Compound, hole transport material, hole transport material for perovskite solar cell, perovskite solar cell, structure, and method for producing perovskite solar cell

Abstract

The present invention provides a compound represented by formula (X). R1 is H or a hydrocarbon group; R2 is an alkoxy group or an alkylthio group; Y2 is N or P; each of C1, C3, and C4 is C; n is 2 or 4; when n is 2, X is any of group (X3) to group (X6) and Y1 is a halogen; and when n is 4, X is group (X1) or group (X2) and Y1 is H or a hydrocarbon group.

Description

Compound, hole transport material, hole transport material for perovskite solar cell, perovskite solar cell, structure, and method for manufacturing perovskite solar cell

[0001] The present disclosure relates to compounds, hole transport materials, hole transport materials for perovskite solar cells, perovskite solar cells, structures, and methods for manufacturing perovskite solar cells.

[0002] In response to growing societal demands for carbon neutrality, there is a need for further expansion of solar power generation. However, currently widespread silicon solar cells have high manufacturing costs and limited installation locations. For this reason, there is a demand for new ultra-lightweight solar cells that can be installed on building walls and windows, as well as factory roofs with low load-bearing capacity, which have been difficult to install in urban areas until now.

[0003] Perovskite solar cells have been developed as an alternative to silicon solar cells. Perovskite solar cells are solar cells that use a metal halide material with a perovskite structure as the light absorption layer. These perovskite solar cells can be manufactured by solution coating, which reduces manufacturing costs and allows them to be formed on curved surfaces.

[0004] An example of the structure of a perovskite solar cell is shown in Figure 1. Figure 1 is a schematic cross-sectional view conceptually illustrating an example of a normal-type perovskite solar cell. As shown in Figure 1, the structure of a perovskite solar cell is such that a layered structure in which a hole transport layer 7 and an electron transport layer 5 are stacked above and below a perovskite layer 6 is sandwiched between electrodes 8 and 4. The operating principle of a perovskite solar cell is that first, holes and electrons are generated by light absorption in the perovskite layer 6. The generated holes and electrons move to the hole transport layer 7 and the electron transport layer 5, respectively, and then further move through these layers to the electrodes 8 and 4.

[0005] The hole transport layer of a perovskite solar cell contains a hole transport material, known as Spiro-OMeTAD, which has the following structure:

[0006]

[0007] Hole transport materials that can replace Spiro-OMeTAD have also been proposed (see, for example, Patent Documents 1 and 2).

[0008] Patent Document 1: International Publication No. 2020 / 036069 Patent Document 2: Chinese Patent No. 115700248

[0009] Perovskite solar cells having a hole transport layer containing a hole transport material are evaluated by their power conversion efficiency (PCE). Examples of PCE include initial PCE and PCE after a durability test. Here, the initial PCE refers to the PCE of a perovskite solar cell after fabrication but before a durability test, and the PCE after a durability test refers to the PCE of a perovskite solar cell after the durability test. The durability test refers to a test in which a perovskite solar cell is left standing under high-temperature (e.g., 85°C) conditions for a certain period of time (e.g., 50 hours or more). As described above, hole transport materials for perovskite solar cells have been known. However, there is a need for perovskite solar cells that contain a hole transport material other than the conventional hole transport materials described above and that have excellent initial PCE and / or PCE after a durability test.

[0010] One aspect of the present disclosure aims to provide a hole transport material with which a solar cell (e.g., a perovskite solar cell) having excellent at least one of an initial PCE and a PCE after a durability test can be produced. Another aspect of the present disclosure aims to provide a hole transport material for a perovskite solar cell with which a perovskite solar cell having excellent at least one of an initial PCE and a PCE after a durability test can be produced. Another aspect of the present disclosure aims to provide a perovskite solar cell having excellent at least one of an initial PCE and a PCE after a durability test. Another aspect of the present disclosure aims to provide a structure including a perovskite solar cell having excellent at least one of an initial PCE and a PCE after a durability test. Another aspect of the present disclosure aims to provide a method for producing a perovskite solar cell with which a perovskite solar cell having excellent at least one of an initial PCE and a PCE after a durability test can be produced. Another aspect of the present disclosure aims to provide a compound having a novel structure.

[0011] Specific means for solving the above problems are as follows: <1> A compound represented by the following formula (X):

[0012]

[0013] In formula (X), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms, and a plurality of Y ２ are each independently a nitrogen atom or a phosphorus atom, and a plurality of C １ are all carbon atoms, n is 2 or 4, when n is 2, X is any one of the groups (X3) to (X6), and a plurality of Y １ are each independently a halogen atom, and when n is 4, X is a group (X1) or a group (X2), and a plurality of Y １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms.１ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of Y ２ are each independently a nitrogen atom or a phosphorus atom, ３ and C ４ In the group (X1), Z is a divalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, and C ３ -Z-C ４ In the group (X2), Z is a tetravalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, and C ３ =Z=C ４ In each of the groups (X3) to (X6), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms; ２ is a nitrogen atom or a phosphorus atom, and two Y ３ are each independently an oxygen atom or a sulfur atom, and two *'s each represent a bonding position.

[0014] <2> The compound according to <1>, wherein X is the group (X5) or the group (X6) when n is 2. <3> The compound according to <1> or <2>, wherein Z in the group (X1) is any one of the following groups (Z11) to (Z19), the following group (Z19A), and the following group (Z19B), and wherein Z in the group (X2) is the following group (Z21).

[0015]

[0016] In each of the groups (Z11) to (Z19), the group (Z19A), the group (Z19B), and the group (Z21), a plurality of R １are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms; ２ is a nitrogen atom or a phosphorus atom, and a plurality of Y ３ are each independently an oxygen atom or a sulfur atom, and two *'s each represent a bonding position.

[0017] <4> The compound according to <3>, wherein Z in the group (X1) is the group (Z11), the group (Z12), the group (Z14), the group (Z16), the group (Z17), the group (Z19A), or the group (Z19B), and Z in the group (X2) is the group (Z21).

[0018] <5> The compound according to <3> or <4>, wherein Z in the group (X1) is the group (Z16), the group (Z17), the group (Z19A), or the group (Z19B). <6> The compound according to any one of <3> to <5>, wherein Z in the group (X1) is the group (Z19A) or the group (Z19B). <7> The compound according to <1>, wherein n is 4, and X is the group (X1) or the group (X2). <8> When n in formula (X) is 2, a plurality of Y １ are all fluorine atoms, and a plurality of Y in each of the formula (X), the group (X1), and the group (X2) ２ are all nitrogen atoms, and in each of the groups (X3) to (X6), two Y ３ at least one of the R １ are all hydrogen atoms, and ２are each independently an unsubstituted alkoxy group having 1 or 2 carbon atoms, or an unsubstituted alkylthio group having 1 or 2 carbon atoms. <9> A hole transport material comprising the compound according to any one of <1> to <8>. <10> A hole transport material for perovskite solar cells comprising the compound according to any one of <1> to <8>. <11> A perovskite solar cell comprising a hole transport layer comprising the compound according to any one of <1> to <8>. <12> A structure comprising the perovskite solar cell according to <11>. <13> A method for producing a perovskite solar cell, comprising: forming a hole transport layer comprising the compound according to any one of <1> to <8>, to obtain components comprising the hole transport layer; storing the components for 1 hour to 48 hours from the completion of formation of the hole transport layer; and sealing the components after the storage.

[0019] According to one aspect of the present disclosure, there is provided a hole transport material capable of producing a solar cell (e.g., a perovskite solar cell) having excellent at least one of an initial PCE and a PCE after a durability test. According to another aspect of the present disclosure, there is provided a hole transport material for a perovskite solar cell capable of producing a perovskite solar cell having excellent at least one of an initial PCE and a PCE after a durability test. According to another aspect of the present disclosure, there is provided a perovskite solar cell having excellent at least one of an initial PCE and a PCE after a durability test. Another aspect of the present disclosure provides a structure including a perovskite solar cell having excellent at least one of an initial PCE and a PCE after a durability test. Another aspect of the present disclosure provides a method for producing a perovskite solar cell, capable of producing a perovskite solar cell having excellent at least one of an initial PCE and a PCE after a durability test. Another aspect of the present disclosure provides a compound having a novel structure.

[0020] 1A and 1B are schematic cross-sectional views conceptually showing an example of a forward-type perovskite solar cell, and 1C are schematic cross-sectional views conceptually showing an example of an inverted-type perovskite solar cell.

[0021] The present disclosure will be described below. However, while the following description of the constituent elements may be based on representative embodiments of the present disclosure, the present disclosure is not limited to such embodiments. In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the upper and lower limits. In the numerical ranges described in stages in the present disclosure, the upper or lower limit described in a certain numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in the present disclosure, the upper or lower limit described in a certain numerical range may be replaced with a value shown in the Examples. In the present disclosure, a combination of preferred embodiments is a more preferred embodiment. In the present disclosure, when multiple substances corresponding to each component are present in the composition, the amount of each component refers to the total amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, "contains primarily" means that the target substance is contained in the largest amount relative to the whole. For example, this means that the content of the target substance is 50% by mass or more as a percentage of the whole. In this disclosure, "mass %" and "weight %" are synonymous, and "parts by mass" and "parts by weight" are synonymous. In this disclosure, "%" indicating the amount of a component is based on mass unless otherwise specified. In the chemical formulas in this disclosure, "*" indicates a bond position, "Me" indicates a methyl group, and "Et" indicates an ethyl group.

[0022] [Compound represented by formula (X), hole transport material] The compound of the present disclosure is also referred to as a compound represented by formula (X) (hereinafter, "compound (X) of the present disclosure" or simply "compound (X)").

[0023]

[0024] In formula (X), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms, and a plurality of Y ２are each independently a nitrogen atom or a phosphorus atom, and a plurality of C １ are all carbon atoms, n is 2 or 4, when n is 2, X is any one of the groups (X3) to (X6), and a plurality of Y １ are each independently a halogen atom, and when n is 4, X is a group (X1) or a group (X2), and a plurality of Y １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms. １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of Y ２ are each independently a nitrogen atom or a phosphorus atom, ３ and C ４ In the group (X1), Z is a divalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, and C ３ -Z-C ４ In the group (X2), Z is a tetravalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, and C ３ =Z=C ４ In each of the groups (X3) to (X6), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms; ２ is a nitrogen atom or a phosphorus atom, and two Y ３ are each independently an oxygen atom or a sulfur atom, and two *'s each represent a bonding position.

[0025] Compound (X) is useful as a hole transport material (preferably a hole transport material for solar cells, more preferably a hole transport material for perovskite solar cells). That is, the hole transport material (preferably a hole transport material for solar cells, more preferably a hole transport material for perovskite solar cells) of the present disclosure contains compound (X). Solar cells (e.g., perovskite solar cells; the same applies hereinafter) containing the hole transport material of the present disclosure are excellent in at least one of initial PCE and PCE after a durability test.

