JP7445767B2 - Photoelectric conversion elements, image sensors, optical sensors, compounds - Google Patents

Description

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

In recent years, the development of devices (for example, imaging devices) having photoelectric conversion films has progressed.
For example, Patent Document 1 discloses a compound represented by the following formula as a compound applicable to an organic photosensitive layer of an optoelectronic component (claims 1 and 19).

Special Publication No. 2013-530978

In recent years, with the demand for improved performance of image pickup devices, optical sensors, and the like, further improvements have been sought in the various characteristics required of photoelectric conversion elements used in these devices.
For example, there is a demand for further improvement in the sensitivity (photoelectric conversion efficiency) of photoelectric conversion elements to relatively long wavelength light (for example, light with a wavelength of 500 nm).
When the present inventors investigated a photoelectric conversion element using the material disclosed in Patent Document 1, it was confirmed that there is room for improvement in the sensitivity of such a photoelectric conversion element to light with a wavelength of 500 nm. Ta.

In view of the above circumstances, it is an object of the present invention to provide a photoelectric conversion element that has excellent sensitivity to light with a wavelength of 500 nm.
Another object of the present invention is to provide an image sensor, an optical sensor, and a compound related to the photoelectric conversion element.

As a result of intensive study on the above-mentioned problems, the present inventors found that the above-mentioned problems could be solved by the following configuration, and completed the present invention.

[1]
A photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order,
A photoelectric conversion element, wherein the photoelectric conversion film contains a compound represented by formula (1).
In formula (1), D is a group represented by any one of formulas (1-1) to (1-11).
Ar is a group represented by formula (2-1) or formula (2-2).
A is a group represented by any one of formulas (3-1) to (3-9).
n1, n2, and n3 each independently represent an integer of 0 to 2.
In formulas (1-1) to (1-11), * represents the bonding position.
X represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One of Y ¹ and Y ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One of Y ³ and Y ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One of Y ⁵ and Y ⁶ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One of Y ⁷ and Y ⁸ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One or more of -CH= contained in the ring structure in the group represented by D in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
In formula (2-1) and formula (2-2), * represents the bonding position.
X ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One or more of -CH= contained in the ring structure in the group represented by Ar in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
In formulas (3-1) to (3-9), * represents the bonding position.
B ¹ and B ² each independently represent a sulfur atom, an oxygen atom, =C(CN) ₂ or =C(CN)(CO ₂ R ¹ ). R ¹ represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
E represents an aromatic ring which may have a group selected from the group consisting of a halogen atom, a methyl group, an ethyl group, and a methoxy group as a substituent. The above-mentioned methyl group, above-mentioned ethyl group, and above-mentioned methoxy group may further have a halogen atom as a substituent.
R represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
G represents -CR ^G = or -N=. R ^G represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
However, at least one of the five G's in formula (3-8) represents -N= or -CR ^G =, and R ^G is a halogen atom, a cyano group, or a substituent. Represents an alkyl group having 1 to 2 carbon atoms that may have a halogen atom.
X ³ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
ArL is a group represented by any one of formulas (Ar1) to (Ar3).
In formulas (Ar1) to (Ar3), * represents the bonding position.
X ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
Y ⁹ represents -CH=, -CR ² =, or -N=. R ² represents a halogen atom or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
[2]
The photoelectric conversion element according to [1], wherein n1, n2, and n3 represent 0.
[3]
The photoelectric conversion element according to [1] or [2], wherein the compound represented by the above formula (1) has a symmetrical structure.
[4]
[1] to [3], where D is a group represented by any of formulas (1-1) to (1-6) and formulas (1-8) to (1-11); The photoelectric conversion element according to any one of.
[5]
The photovoltaic device according to any one of [1] to [4], wherein D is a group represented by any one of formulas (1-1) to (1-6) and formula (1-8). conversion element.
[6]
[1] to [5], where D is a group represented by any one of formula (1-1), formula (1-4) to formula (1-6), and formula (1-8); The photoelectric conversion element according to any one of.
[7]
The photoelectric conversion element according to any one of [1] to [6], wherein D is a group represented by formula (1-6).
[8]
A is any of formula (3-2), formula (3-3), formula (3-5), formula (3-6), formula (3-8), and formula (3-9). The photoelectric conversion element according to any one of [1] to [7], which is a group represented by the following.
[9]
The photovoltaic device according to any one of [1] to [8], wherein A is a group represented by any one of formula (3-2), formula (3-5), and formula (3-8). conversion element.
[10]
The photoelectric conversion element according to any one of [1] to [9], wherein A is a group represented by formula (3-8).
[11]
The photoelectric conversion device according to any one of [1] to [10], wherein the compound represented by the above formula (1) has a molecular weight of 400 to 900.
[12]
The photoelectric conversion element according to any one of [1] to [11], wherein the photoelectric conversion film further contains a dye.
[13]
The photoelectric conversion element according to [12], wherein the photoelectric conversion film is a mixed layer formed of a mixture of the compound represented by the formula (1) and the dye.
[14]
The photoelectric conversion element according to any one of [1] to [13], which has one or more intermediate layers in addition to the photoelectric conversion film between the conductive film and the transparent conductive film.
[15]
The photoelectric conversion element according to any one of [1] to [14], wherein the photoelectric conversion film further contains an n-type semiconductor material.
[16]
The photoelectric conversion element according to [15], wherein the n-type semiconductor material contains fullerenes selected from the group consisting of fullerenes and derivatives thereof.
[17]
An imaging device comprising the photoelectric conversion device according to any one of [1] to [16].
[18]
An optical sensor comprising the photoelectric conversion element according to any one of [1] to [16].
[19]
A compound represented by formula (1).
In formula (1), D is a group represented by any of formulas (1-1) to (1-6) and formulas (1-8) to (1-11).
Ar is a group represented by formula (2-1) or formula (2-2).
A is a group represented by any one of formulas (3-1) to (3-9).
n1, n2, and n3 each independently represent an integer of 0 to 2.
In formulas (1-1) to (1-6) and formulas (1-8) to (1-11), * represents the bonding position.
X represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One of Y ¹ and Y ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One of Y ³ and Y ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One or more of -CH= contained in the ring structure in the group represented by D in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
In formula (2-1) and formula (2-2), * represents the bonding position.
X ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One or more of -CH= contained in the ring structure in the group represented by Ar in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
In formulas (3-1) to (3-9), * represents the bonding position.
B ¹ and B ² each independently represent a sulfur atom, an oxygen atom, =C(CN) ₂ or =C(CN)(CO ₂ R ¹ ). R ¹ represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
E represents an aromatic ring which may have a group selected from the group consisting of a halogen atom, a methyl group, an ethyl group, and a methoxy group as a substituent. The above-mentioned methyl group, above-mentioned ethyl group, and above-mentioned methoxy group may further have a halogen atom as a substituent.
R represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
G represents -CR ^G = or -N=. R ^G represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
However, at least one of the five G's in formula (3-8) represents -N= or -CR ^G =, and R ^G is a halogen atom, a cyano group, or a substituent. Represents an alkyl group having 1 to 2 carbon atoms that may have a halogen atom.
X ³ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
ArL is a group represented by any one of formulas (Ar1) to (Ar3).
In formulas (Ar1) to (Ar3), * represents the bonding position.
X ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
Y ⁹ represents -CH=, -CR ² =, or -N=. R ² represents a halogen atom or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
[20]
The compound according to [19], wherein n1, n2, and n3 represent 0.
[21]
The compound according to [19] or [20], which has a symmetric structure.
[22]
The compound according to any one of [19] to [21], wherein D is a group represented by any one of formulas (1-1) to (1-6) and formula (1-8) .
[23]
[19] to [22], where D is a group represented by any one of formula (1-1), formula (1-4) to formula (1-6), and formula (1-8) A compound according to any one of.
[24]
The compound according to any one of [19] to [23], wherein D is a group represented by formula (1-6).
[25]
A is any of formula (3-2), formula (3-3), formula (3-5), formula (3-6), formula (3-8), and formula (3-9). The compound according to any one of [19] to [24], which is the group represented by:
[26]
The compound according to any one of [19] to [25], wherein A is a group represented by any one of formula (3-2), formula (3-5), and formula (3-8) .
[27]
The compound according to any one of [19] to [26], wherein A is a group represented by formula (3-8).
[28]
The compound according to any one of [19] to [27], which has a molecular weight of 400 to 900.

