (40 mL) were added and heated and stirred at 140°C for 6 hours. After cooling to room temperature, the mixture was quenched with water, and then hexane was added to crystallize and the solid was recovered. The obtained solid was dissolved in a chlorobenzene solution at 140°C, activated carbon was added and stirred, and then the activated carbon was removed using Celite. After concentrating the filtrate, recrystallization was performed in a mixed solvent of chlorobenzene and ethanol to obtain 2.36 g (3.52 mmol, yield 88%) of a pale yellow solid of compound (A026). The sublimation temperature of compound (A026) was 370°C, and it was confirmed that the sublimated compound (A026) was glassy. The identification of the compound was １ This was performed using H-NMR measurement.

[0146] １ H-NMR (CDCl ３ ) δ (ppm): 9.06 (d, J = 1.9 Hz, 1H), 9.02 (t, J = 4.2 Hz, 1H), 8.88 (d, J = 8.9 Hz, 1H), 8.85-8. 81 (m, 5H), 8.75 (d, J = 8.4Hz, 2H), 8.06 (dd, J = 8.3Hz, J = 1.7Hz, 1H), 8.03 (d, J = 8.7Hz, 2 H), 7.96 (dd, J = 8.2Hz, J = 1.3Hz, 2H), 7.80 (d, J = 8.9Hz, 1H), 7.79 (s, 1H), 7.75-7.71 (m , 10H), 7.61 (t, J=7.4Hz, 2H), 7.54 (dd, J=8.9Hz, J=2.5Hz, 2H), 7.35 (d, J=8.6Hz, 2H).

[0147] <Synthesis Example 3> [Synthesis Example 3] Synthesis of Compound (A111)

[0148]

[0149] Under an argon stream, in a 200 mL two-necked flask, add bis([1,1':4',1'']-terphenyl-4-yl)amine (1.42 g, 3.00 mmol), 2-chloro-7-phenyltriphenylene (1.02 g, 3.00 mmol), and NaO2. ｔ ​Bu (0.38 g, 3.91 mmol), palladium acetate (14.8 mg, 65.9 μmol), t-Bu ３ P (24.8 mg, 123 μmol) and xylene (31 mL) were added and the mixture was heated and stirred at 140°C for 6 hours. After cooling to room temperature, the mixture was quenched with water, and then hexane was added to crystallize and the solid was recovered. The obtained solid was dissolved in a chlorobenzene solution at 140°C, activated carbon was added and stirred, and then the activated carbon was removed using Celite. After concentrating the filtrate, recrystallization was performed in a mixed solvent of chlorobenzene and ethanol to obtain 2.04 g (2.63 mmol, yield 88%) of a pale yellow solid of compound (A111). The sublimation temperature of compound (A111) was 385°C, and it was confirmed that the sublimated compound (A111) was glassy. The identification of the compound is as follows: １ This was performed using H-NMR measurement.

[0150] １ H-NMR (CDCl ３ ) δ (ppm): 8.85 (d, J = 1.6 Hz, 1H), 8.74 (d, J = 7.7 Hz, 1H), 8.63 (d, J = 8.8 Hz, 1H), 8.59 (d, J = 9.3 Hz, 1H), 8.46 (d, J = 2.3 Hz, 1H) ), 8.38 (d, J=7.5Hz, 1H), 7.89 (dd, J=8.5Hz, J=1.8Hz, 1H), 7.82 (d, J=7.1Hz, 2H), 7.73-7.41 (m, 26H), 7.38-7.35 (m, 6H).

[0151] <Synthesis Example 4> [Synthesis Example 4] Synthesis of Compound (A113)

[0152]

