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  • Y02E10/549—Organic PV cells

Definitions

• the present invention relates to a compound, a hole transport material, and a photoelectric conversion element using the same.
• perovskite-type solar cells solar cells that use perovskite materials in the photoelectric conversion layer
• solution processing for example, Patent Document 1, Non-Patent Documents 1-2.
• hole transport materials are often used in the element. The purpose of using them is to (1) improve the photoelectric conversion efficiency by enhancing the function of selectively transporting holes, and (2) to protect the perovskite material, which is easily affected by moisture and oxygen, by bonding with the perovskite photoelectric conversion layer (for example, Non-Patent Document 3).
• Spiro-OMeTAD a spirobifluorene organic compound [comparison compound (B-1) shown below]
• B-1 spirobifluorene organic compound
• the problem that the present invention aims to solve is to provide a compound that is useful as a hole transport material for photoelectric conversion elements that can extract electric current efficiently, and to provide a photoelectric conversion element and solar cell that use the compound in the hole transport layer and have high heat resistance.
• the inventors conducted extensive research into improving photoelectric conversion characteristics, and as a result, they designed and developed a compound with a specific structure, and discovered that by using the compound as a hole transport layer in a photoelectric conversion element, it is possible to obtain a photoelectric conversion element and a perovskite solar cell that exhibit good photoelectric conversion characteristics and high heat resistance. That is, the gist of the present invention is as follows.
• R 1 is a hydrogen atom, a halogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent; a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent; an aryloxy group having 6 to 30 carbon atoms which may have a substituent; an amino group having 0 to 60 carbon atoms which may have a substituent; a thio group having 0 to 20 carbon atoms which may have a substituent; a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a monovalent heterocyclic group having 5 to 30 ring atoms which may have a substituent, R 2 to R 29 each independently represent Hydrogen atoms, a linear or branched alkyl group having 1 to 20 carbon atoms
• R 1 is a halogen atom, an amino group having 0 to 60 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, or a monovalent heterocyclic group having 5 to 30 ring atoms which may have a substituent.
• R 6 to R 15 and R 20 to R 29 is a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent.
• a hole transport material comprising the compound described above.
• the hole transport material described above is for use in a hole transport layer of a photoelectric conversion element.
• a photoelectric conversion element having a hole transport layer containing the compound described above.
• the compound according to the present invention and the hole transport layer using the compound make it possible to obtain a photoelectric conversion element and a perovskite solar cell with high heat resistance.
• FIG. 1 is a schematic cross-sectional view illustrating the configuration of a photoelectric conversion element according to an example of the present invention and a comparative example.
• a numerical range expressed using “to” means a range including the numerical values written before and after "to” as the lower and upper limits.
• some or all of the hydrogen atoms present in the compound represented by general formula (1) and the groups represented by R 1 to R 29 may be substituted with deuterium atoms.
• “transparent” and “light-transmitting” refer to a transmittance of light to be used for photoelectric conversion of 50% or more, for example, 80% or more, for example, 90% or more, for example, 99% or more. The transmittance of light can be measured by an ultraviolet-visible spectrophotometer.
• R 1 is a hydrogen atom, a halogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent; a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent; an aryloxy group having 6 to 30 carbon atoms which may have a substituent; an amino group having 0 to 60 carbon atoms which may have a substituent; a thio group having 0 to 20 carbon atoms which may have a substituent; It represents an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a heterocyclic group having 5 to 30 ring atoms which may have a substituent.
• the "halogen atom" represented by R 1 includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
• the number of carbon atoms in the "linear or branched alkyl group having 1 to 20 carbon atoms" in the "linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" represented by R 1 is selected from the range of 1 to 20, and may be selected from the range of, for example, 1 to 12, or may be selected from the range of, for example, 1 to 6.
• linear or branched alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, a 2-ethylhexyl group, a heptyl group, an octyl group, an isooctyl group, a nonyl group, and a decyl group.
• the number of carbon atoms in the "straight-chain or branched alkenyl group having 2 to 20 carbon atoms" in the " straight-chain or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent" represented by R 1 is selected from the range of 2 to 20, and may be selected from the range of, for example, 2 to 12, or may be selected from the range of, for example, 2 to 6.