According to the present invention, a photoelectric conversion element with excellent sensitivity can be provided.
Further, according to the present invention, it is possible to provide an image sensor, an optical sensor, and a compound related to the photoelectric conversion element.

FIG. 1 is a schematic cross-sectional view showing one configuration example of a photoelectric conversion element. FIG. 1 is a schematic cross-sectional view showing one configuration example of a photoelectric conversion element.

Preferred embodiments of the photoelectric conversion element of the present invention will be described below.

In this specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In this specification, when multiple identical symbols indicating the type or number of groups exist in one formula (general formula) indicating a chemical structure, unless otherwise specified, those multiple identical symbols The contents of the symbols are independent, and the contents of the same symbols may be the same or different.

Furthermore, in this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as lower and upper limits.

In this specification, the hydrogen atom may be a light hydrogen atom (normal hydrogen atom) or a deuterium atom (such as a double hydrogen atom).

[Photoelectric conversion element]
The photoelectric conversion element of the present invention is a photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order, wherein the photoelectric conversion film is a compound represented by formula (1) (hereinafter referred to as , also referred to as "specific compounds").
Although the mechanism by which the photoelectric conversion element of the present invention having such a configuration can solve the above problems is not necessarily clear, the present inventors speculate as follows.
That is, in the molecule of the specific compound, the group represented by A acts as an acceptor, and the group represented by D acts as a donor. Here, the specific compound has a form in which two donors are sandwiched between two acceptors, and the presence of the two donors side by side makes it easier to absorb relatively long-wave light. In addition, if the donor site is unsubstituted or halogen-substituted, the transport of holes in the photoelectric conversion film becomes smooth, and if the acceptor part is located at both ends of the molecule, the transport of electrons in the photoelectric conversion film becomes smooth. It is thought that these characteristics contributed synergistically to improve the sensitivity of the photoelectric conversion element to 500 nm light. Furthermore, it is believed that the fact that the acceptor and donor are each selected from groups having appropriate electron-accepting or electron-donating properties also contributes to the improvement in sensitivity to 500 nm light.
Moreover, the photoelectric conversion element of the present invention also has good heat resistance. This is thought to be due to the fact that two donors are present side by side in a specific compound, which tends to cause overlapping of the donors in the specific compounds. This is thought to be due to the fact that even if the photoelectric conversion element is heated, the electron transport properties are less likely to deteriorate, and the performance of the photoelectric conversion element is less likely to change before and after heating.
Furthermore, the photoelectric conversion element of the present invention also has good responsiveness.
Hereinafter, the fact that the photoelectric conversion element has better sensitivity to 500 nm light, responsiveness, and/or heat resistance is also simply referred to as "the effect of the present invention is better."

FIG. 1 shows a schematic cross-sectional view of an embodiment of the photoelectric conversion element of the present invention.
The photoelectric conversion element 10a shown in FIG. 1 includes a conductive film (hereinafter also referred to as a lower electrode) 11 functioning as a lower electrode, an electron blocking film 16A, a photoelectric conversion film 12 containing a specific compound to be described later, and an upper electrode. It has a structure in which a functional transparent conductive film (hereinafter also referred to as an upper electrode) 15 is laminated in this order.
FIG. 2 shows a configuration example of another photoelectric conversion element. The photoelectric conversion element 10b shown in FIG. 2 has a structure in which an electron blocking film 16A, a photoelectric conversion film 12, a hole blocking film 16B, and an upper electrode 15 are laminated in this order on a lower electrode 11. Note that the stacking order of the electron blocking film 16A, the photoelectric conversion film 12, and the hole blocking film 16B in FIGS. 1 and 2 may be changed as appropriate depending on the application and characteristics.

In the photoelectric conversion element 10a (or 10b), it is preferable that light be incident on the photoelectric conversion film 12 via the upper electrode 15.
Further, when using the photoelectric conversion element 10a (or 10b), a voltage can be applied. In this case, it is preferable that the lower electrode 11 and the upper electrode 15 form a pair of electrodes, and a voltage 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, the applied voltage is more preferably 1×10 ⁻⁴ to 1×10 ⁷ V/cm, and even more preferably 1×10 ⁻³ to 5×10 ⁶ V/cm.
Regarding the voltage application method, in FIGS. 1 and 2, it is preferable to apply the voltage so that the electron blocking film 16A side becomes the cathode and the photoelectric conversion film 12 side becomes the anode. When the photoelectric conversion element 10a (or 10b) is used as a photosensor or incorporated into an image sensor, voltage can be applied in a similar manner.
As will be described in detail later, the photoelectric conversion element 10a (or 10b) can be suitably applied to an image sensor.

Below, the form of each layer constituting the photoelectric conversion element of the present invention will be explained in detail.

[Photoelectric conversion film]
A photoelectric conversion film is a film containing a specific compound.
The specific compound will be explained in detail below.

<Compound represented by formula (1) (specific compound)>
The specific compound is a compound represented by the following formula (1).

In formula (1), D is a group represented by any one of formulas (1-1) to (1-11).

In formulas (1-1) to (1-11), * represents the bonding position.

In formulas (1-1) to (1-5) and formulas (1-8) to (1-11), X represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom. X is preferably a sulfur atom or an oxygen atom, more preferably a sulfur atom.

In formula (1-6), one of Y ¹ and Y ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
Y ¹ and Y ² may have a form in which Y ¹ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and Y ² represents -CH=, and Y ² represents a sulfur atom, an oxygen atom, a selenium atom, Alternatively, it may represent a tellurium atom and Y ¹ represents -CH=.
Note that the 5-membered ring containing Y ¹ and Y ² in formula (1-6) is an aromatic ring.

In formula (1-6), one of Y ³ and Y ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
Y ³ and Y ⁴ may have a form in which Y ³ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and Y ⁴ represents -CH=, and Y ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, Alternatively, it may represent a tellurium atom and Y ³ represents -CH=.
Note that the 5-membered ring containing Y ³ and Y ⁴ in formula (1-6) is an aromatic ring.

In formula (1-7), one of Y ⁵ and Y ⁶ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
Y ⁵ and Y ⁶ may have a form in which Y ⁵ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and Y ⁶ represents -CH=, and Y ⁶ represents a sulfur atom, an oxygen atom, a selenium atom, Alternatively, it may represent a tellurium atom and Y ⁵ represents -CH=.
Note that the 5-membered ring containing Y ⁵ and Y ⁶ in formula (1-7) is an aromatic ring.

In formula (1-7), one of Y ⁷ and Y ⁸ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
Y ⁷ and Y ⁸ may have a form in which Y ⁷ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and Y ⁸ represents -CH=, and Y ⁸ represents a sulfur atom, an oxygen atom, a selenium atom, Alternatively, it may represent a tellurium atom and Y ⁷ represents -CH=.
Note that the 5-membered ring containing Y ⁷ and Y ⁸ in formula (1-7) is an aromatic ring.

One or more -CH= (for example, 1 ~10 pieces) may be replaced with -CR ³ = (R ³ is a halogen atom).
R ³ is preferably a fluorine atom, a chlorine atom, or a bromine atom, more preferably a fluorine atom or a chlorine atom, and even more preferably a fluorine atom.
Note that Y ¹ to Y ⁸ in the case of -CH= are also included in the above-mentioned "-CH= included in the ring structure."
For example, the group represented by the formula (1-1) may be a group represented by the following formula (1-1F), and the group represented by the formula (1-6) may be a group represented by the following formula (1-1F). -6F) may also be used.
The meanings of the symbols in the following formulas (1-1F) and (1-6F) are the same as the corresponding symbols in formulas (1-1) and (1-6), respectively.

It is also preferable that the groups represented by formulas (1-1) to (1-11) have a line-symmetric structure and/or a point-symmetric structure. The axis of symmetry in the above-mentioned line-symmetric structure is a line perpendicular to the line segment connecting the atoms directly bonded to the two bond positions (*) in the structural formula. More specifically, the group represented by formula (1-1), which has a line-symmetric structure, has a line-symmetric structure with the broken line shown in the following formula as the axis of symmetry.

For example, in formula (1-1), X on the left side and X on the right side represent the same group, and two -CH= included in the ring structure of formula (1-1) are both replaced with -CF=. , it can be said that such a group represented by formula (1-1) has a line-symmetric structure.
Furthermore, in formula (1-7), both Y ⁵ and Y ⁶ are sulfur atoms, and both -CH= contained in the ring structure of formula (1-7) are replaced by -CR ³ =. When not substituted, such a group represented by formula (1-7) can be said to have a point-symmetric structure.