[0026] In this disclosure, the PCE (Power Conversion Efficiency) in the initial PCE and the PCE after the durability test is a value indicating the energy conversion efficiency, and is calculated based on the standard solar energy on the ground (100 mW / cm at AM1.5G). ２ The output efficiency is the ratio of the maximum output power of the solar cell to the maximum power output of the solar cell, expressed as a percentage. Specifically, it is calculated using the following formula (A):

[0027] PCE (%) = (Jsc (mA / cm ２ )×Voc(V)×FF / 100(mW / cm ２ ))×100...Formula (A)

[0028] In formula (A), Jsc is the short-circuit current (the current that flows when the solar cell circuit is short-circuited (voltage is zero) under light irradiation conditions, divided by the electrode area. The unit is "mA / cm ２ "), Voc is the open-circuit voltage (the potential difference generated across the two ends of the solar cell circuit when the solar cell circuit is in an open state (current is zero) under irradiated conditions; the unit is "V"), and FF is the fill factor (the ratio of the maximum power generated by the solar cell under irradiated conditions to the product of the short-circuit current and the open-circuit voltage; the unit is dimensionless). A higher PCE value indicates a higher energy conversion efficiency. Solar cells including a hole transport layer containing compound (X) of the present disclosure are excellent in at least one of initial PCE and PCE after a durability test.

[0029] The reason why the compound (X) has the above-mentioned effect is thought to be that the compound (X) has the above-mentioned structure, which allows holes to move efficiently inside the compound (X) and suppresses deterioration of the compound (X) during power generation. Such an effect is due to the fact that in the compound (X), the skeleton part of the compound, when n is 2, Y １ is a halogen atom and R ２ is an alkoxy group or an alkylthio group, and the overall structure of the compound when n is 4 is thought to contribute to this.

[0030] <Formula (X) when n is 2; Formula (Xn2)> Formula (X) when n is 2 can be rewritten as the following formula (Xn2). In the present disclosure, a compound represented by the following formula (Xn2) may be referred to as compound (Xn2).

[0031]

[0032] In the compound (Xn2), R ２ has an electron donating function, and Y １ It is considered that R has an electron-withdrawing function and X has an electron-transfer function. ２ is a battery donor group (specifically, an alkoxy group or an alkylthio group), and Y １ is an electron-withdrawing group (specifically, a halogen atom), and X is any one of the groups (X3) to (X6). In the compound (Xn2), these structures ensure molecular planarity, which improves hole mobility within the compound, and as a result, it is believed that the above-mentioned effect (i.e., at least one of the initial PCE and the PCE after the durability test) is obtained.

[0033] <Formula (X) when n is 4: Formula (Xn4X1) and Formula (Xn4X2)> Formula (X) in an embodiment where n is 4 and X is a group (X1) can be rewritten as the following formula (Xn4X1). In the present disclosure, a compound represented by the following formula (Xn4X1) may be referred to as compound (Xn4X1).

[0034]

[0035] Formula (X) in an embodiment in which n is 4 and X is a group (X2) can be rewritten as the following formula (Xn4X2): In the present disclosure, a compound represented by the following formula (Xn4X2) may be referred to as compound (Xn4X2).

[0036]

[0037] In the compound (Xn4X1) and the compound (Xn4X2), R ２ has an electron-donating function. In the compound (Xn4X1) and the compound (Xn4X2), the group (X1) and the group (X2) form a structure with a broadened area. In the compound (Xn4X1) and the compound (Xn4X2), these structures are thought to improve the mobility of holes within the compound, resulting in the above-mentioned effect (i.e., at least one of the initial PCE and the PCE after the durability test).

[0038] <R １ In formula (X), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms. １ Specific examples of the substituted or unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms represented by the formula (I) include: a linear alkyl group having 1 to 3 carbon atoms, such as a methyl group, an ethyl group, or an n-propyl group; a monoalkyl-substituted alkyl group having 3 carbon atoms, such as an isopropyl group; a cyclic alkyl group having 3 carbon atoms, such as a 1,1,2-trimethylpropyl group or a 1,2,2-trimethylpropyl group; and the like. R １ is preferably a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 2 carbon atoms, and more preferably a hydrogen atom.

[0039] <R ２ In formula (X), a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms, or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms. ２ Specific examples of the substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms represented by the formula (I) include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group. ２As the substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms represented by the formula (I), an unsubstituted alkoxy group having 1 to 5 carbon atoms is preferable, an unsubstituted alkoxy group having 1 to 3 carbon atoms is more preferable, and a methoxy group is even more preferable.

[0040] R ２ Specific examples of the substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms represented by the formula (I) include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, and a pentylthio group. ２ The substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms represented by the following formula is preferably an unsubstituted alkylthio group having 1 to 5 carbon atoms, more preferably an unsubstituted alkylthio group having 1 to 3 carbon atoms, and even more preferably a methylthio group.

[0041] <Y ２ In formula (X), a plurality of Y ２ are each independently a nitrogen atom or a phosphorus atom. ２ is preferably a nitrogen atom.

[0042] From the viewpoint of improving PCE after durability test, multiple Y ２ At least one of the Y ２ It is preferred that all of the groups are nitrogen atoms.

[0043] <n> In formula (X), n is 2 or 4.

[0044] <Y when n is 2 １ In formula (X), when n is 2 (i.e., in formula (Xn2)), a plurality of Y １ are each independently a halogen atom. １ The halogen atom represented by the formula (I) is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, more preferably a fluorine atom, a chlorine atom, or a bromine atom, even more preferably a fluorine atom or a chlorine atom, and still more preferably a fluorine atom.

[0045] When n is 2, from the viewpoint of improving the PCE after the durability test, a plurality of Y １ At least one of the Y１ It is preferred that all of these are fluorine atoms.

[0046] <Y when n is 4 １ In the formula (X), when n is 4 (i.e., in the formula (Xn4X1) or the formula (Xn4X2)), a plurality of Y １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms. １ is R １ The same applies to the preferred embodiments.

[0047] <X when n is 2> In formula (X), when n is 2 (that is, in formula (Xn2)), X is any one of groups (X3) to (X6).

[0048]

[0049] In each of the groups (X3) to (X6), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms; ２ is a nitrogen atom or a phosphorus atom, and two Y ３ are each independently an oxygen atom or a sulfur atom, and two *'s each represent a bonding position.

[0050] In the formula (X), when n is 2, X has the above-described structure, so that the planarity of the compound (Xn2) is maintained, and the heteroatom (e.g., Y ３ It is believed that the lone electron pairs of the oxygen or sulfur atoms (represented by the formula: ##EQU1##) efficiently passivate defects in the adjacent perovskite layer. As a result, it is believed that the above-mentioned effects (i.e., at least one of the initial PCE and the PCE after the durability test) can be obtained.

[0051] When n is 2, X is any one of the groups (X3) to (X6). When n is 2, X (i.e., any one of the groups (X3) to (X6)) has two Y３ Preferably, at least one of the two Y ３ It is more preferable that two of them are sulfur atoms. That is, when n is 2, X (i.e., any one of the groups (X3) to (X6)) preferably contains one or more thiophene rings, and more preferably contains two thiophene rings.

[0052] When n is 2 (i.e., in formula (Xn2)), X (i.e., any one of the groups (X3) to (X6)) is C １ -X-C １ The shortest number of bonds connecting these is 6 or 7.

[0053] In the present disclosure, C １ -X-C １ The shortest number of bonds connecting C １ -X-C １ In the present disclosure, the "number of bonds" in counting the number of shortest bonds refers to the number of single bonds, double bonds, or triple bonds. That is, in counting the number of shortest bonds, one double bond and one triple bond are both counted as one bond.

[0054] As mentioned above, C １ -X-C １ is 6 or 7. From the viewpoint of improving the PCE after durability test, the above-mentioned minimum number of bonds is preferably 6.

[0055] Specific examples of X when n is 2 (i.e., in formula (Xn2)) are shown below. However, when n is 2 (i.e., in formula (Xn2)), X is not limited to the following specific examples.

[0056]

[0057] When n is 2 (that is, in formula (Xn2)), X is preferably a group (X5) or a group (X6), and more preferably a group (X5a) shown below.

[0058]

[0059] <X when n is 4> When n is 4, X is the following group (X1) or the following group (X2).

[0060]

[0061] In each of the group (X1) and the group (X2), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of Y ２ are each independently a nitrogen atom or a phosphorus atom, ３ and C ４ In the group (X1), Z is a divalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, and C ３ -Z-C ４ In the group (X2), Z is a tetravalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, and C ３ =Z=C ４ is a tetravalent organic group in which the shortest number of bonds connecting R is 3 to 20. １ The preferred embodiments are as described above.

[0062] In the group (X1), Z is a divalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, ３ -Z-C ４ is a divalent organic group having a minimum number of bonds connecting 3 to 20.

[0063] In the group (X2), Z is a tetravalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, ３ =Z=C ４ is a tetravalent organic group in which the shortest number of bonds connecting the above is 3 to 20.

[0064] In the present disclosure, C ３ -Z-C ４ The shortest number of bonds connecting C ３ -Z-C ４As mentioned above, when counting the number of shortest bonds, one double bond and one triple bond are both counted as one bond. ３ =Z=C ４ The meaning of the shortest number of connections connecting is also the same.

[0065] C ３ -Z-C ４ The minimum number of bonds connecting the C is 3 to 20. ３ -Z-C ４ The minimum number of bonds connecting C is preferably 4 or more, more preferably 5 or more, and even more preferably 6 or more. ３ -Z-C ４ The minimum number of bonds connecting C is preferably 15 or less, more preferably 12 or less, even more preferably 10 or less, and even more preferably 9 or less. ３ -Z-C ４ The minimum number of bonds connecting the above is preferably 4 to 15, more preferably 5 to 12, even more preferably 5 to 10, and even more preferably 6 to 9.

[0066] C ３ =Z=C ４ The preferred range of the shortest number of bonds connecting ３ -Z-C ４ The preferred range of the shortest number of bonds connecting the two is the same as that.

[0067] Specific examples of Z in the group (X1) are shown below: However, Z in the group (X1) is not limited to the following specific examples.

[0068]

[0069]

[0070] Specific examples of Z in the group (X2) are shown below: However, Z in the group (X2) is not limited to the following specific examples.

[0071]

[0072] As the compound (X) of the present disclosure, from the viewpoint of more effectively obtaining the effects of the compound (X), a compound in which n is 4 and X is a group (X1) or a group (X2) is preferred (i.e., the compound (Xn4X1) or the compound (Xn4X2) is preferred).