• the "straight-chain or branched alkynylene group having 2 to 20 carbon atoms” include ethenyl group (vinyl group), 1-propenyl group, 2-propenyl group (allyl group), 1-methylethenyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 1-hexenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, and straight-chain or branched alkenyl group having 2 to 20 carbon atoms to which a plurality of these alkenyl groups are bonded.
• the number of carbon atoms in the "straight-chain or branched alkoxy group having 1 to 20 carbon atoms" in the "straight-chain or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent" represented by R 1 is selected from the range of 1 to 20, and may be selected from the range of, for example, 1 to 12, or may be selected from the range of, for example, 1 to 6.
• the "straight-chain or branched alkoxy group having 1 to 20 carbon atoms" include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an n-pentyloxy group, an n-hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, an isopropoxy group, an isobutoxy group, an s-butoxy group, a t-butoxy group, an isooctyloxy group, and a t-octyloxy group.
• aryloxy group having 6 to 30 carbon atoms include a phenoxy group, a tolyloxy group, a biphenylyloxy group, a terphenylyloxy group, a naphthyloxy group, an anthryloxy group, a phenanthryloxy group, a fluorenyloxy group, and an indenyloxy group.
• the "amino group having 0 to 60 carbon atoms" in the "amino group having 0 to 60 carbon atoms which may have a substituent" represented by R 1 may be an unsubstituted amino group, a mono-substituted amino group, or a di-substituted amino group.
• substituent of each substituted amino group include an alkyl group, an aryl group, and an acyl group.
• the hydrogen atom of each of these groups may be substituted with a substituent selected from the following substituent group A.
• the alkyl group and the alkyl group constituting the acyl group For the explanation and specific examples of the alkyl group and the alkyl group constituting the acyl group, the above description of the "linear or branched alkyl group having 1 to 20 carbon atoms" can be referred to, and for the explanation and specific examples of the aryl group, the below description of the "monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms" can be referred to. Note that the two substituents bonded to the nitrogen atom of the di-substituted amino group do not bond to each other to form a cyclic structure, and such a group having a cyclic structure is included in the "heterocyclic group" described later in the present invention.
• the number of carbon atoms in the "amino group having 0 to 60 carbon atoms" is selected from the range of 0 to 60, and may be selected from the range of 0 to 30, for example, from the range of 2 to 11, or may be selected from the range of 12 to 24.
• amino group having 0 to 60 carbon atoms include an unsubstituted amino group (-NH 2 ), monosubstituted amino groups such as methylamino, ethylamino, acetylamino, and phenylamino, and disubstituted amino groups such as dialkylamino groups such as dimethylamino and diethylamino, diarylamino groups such as diphenylamino, and acetylphenylamino.
• the "amino group having 0 to 60 carbon atoms which may have a substituent” is an amino group having 0 to 60 carbon atoms which may be substituted with an alkyl group or an aryl group.
• the "thio group having 0 to 20 carbon atoms" in the "thio group having 0 to 20 carbon atoms which may have a substituent" represented by R 1 may be an unsubstituted thio group (thiol group: -SH) or a substituted thio group in which a hydrogen atom of a thiol group is substituted with a substituent.
• the number of carbon atoms in the substituted thio group is preferably in the range of 1 to 18, and may be, for example, in the range of 1 to 12, for example, in the range of 1 to 6.
• substituent of the substituted thio group examples include an alkyl group and an aryl group, and the hydrogen atom of each of these groups may be substituted with a substituent selected from the following substituent group A.
• substituent group A For an explanation and specific examples of the alkyl group which is a substituent of the thio group, the above description of the "linear or branched alkyl group having 1 to 20 carbon atoms" can be referred to, and for an explanation and specific examples of the aryl group, the below description of the "monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms" can be referred to.
• Typical examples of the substituted thio group include a linear or branched alkylthio group having 1 to 20 carbon atoms, which may have a substituent, and an arylthio group having 6 to 30 carbon atoms, which may have a substituent.
• Specific examples of the "thio group having 0 to 20 carbon atoms" include an unsubstituted thio group (thiol group: -SH), an alkylthio group (e.g., a methylthio group, an ethylthio group, a propylthio group), an arylthio group (e.g., a phenylthio group, a biphenylthio group), and the like.