The two Ds present in formula (1) are preferably groups represented by the same formula, and more preferably have the same structure. Here, the above two Ds having the same structure does not only mean that the two Ds are expressed by the same formula, but also the specific structure of Ds expressed by the same formula (-Ar -) It means that they are the same when looking at _n2 as the center.

In view of the superior effects of the present invention, the group represented by D in formula (1) is selected from formulas (1-1) to (1-6) and formulas (1-8) to (1- It is preferably a group represented by any one of formulas (1-1) to (1-6) and formula (1-8). More preferably, it is a group represented by any one of formula (1-1), formula (1-4) to formula (1-6), and formula (1-8); A group represented by -6) is particularly preferred.

In formula (1), Ar is a group represented by formula (2-1) or formula (2-2).

In formula (2-1) and formula (2-2), * represents the bonding position.
X ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One or more of -CH= contained in the ring structure in the group represented by Ar in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
That is, one or more (for example, 1 to 2) of -CH= constituting the group represented by formula (2-1) may be replaced with -CR ³ = (R ³ is a halogen atom) .
One or more (for example, 1 to 4) of -CH= constituting the group represented by formula (2-2) may be each replaced with -CR ³ = (R ³ is a halogen atom).
R ³ is preferably a fluorine atom, a chlorine atom, or a bromine atom, more preferably a fluorine atom or a chlorine atom, and even more preferably a fluorine atom.

In formula (1), n1, n2, and n3 each independently represent an integer of 0 to 2. n1, n2, and n3 are each independently preferably an integer of 0 to 1, and more preferably 0.
Further, it is also preferable that n1 and n3 have the same value.
When n2 is 2, the two Ars in (Ar) _n2 are preferably groups represented by the same formula, and more preferably have the same structure.
It is also preferable that (Ar) _n2 has a symmetrical structure as a whole. Note that (Ar) _n2 having a symmetrical structure as a whole means that it satisfies any of Requirements 1 to 3 below.

Requirement 1: In formula (1), n2 is 0.

Requirement 2: In formula (1), n2 is 1, and (Ar) the group represented by formula (2-1) or formula (2-2), which is Ar in _n2 , is shown in the following formula. It has a line-symmetrical structure with the broken line as the axis of symmetry.
Whether or not Ar has a line-symmetric structure is determined by taking into account that --CH= included in the ring structure may be replaced with --CR ³ =. For example, in formula (2-1) below, if -CH= on the left side of the ring structure is replaced with -CF=, then -CH= on the right side of the ring structure is also replaced with -CF=. Only the following formula (2-1) is said to have a line-symmetric structure.

Requirement 3: In formula (1), n2 is 2, and Ar present at the farthest position from A in the group represented by "A-(Ar) _n1 -D-Ar-" and "-Ar-D In the group represented by "-(Ar) _n3 -A", the two Ar atoms present at the farthest position from A are groups having the same structure.
Here, the above two Ars having the same structure does not only mean that the two Ars are represented by the same formula, but also that the specific structures of the Ars represented by the same formula are the same. It means that.

It is also preferable that (Ar) _n1 and (Ar) _n3 have the same structure. For example, when n1 and n3 are both 2, it is preferable that the two Ars directly bonded to A in (Ar) _n1 and (Ar) _n3 are groups represented by the same formula, and have the same structure. It is more preferable. The two Ars directly bonded to D in (Ar) _n1 and (Ar) _n3 are preferably groups represented by the same formula, and more preferably have the same structure.
Here, the above two Ars having the same structure does not only mean that the two Ars are expressed by the same formula, but also the specific structure of Ars expressed by the same formula (Ar) This means that they are the same when looking at _n2 as the center.

In formula (1), A is a group represented by any of formulas (3-1) to (3-9).

In formulas (3-1) to (3-9), * represents the bonding position.

B ¹ in formula (3-1), formula (3-2), formula (3-6), and formula (3-7), and formula (3-3) and formula (3-4) ) each independently represents a sulfur ^atom , an oxygen atom, =C(CN) ₂ or =C(CN)(CO ₂ R ¹ ).
R ¹ represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent. The halogen atom that the alkyl group may have as a substituent is preferably a fluorine atom, a chlorine atom, or a bromine atom, more preferably a fluorine atom or a chlorine atom, and even more preferably a fluorine atom.

In formula (3-2), E represents an aromatic ring which may have a group selected from the group consisting of a halogen atom, a methyl group, an ethyl group, and a methoxy group as a substituent.
The aromatic ring may be monocyclic or polycyclic.
The number of ring member atoms in the aromatic ring is preferably 5 to 15.
The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocycle.
Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. Examples of the aromatic heterocycle include a quinoxaline ring, a pyrazine ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, and an oxazole ring.
The number of substituents (groups selected from the group consisting of halogen atoms, methyl groups, ethyl groups, and methoxy groups) that the aromatic ring has is, for example, 0 to 10.
The methyl group, ethyl group, and methoxy group that the aromatic ring may have as a substituent may further have a halogen atom as a substituent.

In formula (3-3), formula (3-4), formula (3-6), and formula (3-7), R has 1 to 2 carbon atoms, which may have a halogen atom as a substituent. represents an alkyl group. The halogen atom that the alkyl group may have as a substituent is preferably a fluorine atom, a chlorine atom, or a bromine atom, more preferably a fluorine atom or a chlorine atom, and even more preferably a fluorine atom. The number of carbon atoms in the alkyl group is preferably 1.

In formulas (3-8) and (3-9), G represents -CR ^G = or -N=. R ^G represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
However, at least one of the five G's in formula (3-8) represents -N= or -CR ^G =, and R ^G is a halogen atom, a cyano group, or a substituent. Represents an alkyl group having 1 to 2 carbon atoms that may have a halogen atom.
The halogen atom that the alkyl group may have as a substituent is preferably a fluorine atom, a chlorine atom, or a bromine atom, more preferably a fluorine atom or a chlorine atom, and even more preferably a fluorine atom. The number of carbon atoms in the alkyl group is preferably 1. Further, the alkyl group preferably has a halogen atom as a substituent.
Examples of the group represented by formula (3-8) include a phenyl group, a pyridinyl group, a pyrimidinyl group, and a pyridazinyl group, which may have a group selected from the group consisting of a halogen atom and a cyano group as a substituent. , pyrazinyl group, triazinyl group (1,2,3-triazinyl group, 1,2,4-triazinyl group, 1,3,5-triazinyl group, etc.), and tetrazinyl group (1,2,4,5-tetrazinyl group) etc.).

In formula (3-9), X ³ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
Examples of the group represented by formula (3-9) include a 2-thienyl group, a 2-furanyl group, and a 2-thienyl group, which may have a group selected from the group consisting of a halogen atom and a cyano group as a substituent. -Selenophenyl group and 2-tellurophenyl group. One or more (for example, 1 to 3) of -CH= ring member atoms in the 2-thienyl group, 2-furanyl group, 2-selenophenyl group, and 2-tellurophenyl group are -N = may be replaced.

In formula (3-5), ArL is a group represented by any one of formulas (Ar1) to (Ar3).

In formulas (Ar1) to (Ar3), * represents the bonding position. Among the two bonding positions (*), one is the bonding position with -CN in formula (3-5), and the other matches the bonding position (*) in formula (3-5). .
In formula (Ar2) and formula (Ar3), X ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
In formula (Ar2) and formula (Ar3), Y ⁹ represents -CH=, -CR ² =, or -N=. R ² represents a halogen atom or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
R ² represents a halogen atom or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
In addition, when Y ⁹ is -CH=, the hydrogen atom in Y ⁹ which is -CH= may be substituted to become a bonding position (*).
In other words, Y ⁹ is -CR ² =, -C(*)=, unsubstituted -CH ₂ =, or -N=.
That is, out of a total of four elements, two -CH ₂ = and two Y ⁹ in formula (Ar2), two are -C(*)=.
Similarly, out of a total of four elements, two -CH ₂ = and two Y ⁹ in formula (Ar3), two are -C(*)=.
For example, the group represented by formula (3-5) may be a group represented by formula (3-5A) below.

In addition, as the group represented by A in formula (1), there are groups that can correspond to the group represented by formula (3-5) and at the same time can correspond to groups represented by other formulas. In this case, such a group is treated as a group represented by formula (3-5).