[0073] Z in the group (X1) is preferably any one of the following groups (Z11) to (Z19), the following group (Z19A), and the following group (Z19B). Z in the group (X2) is preferably the following group (Z21).

[0074]

[0075] In each of the groups (Z11) to (Z19), the group (Z19A), the group (Z19B), and the group (Z21), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms; ２ is a nitrogen atom or a phosphorus atom, and a plurality of Y ３ are each independently an oxygen atom or a sulfur atom, and two *'s each represent a bonding position.

[0076] Z in the group (X1) is more preferably a group (Z11), a group (Z12), a group (Z14), a group (Z16), a group (Z17), a group (Z19A), or a group (Z19B), even more preferably a group (Z16), a group (Z17), a group (Z19A), or a group (Z19B), even more preferably a group (Z19A) or a group (Z19B), and even more preferably a group (Z19A).

[0077] <Exemplary Compounds When n is 2> Specific examples of compound (X) of the present disclosure when n is 2 [exemplary compounds (X-01) to (X-10)] are shown below. However, compound (X) of the present disclosure when n is 2 is not limited to the following specific examples. In the exemplary compounds of the present disclosure, Me and Et mean a methyl group and an ethyl group, respectively.

[0078]

[0079] <Exemplary Compounds When n is 4 and X is Group (X1)> Specific examples of the compound (X) of the present disclosure when n is 4 and X is group (X1) [exemplary compounds (X-101) to (X-115)] are shown below. However, the compound (X) of the present disclosure when n is 4 and X is group (X1) is not limited to the following specific examples.

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] A specific example of the compound (X) of the present disclosure, in which n is 4 and X is a group (X2) [exemplary compound (X-201)], is shown below.

[0086]

[0087] Compound (X) of the present disclosure can be synthesized by conventional techniques in organic synthetic chemistry, such as coupling and dehydrohalogenation. This will be explained in more detail in the Examples section below. Since it does not require the use of expensive raw materials, production costs can be reduced.

[0088] As a particularly preferred embodiment of the compound (X) of the present disclosure, when n in formula (X) is 2, a plurality of Y １ are all fluorine atoms, and a plurality of Y in each of formula (X), group (X1), and group (X2) ２ are all nitrogen atoms, and in any one of the groups (X3) to (X6), two Y ３ at least one (more preferably two) of R is a sulfur atom; and １ are all hydrogen atoms, and a plurality of R ２are each independently an unsubstituted alkoxy group having 1 or 2 carbon atoms, or an unsubstituted alkylthio group having 1 or 2 carbon atoms.

[0089] [Perovskite solar cell] The perovskite solar cell of the present disclosure comprises a hole transport layer containing the compound (X) of the present disclosure (or the hole transport material for perovskite solar cells of the present disclosure). The perovskite solar cell of the present disclosure may also contain other elements.

[0090] Specific examples of the perovskite solar cell of the present disclosure will be described below with reference to FIGS. 1 and 2.

[0091] Fig. 1 is a schematic cross-sectional view conceptually showing an example of a forward perovskite solar cell (forward structural element 1). Fig. 2 is a schematic cross-sectional view conceptually showing an example of an inverted perovskite solar cell (inverted structural element 2).

[0092] As shown in Figures 1 and 2, a perovskite solar cell typically comprises a substrate 3, a first electrode 4, a second electrode 8, a perovskite layer 6, a hole transport layer 7, and an electron transport layer 5. Perovskite solar cells include a forward structure element 1, in which the first electrode is a negative electrode and the second electrode is a positive electrode, and the substrate 3, the first electrode 4, the electron transport layer 5, the perovskite layer 6, the hole transport layer 7, and the second electrode 8 are stacked in this order, as shown in Figure 1, and an inverted structure element 2, in which the first electrode is a positive electrode and the second electrode is a negative electrode, and the substrate 3, the first electrode 4, the hole transport layer 7, the perovskite layer 6, the electron transport layer 5, and the second electrode 8 are stacked in this order, as shown in Figure 2. Note that the perovskite solar cell of the present disclosure preferably includes the forward structure element 1 shown in Figure 1.

[0093] <Substrate 3> There is no particular problem with the substrate 3 as long as it has the function of holding the layers laminated on the substrate, but a transparent substrate with a total light transmittance of 50% or more is preferable. Transparent substrates are not particularly limited, but examples thereof include glass and transparent resins such as acrylic resin, polyolefin resin, polyester resin, polycarbonate resin, and polyamide resin. The substrate 3 may be replaced by a first electrode.

[0094] <First Electrode 4> The first electrode 4 may be made of a material that is conductive and transmits light, such as tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), zinc oxide (ZnO), or tin oxide (SnO ２ Examples of suitable materials include indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), aluminum-doped zinc (AZO), and graphene. These materials may be used alone or in combination. They may also be used in combination with a non-transparent electrode material through patterning. The thickness of the first electrode 4 is, for example, 200 nm to 1200 nm. It is desirable to adjust the resistance value to 5 to 15 Ω / □. The first electrode 4 can be formed by vapor deposition, sputtering, or a coating method (e.g., spraying, spin coating, and dip coating). The first electrode 4 may be cleaned, ozone-treated, plasma-treated, or the like before the next layer is deposited thereon.

[0095] <Second Electrode 8> Examples of the second electrode 8 that can be used include: metals such as gold, silver, aluminum, copper, platinum, rhodium, indium, titanium, iron, nickel, tin, zinc, and molybdenum; oxides of the above-mentioned metals; alloys containing any of the above-mentioned metals; and conductive carbon materials. The second electrode 8 may be a single layer or a double layer using different materials. The material used for the first electrode 4 can also be used as the material for the second electrode 8. The thickness of the second electrode 8 is, for example, 50 nm to 100 nm. The second electrode 8 can be formed by vapor deposition, sputtering, or a coating method (e.g., spraying, spin coating, and dip coating).

[0096] <Perovskite Layer 6> The perovskite layer 6 is made of ABX ３ In this case, A is a monovalent cation, preferably an alkali metal cation or an organic cation, more preferably a cesium cation, a francium cation, or RNH ３ ＋(R is an alkyl group having 1 to 10 carbon atoms), or NH ２ CHNH ２ ＋ B is a divalent cation, preferably a divalent cation of a transition metal element or an element of Groups 13 to 15, more preferably Pb ２＋ , Sn ２＋ , or Ge ２＋ X is an anion, preferably a halogenated anion. A, B, and X may each be a single anion or a combination of two or more anions. Specifically, RNH ３ PbX ３ , R(NH ２ ) ２ PbX ３ , RNH ３ SnX ３ , R(NH ２ ) ２ SnX ３ (R is an alkyl group having 1 to 10 carbon atoms), and complexes of these with dimethylformamide. These may be used alone or in combination of two or more. The thickness of the perovskite layer 6 is, for example, 100 nm to 1200 nm. The perovskite layer 6 can be formed by dissolving the components that form the perovskite layer 6 in a solvent and applying the solution by spraying, spin coating, dip coating, die coating, or the like.

[0097] A passivation layer (not shown) may be provided on the perovskite layer 6 (i.e., between the perovskite layer 6 and the hole transport layer 7 in the normal structure device 1 shown in FIG. 1 , or between the perovskite layer 6 and the electron transport layer 5 in the inverted structure device 2 shown in FIG. 2 ). The passivation layer may contain a Lewis base, an organic salt compound, or the like. Examples of Lewis bases include heterocyclic compounds such as pyridine, quinoline, and pyridine-containing compounds (e.g., 9-(pyridin-4-yl)-9H-carbazole). Examples of organic salt compounds include ammonium halide salts such as phenethylamine hydroiodide (PEAI) and butylamine hydroiodide (BAI).

[0098] <Hole Transport Layer 7> The hole transport layer 7 contains the compound (X) of the present disclosure (or the hole transport material for perovskite solar cells of the present disclosure). The hole transport layer 7 may contain one or more types of the compound (X) of the present disclosure (or the hole transport material for perovskite solar cells of the present disclosure). The hole transport layer 7 is formed, for example, using a composition (hereinafter also referred to as a "hole transport layer-forming composition") containing the compound (X) of the present disclosure (or the hole transport material for perovskite solar cells of the present disclosure). Specifically, the hole transport layer 7 can be formed by applying the hole transport layer-forming composition by a spray method, a doctor blade method, a bar coating method, a spin coating method, a dip coating method, a die coating method, or the like, or by printing by a screen printing method. Thereafter, the solvent, described below, may be dried while heating as necessary. The thickness of the hole transport layer 7 may be, for example, 10 nm to 500 nm, or 50 nm to 200 nm. The hole transport layer-forming composition may contain a solvent. The solvent is not particularly limited as long as it can dissolve the compound (X) of the present disclosure. Examples of the solvent include hydrocarbon solvents, halogenated hydrocarbon solvents, aromatic solvents, and dimethyl sulfoxide. Halogenated hydrocarbon solvents are preferred, and 1,1,2,2-tetrachloroethane, chloroform, and chlorobenzene are more preferred. The hole transport layer-forming composition may further contain a dopant, but it does not necessarily need to. Examples of the dopant include p-type dopants such as lithium (fluorosulfonyl) (trifluoromethyl) imide, lithium bis(fluorosulfonyl) imide (Li-TFSI), FK209 [tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III) tris(bis(trifluoromethylsulfonyl)imide)], and lithium bis(trifluoromethanesulfonyl)imide. These may be used alone or in combination of two or more.The p-type dopant may include lithium bis(fluorosulfonyl)imide (Li-TFSI) and FK209 [tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III) tris(bis(trifluoromethylsulfonyl)imide)]. The composition for forming a hole transport layer can be produced by dissolving or mixing compound (X) of the present disclosure and other optional components in the above-mentioned solvent.

[0099] <Electron Transport Layer 5> The electron transport layer 5 includes a semiconductor. Examples of the semiconductor include organic n-type semiconductors and inorganic n-type semiconductors. The band gap of the semiconductor can be 1.5 to 4.5 eV. Examples of organic n-type semiconductors include imide compounds, quinone compounds, fullerenes and their derivatives. Examples of inorganic n-type semiconductors include metal oxides and perovskite oxides. Examples of metal elements include transition metals and typical metals of groups 12 to 15, with titanium dioxide being preferred. Examples of titanium dioxide (titania) include compact titania and porous titania. These titanias can also be treated with titanium tetrachloride. Examples of perovskite oxides include SrTiO ３ , CaTiO ３ The electron transport layer 5 has a thickness of, for example, 10 nm to 500 nm. The electron transport layer 5 can be formed by a spray method, a spin coating method, a vacuum deposition method, or the like.