[0153] Under an argon stream, in a 200 mL two-necked flask, add bis(2-phenantrenyl)amine (0.90 g, 2.44 mmol), 2-chloro-7-phenyltriphenylene (0.83 g, 2.44 mmol), and NaO2. ｔ Bu (0.31 g, 3.17 mmol), palladium acetate (10.7 mg, 47.7 μmol), t-Bu ３ ​P (22.4 mg, 111 μmol) and xylene (26 mL) were added and the mixture was heated and stirred at 140°C for 6 hours. After cooling to room temperature, the mixture was quenched with water, and then hexane was added to crystallize and the solid was recovered. The obtained solid was dissolved in a chlorobenzene solution at 140°C, activated carbon was added and stirred, and then the activated carbon was removed using Celite. After concentrating the filtrate, recrystallization was performed in a mixed solvent of chlorobenzene and ethanol to obtain 1.61 g (2.40 mmol, yield 98%) of a pale yellow solid of compound (A113). The sublimation temperature of compound (A113) was 370°C, and it was confirmed that the sublimated compound (A113) was glassy. The identification of the compound was １ This was performed using H-NMR measurement.

[0154] １ H-NMR (CDCl ３ ) δ (ppm): 8.83 (d, J = 1.8Hz, 1H), 8.70 (d, J = 7.6Hz, 1H), 8.64-8.57 (m, 6H), 8.48 (d, J = 2.4Hz, 1H), 8.26 (d, J = 7.9Hz) , 1H), 7.89-7.85 (m, 3H), 7.80 (d, J = 8.6Hz, 2H), 7.71-7.50 (m, 16H), 7.46 (t, J = 7.0Hz, 1H), 7.41 (t, J = 7.4Hz, 1H).

[0155] <Synthesis Example 5> [Synthesis Example 5] Synthesis of Compound (A116)

[0156]

[0157] Under an argon stream, in a 200 mL two-necked flask, add N-([1,1':4',1'']-terphenyl-4-yl)-(2-phenantrenyl)amine (1.27 g, 3.01 mmol), 2-chloro-7-phenyltriphenylene (1.02 g, 3.00 mmol), and NaO2. ｔ Bu (0.38 g, 3.90 mmol), palladium acetate (14.8 mg, 65.9 μmol), t-Bu ３ ​P (24.4 mg, 121 μmol) and xylene (31 mL) were added and the mixture was heated and stirred at 140°C for 4 hours. After cooling to room temperature, the mixture was quenched with water, and then hexane was added to crystallize and the solid was recovered. The obtained solid was dissolved in a chlorobenzene solution at 140°C, activated carbon was added and stirred, and then the activated carbon was removed using Celite. After concentrating the filtrate, recrystallization was performed in a mixed solvent of chlorobenzene and ethanol to obtain 2.11 g (2.91 mmol, yield 97%) of a pale yellow solid of compound (A116). The sublimation temperature of compound (A116) was 390°C, and it was confirmed that the sublimated compound (A116) was glassy. The identification of the compound was １ This was performed using H-NMR measurement.

[0158] １ H-NMR (CDCl ３ ) δ (ppm): 8.85 (d, J = 1.8Hz, 1H), 8.73 (d, J = 7.8Hz, 1H), 8.65-8.59 (m, 4H), 8.48 (d, J = 2.3Hz, 1H), 8.33 (d, J=7.8Hz, 1H), 7.88 (t, J=7.6Hz, 2H), 7.82 (d, J=7.2Hz, 2H), 7.74-7.52 (m, 19H), 7.49-7.35 (m, 6H).

[0159] <Synthesis Example 6> [Synthesis Example 6] Synthesis of Compound (A122)

[0160]

[0161] Under an argon stream, in a 200 mL two-necked flask, add bis(9,9-dimethylfluoren-2yl)amine (1.21 g, 3.00 mmol), 2-chloro-7-phenyltriphenylene (1.02 g, 3.00 mmol), and NaO2. ｔ Bu (0.38 g, 3.96 mmol), palladium acetate (13.7 mg, 61.0 μmol), t-Bu ３ ​P (20.8 mg, 103 μmol) and xylene (31 mL) were added and the mixture was heated and stirred at 140°C for 4 hours. After cooling to room temperature, the mixture was quenched with water, and then hexane was added to crystallize and the solid was recovered. The obtained solid was dissolved in a chlorobenzene solution at 140°C, activated carbon was added and stirred, and then the activated carbon was removed using Celite. After concentrating the filtrate, recrystallization was performed in a mixed solvent of chlorobenzene and ethanol to obtain 1.65 g (2.34 mmol, yield 78%) of a pale yellow solid of compound (A122). The sublimation temperature of compound (A122) was 330°C, and it was confirmed that the sublimated compound (A122) was glassy. The identification of the compound was １ This was performed using H-NMR measurement.