It is also preferable that two A's in formula (1) have the same structure. Here, the above two A's having the same structure does not only mean that the two A's are expressed by the same formula, but also that the specific structures of the A's that are expressed by the same formula are the same. means.

From the viewpoint that the effect of the present invention is more excellent, the group represented by A in formula (1) is selected from formula (3-2), formula (3-3), formula (3-5), and formula (3-6). , formula (3-8), and formula (3-9) are preferable, and formula (3-2), formula (3-5), and formula (3- A group represented by any one of formula (3-8) is more preferable, and a group represented by formula (3-8) is even more preferable.

It is preferable that the specific compound has a symmetrical structure.
Note that the specific compound having a symmetrical structure specifically means that it satisfies any of the following requirements A to C.

Requirement A: In formula (1), n2 is 0, and the group represented by "A-(Ar) _n1 -D-" and the group represented by "-D-(Ar) _n3 -A" are They are groups with the same structure.

Requirement B: In formula (1), n2 is 1, and the group represented by "A-(Ar) _n1 -D-" in formula (1) and "-D-(Ar) _n3 -A" The group represented by the formula (2-1) or formula (2-2) which is a group having the same structure as the group represented and Ar in (Ar) _n2 is a group shown in the following formula. It has a line-symmetric structure with the broken line as the axis of symmetry.
The method for determining whether Ar has a line-symmetric structure is as described above.

Requirement C: In formula (1), n2 is 2, and a group represented by "A-(Ar) _n1 -D-Ar-" and a group represented by "-Ar-D-(Ar) _n3 -A" is a group having the same structure as the group described above.

Specific examples of the group represented by "-(Ar) _n1 -D-(Ar) _n2 -D-(Ar) _n3 -" in formula (1) are shown below. In the following, "*" represents the bonding position.

Specific examples of the group represented by A in formula (1) are shown below. In the following, "*" represents the bonding position.

The molecular weight of the specific compound is not particularly limited, and is preferably from 400 to 1,200, more preferably from 400 to 900. If the molecular weight is 1200 or less, the deposition temperature will not become high and decomposition of the compound will not easily occur. When the molecular weight is 400 or more, the glass transition point of the deposited film is not lowered, and the heat resistance of the photoelectric conversion element is improved.

The specific compound is particularly useful as a material for a photoelectric conversion film used in an image sensor, an optical sensor, or a photovoltaic cell. Further, the specific compound can also be used as a coloring material, a liquid crystal material, an organic semiconductor material, a charge transport material, a pharmaceutical material, and a fluorescent diagnostic material.

The specific compound is preferably a compound having an ionization potential of -5.0 to -6.0 eV in a single film in terms of energy level matching with an n-type semiconductor material described below.

The maximum absorption wavelength of the specific compound is not particularly limited, and is preferably in the range of 350 to 550 nm, more preferably in the range of 400 to 550 nm, for example.
The above maximum absorption wavelength is a value measured in a solution state (solvent: chloroform) after adjusting the absorption spectrum of the compound to be measured to a concentration such that the absorbance is 0.5 to 1. However, when the specific compound is not dissolved in chloroform, the maximum absorption wavelength is determined by vapor-depositing the specific compound and using the specific compound in a film state.

Certain compounds also tend to absorb light at relatively long wavelengths. Therefore, when attempting to produce a panchromatic photoelectric conversion element using a photoelectric conversion film containing a specific compound as well as a dye and an n-type semiconductor material (preferably fullerenes), which will be described later, it is necessary to select materials (especially dyes). Another advantage is that there is a large degree of freedom.

The maximum absorption wavelength of the photoelectric conversion film is not particularly limited, and is preferably in the range of 300 to 800 nm, more preferably in the range of 400 to 700 nm, for example.

From the viewpoint of the responsiveness of the photoelectric conversion element, the content of the specific compound in the photoelectric conversion film (=thickness of the specific compound in terms of a single layer/thickness of the photoelectric conversion film x 100) is 15 to 75% by volume. It is preferably 20 to 60% by volume, more preferably 25 to 40% by volume.
One type of specific compound may be used alone, or two or more types may be used.

<Pigment>
It is preferable that the photoelectric conversion film contains a dye as a component other than the above-mentioned specific compound.
The above dye is preferably an organic dye.
Examples of the above dyes include cyanine dyes, styryl dyes, hemicyanine dyes, merocyanine dyes (including zeromethine merocyanine (simple merocyanine)), rhodacyanine dyes, allopolar dyes, oxonol dyes, hemioxonol dyes, squalium dyes, croconium dyes, and azamethine. Dyes, coumarin dyes, arylidene dyes, anthraquinone dyes, triphenylmethane dyes, azo dyes, azomethine dyes, metallocene dyes, fluorenone dyes, fulgide dyes, perylene dyes, phenazine dyes, phenothiazine dyes, quinone dyes, diphenylmethane dyes, polyene dyes, acridine Pigments, acridinone dyes, quinoxaline dyes, diphenylamine dyes, quinophthalone dyes, phenoxazine dyes, phthaloperylene dyes, dioxane dyes, porphyrin dyes, chlorophyll dyes, phthalocyanine dyes, subphthalocyanine dyes, metal complex dyes, paragraph of JP 2014-82483 A Compounds described in [0083] to [0089], compounds described in paragraphs [0029] to [0033] of JP 2009-167348, paragraphs [0197] to [0227] of JP 2012-77064, Compounds described in paragraphs [0035] to [0038] of WO2018-105269, compounds described in paragraphs [0041] to [0043] of WO2018-186389, paragraph [0043] of WO2018-186397, Compounds described in paragraphs [0078] to [0083] of WO2019-009249, compounds described in paragraphs [0054] to [0056] of WO2019-049946, WO2019 Compounds described in paragraphs [0059] to [0063] of WO2019-098161, and paragraphs [0085] to [0085] of WO2020-013246. Examples include the compounds described in [0114].

Dye content (=(Film thickness in terms of a single layer of the dye/(Film thickness in terms of a single layer of the specific compound + Monolayer of the dye) relative to the total content of the specific compound and the dye in the photoelectric conversion film The film thickness (layer equivalent)×100)) is preferably 15 to 75% by volume, more preferably 20 to 60% by volume, and even more preferably 25 to 50% by volume.
In addition, one type of dye may be used alone or two or more types may be used.

<n-type semiconductor material>
It is also preferable that the photoelectric conversion film further contains an n-type semiconductor material as a component other than the above-mentioned specific compound and dye.
The n-type semiconductor material is an acceptor organic semiconductor material (compound), and refers to an organic compound that has the property of easily accepting electrons.
More specifically, the n-type semiconductor material is preferably an organic compound that, when used in contact with the above-mentioned specific compound, has a larger electron affinity than the specific compound.
In this specification, the electron affinity value is the inverse of the LUMO value obtained by calculating B3LYP/6-31G (d) using Gaussian'09 (Software manufactured by Gaussian) ) is used.
Further, the n-type semiconductor material is preferably an organic compound that has a larger electron affinity than the dye when used in contact with the above-mentioned dye.
The electron affinity of the n-type semiconductor material is preferably 3.0 to 5.0 eV.

The n-type semiconductor material includes, for example, fullerenes selected from the group consisting of fullerenes and derivatives thereof, fused aromatic carbocyclic compounds (for example, naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, and , fluoranthene derivatives); 5- to 7-membered heterocyclic compounds having at least one of a nitrogen atom, an oxygen atom, and a sulfur atom (e.g., pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine) , cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, thiazole, etc.); polyarylene compounds; fluorene compounds; cyclopentadiene compounds; silyl compounds; 1,4,5,8-naphthalenetetracarvone Acid anhydrides; 1,4,5,8-naphthalenetetracarboxylic acid anhydride imide derivatives, oxadiazole derivatives; anthraquinodimethane derivatives; diphenylquinone derivatives; bathocuproine, bathophenanthroline, and their derivatives; triazole compounds; Styrylarylene derivatives; metal complexes having a nitrogen-containing heterocyclic compound as a ligand; silole compounds; and compounds described in paragraphs [0056] to [0057] of JP-A No. 2006-100767.

Among these, the n-type semiconductor material preferably contains fullerenes selected from the group consisting of fullerenes and derivatives thereof.
Examples of fullerene include fullerene C60, fullerene C70, fullerene C76, fullerene C78, fullerene C80, fullerene C82, fullerene C84, fullerene C90, fullerene C96, fullerene C240, fullerene C540, and mixed fullerene.
Examples of fullerene derivatives include compounds obtained by adding a substituent to the above-mentioned fullerene. The substituent is preferably an alkyl group, an aryl group, or a heterocyclic group. The fullerene derivative is preferably a compound described in JP-A No. 2007-123707.