[0100] <Others> The perovskite solar cell of the present disclosure may include elements that can be included in ordinary perovskite solar cells (for example, a blocking layer, an element encapsulation member (for example, a glass plate)), as long as the addition does not impair the purpose of the perovskite solar cell of the present disclosure.

[0101] [Structure] A structure of the present disclosure comprises the perovskite solar cell of the present disclosure described above. Because the perovskite solar cell of the present disclosure has a high PCE after durability testing, comprising the perovskite solar cell of the present disclosure in a structure of the present disclosure can reduce the frequency of solar cell replacement. Examples of structures include buildings (sloped roof or flat roof deck), buildings (facades and roofs), hand holds, portable devices, stationary devices, self-propelled vehicles (cars, trains, motorcycles, scooters, trucks, and the like), manual devices, boats, parking lots, water surfaces (buoy sets, piers, underwater anchors, mooring ropes, or docks), price tags, plastic, wearable products, household items, and the like.

[0102] [Method for manufacturing perovskite solar cell] There are no particular limitations on the method for manufacturing the perovskite solar cell of the present disclosure.

[0103] A preferred example of the method for producing a perovskite solar cell according to the present disclosure includes the steps of: forming a hole transport layer containing compound (X) according to the present disclosure (or a hole transport material for perovskite solar cells according to the present disclosure) to obtain components including the hole transport layer; storing the components for 1 hour to 48 hours from the time when the formation of the hole transport layer is completed; and sealing the components after storage.

[0104] According to the production method of the above example, the initial PCE and the PCE after durability testing of the obtained perovskite solar cell are further improved. Although the reason for this is not clear, it is presumed that the storage step described above changes the structure of compound (X) to a structure suitable for hole transport (e.g., an intramolecular packing structure and / or an intermolecular packing structure) during storage.

[0105] The storage time in the storage step is preferably 1 hour to 48 hours, more preferably 2 hours to 40 hours. There is no particular limitation on the humidity in the storage step. The humidity is preferably 15% to 30%, more preferably 18% to 24%. There is no particular limitation on the atmosphere in the storage step. Storage can be carried out, for example, in air or nitrogen.

[0106] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples. The materials, amounts used, proportions, and processing procedures shown in the following examples can be changed as appropriate without departing from the spirit of the present disclosure.

[0107] [Synthesis of Compound (X) and Comparative Compounds] As Compound (X), compounds (X-01), (X-09), (X-101) to (X-105), and (X-201) were synthesized. In addition, as comparative compounds, compounds (C-1) and (C-2) were synthesized. Details are shown below.

[0108] <Synthesis of Compound (X-01)> Compound (X-01) was synthesized according to the following reaction scheme. Compound (X-01) is a compound (X) in which n is 2 and Y １ is a halogen atom (fluorine atom).

[0109]

[0110]

[0111] Detailed procedures of the above reaction scheme are shown below: In the following explanation, the numbers in parentheses after the compound names correspond to the compound numbers in the above reaction scheme.

[0112] All reagents, including 4-bromothioanisole (1), 3-fluroaniline (2), and 3,3'-dibromo-2,2'-bithiophene, were purchased commercially and used without further purification. Solvents were purified according to standard methods and dried as necessary.

[0113] Synthesis of 3-fluoro-N,N-bis(4-(methylthio)phenyl)aniline (compound (3)). A solution of 4-bromothioanisole (1) (22.70 g, 112.5 mmol), 3-fluroaniline (2) (5 g, 44.9 mmol), t-BuONa (25.9 g, 269 mmol), and (t-Bu)P (0.362 g, 1.8 mmol) in dry toluene (100 mL) was degassed with nitrogen for 30 minutes. Next, Pd2(dba)3 (411 mg, 0.45 mmol) was added under a nitrogen atmosphere, and the resulting mixture was refluxed at 140 °C for 24 hours. After cooling to room temperature, the crude product was extracted with chloroform, washed with water, and concentrated in vacuo. Compound (3) was purified by column chromatography (hexane / chloroform, 3:1, v / v) and obtained as a pale green liquid. 1 H NMR(600MHz, CDCl3)δ:7.18-7.19(d, 4H), 7.12-7.16(m, 1H), 7.01-7.03(d, 4H), 6.77-6.78(d, 1H), 6.69-6.70(d, 1H), 6.62-6.65(t, 1H), 2.47(s, 6H); 13 C NMR(150MHz, CDCl3)δ:16.82, 108.87, 109.01, 109.49, 109.65, 118.11, 118.12, 125.53, 128.57, 130.30, 130.36, 133.03, 144.79, 149.40, 149.47, 162.84, 164.46.

[0114] Synthesis of 4-bromo-3-fluoro-N,N-bis(4-(methylthio)phenyl)aniline (compound (4)): To a solution of compound (3) (20 g, 56.26 mmol) in DMF (100 mL) was added commercially available N-Bromosuccinimide (11 g, 61.79 mmol) at 0 °C. The reaction mixture was stirred in the dark at 0 °C for 15 minutes, then the solution temperature was raised to 40 °C and stirred for 24 hours. After the reaction was complete, the crude product was quenched with water and extracted with chloroform. The residue was purified by column chromatography (hexane / chloroform, 3:1, v / v) to obtain compound (4) as a pale green viscous oil (0.85 g). 1 H NMR(600MHz, CDCl3)δ:7.29-7.31(m, 1H), 7.18-7.19(d, 4H), 7.01-7.03(d, 4H), 6.76-6.77(d, 1H), 6.67-6.68(d, 1H), 2.47(s, 6H); 13 C NMR(150MHz, CDCl3)δ:14.31, 100.23, 100.37, 109.88, 110.05, 118.74, 125.64, 128.39, 128.44, 133.46, 133.74, 144.14, 148.65, 148.74, 158.71, 160.35

[0115] Synthesis of 3-fluoro-N,N-bis(4-(methylthio)phenyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (compound (5)). Compound (4) (12 g, 27.62 mmol) and commercially available bis(pinacolato)diboron (7 g, 27.62 mmol) were dissolved in 200 mL of dry dioxane along with potassium acetate (13.5 g, 138 mmol) and Pd(dppf)Cl (3 g, 4.1 mmol). The mixture was heated to 110 °C under a nitrogen atmosphere and stirred for 24 h. The crude product was extracted with chloroform, washed with water, and purified by column chromatography (hexane / chloroform, 2:1, v / v) to give compound (5) as an orange-red solid (0.68 g). 1 H NMR(600MHz, CDCl3)δ:7.52-7.55(t, 1H), 7.17-7.18(d, 4H), 7.03-7.04(d, 4H), 6.72-6.73(d, 1H), 6.59-6.61(d, 1H), 2.47(s, 6H), 1.34(s, 12H); 13 C NMR(150MHz, CDCl3)δ:16.52, 24.95, 83.69, 107.37, 107.56, 116.16, 125.47, 126.17, 128.27, 128.49, 137.48, 137.55, 144.02, 152.32, 152.39, 167.56, 169.21.

[0116] Synthesis of 2,6-dibromo-4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole (compound (6)). 4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole (0.5 g, 1.75 mmol), synthesized according to a published procedure (Mabrouk et al., J. Mater. Chem. A, 2018, 6, 7950-7958 and its supporting information), was dissolved in dry DMF (100 mL) and commercially available N-bromosuccinimide (0.72 g, 4.02 mmol) was added at 0 °C. The reaction mixture was stirred in the dark at 0 °C for 15 min, then the solution temperature was raised to 30 °C and stirred for 24 h. After completion of the reaction, the crude product was quenched with water and extracted with chloroform. The residue was purified by column chromatography (Hexane / chloroform, 3:1, v / v) to obtain compound (6) as a white solid (0.75 g). 1 H NMR(600MHz, CDCl3)δ:7.38(d, J=8.4Hz, 2H), 7.08(s, 2H), 7.03(d, J=8.4Hz, 2H), 3.88(s, 3H). 13 C NMR(151MHz, CDCl3)δ:158.56, 141.28, 132.04, 124.68, 116.22, 115.35, 115.19, 110.42, 77.37, 77.16, 76.95, 55.78.

[0117] Synthesis of 4,4'-(4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole-2,6-diyl)bis(3-fluoro-N,N-bis(4-(methylthio)phenyl)aniline) (DTP-OFTPASMe2) (Compound (X-01)) Compound (5) (0.32 g, 0.67 mmol), compound (6) (0.1 g, 0.225 mmol), an aqueous 2MK2CO3 solution, and Pd(PPh3)4 (4 mol%) were added to a 50 mL reaction flask. Next, THF (30 mL) was added to the flask under a nitrogen atmosphere. The reaction mixture was heated at 90 °C for 24 hours under a nitrogen atmosphere. The crude product was extracted with chloroform, washed with water, and purified by column chromatography using chloroform to obtain the compound DTP-OFTPASMe2 (compound (X-01)) as a dark green solid (0.18 g). 1 H NMR(600MHz, CDCl3)δ:7.50-7.51(d, 2H), 7.44(m, 2H), 7.38(s, 2H)7.19-7.20(d,8H), 7.04-7.07(m, 10H), 6.75-6.79(dd, 4H), 3.88(s, 3H), 2.48(s, 6H); 13 C NMR(150MHz, CDCl3)δ:16.63, 55.75, 109.43, 115.73, 116.70, 117.89, 124.64, 125.65, 128.40, 132.72, 133.44, 144.21, 147.63, 158.11.

[0118] <Synthesis of Compound (X-03)> Compound (X-03) was synthesized according to the following reaction scheme. Compound (X-03) is a compound (X) in which n is 2 and Y １ is a halogen atom (fluorine atom).

[0119]

[0120]

[0121] Detailed procedures of the above reaction scheme are shown below: In the following explanation, the numbers in parentheses after the compound names correspond to the compound numbers in the above reaction scheme.

[0122] All reagents, including 4-iodoanisole (1), 3-fluroaniline (2), 3-fluoro-N,N-bis(4-methoxyphenyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (5), and 3,3'-dibromo-2,2'-bithiophene (6), were purchased commercially and used without further purification. Solvents were purified according to standard methods and dried as necessary.

[0123] Synthesis of 3-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (3)). 4-iodoanisole (1) (12.5 g, 53.68 mmol), 3-fluroaniline (2) (2 g, 21.47 mmol), CuI (1.47 g, 7.72 mmol), 2,2'-bipyridine (1.20 g, 7.72 mmol), and t-BuOK (9.6 g, 85.88 mmol) were added to dry toluene (100 mL) under a nitrogen atmosphere, and the resulting mixture was refluxed for 48 h. After cooling to room temperature, the crude product was extracted with chloroform and washed with water. Compound (3) was obtained as a brown solid (4.16 g) by column chromatography (hexane / chloroform, 2:1, v / v).