[0162] １ H-NMR (CDCl ３ ) δ (ppm): 8.83 (d, J = 1.6 Hz, 1H), 8.72 (d, J = 8.0 Hz, 1H), 8.62 (d, J = 8.7 Hz, 1 H), 8.55 (d, J=9.4Hz, 1H), 8.47 (d, J=2.3Hz, 1H), 8.29 (d, J=7.8Hz, 1H), 7. 89 (dd, J=8.4Hz, J=1.7Hz, 1H), 7.82 (d, J=8.2Hz, 2H), 7.70-7.61 (m, 5H), 7 .56-7.50 (m, 4H), 7.44-7.26 (m, 9H), 7.22 (d, J=8.4Hz, 2H), 1.44 (s, 12H).

[0163] <Glass Transition Temperature and HOMO Level> Compound A026 from Synthesis Example 1, as well as comparative compounds 1 and 2 described in Reference 1, and comparative compound 3 described in Reference 3, were prepared. The glass transition temperature was measured using a differential scanning calorimeter (Hitachi High-Tech DSC7020) with an aluminum pan at a sweep rate of 10°C / min. For the HOMO level, density functional theory (DFT) was performed using Gaussian 16 software with the B3LYP functional and 6-31G(d) basis function calculation conditions to optimize the molecular structure and calculate the HOMO level. The obtained glass transition temperature and HOMO level (calc.HOMO) results are summarized in the table below.

[0164] ​

[0165]

[0166] The results in the table above show that compound (A026) represented by formula (1) exhibits superior thermal stability of the film compared to comparative compound 1, comparative compound 2, and comparative compound 3, making it suitable as a material for photoelectric conversion elements.

[0167] <Example of Element - 1 (See Figure 1)> As shown in Figure 1, an image sensor 100 was fabricated as a photoelectric conversion element having a stacked structure consisting of a first electrode 1, a hole blocking layer 2, a photoelectric conversion layer 3, an electron blocking layer 4, a hole transport promoting layer 5, and a second electrode 6, and the dark current, external quantum efficiency, and responsiveness of the image sensor were evaluated.

[0168] (Preparation of the first electrode 1) As a substrate on which the first electrode was mounted, a glass substrate with a transparent ITO electrode was prepared, on which a 2 mm wide indium-tin (ITO) film (thickness 110 nm) was patterned in stripes. Next, this substrate was cleaned with isopropyl alcohol and then surface-treated by ozone ultraviolet cleaning.

[0169] (Preparation for vacuum deposition) After cleaning and surface treatment, each layer was deposited using the vacuum deposition method on the substrate to form a laminated structure.

[0170] First, the glass substrate is introduced into the vacuum deposition chamber, and 7.0 × 10 －５ The pressure was reduced to Pa. Then, each layer was fabricated according to the deposition conditions for each layer, in the following order.

[0171] (Preparation of Hole Block Layer 2) Hole block layer 2 was prepared by depositing 4,6-bis(3,5-di(pyridine-4-yl)phenyl)-2-methylpyrimidine, which had been purified by sublimation, at a rate of 0.10 nm / second to a thickness of 10 nm.

[0172] (Fabrication of photoelectric conversion layer (light-receiving layer) 3) DiPh-BTBT, F6-SubPc-OC6F5, and fullerene (C60) were co-deposited at a deposition rate ratio of 4:4:2 to a thickness of 200 nm to fabricate the photoelectric conversion layer 3. The deposition rate was 0.15 nm / second.

[0173] (Fabrication of electron blocking layer 4) Compound A026 obtained in Synthesis Example-1 was deposited as a 10 nm film at a rate of 0.10 nm / second to fabricate electron blocking layer 4.

[0174] (Fabrication of hole transport-promoting layer 5) Compound 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN) was deposited at a rate of 0.10 nm / second to a thickness of 10 nm to produce hole transport-promoting layer 5. The energy level of the lowest unoccupied orbital (LUMO) obtained by structural optimization calculation using density functional theory B3LYP / 6-31G(d) for the compound was -4.6 eV.