When the photoelectric conversion film contains an n-type semiconductor material, the content of the n-type semiconductor material (=(monoton of the n-type semiconductor material) with respect to the total content of the specific compound, optionally added dye, and n-type semiconductor material) Thickness in layer terms/(Thickness in terms of a single layer of specific compound + Thickness in terms of a single layer of dye + Thickness in terms of a single layer of n-type semiconductor material) x 100)) is 15 to 75. % by volume is preferred, 20 to 60 vol.% is more preferred, and 25 to 50 vol.% is even more preferred.
Note that one kind of n-type semiconductor material may be used alone, or two or more kinds of n-type semiconductor materials may be used.

In addition, when the n-type semiconductor material contains fullerenes, the content of fullerenes relative to the total content of the n-type semiconductor material (=(thickness of fullerenes in terms of a single layer/each n-type in terms of a single layer) The total thickness of the semiconductor material (×100) is preferably 50 to 100% by volume, more preferably 80 to 100% by volume.
In addition, one type of fullerene may be used alone, or two or more types may be used.

The molecular weight of the n-type semiconductor material is preferably from 200 to 1,200, more preferably from 200 to 1,000.

It is preferable that the photoelectric conversion film is substantially composed only of a specific compound, a dye, and an n-type semiconductor material. A photoelectric conversion film is substantially composed only of a specific compound, a dye, and an n-type semiconductor material when the total content of the specific compound, dye, and n-type semiconductor material is 95% of the total mass of the photoelectric conversion film. It means ~100% by mass.

The photoelectric conversion film is preferably a mixed layer formed by mixing a specific compound and a dye.
Moreover, when the photoelectric conversion film contains an n-type semiconductor material, it is preferable that the photoelectric conversion film is a mixed layer formed in a state in which a specific compound, a dye, and an n-type semiconductor material are mixed.
A mixed layer is a layer in which two or more types of materials are mixed in a single layer.

A photoelectric conversion film containing a specific compound is a non-luminous film and has different characteristics from an organic light emitting diode (OLED). A non-luminescent film is intended to be a film with a luminescence quantum efficiency of 1% or less, preferably 0.5% or less, more preferably 0.1% or less.

<Film formation method>
The photoelectric conversion film can be mainly formed by a dry film forming method. Dry film forming methods include, for example, physical vapor deposition methods such as evaporation methods (especially vacuum evaporation methods), sputtering methods, ion plating methods, and MBE (Molecular Beam Epitaxy) methods, and CVD methods such as plasma polymerization. (Chemical Vapor Deposition) method. Among these, vacuum evaporation is preferred. When forming a photoelectric conversion film by a vacuum evaporation method, manufacturing conditions such as degree of vacuum and evaporation temperature can be set according to conventional methods.

The thickness of the photoelectric conversion film is preferably 10 to 1000 nm, more preferably 50 to 800 nm, even more preferably 50 to 500 nm, particularly preferably 50 to 400 nm.

<Electrode>
The electrodes (upper electrode (transparent conductive film) 15 and lower electrode (conductive film) 11) are made of a conductive material. Examples of the conductive material include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof.
Since light is incident from the upper electrode 15, it is preferable that the upper electrode 15 is transparent to the light to be detected. The material constituting the upper electrode 15 is, for example, antimony tin oxide (ATO), fluorine doped tin oxide (FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO). Conductive metal oxides such as indium tin oxide (IZO) and indium zinc oxide (IZO); thin films of metals such as gold, silver, chromium, and nickel; combinations of these metals and conductive metal oxides; Mixtures or laminates; organic conductive materials such as polyaniline, polythiophene, and polypyrrole; and carbon materials such as graphene and carbon nanotubes. Among these, conductive metal oxides are preferred from the viewpoint of high conductivity and transparency.

Normally, making the conductive film thinner than a certain range causes a sudden increase in resistance value, but in the solid-state image sensor incorporating the photoelectric conversion element according to this embodiment, the sheet resistance may be, for example, 100 to 10,000 Ω/□. , there is a large degree of freedom in the range of film thickness that can be made thinner. Furthermore, the thinner the upper electrode (transparent conductive film) 15 is, the less light it absorbs, and generally the light transmittance increases. An increase in light transmittance is preferable because it increases light absorption in the photoelectric conversion film and increases photoelectric conversion ability. Considering the suppression of leakage current, increase in the resistance value of the thin film, and increase in transmittance due to thinning, the thickness of the upper electrode 15 is preferably 5 to 100 nm, more preferably 5 to 20 nm.

Depending on the purpose, the lower electrode 11 may be transparent or may not be transparent and may reflect light. The material constituting the lower electrode 11 is, for example, tin oxide doped with antimony or fluorine (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). conductive metal oxides such as gold, silver, chromium, nickel, titanium, tungsten, and aluminum; conductive compounds such as oxides or nitrides of these metals (for example, titanium nitride (TiN) mixtures or laminates of these metals and conductive metal oxides; organic conductive materials such as polyaniline, polythiophene, and polypyrrole; and carbon materials such as graphene and carbon nanotubes. It will be done.

The method of forming the electrode is not particularly limited, and can be appropriately selected depending on the electrode material. Specifically, wet methods such as printing methods and coating methods; physical methods such as vacuum evaporation methods, sputtering methods, and ion plating methods; and chemical methods such as CVD and plasma CVD methods. , etc.
When the material of the electrode is ITO, methods such as electron beam method, sputtering method, resistance heating vapor deposition method, chemical reaction method (sol-gel method, etc.), and coating of indium tin oxide dispersion can be used.

<Charge blocking film: electron blocking film, hole blocking film>
It is also preferable that the photoelectric conversion element of the present invention has one or more intermediate layers in addition to the photoelectric conversion film between the conductive film and the transparent conductive film. Examples of the intermediate layer include a charge blocking film. When the photoelectric conversion element has this film, the characteristics (photoelectric conversion efficiency, responsiveness, etc.) of the resulting photoelectric conversion element are more excellent. Examples of the charge blocking film include an electron blocking film and a hole blocking film. Each film will be explained in detail below.

(electron blocking film)
The electron blocking film is a donor organic semiconductor material (compound), and for example, the following p-type semiconductor materials can be used. The p-type semiconductor materials may be used alone or in combination of two or more.

The p-type semiconductor material is, for example, a triarylamine compound (for example, N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), 4,4 '-Bis[N-(naphthyl)-N-phenyl-amino]biphenyl (α-NPD), compound described in paragraphs [0128] to [0148] of JP2011-228614A, JP2011-176259A Compounds described in paragraphs [0052] to [0063] of the publication, compounds described in paragraphs [0119] to [0158] of JP2011-225544A, [0044] to [0051] of JP2015-153910A ] and the compounds described in paragraphs [0086] to [0090] of JP2012-94660A), pyrazoline compounds, styrylamine compounds, hydrazone compounds, polysilane compounds, thiophene compounds (for example, thieno Thiophene derivative, dibenzothiophene derivative, benzodithiophene derivative, dithienothiophene derivative, [1]benzothieno[3,2-b]thiophene (BTBT) derivative, thieno[3,2-f:4,5-f']bis [1] Benzothiophene (TBBT) derivatives, compounds described in paragraphs [0031] to [0036] of JP2018-14474, compounds described in paragraphs [0043] to [0045] of WO2016-194630, WO2017- Compounds described in paragraphs [0025] to [0037] and [0099] to [0109] of No. 159684, compounds described in paragraphs [0029] to [0034] of JP2017-076766, paragraph of WO2018-207722 Compounds described in [0015] to [0025], compounds described in paragraphs [0045] to [0053] of JP2019-54228, compounds described in paragraphs [0045] to [0055] of WO2019-058995, WO2019- Compounds described in paragraphs [0063] to [0089] of 081416, compounds described in paragraphs [0033] to [0036] of JP2019-80052, compounds described in paragraphs [0044] to [0054] of WO2019-054125 , compounds described in paragraphs [0041] to [0046] of WO2019-093188, etc.), cyanine compounds, oxonol compounds, polyamine compounds, indole compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, fused aromatic carbocyclic compounds ( For example, naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pentacene derivatives, pyrene derivatives, perylene derivatives, and fluoranthene derivatives), porphyrin compounds, phthalocyanine compounds, triazole compounds, oxadiazole compounds, imidazole compounds, polyarylalkane compounds , pyrazolone compounds, amino-substituted chalcone compounds, oxazole compounds, fluorenone compounds, silazane compounds, and metal complexes having nitrogen-containing heterocyclic compounds as ligands.
Examples of the p-type semiconductor material include compounds having a smaller ionization potential than the n-type semiconductor material, and if this condition is satisfied, the above-mentioned dyes can also be used.