[0124] Synthesis of 4-bromo-2-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (4)): Compound (3) (1.0 g, 3.09 mmol) was dissolved in DMF (50 mL), and NBS (0.66 g, 3.71 mmol) was added at 0 °C. The reaction mixture was then cooled to room temperature and stirred at 40 °C in the dark for 16 hours. The mixture was then quenched with water and extracted with chloroform. The organic solvent was removed, and the residue was purified by column chromatography (hexane / chloroform, 2:1, v / v) to obtain compound (4) as a pale green viscous oil (1.11 g).

[0125] Synthesis of 3-fluoro-N,N-bis(4-(methyloxy)phenyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (compound (5)): Compound (4) (12 g, 29.90 mmol), bis(pinacolato)diborane (11.40 g, 44.85 mmol), potassium acetate (14.6 g, 149.5 mmol), and Pd(dppf)Cl (4.3 g, 5.98 mmol) were dissolved in dry dioxane. Under a nitrogen atmosphere, the mixture was heated to 110 °C and stirred for 48 hours. The crude product was extracted with chloroform, washed with water, and purified by column chromatography (hexane / chloroform, 2:1, v / v) to obtain compound (5) as a yellow solid (8.73 g). 1 H NMR (600 MHz, CDCl3)δ:7.44(d, J = 7.7 Hz, 1H), 7.04(d, J = 8.5 Hz, 4H), 6.81(d, J = 8.5 Hz, 4H), 6.55(d, J = 8.3 Hz, 1H), 6.42(d, J = 12.3 Hz, 1H), 3.75(s, 6H), 1.29(s, 12H); 13 C NMR (151 MHz, CDCl3)δ 169.36, 167.71, 156.84, 153.59, 139.60, 137.30, 127.73, 114.95, 113.55 , 104.76, 104.57, 83.61, 83.46, 77.37, 77.16, 76.95, 55.56, 25.13, 24.89

[0126] Synthesis of 4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole (compound 7) Compound 7 was synthesized according to the published procedure (Mabrouk et al., J. Mater. Chem. A, 2018, 6, 7950-7958 and its supporting information) as follows: A mixture of 3,3'-dibromo-2,2'-bithiophene 6 (1.62 g, 5 mmol), tert-butoxide (1.92 g, 20 mmol), Pd2(dba)3 (46 mg, 0.05 mmol), dppf (112 g, 0.2 mmol), and anhydrous toluene (20 mL) was added to a 100 mL two-neck round-bottom flask and stirred at room temperature for 5 min under an argon atmosphere. p-Anisidine (0.8 g, 6.5 mmol) was then added, and the resulting mixture was heated at reflux for two nights. After evaporation of the solvent, the remaining crude product was purified by column chromatography on silica gel eluting with DCM:PE (1:25 to 1:10 v / v) to give compound (7) as a pale yellow solid (1.14 g).

[0127] Synthesis of 2,6-dibromo-4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole (compound (8))) Compound (7) (0.5 g, 1.75 mmol) was dissolved in dry THF (100 mL) and N-bromo succinimide (0.72 g, 4.02 mmol) was added at 0 °C. The mixture was stirred in the dark at 0 °C for 15 min, then the solution temperature was raised to 30 °C and stirred for 24 h. After the reaction was completed, the crude product was quenched with water and extracted with chloroform. The residue was purified by column chromatography (hexane / chloroform, 3:1, v / v) to obtain compound (8) as a white solid (0.75 g). 1 H NMR (600 MHz, CDCl3)δ:7.38 (d, J = 8.4 Hz, 2H), 7.08 (s, 2H), 7.03 (d, J =8.4 Hz, 2H), 3.88 (s, 3H); 13C NMR (150 MHz, CDCl3) δ 158.56, 141.28, 132.04, 124.68, 116.22, 115.35, 115.19, 110.42, 77.37, 77.16, 76.95, 55.78.

[0128] Synthesis of 4,4'-(4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole-2,6-diyl)bis(3-fluoro-N,N-bis(4-methoxyphenyl)aniline) (DTP-OFTPAOMe2) (Compound (X-03)) Compound (5) (0.608 g, 1.35 mmol) and compound (8) (0.2 g, 0.451 mmol) were added to tetrahydrofuran (15 mL, degassed with nitrogen), followed by the addition of Pd(PPh3)4 (31.2 mg, 0.06 mmol) and K2CO3 solution (5 mL, 2.0 M, degassed with nitrogen), and the mixture was refluxed for 24 hours. After cooling to room temperature, the mixture was extracted with dichloromethane and washed with water. The solvent in the organic phase was removed, and the residue was purified using column chromatography (Hexane: Chloroform, 1:9, v / v) to obtain DTP-OFTPAOMe2 (compound (X-03)) as a red solid (0.32 g). 1 H NMR (600 MHz, CDCl3)δ: 7.51(d, 2H), 7.38(d, 2H), 7.33(s, 2H), 7.08(dd, 10H), 6.89 - 6.83(m, 8H), 6.64(ddd, 4H), 3.88(s, 3H), 3.81(s, 12H); 13 C NMR (151MHz, CDCl3) δ 160.46, 160.09, 158.82, 158.02, 157.07, 156.59, 153.31, 149.15, 145.90, 144.54, 139.94 , 132.90, 128.32, 127.30, 124.67, 115.28, 115.06, 114.96, 109.70, 106.76, 106.59, 55.62

[0129] Synthesis of Compound (X-09), Compound (C-1), and Compound (C-2) Compound (X-16), a specific example of Compound (X), and comparative compounds Compounds (C-1) and (C-2), were synthesized according to the following reaction scheme. Compound (X-09), like Compound (X-01), is Compound (X) in which n is 2 and Y １ is a halogen atom (fluorine atom). The comparative compounds (C-1) and (C-2) are compounds in which n is 2 in formula (X), but Y １ is not a halogen atom.

[0130]

[0131]

[0132] The detailed procedure for the above reaction scheme is shown below. Compounds (8), (9), (10), and (11) were purchased from Sigma-Aldrich, J&K, or Energy and used without further purification. Toluene, dimethylsulfoxide (DMSO), and tetrahydrofuran (THF) were freshly distilled before use. Other solvents were used directly. Compounds (12) and (15) were synthesized according to a reported procedure (Mabrouk et al., J. Mater. Chem. A, 2018, 6, 7950-7958 and supporting information). 2,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[1,2-b:4,5-b']dithiophene was also synthesized according to a reported procedure (Nishinaga, S. et al., J. Org. Chem. 2018, 83, 5506-5515 and supporting information).

[0133] Synthesis of 2-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (13)) and 3-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (14)). 2-Fluoroaniline (compound (10)) or 3-Fluoroaniline (compound (11)) (12 g, 128.85 mmol), 4-bromothioanisole (compound (8)) (50.6 g, 270.58 mmol), t-BuONa (37 g, 386 mmol), and (t-Bu)P (1 g, 5.15 mmol) were dissolved in dry toluene (250 mL) under a nitrogen atmosphere. Next, Pd(dba) (1.18 g, 1.28 mmol) was added, and the resulting mixture was refluxed at 140 °C for 48 h. After cooling to room temperature, the crude product was extracted with chloroform and washed with water. Compounds (13) and (14) were obtained as brown solids by column chromatography (hexane / chloroform, 2:1, v / v) (20.0 g for compound (6) and 25.0 g for compound (7)).

[0134] NMR results of 2-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (13)) 1 H NMR(600MHz, CDCl3)δ:7.48(s, 4H), 7.29(d, J=11.7Hz, 10H), 7.16(d, J=8.5Hz, 15H), 7.02(d, J=8.4Hz, 15H), 4.01(s, 22H); 13 C NMR (126 MHz, CDCl3) δ: 158.63, 156.64, 155.34, 141.49, 135.71, 127.92, 124.74, 124.05, 117.05, 114.60, 77.41, 77.16, 76.91, 55.64. NMR results for 3-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (14)) 1H NMR(600MHz, CDCl3)δ:7.29(d, J=8.7Hz, 4H), 7.06(d, J=8.7Hz, 4H), 6.87(d, J=8.2Hz, 1H), 6.81(d, J=11.8Hz, 1H), 6.71(t, J=7.8Hz, 1H), 3.99(s, 6H); 13 C NMR(151MHz, CDCl3)δ:164.37, 162.76, 156.38, 150.68, 148.62, 140.26, 129.90, 127.17, 125.41, 115.31, 114.76, 113.84, 106.62, 106.24, 106.23, 77.37, 77.16, 76.95, 55.43.

[0135] Synthesis of 4-bromo-2-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (16)) and 4-bromo-3-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (17)). To a solution of compound (13) or (14) (20 g, 61.84 mmol) in DMF (100 mL) was added commercially available N-Bromosuccinimide (13 g, 74.21 mmol) at 0 °C. The reaction mixture was stirred in the dark at 0 °C for 15 minutes, then the solution temperature was raised to 40 °C and stirred for 24 hours. After completion of the reaction, the crude product was quenched with water and extracted with chloroform. The solvent in the organic phase was removed, and the residue was purified by column chromatography (hexane / chloroform, 2:1, v / v) to obtain compound (16) or (17) as a pale green viscous oil (28.0 g of compound (16) or 28.0 g of compound (17)).

[0136] NMR results of 4-bromo-2-fluoro-N,N-bis(4-methoxyphenyl)aniline (compound (16)) 1 H NMR(600MHz, CDCl3)δ:7.21(d, J=10.6Hz, 1H), 7.14(d, J=8.8Hz, 1H), 6.92(d, J=8.4Hz, 4H), 6.79(d, J=8.4Hz, 4H), 3.78(s, 6H); 13C NMR(126MHz, CDCl3)δ: 155.68; ・4-Bromo-3-fluoro-N,N-bis(4-methoxyphenyl)aniline(compound(17) )of the snail 1 H NMR(600MHz, CDCl3)δ: 7.26-7.20(m, 4H), 7.10(d, J=8.6Hz, 12H), 6.88(d, J=8.7Hz, 12H), 6.67(d, J=11.2Hz, 3H), 6.58(d, J=8.7Hz, 3H), 3.81(s, 18H); 13 C NMR(151MHz, CDCl3)δ: 156.66, 149.94, 139.68, 132.99, 127.25, 115.88, 114.98, 107.04, 106.87, 97.62, 97.48, 55.48.