• the aromatic ring constituting the "monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms" in the "monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent" represented by R 1 may be a single ring, a condensed ring in which two or more rings are condensed, or a linked ring in which two or more rings are linked by a single bond.
• the number of condensed rings is, for example, 2 to 6, e.g., 2 to 4.
• the aromatic ring contains two or more rings. In the case of a condensed ring, it becomes a "condensed polycyclic aromatic group".
• the number of linked rings is, for example, 2 to 6, e.g., 2 to 4.
• the number of carbon atoms forming the aromatic ring is selected from the range of 6 to 30, and may be selected from the range of 6 to 22 or 6 to 18, and may be selected from the range of 6 to 14 or 6 to 10, for example.
• the "monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms” include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, an anthracenyl group (anthryl group), a phenanthryl group, a fluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, and a triphenylenyl group.
• the heterocycle constituting the "monovalent heterocyclic group having 5 to 30 ring atoms" in the "monovalent heterocyclic group having 5 to 30 ring atoms which may have a substituent" represented by R 1 may be a single ring or a condensed ring in which two or more rings are condensed. In the case of a condensed ring, the number of condensed rings is, for example, 2 to 6, for example, 2 to 4.
• the heterocycle may be an aromatic heterocycle or an aliphatic heterocycle. In one embodiment of the present invention, the heterocycle contains two or more rings. Examples of heteroatoms constituting the heterocycle include a nitrogen atom, an oxygen atom, and a sulfur atom.
• the number of ring atoms of the aromatic heterocycle may be selected from the range of 5 to 30, for example, from the range of 5 to 18.
• aromatic heterocyclic groups among "monovalent heterocyclic groups having 5 to 30 ring atoms” include pyridyl, pyrimidinyl, triazinyl, thienyl, furyl (furanyl), pyrrolyl, imidazolyl, pyrazolyl, triazolyl, quinolyl, isoquinolyl, naphthyldinyl, acridinyl, phenanthrolinyl, benzofuranyl, benzothienyl, oxazolyl, indolyl, carbazolyl, benzoxazolyl, thiazolyl, benzothiazolyl, quinoxalinyl, benzimidazolyl, pyrazolyl, dibenzofuranyl, dibenzothienyl, and carbonylyl groups.
• the bonding position of these groups is not particularly limited, and for example, in the case of a pyridyl group, it may be any of a 2-pyridyl group, a 3-pyridyl group, and a 4-pyridyl group (for example, a 4-pyridyl group can be selected).
• the aromatic heterocyclic group is bonded through a carbon atom.
• the aromatic heterocyclic group is bonded through a nitrogen atom.
• aliphatic heterocyclic group among the "monovalent heterocyclic group having 5 to 30 ring atoms” include groups bonded through a nitrogen atom such as a morpholino group, a pyrrolidino group, a piperidino group, and a piperazino group, and groups bonded through a carbon atom such as a tetrahydrofuryl group and a tetrahydrothienyl group.
• the "monovalent heterocyclic group having 5 to 30 ring atoms which may have a substituent" that R 1 can take is a monovalent aromatic heterocyclic group bonded through a nitrogen atom which may have a substituent and has 5 to 30 ring atoms, or a monovalent aliphatic heterocyclic group having 5 to 30 ring atoms which may have a substituent.
• the "monovalent heterocyclic group having 5 to 30 ring atoms which may be substituted" that can be taken by R 1 is a monovalent aromatic heterocyclic group bonded via a nitrogen atom having 5 to 30 ring atoms which may be substituted, and can be divided into a group of substituted or unsubstituted carbazol-9-yl groups and other groups.
• the "monovalent heterocyclic group having 5 to 30 ring atoms which may be substituted" that can be taken by R 1 is a monovalent aliphatic heterocyclic group having 5 to 30 ring atoms which may be substituted, particularly a monovalent aliphatic heterocyclic group bonded via a nitrogen atom having 5 to 30 ring atoms which may be substituted.
• R 1 is a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, "a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent”, “a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent”, “an aryloxy group having 6 to 30 carbon atoms which may have a substituent”, “an amino group having 1 to 60 carbon atoms which may have a substituent”, “a thio group having 0 to 20 carbon atoms which may have a substituent", "a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent", or "a ring-forming group which may have a substituent”.