Additionally, polymeric materials can also be used as the electron blocking film.
Examples of the polymeric material include polymers such as phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, and diacetylene, and derivatives thereof.

Note that the electron blocking film may be composed of a plurality of films.
The electron blocking film may be composed of an inorganic material. In general, inorganic materials have a higher dielectric constant than organic materials, so when an inorganic material is used for an electron blocking film, more voltage is applied to the photoelectric conversion film, increasing photoelectric conversion efficiency. Inorganic materials that can be used as electron blocking films include, for example, calcium oxide, chromium oxide, copper chromium oxide, manganese oxide, cobalt oxide, nickel oxide, copper oxide, copper gallium oxide, copper strontium oxide, niobium oxide, molybdenum oxide, and copper indium oxide. , indium silver oxide, and iridium oxide.

(hole blocking membrane)
The hole blocking film is an acceptor organic semiconductor material (compound), and the above-mentioned n-type semiconductor material can be used.

The method for producing the charge blocking film is not particularly limited, and examples thereof include dry film formation and wet film formation. Examples of the dry film forming method include a vapor deposition method and a sputtering method. The vapor deposition method may be either a physical vapor deposition (PVD) method or a chemical vapor deposition (CVD) method, and a physical vapor deposition method such as a vacuum vapor deposition method is preferable. Examples of wet film forming methods include inkjet method, spray method, nozzle printing method, spin coating method, dip coating method, casting method, die coating method, roll coating method, bar coating method, and gravure coating method. In terms of patterning accuracy, the inkjet method is preferred.

The thickness of each charge blocking film (electron blocking film and hole blocking film) is preferably 3 to 200 nm, more preferably 5 to 100 nm, and even more preferably 5 to 30 nm.

<Substrate>
The photoelectric conversion element may further include a substrate. The type of substrate used is not particularly limited, and examples thereof include semiconductor substrates, glass substrates, and plastic substrates.
Note that the position of the substrate is not particularly limited, and a conductive film, a photoelectric conversion film, and a transparent conductive film are usually laminated in this order on the substrate.

<Sealing layer>
The photoelectric conversion element may further include a sealing layer. The performance of photoelectric conversion materials may deteriorate significantly due to the presence of deterioration factors such as water molecules. Therefore, the entire photoelectric conversion film is covered with a sealing layer made of dense ceramics such as metal oxide, metal nitride, or metal nitride oxide, or diamond-like carbon (DLC), which does not allow water molecules to penetrate. By covering and sealing, the above deterioration can be prevented.
Note that the material for the sealing layer may be selected and manufactured according to the description in paragraphs [0210] to [0215] of JP-A No. 2011-082508.

[Image sensor, optical sensor]
An example of a use of a photoelectric conversion element is an image sensor. An image sensor is an element that converts optical information of an image into an electrical signal. Usually, multiple photoelectric conversion elements are arranged in a matrix on the same plane, and each photoelectric conversion element (pixel) converts an optical signal into an electrical signal. This refers to a device that can convert the image into an electrical signal and output that electrical signal to the outside of the image sensor one by one pixel by pixel. To this end, each pixel is composed of one or more photoelectric conversion elements and one or more transistors.
The image sensor is installed in an image sensor such as a digital camera and a digital video camera, an electronic endoscope, and an image sensor module such as a mobile phone.

The photoelectric conversion element of the present invention is also preferably used in an optical sensor having the photoelectric conversion element of the present invention. The optical sensor may be used as the photoelectric conversion element alone, or as a line sensor in which the photoelectric conversion elements are arranged in a straight line, or as a two-dimensional sensor in which the photoelectric conversion elements are arranged in a planar manner.

[Compound]
The invention also relates to compounds.
In the compound of the present invention, in the above general formula (1), D is one of the above formulas (1-1) to (1-6) and (1-8) to (1-11). It is the same as the above-mentioned specific compound except that it is a group represented by any of the above, and the preferable conditions and the like are also the same.

The present invention will be explained in more detail below based on Examples. The materials, amounts used, proportions, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the Examples shown below.

[Compound (evaluation compound)]
<Synthesis of compound 4>
Compound 4 used in the test described below was synthesized according to the scheme below.

Under a nitrogen atmosphere, compound (4-a) (0.478 g, 1.271 mmol), bis(tributyltin) (1.106 g, 1.907 mmol), and DMF (N,N-dimethylformamide, 7. 5 mL) and mixed. Thereafter, vacuum degassing and nitrogen replacement in the flask were repeated three times. After adding tetrakis(triphenylphosphine)palladium (0.029 g, 0.025 mmol) to the flask, vacuum degassing and nitrogen substitution in the flask were repeated three times. After reacting the contents of the flask at 100° C. for 2 hours under a nitrogen atmosphere, the precipitated solid (crude product) was filtered off. The obtained crude product (filtrate) was heated in chlorobenzene at 140°C for 1 hour, then filtered while hot, and the obtained solid (filtrate) was purified by sublimation under reduced pressure to obtain compound 4. Ta.

<Synthesis of compound 10>
Compound 10 used in the test described below was synthesized according to the scheme below.

Under a nitrogen atmosphere, compound (10-a) (1.057 g, 1.00 mmol), compound (10-b) (0.506 g, 2.40 mmol), and DMF (N,N-dimethylformamide, 15.9 mL) and mixed. Thereafter, vacuum degassing and nitrogen replacement in the flask were repeated three times. After adding tris(dibenzylideneacetone)dipalladium (0.018 g, 0.020 mmol) and tri(o-tolyl)phosphine (0.024 g, 0.080 mmol) to the flask, the flask was degassed under reduced pressure. Nitrogen substitution was repeated three times. After reacting the contents of the flask at 100° C. for 4 hours under a nitrogen atmosphere, the precipitated solid (crude product) was filtered off. The obtained crude product (filtrate) was heated in chlorobenzene at 140°C for 1 hour, then filtered while hot, and the obtained solid (filtrate) was purified by sublimation under reduced pressure to obtain compound 10. Ta.

<Synthesis of compound 12>
Compound 12 used in the test described below was synthesized according to the scheme below.

Under a nitrogen atmosphere, compound (12-a) (0.397 g, 1.00 mmol), compound (12-b) (0.543 g, 1.50 mmol), and cesium carbonate (0.489 g, 1.50 mmol) were placed in a three-necked flask. , THF (tetrahydrofuran, 10 mL), and water (1 mL) were added and mixed. Thereafter, vacuum degassing and nitrogen replacement in the flask were repeated three times. After adding [1,1-bis(diphenylphosphino)ferrocene]dichloropalladium (0.037 g, 0.050 mmol) to the flask, vacuum degassing and nitrogen replacement in the flask were repeated three times. After reacting the contents of the flask at 100° C. for 5 hours under a nitrogen atmosphere, the precipitated solid (crude product) was filtered off. The obtained crude product (filtrate) was suspended and washed with 20 mL of water, heated in chlorobenzene at 140°C for 1 hour, filtered while hot, and the obtained solid (filtrate) was sublimated under reduced pressure. Compound 12 was obtained by purification.

The above-mentioned compounds 4, 10, and 12 correspond to specific compounds.
Other specific compounds were also synthesized with reference to the synthesis method described above.
The measurement results of each synthesized specific compound by ESI-MS (electrospray ionization mass spectrometry) were as follows.

＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
Compound ESI-MS measurement results (m/z (M ⁺ ))
－－－－－－－－－－－－－－－－－－－－－－－－－－
1 591.93
2 596.00
3 603.85
4 591.93
5 721.85
6 649.89
7 677.92
8 545.92
9 809.97
10 738.00
11 636.03
12 634.04
13 766.04
14 680.05
15 591.93
16 634.04
17 703.88
18 691.96
19 738.00
20 884.18
21 747.98
22 848.09
23 813.87
24 731.87
25 797.78
26 786.07
27 744.00
28 709.90
29 574.88
30 700.95
31 790.04
32 677.95
33 786.03
34 791.93
35 842.03
36 796.06
37 696.03
38 766.04
39 861.86
40 826.12
41 724.15
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝

Compounds 1 to 41, which are specific compounds, and compounds R1 to R3, which are comparative compounds, are shown below.
Hereinafter, the specific compound and the comparative compound are also collectively referred to as evaluation compounds.