[0137] Synthesis of 4,4'-(benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(N,N-bis(4-methoxyphenyl)aniline) (compound (C-2)), 4,4'-(benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(2-fluoro-N,N-bis(4-methoxyphenyl)aniline) (compound (C-1)), and 4,4'-(benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(3-fluoro-N,N-bis(4-methoxyphenyl)aniline) (compound (X-09)) 2,6-Bis(4,4,5,5-tetramethyl-1,3, 2-dioxaborolan-2-yl)benzo[1,2-b:4,5-b']dithiophene (0.3 g, 0.67 mmol) and compound (15), (16), or (17) (0.78 g, 0.81 g, 0.81 g, 1.42 mmol) were added to nitrogen-degassed tetrahydrofuran (15 mL) along with Pd(PPh3)4 (0.077 g, 0.06 mmol) and nitrogen-degassed K2CO3 solution (6 mL, 2.0 M), and the mixture was refluxed at 90 °C for 24 h. After cooling to room temperature, the mixture was extracted with chloroform and washed with water. The solvent in the organic phase was removed, and the residue was purified by column chromatography (chloroform) to obtain 0.28 g, 0.3 g, and 0.3 g of compound (C-2), compound (C-1), or compound (X-16) as a pale yellow solid, respectively.

[0138] NMR results of 4,4'-(benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(N,N-bis(4-methoxyphenyl)aniline) (compound (C-2)) 1H NMR(600MHz, CDCl3)δ:8.07(s, 1H), 7.51(d, J=8.7Hz, 2H), 7.39(s, 1H), 7.15-7.05(m, 4H), 6.95(d, J=8.7Hz, 2H), 6.90-6.80(m, 4H), 3.81(s, 6H); 13 C NMR(151MHz, CDCl3)δ156.25, 149.00, 144.40, 140.54, 138.60, 136.78, 127.12, 126.98, 126.19, 120.19, 116.78, 114.88, 55.62. ・4, 4'-(benzo[1, 2-b:4, 5-b']dithiophene-2, 6-diyl)bis(2-fluoro-N, N-bis(4-methoxyphenyl)aniline)(synthesis of snail(1)). 1 H NMR(600MHz, CDCl3)δ: 8.13(s, 1H), 7.46(s, 1H), 7.39(dd, J=23.6, 10.0Hz, 2H), 7.07(t, J=7.8Hz, 1H), 6.99(d, J=8.2Hz, 4H), 6.83(d, J=8.2Hz, 4H), 3.80(s, 6H); 13 C NMR(151MHz, CDCl3)δ:157.70; 118.39, 116.56, 114.89, 114.65, 60.55, 55.62. ・4,4'-(benzo[1,2-b:4,5-b']dithiophene-2,6-diyl)bis(3-fluoro-N, N-bis(4-methoxyphenyl)aniline)(anhydrolytic acid(basic) of N-bis(4-methoxyphenyl)aniline). 1H NMR(600MHz, CDCl3)δ:8.12(s, 1H), 7.58(s, 1H), 7.44(t, J=8.7Hz, 1H), 7.12(d, J=8.7Hz, 4H), 6.88(d, J=8.7Hz, 4H), 6.66(dd, J=20.0, 11.6Hz, 2H), 3.82(s, 6H); 13 C NMR(151MHz, CDCl3)δ:161.25, 159.59, 156.82, 150.21, 139.65, 138.59, 138.22,136.40, 129.51, 127.57, 120.36, 115.97, 115.03, 114.70, 113.38, 106.20, 106.02,55.63.

[0139] <Synthesis of Compounds (X-101), (X-102), (X-103), (X-105), (X-104), and (X-113)> Compounds (X-101), (X-102), (X-103), (X-105), (X-104), and (X-113), which are specific examples of compound (X), were synthesized according to the following reaction scheme. These compounds are specific examples of compound (X) in which n is 4 and X is group (X1).

[0140]

[0141]

[0142] The detailed procedure of the above reaction scheme is shown below.

[0143] Synthesis of 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)phenanthrene-9,10-dione (compound (23)). Commercially available 3,6-dibromophenanthrene-9,10-dione (compound (21)) (5 ​​g, 5.46 mmol) and 4-methoxy-N-(4-methoxyphenyl)-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)aniline (compound (22)) (5.89 g, 13.66 mmol) were dissolved in 50 mL of THF. Next, 2MK2CO3 aqueous solution (10 mL) and Pd(PPh3)4 (5 mol%) were added to a flask under a nitrogen atmosphere. The reaction mixture was heated at 90 °C under a nitrogen atmosphere for 24 h. After cooling to room temperature and concentrating, the residue was extracted with chloroform and water. The organic layer was dried over MgSO4, the solvent was removed by evaporation, and the crude product was purified by column chromatography using chloroform. Compound (23) was obtained as a dark red solid (6.0 g). 1 H NMR(600MHz, CDCl3)δ:8.14(s, 2H), 7.56(d, J=8.0Hz, 1H), 7.50(d, J=8.1Hz, 2H), 7.12(d, J=8.1Hz, 4H), 7.00(d, J=8.0Hz, 2H), 6.88(d, J=8.1Hz, 4H), 3.82(s, 6H). 13 C NMR(151MHz, CDCl3)δ:179.96, 156.52, 149.90, 148.13, 140.15, 136.23, 131.20, 130.16, 129.14, 127.95, 127.28, 127.04, 121.32, 119.68, 114.96, 77.37, 77.16, 76.95, 55.59.

[0144] Synthesis of 4,4',4'',4'''-(1,4-phenylenebis(1H-phenanthro[9,10-d]imidazole-2,6,9-triyl))tetrakis(N,N-bis(4-methoxyphenyl)aniline)(O-FDIMD-Ph) (Compound (X-101)) A mixture of commercially available terephthalaldehyde (Compound (24)) (0.067 g, 0.284 mmol), 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)phenanthrene-9,10-dione (Compound (23)) (0.5 g, 0.568 mmol), ammonium acetate (0.43 g, 5.68 mmol), and glacial acetic acid (15 mL) was refluxed at 140 °C for 48 hours. After completion of the reaction, the reaction mixture was cooled to room temperature. The precipitated compound was filtered and washed several times with MeOH. The compound was recrystallized from chloroform and methanol to obtain (O-FDIMD-Ph) (compound (X-101)) as a dark green solid (0.35 g). 1 H NMR(600MHz, CDCl3)δ:9.21-8.10(m, 3H), 7.78(m, 2H), 7.55-7.54(m, 4H), 7.26(m, 2H), 7.10-7.04(m, 12H), 6.86(m, 8H), 3.82(s, 12H). 13 C NMR(151MHz, CDCl3)δ:156.11, 148.64, 141.57, 140.91, 140.02, 132.80, 129.02128.08, 126.90, 126.33, 126.13, 120.74, 114.91, 55.65.

[0145] Synthesis of 4,4',4'',4''''-(pyridine-2,6-diylbis(1H-phenanthro[9,10-d]imidazole-2,6,9-triyl))tetrakis(N,N-bis(4-methoxyphenyl)aniline)(O-FDIMD-Py) (compound (X-102)) A mixture of commercially available pyridine-2,6-dicarbaldehyde (compound (25)) (0.041 g, 0.284 mmol), 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)phenanthrene-9,10-dione (compound (23)) (0.5 g, 0.568 mmol), ammonium acetate (0.43 g, 5.68 mmol), and glacial acetic acid (15 mL) was refluxed at 140 °C for 48 hours. After the reaction was completed, the reaction mixture was cooled to room temperature. The precipitated compound was filtered and washed several times with MeOH. The compound was recrystallized from chloroform and methanol to obtain (O-FDIMD-Py) (compound (X-102)) as a black solid (0.4 g). 1 H NMR(600MHz, CDCl3)δ:9.26-8.46(m, 3H), 8.14-8.10(m, 1H), 7.80(m, 2H), 7.60-7.46(m, 4H), 7.11-6.97(m, 12H), 6.87-6.71(m, 13H), 3.816(s, 12H). 13 C NMR(151MHz,CDCl3)δ:180.08, 156.55, 156.10, 155.93, 149.91, 148.19, 141.49, 140.88, 140.20,137.88, 136.26, 131.26, 130.27, 129.12, 128.10, 128.03, 127.91, 127.30, 127.07,126.89, 126.67, 121.31, 120.70, 119.98, 114.90, 114.83, 55.63.

[0146] Synthesis of 4,4',4'',4'''-([2,2'-bithiophene]-5,5'-diylbis(1H-phenanthro[9,10-d]imidazole-2,6,9-triyl))tetrakis(N,N-bis(4-methoxyphenyl)aniline)(O-FDIMD-Th-Th) (compound (X-103)) A mixture of 10-dione (compound (23)) (0.5 g, 0.568 mmol), ammonium acetate (0.43 g, 5.68 mmol), and glacial acetic acid (15 mL) was refluxed at 140 °C for 48 hours. After the reaction was completed, the reaction mixture was cooled to room temperature. The precipitated compound was filtered and washed several times with MeOH. The compound was recrystallized from chloroform and methanol to obtain (O-FDIMD-Th-Th) (compound (X-103)) as a brown solid (0.32 g). 1 H NMR(600MHz, CDCl3)δ9.27-8.47(m, 4H), 8.14-8.09(m, 1H), 7.82(m, 2H), 7.57-7.46(m, 4.H), 7.10-6.97(m, 10H), 6.86-6.81(m, 11H), 3.8(s, 12H). 13 C NMR(151MHz, CDCl3)δ180.08, 156.60, 156.14, 149.96, 148.65, 148.38, 148.26, 141.52, 140.96, 140.27, 140.00, 136.33, 132.81, 131.86, 131.48, 130.42, 129.04, 128.11, 128.03, 127.35, 126.95, 126.79, 120.78, 119.80, 115.04, 114.96, 55.69.

[0147] Synthesis of 4,4',4'',4'''-(thieno[3,2-b]thiophene-2,5-diylbis(1H-phenanthro[9,10-d]imidazole-2,6,9-triyl))tetrakis(N,N-bis(4-methoxyphenyl)aniline)(O-FDIMD-TT) (compound (X-105)) Commercially available dithieno[3,2-b:2',3'-d]thiophene-2,6-dicarbaldehyde (compound (27)) (0.060 g, 0.284 mmol), 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)phenanthrene-9, A mixture of 10-dione (compound (23)) (0.5 g, 0.568 mmol), ammonium acetate (0.43 g, 5.68 mmol), and glacial acetic acid (15 mL) was refluxed at 140 °C for 48 hours. After the reaction was completed, the reaction mixture was cooled to room temperature. The precipitated compound was filtered and washed several times with MeOH. The compound was recrystallized from chloroform and methanol to obtain (O-FDIMD-TT) (compound (X-105)) as a brown solid (0.4 g). 1 H NMR(600MHz, CDCl3)δ:9.20-9.00(m, 1H), 9.00(s, 5H), 8.64-8.42(m, 2H), 8.12-8.07(m, 2H), 7.83-7.77(m, 1H), 7.58-7.45(m, 4H), 7.10-6.97(m, 12H), 6.86-6.85(m,11H), 3.82(s, 12H). 13 C NMR(151MHz, CDCl3)δ:180.09, 156.53, 156.07, 149.88, 148.56, 148.14, 141.39, 140.90, 140.21, 139.87, 136.25, 132.76, 131.74, 129.12, 128.95, 128.04, 127.95, 127.28, 126.88, 126.72, 126.29, 120.71, 120.42, 119.72, 114.97, 114.89, 55.63.