• linear or branched alkyl groups having 1 to 18 carbon atoms such as ethenyl group (vinyl group), 1-propenyl group, 2-propenyl group (allyl group), 1-butenyl group, 2-butenyl group, 1-pentenyl group, 1-hexenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, and 1-ethylethenyl group; linear or branched alkenyl groups having 2 to 18 carbon atoms, such as ethenyl group (vinyl group), 1-propenyl group, 2-methyl-2-propenyl group, and 1-ethylethenyl group; alkoxy groups having 1 to 18 carbon atoms, such as methoxy group, ethoxy group, propoxy group, t-butoxy group, pentyloxy group, and hexyloxy group; aromatic hydrocarbon groups of 30; heterocyclic groups having 5 to 20 ring atoms such as a pyridy
• substituted substituents may be contained in only one or more groups, and when contained in more than one group, they may be the same or different from each other.
• the hydrogen atoms of the substituents constituting the substituent group A may be further substituted with a substituent selected from the substituent group A.
• R 1 in general formula (1) is a hydrogen atom, a halogen atom (e.g., a chlorine atom), a hydroxyl group, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 30 carbon atoms which may have a substituent, an amino group having 0 to 60 carbon atoms which may have a substituent (e.g., an alkyl group or an aryl group), a thiol group, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a monovalent heterocyclic group having 5 to 30 ring atoms which may have a substituent (preferably a monovalent aromatic heterocyclic group which is bonded
• R 1 in general formula (1) is a halogen atom (e.g., a chlorine atom), an amino group having 0 to 60 carbon atoms which may have a substituent, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent.
• R 1 in general formula (1) is a halogen atom (e.g., a chlorine atom), a monovalent heterocyclic group having 5 to 30 ring atoms which may have a substituent, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent.
• R 2 to R 29 each independently represent Hydrogen atoms, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent; a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent; a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent; It represents an amino group having 0 to 20 carbon atoms which may have a substituent, or a thio group having 0 to 20 carbon atoms which may have a substituent.
• examples of the "straight-chain or branched alkyl group having 1 to 20 carbon atoms" in the “straight-chain or branched alkyl group having 1 to 20 carbon atoms which may have a substituent " represented by R 2 to R 29 include the same as the "straight-chain or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" represented by R 1 in general formula (1).
• examples of the "straight-chain or branched alkenyl group having 2 to 20 carbon atoms" in the “straight-chain or branched alkenyl group having 2 to 20 carbon atoms, which may have a substituent", represented by R 2 to R 29, include the same as the "straight-chain or branched alkenyl group having 2 to 20 carbon atoms, which may have a substituent" represented by R 1 in general formula (1).
• cycloalkyl group having 3 to 12 carbon atoms in the "cycloalkyl group having 3 to 12 carbon atoms which may have a substituent" represented by R 2 to R 29 include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, a cyclododecyl group, a 4-methylcyclohexyl group, a 4-ethylcyclohexyl group, etc.
• the number of carbon atoms in the cycloalkyl group may be selected within the range of 3 to 10, for example.
• examples of the "straight-chain or branched alkoxy group having 1 to 20 carbon atoms" in the “straight-chain or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent " represented by R 2 to R 29 include the same as the "straight-chain or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent" represented by R 1 in general formula (1).
• thio group having 1 to 20 carbon atoms in the "thio group having 1 to 20 carbon atoms which may have a substituent" represented by R 2 to R 29 can be the "thio group having 1 to 20 carbon atoms which may have a substituent" represented by R 1 in general formula (1).
• examples of the "substituents" in the "linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent”, “linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent”, “cycloalkyl group having 3 to 12 carbon atoms which may have a substituent”, “linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent”, “amino group having 0 to 20 carbon atoms which may have a substituent”, or "thio group having 0 to 20 carbon atoms which may have a substituent” represented by R 2 to R 29 can be the same as the "substituents" in the "linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent” represented by R 1 in general formula (1).
• R 10 and R 11 , R 24 and R 25 may be bonded to each other to form a ring.
• R 10 and R 11 , R 24 and R 25 may be bonded to each other via a single bond, an oxygen atom, a sulfur atom, a selenium atom, or a nitrogen atom to form a ring.