[Dye (evaluation pigment)]
The dyes shown below were used as evaluation dyes for evaluation in Examples and in the production of photoelectric conversion elements to be described later.

[N-type semiconductor material]
Fullerene C60 was used as an n-type semiconductor material for evaluation in Examples and in the production of a photoelectric conversion element to be described later.

[test]
<Example and comparative example: Production of photoelectric conversion element>
A photoelectric conversion element having the form shown in FIG. 2 was produced using the obtained compound. Here, the photoelectric conversion element includes a lower electrode 11, an electron blocking film 16A, a photoelectric conversion film 12, a hole blocking film 16B, and an upper electrode 15.
Specifically, amorphous ITO is formed into a film by sputtering on a glass substrate to form a lower electrode 11 (thickness: 30 nm), and the following compound (C-1) is further deposited on the lower electrode 11 in a vacuum. A film was formed by heating vapor deposition to form an electron blocking film 16A (thickness: 10 nm).
Furthermore, with the temperature of the substrate controlled at 25° C., an evaluation compound (any of the evaluation compounds described above), an n-type semiconductor material (fullerene C60), and optionally A dye (one of the evaluation dyes mentioned above) was set at a deposition rate of 2.0 Å/sec, and a film was co-deposited using a vacuum evaporation method so that each layer had a thickness of 100 nm in terms of a single layer, and the total film thickness was determined. A photoelectric conversion film 12 was formed as a mixed layer with a thickness of 300 nm or 200 nm (photoelectric conversion film forming step).
Further, the following compound (C-2) was deposited on the photoelectric conversion film 12 to form a hole blocking film 16B (thickness: 10 nm).
Further, amorphous ITO was deposited on the hole blocking film 16B by sputtering to form the upper electrode 15 (transparent conductive film) (thickness: 10 nm). After forming an SiO film as a sealing layer on the upper electrode 15 by a vacuum evaporation method, an aluminum oxide (Al ₂ O ₃ ) layer was formed thereon by an ALCVD (Atomic Layer Chemical Vapor Deposition) method. Alternatively, a photoelectric conversion element (also simply referred to as "element") of a comparative example was produced.

<Evaluation of photoelectric conversion efficiency (sensitivity)>
The driving of each element obtained was confirmed. A voltage was applied to each element so that the electric field strength was 2.0×10 ⁵ V/cm. Thereafter, light was irradiated from the upper electrode (transparent conductive film) side to evaluate the photoelectric conversion efficiency (external quantum efficiency) at a wavelength of 500 nm. The external quantum efficiency was measured using a constant energy quantum efficiency measurement device manufactured by Optel. The amount of light irradiated was 50 μW/cm ² .
"AA" if the external quantum efficiency is 95% or more, "A" if it is 92% or more and less than 95%, "B" if it is 90% or more and less than 92%, and "B" if it is 87% or more and less than 90%. Sensitivity was evaluated as "C", "D" for 85% or more and less than 87%, "E" for 82% or more and less than 85%, and "F" for less than 82%.
Practically speaking, it is preferable that the evaluation be "D" or higher.

<Measurement of responsiveness>
Using each of the obtained elements, the following responsiveness evaluation was performed.
Specifically, a voltage was applied to the element to have an intensity of 2.0×10 ⁵ V/cm. Thereafter, an LED (light emitting diode) was turned on momentarily to irradiate light from the upper electrode (transparent conductive film) side, and the photocurrent at that time was measured with an oscilloscope. At this time, the intensity of the current (signal strength) before irradiation with light is 0%, and the maximum signal strength measured by irradiation with light is 100%, and the signal strength after irradiation with light is from 0% to 100%. The time required to reach 97% (rise time) was determined for each element.
When the rise time of the element of Comparative Example 1 was set to 1, the relative value of the rise time of each element was determined.
In addition, when the above relative value of the rise time is less than 0.10, it is "AA", when it is 0.10 or more and less than 0.15, it is "A", and when it is 0.15 or more and less than 0.20, it is "B". , "C" for 0.20 or more and less than 0.25, "D" for 0.25 or more and less than 0.30, "E" for 0.30 or more and less than 1.00, and "E" for 0.30 or more and less than 1.00. The response was evaluated as "F" in the case of .
Practically, it is preferable that it is "D" or higher.

<Evaluation of heat resistance>
Each of the obtained devices was heat-treated at 160° C. for 1 hour in a glove box. Thereafter, the external quantum efficiency was evaluated in the same manner as in <Evaluation of photoelectric conversion efficiency (sensitivity)> described above. The external quantum efficiency before the heat treatment was set as 1, and the relative value of the external quantum efficiency after the same element was heat treated was calculated.
If the above relative value is 0.99 or more, "AA", if it is 0.98 or more and less than 0.99, "A", if it is 0.97 or more and less than 0.98, "B", or 0.96 or more. "C" if less than 0.97, "D" if 0.95 or more and less than 0.96, "E" if 0.90 or more and less than 0.95, "F" if less than 0.90 The heat resistance was evaluated as follows.
Practically speaking, it is desirable to have an evaluation of "D" or higher.

Table 1 below shows the characteristics of the photoelectric conversion element of each Example or Comparative Example and the results of tests conducted using the photoelectric conversion element of each Example or Comparative Example.
In the table, the "Type" column in the "Compound" column indicates the type of compound used as an evaluation compound in the production of the device.
The "D" column in the "Compound" column indicates that when a specific compound is used as an evaluation compound, the group represented by D in the specific compound is represented by formula (1-1) to formula (1-11). Indicates which group it is. When there are multiple types of groups represented by D, the "Compound" column indicates which of the groups represented by formulas (1-1) to (1-11) each of the multiple Ds is. "A" column indicates, when a specific compound is used as an evaluation compound, the group represented by A in the specific compound is any of the groups represented by formulas (3-1) to (3-9). Show that. When there are multiple types of groups represented by A, indicate which of the groups represented by formulas (3-1) to (1-9) is for the multiple A's.
The "Ar1/Ar3" column in the "Compound" column indicates that when a specific compound is used as an evaluation compound, Ar in the groups represented by (-Ar-) _n1 and (-Ar-) _n3 in the specific compound is , formula (2-1) and formula (2-2). If the values of n1 and n3 are 0, nothing is written.
The "Ar2" column in the "Compound" column indicates that when a specific compound is used as an evaluation compound, Ar in the group represented by (-Ar-) _n2 in the specific compound is the formula (2-1) and the formula Indicates which group is represented by (2-2). If the value of n2 is 0, nothing is written.
The "Symmetry" column in the "Compound" column indicates whether or not the specific compound has a symmetric structure when the specific compound is used as an evaluation compound. If the structure is symmetrical, it is marked as "A", and if it is not, it is marked as "B".
The "dye" and "n-type semiconductor material" columns indicate the type of dye or n-type semiconductor material used in the fabrication of the device, respectively. Note that in Example 42, no dye was used in the fabrication of the device.

From the results shown in Table 1, it was confirmed that the photoelectric conversion element of the present invention using a specific compound in the photoelectric conversion film has excellent effects of the present invention.
On the other hand, when a compound different from the specific compound was used, the resulting photoelectric conversion element was inferior in sensitivity, responsiveness, and heat resistance compared to the electric conversion element of the present invention.

From the results shown in the table, it was confirmed that it is preferable for the photoelectric conversion film to contain a dye, since the effects of the present invention are more excellent (see comparison of the results of Example 10 and Example 42, etc.).

It was confirmed that it is preferable that the specific compound has a symmetrical structure in order to obtain better effects of the present invention.

It has been confirmed that n1 to n3 in formula (1) preferably represent 0 in order to obtain better effects of the present invention.

In view of the superior effects of the present invention, the group represented by D in formula (1) is selected from formulas (1-1) to (1-6) and formulas (1-8) to (1- It is preferably a group represented by any one of formulas (1-1) to (1-6) and formula (1-8). More preferably, it is a group represented by any one of formula (1-1), formula (1-4) to formula (1-6), and formula (1-8); It was confirmed that the group represented by -6) is particularly preferable (in Examples 1 to 23 and 31 to 41, the group corresponding to A in the specific compound is a group represented by the same formula) (See comparison of results between Examples, etc.).