[0148] ・4, 4', 4'', 4'''-(dithieno[3, 2-b:2', 3'-d]thiophene-2, 6-diylbis(1H-phenanthro[9, 10-d]imidazole-2, 6, 9-triyl))tetrakis(N, Synthesis of N-bis(4-methoxyphenyl)aniline)(O-FDIMD-TTT) (compound (X-104)) Commercially available dithieno[3, 2-b:2', 3'-d]thiophene-2, 6-dicarbaldehyde (compound (28)) (0.077g, 0.284mmol), 3, 6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)phenanthrene-9, A mixture of 10-dione (compound (23)) (0.5 g, 0.568 mmol), ammonium acetate (0.43 g, 5.68 mmol), and glacial acetic acid (15 mL) was refluxed at 140 °C for 48 hours. After the reaction was completed, the reaction mixture was cooled to room temperature. The precipitated compound was filtered and washed several times with MeOH. The compound was recrystallized from chloroform and methanol to obtain (O-FDIMD-TTT) (compound (X-104)) as a brown solid (0.39 g). 1 H NMR(600MHz, CDCl3)δ:9.25-8.77(m, 1H), 8.52(s, 1H), 8.13-8.08(m, 2H), 7.81-7.79(m, 1H), 7.58-7.45(m, 5H), 7.10-6.97(m, 12H), 6.86-6.85(m, 10H), 3.82(s, 12H). 1313C NMR (151 MHz, CDCl3) δ: 180.08, 156.53, 156.08, 149.88, 148.59, 148.16, 141.44, 140.89, 140.20, 139.91, 136.24, 132.73, 131.25, 130.25, 129.11, 128.96, 128.03, 127.96, 127.29, 127.03, 126.88, 127.73, 126.30, 126.02, 120.71, 120.14, 119.72, 114.97, 114.89, 55.63.

[0149] ・ Synthesis of 4,4’,4'',4'''-((4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole-2,6-diyl)bis(1H-phenanthro[9,10-d]imidazole-2,6,9-triyl))tetrakis(N,N-bis(4-methoxyphenyl)aniline) (Compound (X-113))

[0150] Synthesis of 4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole-2,6-dicarbaldehyde (compound 29) was synthesized according to a published procedure (Mabrouk et al., J. Mater. Chem. A, 2018, 6, 7950-7958 and its supporting information) as follows: Compound 29 (0.5 g) was synthesized as follows: POCl3 (0.6 mL, 3.5 mmol) was added dropwise to DMF (0.3 mL, 3.5 mmol) at 0 °C under an argon atmosphere. The mixture was stirred at 0 °C for 15 min, and then the flask was cooled to room temperature for 0.5 h. Compound 29 (0.5 g, 1.75 mmol) was dissolved in 1,2-dichloroethane, and the solution was added to the reagent flask. The mixture was stirred at 80 °C for 48 h. The reaction mixture was washed with saturated NaHCO3 (40 mL x 2), deionized water (40 mL x 2), brine (100 mL), and extracted with chloroform (100 mL x 3). The extract was dried over MgSO4, and the solvent was removed in vacuo to give the crude product. The crude product was purified by SiO2 column chromatography using chloroform / hexane (3:1) as an eluent to give compound (29) as a red solid (0.33 g). 1 H NMR(600MHz, CDCl3)δ:9.91(s, 2H), 7.73(s, 2H), 7.48(d, J = 6.3 Hz, 2H), 7.11(d, J = 5.8 Hz, 2H), 3.91(s, 3H); 13 C NMR(151 MHz, CDCl3)δ 183.39, 159.28, 147.07, 144.56, 130.92, 125.11, 123.12, 120.05, 115.57, 77.37, 77.16, 76.95, 55.87

[0151]

[0152] Synthesis of 4,4',4'',4'''-((4-(4-methoxyphenyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole-2,6-diyl)bis(1H-phenanthro[9,10-d]imidazole-2,6,9-triyl))tetrakis(N,N-bis(4-methoxyphenyl)aniline) (compound (X-113)) The above-mentioned compound (23) (0.333 g, 0.41 mmol), the above-mentioned compound (29) (0.07 g, 0.205 mmol), ammonium acetate (0.43 g, 5.68 mmol), and glacial acetic acid (15 mL) were mixed and refluxed at 140°C for 48 hours. After completion of the reaction, the mixture was cooled to room temperature, and the precipitated compound was filtered and washed several times with MeOH. The compound was recrystallized again from chloroform and MeOH to obtain compound (X-113) as a black solid (0.25 g). 1 H NMR(600MHz, CDCl3)δ:9.41-9.30(s, 1H), 8.88-8.84(m, 1H), 8.56-8.41(m, 2H), 8.12(m, 3H), 7.81(m, 3H), 7.54-7.35 (m, 11H), 7.17-7.09(m, 12H), 6.98-6.97(m, 15H), 6.87-6.85(m, 10H), 6.71(m, 10H), 3.81-3.76(m, 27H); 13 C NMR(151 MHz, CDCl3)δ180.10, 156.53, 156.08, 155.87, 149.91, 148.20, 140.97, 140.85, 140.18, 136.28, 131.26, 130.24, 129.11, 127.96, 127.29, 127.06, 126.87, 126.75, 126.62, 121.32, 120.98, 119.71, 114.97, 114.80, 55.82, 55.57.

[0153] <Synthesis of Compound (X-201)> Compound (X-201), a specific example of compound (X), was synthesized according to the following reaction scheme. Compound (X-201) is a specific example of compound (X) in which n is 4 and X is group (X2).

[0154]

[0155]

[0156] The detailed procedure of the above reaction scheme is shown below.

[0157] Compounds 22 and 34 and other commercially available reagents were purchased from Sigma-Aldrich, J&K, or Energy and used without further purification. Toluene, dimethylsulfoxide (DMSO), and tetrahydrofuran (THF) were freshly distilled before use. Other solvents were used directly.

[0158] Synthesis of 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)phenanthrene-9,10-dione (compound (35)). Compound (34) (5 g, 5.46 mmol) and 4-methoxy-N-(4-methoxyphenyl)-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)aniline (compound (22)) (5.89 g, 13.66 mmol) were dissolved in 50 mL of THF. Next, 2MK2CO3 aqueous solution (10 mL) and Pd(PPh3)4 (5 mol%) were added to a flask under a nitrogen atmosphere. The reaction mixture was heated at 90 °C under a nitrogen atmosphere for 24 hours. After cooling to room temperature and concentrating, the residue was extracted with chloroform and water. The organic layer was dried over MgSO4, and the solvent was removed by evaporation. The crude product was purified by column chromatography using chloroform to give compound (35) (6.0 g) as a dark red color. 1 H NMR(600MHz, CDCl3)δ:8.14(s, 2H), 7.56(d, J=8.0Hz, 1H), 7.50(d, J=8.1Hz, 2H), 7.12(d, J=8.1Hz, 4H), 7.00(d, J=8.0Hz, 2H), 6.88(d, J=8.1Hz, 4H), 3.82(s, 6H). 13C NMR(150MHz, CDCl3)δ:179.96, 156.52, 149.90, 148.13, 140.15, 136.23, 131.20, 130.16, 129.14, 127.95, 127.28, 127.04, 121.32, 119.68, 114.96, 77.37, 77.16, 76.95, 55.59.

[0159] Synthesis of 4,4',4'',4'''-(1,4-phenylenebis(1H-phenanthro[9,10-d]imidazole-2,6,9-triyl))tetrakis(N,N-bis(4-methoxyphenyl)aniline)TPAOMe2-FDIMD-Ph (compound (36)). Commercially available dicarbaldehyde (0.037 g, 0.272 mmol) and compound (35) (0.44 g, 0.568 mmol) were dissolved in acetic acid (20 mL). Finally, ammonium acetate (0.42 g, 5.44 mmol) was added to the reaction mixture, and the reaction flask was refluxed at 140 °C for 48 h. After the reaction was completed, the reaction mixture was cooled to room temperature. The precipitate was filtered and washed several times with MeOH to obtain green-black compound (36) (0.35 g). 1 H NMR(600MHz, CDCl3)δ:9.21-8.10(m, 3H), 7.78(m, 2H), 7.55-7.54(m, 4H), 7.26(m, 2H), 7.10-7.04(m, 12H), 6.86(m, 8H), 3.82(s, 12H). 13 C NMR(151MHz, CDCl3)δ:156.11, 148.64, 141.57, 140.91, 140.02, 132.80, 129.02128.08, 126.90, 126.33, 126.13, 120.74, 114.91, 55.65.

[0160] Synthesis of 4,4',4'',4'''-(cyclohexa-2,5-diene-1,4-diylidenebis(2H-phenanthro[9,10-d]imidazole-6,9-diyl-2-ylidene))tetrakis(N,N-bis(4-methoxyphenyl)aniline)(TPAOMe2-FDIMD-Ph-NIR) (compound (X-201)). Compound (36) (0.1 g, 0.057 mmol) dissolved in 40 mL of benzene was mixed with a 5 M solution of potassium hydroxide (10 mL) and stirred at room temperature. When potassium ferricyanide (0.11 g, 0.347 mmol) was added to the mixture, the color of the solution immediately changed to deep blue. After stirring at room temperature for 6 hours, the organic layer was extracted with dichloromethane and washed with water. The extract was dried over MgSO4, filtered, and the filtrate was concentrated to obtain a crude product, which was recrystallized from dichloromethane / hexanes to obtain compound (X-201) as a blue-green solid (0.07 g). 1 H NMR (600MHz, CDCl3)δ:8.19(m, 9H), 7.56(m, 4H), 7.11-7.02(m, 7H), 6.87(s, 15H), 3.82(s, 12H). 13 C NMR(150MHz, CDCl3)δ:207.78, 205.63, 204.01, 199.78, 195.77, 195.43, 184.86, 174.82, 170.43, 164.10, 160.16, 156.10, 144.92, 141.06, 135.04, 127.34, 114.95, 112.96, 55.70.

[0161] [Preparation of Spiro-OMeTAD] Spiro-OMeTAD was prepared as a comparative compound.