[0175] (Fabrication of the second electrode 6) Finally, a metal mask was positioned perpendicular to the ITO stripe on the substrate, and the second electrode 6, which is the upper electrode, was deposited. Specifically, gold was deposited at a rate of 0.1 nm / second to a thickness of 80 nm to fabricate the second electrode 6, which is the upper electrode.

[0176] As a result, the area is 4 mm² as shown in Figure 1. ２ A photoelectric conversion element 100 for imaging was fabricated. The film thickness of each element was measured using a stylus-type film thickness gauge (DEKTAK, Bruker).

[0177] Furthermore, this element was sealed in a nitrogen atmosphere glove box with an oxygen and moisture concentration of 1 ppm or less. The sealing was performed using bisphenol F type epoxy resin (manufactured by Nagase ChemteX Corporation) to seal the glass sealing cap and the film-deposited substrate (element).

[0178] The dark current, external quantum efficiency, and response time were evaluated when a voltage of 2.6V was applied to the image sensor fabricated as described above. Dark current was measured using a Keithley 2636B source measure unit. External quantum efficiency was measured using a solar cell spectroscopic sensitivity analyzer (Soma Optical Co., Ltd.). The illumination wavelength was 560 nm, and the intensity was 50 μW / cm². ２ The measurement was performed using the following method. Response time was measured by applying a light pulse and then measuring the time it took for the current value to return to its pre-irradiation state.

[0179] Note that the dark current, external quantum efficiency, and response time are relative values ​​with the results from Comparative Example 1 set as the baseline value (1.0). A lower dark current value indicates better performance, a higher external quantum efficiency value indicates better performance, and a shorter response time indicates better performance. The obtained measurement results are shown in the table below.

[0180] <Element Example 1, Element Comparative Examples 1 and 2> Except for using comparative compound 1, comparative compound 2, or comparative compound 3 described in reference document 1, an imaging photoelectric conversion element was fabricated and evaluated in the same manner as in Element Example 1. The obtained measurement results are shown in the table below.

[0181]

[0182] The results in the table above show that by forming a layer using compounds represented by formulas (1) and (2) as materials for the photoelectric conversion element of an image sensor, a photoelectric conversion element for imaging can be realized with reduced dark current and superior responsiveness compared to the case where a layer is formed using comparative examples 1 to 3.

[0183] An image sensor equipped with a photoelectric conversion element according to one aspect of the present invention can be applied, for example, to image sensors in digital cameras and digital video cameras, image sensors built into mobile phones and the like, and image input devices for driver assistance systems.

[0184] 1. First electrode 2. Hole blocking layer 3. Photoelectric conversion layer (light receiving layer) 4. Electron blocking layer (hole transport layer) 5. Hole transport enhancement layer 6. Second electrode 10. Organic layer 100. Image sensor

Claims

1. A photoelectric conversion element for an imaging device, comprising a first electrode, a photoelectric conversion layer, an electron blocking layer, and a second electrode in this order, wherein the photoelectric conversion layer contains at least two kinds of organic materials, and the electron blocking layer contains a compound represented by the following formula (1); In the formula (1), Ar １ is selected from hydrogen, an aromatic hydrocarbon group having 6 to 30 carbon atoms, and a heteroaryl group containing oxygen or sulfur having 3 to 30 carbon atoms, and L １ and L ４ are each independently selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms and a heteroaryl group containing oxygen or sulfur having 3 to 30 carbon atoms, and Ar ２ and Ar ３ as well as L ２ and L ３ are each independently selected from an aromatic hydrocarbon group containing a monocyclic or condensed ring of 3 rings or less, and a heteroaryl group containing oxygen or sulfur having 3 to 30 carbon atoms and containing a monocyclic or condensed ring of 3 rings or less, and n １ to n ４ are each independently represented by an integer of 0 to 3, and when n １ to n ４ is 0, L １ to L ４ represents a single bond, and Ar １ to Ar ３ , and L １ to L ４ are each independently substituted with at least one substituent selected from the group consisting of a nitro group, a halogen atom, a halogenated alkyl group, an acyl group, a sulfonyl group, a phosphoryl group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a bicycloalkyl group having 4 to 20 carbon atoms, a tricycloalkyl group having 5 to 20 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms, or are unsubstituted, a photoelectric conversion element for an imaging device.