From the viewpoint that the effect of the present invention is more excellent, the group represented by A in formula (1) is selected from formula (3-2), formula (3-3), formula (3-5), and formula (3-6). , formula (3-8), and formula (3-9) are preferable, and formula (3-2), formula (3-5), and formula (3- It was confirmed that a group represented by any one of formula (3-8) is more preferable, and a group represented by formula (3-8) is even more preferable (in Examples 1 to 23 and 31 to 41). , Comparison of results between Examples in which the group corresponding to D in a specific compound is a group represented by the same formula, etc.).

10a, 10b Photoelectric conversion element 11 Conductive film (lower electrode)
12 Photoelectric conversion film 15 Transparent conductive film (upper electrode)
16A Electron blocking film 16B Hole blocking film

Claims (28)

A photoelectric conversion element having a conductive film, a photoelectric conversion film, and a transparent conductive film in this order,
A photoelectric conversion element, wherein the photoelectric conversion film contains a compound represented by formula (1).
In formula (1), D is a group represented by any one of formulas (1-1) to (1-11).
Ar is a group represented by formula (2-1) or formula (2-2).
A is a group represented by any one of formulas (3-1) to (3-9).
n1, n2, and n3 each independently represent an integer of 0 to 2.
However, when the compound represented by the formula (1) has a symmetrical structure, n2 represents 0 or 1. When the compound represented by the formula (1) has an asymmetric structure, the compound represented by the formula (1) is the compound (29) or the compound (30).
In formulas (1-1) to (1-11), * represents the bonding position.
X represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One of Y ¹ and Y ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One of Y ³ and Y ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One of Y ⁵ and Y ⁶ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One of Y ⁷ and Y ⁸ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One or more of -CH= contained in the ring structure in the group represented by D in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
In formula (2-1) and formula (2-2), * represents the bonding position.
X ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One or more of -CH= contained in the ring structure in the group represented by Ar in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
In formulas (3-1) to (3-9), * represents the bonding position.
B ¹ and B ² each independently represent a sulfur atom, an oxygen atom, =C(CN) ₂ or =C(CN)(CO ₂ R ¹ ). R ¹ represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
E represents an aromatic ring which may have a group selected from the group consisting of a halogen atom, a methyl group, an ethyl group, and a methoxy group as a substituent. The methyl group, the ethyl group, and the methoxy group may further have a halogen atom as a substituent.
R represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
G represents -CR ^G = or -N=. R ^G represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
However, at least one of the five G's in formula (3-8) represents -N= or -CR ^G =, and R ^G is a halogen atom, a cyano group, or a substituent. Represents an alkyl group having 1 to 2 carbon atoms that may have a halogen atom.
X ³ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
ArL is a group represented by any one of formulas (Ar1) to (Ar3).
In formulas (Ar1) to (Ar3), * represents the bonding position.
X ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
Y ⁹ represents -CH=, -CR ² =, or -N=. R ² represents a halogen atom or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
The photoelectric conversion element according to claim 1, wherein n1, n2, and n3 represent 0. The photoelectric conversion element according to claim 1 or 2, wherein the compound represented by formula (1) has a symmetrical structure. Any one of claims 1 to 3, wherein D is a group represented by any one of formulas (1-1) to (1-6) and formulas (1-8) to (1-11). The photoelectric conversion element according to item 1. The photovoltaic device according to any one of claims 1 to 4, wherein D is a group represented by any one of formulas (1-1) to (1-6) and formula (1-8). conversion element. Any one of claims 1 to 5, wherein D is a group represented by any one of formula (1-1), formula (1-4) to formula (1-6), and formula (1-8). The photoelectric conversion element according to item 1. The photoelectric conversion element according to any one of claims 1 to 6, wherein D is a group represented by formula (1-6). A is any of formula (3-2), formula (3-3), formula (3-5), formula (3-6), formula (3-8), and formula (3-9). The photoelectric conversion element according to any one of claims 1 to 7, which is a group represented by the following formula. The photovoltaic device according to any one of claims 1 to 8, wherein A is a group represented by any one of formula (3-2), formula (3-5), and formula (3-8). conversion element. The photoelectric conversion element according to any one of claims 1 to 9, wherein A is a group represented by formula (3-8). The photoelectric conversion element according to any one of claims 1 to 10, wherein the compound represented by formula (1) has a molecular weight of 400 to 900. The photoelectric conversion element according to any one of claims 1 to 11, wherein the photoelectric conversion film further contains a dye. The photoelectric conversion element according to claim 12, wherein the photoelectric conversion film is a mixed layer formed by mixing the compound represented by the formula (1) and the dye. The photoelectric conversion element according to claim 1, further comprising one or more intermediate layers in addition to the photoelectric conversion film between the conductive film and the transparent conductive film. The photoelectric conversion element according to any one of claims 1 to 14, wherein the photoelectric conversion film further contains an n-type semiconductor material. The photoelectric conversion element according to claim 15, wherein the n-type semiconductor material contains fullerenes selected from the group consisting of fullerenes and derivatives thereof. An imaging device comprising the photoelectric conversion device according to any one of claims 1 to 16. An optical sensor comprising the photoelectric conversion element according to any one of claims 1 to 16. A compound represented by formula (1).
In formula (1), D is a group represented by any of formulas (1-1) to (1-6) and formulas (1-8) to (1-11).
Ar is a group represented by formula (2-1) or formula (2-2).
A is a group represented by any one of formulas (3-1) to (3-9).
n1, n2, and n3 each independently represent an integer of 0 to 2.
However, when the compound represented by the formula (1) has a symmetrical structure, n2 represents 0 or 1. When the compound represented by the formula (1) has an asymmetric structure, the compound represented by the formula (1) is the compound (29) or the compound (30).
In formulas (1-1) to (1-6) and formulas (1-8) to (1-11), * represents the bonding position.
X represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One of Y ¹ and Y ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One of Y ³ and Y ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom, and the other represents -CH=.
One or more of -CH= contained in the ring structure in the group represented by D in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
In formula (2-1) and formula (2-2), * represents the bonding position.
X ² represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
One or more of -CH= contained in the ring structure in the group represented by Ar in formula (1) may be replaced with -CR ³ =. R ³ represents a halogen atom.
In formulas (3-1) to (3-9), * represents the bonding position.
B ¹ and B ² each independently represent a sulfur atom, an oxygen atom, =C(CN) ₂ or =C(CN)(CO ₂ R ¹ ). R ¹ represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
E represents an aromatic ring which may have a group selected from the group consisting of a halogen atom, a methyl group, an ethyl group, and a methoxy group as a substituent. The methyl group, the ethyl group, and the methoxy group may further have a halogen atom as a substituent.
R represents an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
G represents -CR ^G = or -N=. R ^G represents a hydrogen atom, a halogen atom, a cyano group, or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
However, at least one of the five G's in formula (3-8) represents -N= or -CR ^G =, and R ^G is a halogen atom, a cyano group, or a substituent. Represents an alkyl group having 1 to 2 carbon atoms that may have a halogen atom.
X ³ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
ArL is a group represented by any one of formulas (Ar1) to (Ar3).
In formulas (Ar1) to (Ar3), * represents the bonding position.
X ⁴ represents a sulfur atom, an oxygen atom, a selenium atom, or a tellurium atom.
Y ⁹ represents -CH=, -CR ² =, or -N=. R ² represents a halogen atom or an alkyl group having 1 to 2 carbon atoms which may have a halogen atom as a substituent.
20. A compound according to claim 19, wherein n1, n2 and n3 represent 0. 21. The compound according to claim 19 or 20, which has a symmetric structure. The compound according to any one of claims 19 to 21, wherein D is a group represented by any one of formulas (1-1) to (1-6) and formula (1-8). . Any one of claims 19 to 22, wherein D is a group represented by any one of formula (1-1), formula (1-4) to formula (1-6), and formula (1-8). The compound according to item 1. The compound according to any one of claims 19 to 23, wherein D is a group represented by formula (1-6). A is any of formula (3-2), formula (3-3), formula (3-5), formula (3-6), formula (3-8), and formula (3-9). A compound according to any one of claims 19 to 24, which is a group represented by: The compound according to any one of claims 19 to 25, wherein A is a group represented by any one of formula (3-2), formula (3-5), and formula (3-8). . The compound according to any one of claims 19 to 26, wherein A is a group represented by formula (3-8). Compound according to any one of claims 19 to 27, having a molecular weight of 400 to 900.