[0162] Examples 101 and 102, Comparative Examples 1 and 2, and Examples 201 to 206 Preparation of Composition for Forming Hole Transport Layer Compound (X) or a comparative compound shown in Table 1 was dissolved in chlorobenzene to prepare a solution having the concentration [mg / mL] shown in Table 1. To the resulting solution, 18 μL of a 520 mg / mL acetonitrile solution of Li-TFSI (Lithium Bis(trifluoromethanesulfonyl)imide) (manufactured by Tokyo Chemical Industry Co., Ltd., >98.0% (T)), 29 μL of a 300 mg / mL acetonitrile solution of FK209 [tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III) tris(bis(trifluoromethylsulfonyl)imide)] (manufactured by Tokyo Chemical Industry Co., Ltd., >95.0% (T)), and 30 μL of 4-tert-butylpyridine (manufactured by Tokyo Chemical Industry Co., Ltd., >96.0% (T)) were added (i.e., the dopant was added), thereby obtaining a composition for forming a hole transport layer.

[0163] <Preparation of perovskite solar cells (immediately after film formation) for initial PCE measurement> A 100 nm thick ITO layer, a 50 nm thick SnO ２ layer, and a 650 nm thick perovskite layer (Cs ０．０５ (FA ０．８５ MA ０．１５ ) ０．９５ Pb(I ０．８５ Br ０．１５ ) ３) were laminated in this order. Next, a chlorobenzene solution (15 mM) of pyridine-carbazole (also known as 9-(pyridin-4-yl)-9H-carbazole) prepared according to the method described in the supporting information of the literature "ACS Appl. Energy Mater. 2022, 5, 15819-15827" was spin-coated on the perovskite layer at a speed of 3000 rpm for 30 seconds, followed by drying to form a passivation layer, thereby obtaining a laminate. The above-described hole transport layer-forming composition was spin-coated on the passivation layer of the resulting laminate, followed by vacuum storage to remove the solvent, thereby forming a hole transport layer. An 80 nm-thick Au layer was formed on the resulting hole transport layer. This resulted in a perovskite solar cell (immediately after film formation) for initial PCE measurement (hereinafter also referred to as "cell for initial PCE measurement (immediately after film formation)" or "cell immediately after film formation").

[0164] The laminated structure of the battery for measuring the initial PCE is a laminated structure having a glass substrate on one side.

[0165] <Preparation of Perovskite Solar Cell for Initial PCE Measurement (Stored at Room Temperature and in the Atmosphere After Film Formation)> The cell for initial PCE measurement prepared as described above (immediately after film formation) was left in an atmospheric environment at a temperature of 20°C, an oxygen concentration of 21%, and a humidity of 20% for 24 hours after the hole transport layer was formed. This resulted in a perovskite solar cell for initial PCE measurement (stored at room temperature and in the atmosphere after film formation) (hereinafter also referred to as "cell for initial PCE measurement (stored at room temperature and in the atmosphere after film formation)" or "cell after storage").

[0166] <Initial PCE Measurement> The initial PCE of each of the batteries immediately after film formation and the batteries after storage (hereinafter also referred to as "initial PCE measurement batteries") was measured by a method conforming to the crystalline solar cell output measurement method of JIS C 8913. The initial PCE was measured by irradiating the initial PCE measurement batteries with light from a measurement light source of a solar simulator (HAL-320, Asahi Spectroscopy). The light intensity from the measurement light source was 100 mW / cm using a reference solar cell. ２The measurement area of ​​the initial PCE measurement battery was adjusted to 0.095 cm using a shadow mask. ２ More specifically, the initial PCE was measured as follows. The measurement area (0.10 cm) of the battery for initial PCE measurement was adjusted to be ２ ) was irradiated with the above-mentioned light, and the J-V curve characteristics were measured using a source meter (2400 model, Keithley Instruments). From the obtained J-V curve characteristics, the short-circuit current (Jsc (mA / cm ２ The open circuit voltage (Voc (V)), open circuit voltage (Voc (V)), and fill factor (FF) were calculated, and the photoelectric conversion efficiency (PCE) was calculated based on these values ​​using the above-mentioned formula (A). The obtained PCE was defined as the initial PCE. The results are shown in Table 1.

[0167] In the "Initial PCE (%)" column of Table 1, the "Immediately after film formation" column and the "After film formation, stored at room temperature and in the atmosphere" column show the initial PCE (%) of the battery immediately after film formation and the initial PCE (%) of the battery after storage, respectively. Table 1 further shows the short-circuit current (Jsc (mA / cm)) of the above-mentioned immediately after film formation battery. ２ The open circuit voltage (Voc (V)), open circuit voltage (Voc (V)), and fill factor (FF) are also shown. In Table 1, "-" means that the measurement was omitted.

[0168] <Preparation of perovskite solar cell for PCE measurement after durability test> A cell immediately after film deposition was obtained by the same method as for the above-mentioned cell immediately after film deposition. A glass substrate measuring 2.5 cm × 1.7 cm was laminated on the Au layer of the obtained cell immediately after film deposition, and the end faces of the obtained laminate were sealed to prepare a perovskite solar cell for PCE measurement after durability test (hereinafter also referred to as "cell for PCE measurement after durability test").

[0169] The laminated structure of the battery for measuring PCE after the durability test was a laminated structure with glass substrates on both sides.

[0170] After the durability test, the battery for PCE measurement was placed in a solar cell durability evaluation device set at a temperature of 85° C., and a durability test was carried out. In this durability test, a white LED (100 mW / cm ) was used at the start of the test (i.e., 0 hour after the start of the durability test), 50 hours later (i.e., 50 hours after the start of the durability test), and 150 hours later (i.e., 150 hours after the start of the durability test). ２ ) and, while maintaining the temperature at 85°C, the PCE was measured in the same manner as in the measurement of the initial PCE described above. For Example 207, the PCE after 1000 hours (i.e., 1000 hours after the start of the durability test) was also measured. The obtained results were designated as PCE after durability test. The obtained results are shown in Table 1. In Table 1, for each of the values ​​after 50 hours, 150 hours, and 1000 hours, the remaining PCE from the start of the durability test (= PCE after 50 hours, 150 hours, or 1000 hours / PCE at the start of the durability test) is also shown as the value in parentheses.

[0171]

[0172] As shown in Table 1, each Example using a specific example of Compound (X) as the hole transport material in the hole transport layer had a superior initial PCE (%) compared to Comparative Examples 102 and 103, which used the comparative compounds Compounds C-1 and C-2. Because Comparative Examples 102 and 103 had inferior initial PCE (%) compared to the other Examples, evaluation of the PCE after the durability test was omitted for these Comparative Examples. Furthermore, each Example had a superior PCE (%) after the durability test (specifically, after 50 hours and 150 hours) compared to Comparative Example 101, which used the comparative compound Spiro-OMeTAD. Comparative Example 101 had good initial PCE and PCE at the start of the durability test, but the PCE decreased to 0% after 50 hours and 150 hours from the start of the durability test.

[0173] Example 301 The same procedure as in Example 201 was carried out to prepare a composition for forming a hole transport layer, except that the Li-TFSI solution, the FK209 solution, and 4-tert-butylpyridine were not added (i.e., no dopant was added). The results are shown in Table 2. In Table 2, "-" indicates that the measurement was omitted.

[0174]

[0175] As shown in Table 2, Example 301 to which no dopant was added also exhibited good initial PCE and PCE after durability test, similar to Example 201 to which a dopant was added.

[0176] The disclosures of Japanese Patent Application No. 2024-125956 filed on August 1, 2024 and Japanese Patent Application No. 2025-082899 filed on May 16, 2025 are incorporated herein by reference in their entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A compound represented by the following formula (X): [wherein in formula (X), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms, and a plurality of Y ２ are each independently a nitrogen atom or a phosphorus atom, and a plurality of C １ are all carbon atoms, n is 2 or 4, when n is 2, X is any one of the groups (X3) to (X6), and a plurality of Y １ are each independently a halogen atom, and when n is 4, X is a group (X1) or a group (X2), and a plurality of Y １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms. １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of Y ２ are each independently a nitrogen atom or a phosphorus atom, ３ and C ４ In the group (X1), Z is a divalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, and C ３ -Z-C ４ In the group (X2), Z is a tetravalent linking group having 6 to 25 carbon atoms and containing at least one of an aromatic hydrocarbon group and an aromatic heterocyclic group, and C ３ =Z=C ４ In each of the groups (X3) to (X6), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms; ２ is a nitrogen atom or a phosphorus atom, and two Y ３ are each independently an oxygen atom or a sulfur atom, and two *'s each represent a bonding position.

2. The compound according to claim 1, wherein when n is 2, X is the group (X5) or the group (X6).

3. The compound according to claim 1, wherein Z in the group (X1) is any one of the following groups (Z11) to (Z19), the following group (Z19A), and the following group (Z19B), and Z in the group (X2) is the following group (Z21). [In each of the groups (Z11) to (Z19), the group (Z19A), the group (Z19B), and the group (Z21), a plurality of R １ are each independently a hydrogen atom or an unsubstituted aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R ２ are each independently a substituted or unsubstituted alkoxy group having 1 to 5 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 5 carbon atoms; ２ is a nitrogen atom or a phosphorus atom, and a plurality of Y ３ are each independently an oxygen atom or a sulfur atom, and two *'s each represent a bonding position.

4. The compound according to claim 3, wherein Z in the group (X1) is the group (Z11), the group (Z12), the group (Z14), the group (Z16), the group (Z17), the group (Z19A), or the group (Z19B), and Z in the group (X2) is the group (Z21).

5. The compound according to claim 3, wherein Z in the group (X1) is the group (Z16), the group (Z17), the group (Z19A), or the group (Z19B).

6. The compound according to claim 3, wherein Z in the group (X1) is the group (Z19A) or the group (Z19B).

7. The compound according to claim 1, wherein n is 4 and X is the group (X1) or the group (X2).

8. When n in formula (X) is 2, a plurality of Y １ are all fluorine atoms, and a plurality of Y in each of the formula (X), the group (X1), and the group (X2) ２ are all nitrogen atoms, and in each of the groups (X3) to (X6), two Y ３ at least one of the R １ are all hydrogen atoms, and ２ The compound according to claim 1 , wherein each of the groups independently represents an unsubstituted alkoxy group having 1 or 2 carbon atoms or an unsubstituted alkylthio group having 1 or 2 carbon atoms.

9. A hole transport material comprising the compound according to any one of claims 1 to 8.

10. A hole transport material for perovskite solar cells, comprising the compound according to any one of claims 1 to 8.

11. A perovskite solar cell comprising a hole transport layer containing the compound according to any one of claims 1 to 8.

12. A structure comprising the perovskite solar cell of claim 11.

13. A method for manufacturing a perovskite solar cell, comprising the steps of: forming a hole transport layer containing the compound according to any one of claims 1 to 8, and obtaining a component comprising said hole transport layer; storing said component for 1 to 48 hours from the time when formation of said hole transport layer is completed; and sealing said component after said storage.

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