2. In formula (1) above, n １ is represented by an integer of 0 or 1, Ar １ However, it is selected from aromatic hydrocarbon groups including hydrogen atoms, six-membered monocyclic rings, and fused rings with 10 to 15 carbon atoms, L １ The photoelectric conversion element for an image sensor according to claim 1, wherein the group is selected from a single bond, a six-membered monoring, and an aromatic hydrocarbon group having 10 to 15 carbon atoms.

3. In formula (1) above, n ４ is represented by an integer of 0 or 1, L ４ The photoelectric conversion element for an image sensor according to claim 1, wherein the group is selected from a single bond, a six-membered monoring, or an aromatic hydrocarbon group having 10 to 15 carbon atoms.

4. In formula (1) above, L ４ The photoelectric conversion element for an image sensor according to claim 3, wherein the monoring is a phenylene group and the fused ring is a naphthylene group.

5. In formula (1) above, n ２ and n ３ However, each is independently represented by an integer between 0 and 2, Ar ２ and Ar ３ and L ２ and L ３ The photoelectric conversion element for an image sensor according to claim 1, wherein at least one of the elements is selected from the three or fewer fused rings.

6. In formula (1) above, Ar ２ and L ２ The combination includes at least one of the three or fewer fused rings, Ar ３ and L ３ The photoelectric conversion element for an image sensor according to claim 5, wherein the combination is the combination of the single rings.

7. In formula (1) above, n ２ and n ３ However, each is represented independently by 1 to 2, Ar ２ and L ２ , and Ar ３ and L ３ The photoelectric conversion element for an image sensor according to claim 1, wherein each of the elements is selected from the single ring or from the three or fewer fused rings.

8. The photoelectric conversion element for an image sensor according to claim 7, wherein the three or fewer fused rings in formula (1) are two fused rings.

9. The photoelectric conversion element for an image sensor according to claim 1, wherein the glass transition temperature of the compound represented by formula (1) is 150°C or higher.

10. The photoelectric conversion element for an image sensor according to claim 1, wherein the photoelectric conversion layer comprises at least three materials.

11. The photoelectric conversion element for an image sensor according to claim 1, wherein the photoelectric conversion layer contains a fullerene.

12. A photoelectric element for an image sensor according to claim 1, comprising a first electrode, a photoelectric conversion layer, an electron blocking layer, a hole transport promoting layer, and a second electrode in this order, wherein the hole transport promoting layer contains an acceptor-like organic material.

13. The photoelectric conversion element for an image sensor according to claim 12, wherein the acceptor organic material has an energy level of the lowest unoccupied orbital (LUMO) obtained by structural optimization calculation by density functional calculation B3LYP / 6-31G(d) of -2.7 eV or less.

14. The photoelectric conversion element for an image sensor according to claim 12, wherein the acceptor organic material is a compound having a cyano group.

15. The photoelectric conversion element for an image sensor according to claim 1, wherein the first electrode is an electron collecting electrode and the second electrode is a hole collecting electrode.

16. Compounds represented by the following formula (2): In the above formula (2), Ar ４ Ar is selected from a phenyl group, a naphthyl group, and a biphenyl group. ５ and Ar ６ Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linking, and fused rings, and is substituted or unsubstituted. １ ~R １５ Each is independently selected from a hydrogen atom, a C1-C10 alkyl group, and an aromatic hydrocarbon group, wherein the aromatic hydrocarbon group has C6-C15 and is selected from monocyclic, linking, and fused rings, and is substituted or unsubstituted. ５ and Ar ６ And R １ ~R １５ These may be linked to each other to form a six-membered aromatic ring, and Ar ５ ~Ar ６ If R is a hydrogen atom, １ ~R ８ Any two locations, and R ９ ~R １５ Any two of these points are linked to each other to form a six-membered aromatic ring.

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