• at least one pair of R 10 and R 11 , R 24 and R 25 may be bonded to each other via a single bond, for example, R 10 and R 11 may be bonded to each other via a single bond, and R 24 and R 25 may be bonded to each other via a single bond.
• R 10 and R 11 , R 24 and R 25 are not bonded to each other to form a ring.
• a compound in which R 10 and R 11 , R 24 and R 25 are not bonded to each other to form a ring is preferred in that it has a higher solubility in a commonly used solvent than a compound in which R 10 and R 11 , R 24 and R 25 are bonded to each other to form a ring.
• R 2 to R 29 is preferably a substituent that R 2 to R 29 can take.
• the number of substituents among R 2 to R 29 is preferably within the range of 1 to 12, for example, may be within the range of 1 to 8, or may be within the range of 4 to 8.
• the substituents may be the same or different. It is preferable that they are the same.
• R 8 , R 13 , R 22 and R 27 are substituents, and for example, all of them may be substituents.
• the substituents represented by R 2 to R 29 are linear or branched alkoxy groups having 1 to 20 carbon atoms which may have a substituent, linear or branched alkylthio groups having 1 to 20 carbon atoms which may have a substituent, and amino groups having 0 to 60 carbon atoms (preferably disubstituted amino groups) which may have a substituent.
• the substituents represented by R 2 to R 29 are linear or branched alkoxy groups having 1 to 20 carbon atoms which may have a substituent.
• R 2 to R 5 and R 16 to R 19 are hydrogen atoms.
• R 6 , R 10 , R 11 , R 15 , R 20 , R 24 , R 25 , and R 29 are hydrogen atoms.
• one triarylamino group is bonded to any one of the 1st to 4th positions of the carbazole, and one triarylamino group is bonded to any one of the 5th to 8th positions of the carbazole.
• one triarylamino group is bonded to the 2nd or 3rd position of the carbazole, and one triarylamino group is bonded to the 6th or 7th position of the carbazole.
• the bonding positions of the two carbazoles in the general formula (1) are preferably the same as each other.
• the compound represented by the general formula (1) is preferably a compound represented by the following general formula (2) in which triarylamino groups are substituted at the 3rd and 6th positions of the carbazole, or a compound represented by the following general formula (3) in which triarylamino groups are substituted at the 2nd and 7th positions of the carbazole.
• R 2 to R 29 in the general formulas (2) and (3) have the same definition as R 2 to R 29 in the general formula (1).
• Compound group 1 in which R 1 is a monovalent heterocyclic group having 5 to 30 ring atoms which may have a substituent, can be mentioned as an example of the compound group represented by general formula (1).
• Compound group 1 includes compound group 1a, in which R 1 is a monovalent aromatic heterocyclic group bonded via a carbon atom having 5 to 30 ring atoms which may have a substituent, compound group 1b, in which R 1 is a diarylamino group having 5 to 30 ring atoms which may have a substituent (provided that two aryl groups are linked to each other to form a cyclic structure), compound group 1c, in which R 1 is a monovalent aromatic heterocyclic group bonded via a nitrogen atom having 5 to 30 ring atoms which may have a substituent (excluding those belonging to compound group 1b), compound group 1d, in which R 1 is a monovalent aliphatic heterocyclic group bonded via a carbon atom having 5 to 30 ring atoms which may have a
• the heterocyclic group has a substituent.
• the heterocyclic group has no substituent and is unsubstituted.
• Each of the compound groups 1a to 1e can further satisfy at least one of the following additional conditions.
• One additional condition is that 4 to 8 of R 2 to R 29 are substituents which R 2 to R 29 may take.
• One additional condition is that at least one (e.g. all) of R 8 , R 13 , R 22 and R 27 is a substituent which R 2 to R 29 may take.
• R 2 to R 29 is a substituent, and the substituent taken by R 2 to R 29 is a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent.
• R 2 to R 29 is a substituent, and the substituent taken by R 2 to R 29 is a linear or branched alkylthio group having 1 to 20 carbon atoms which may have a substituent.
• R 2 to R 29 is a substituent, and the substituent represented by R 2 to R 29 is a disubstituted amino group having 2 to 60 carbon atoms which may have a substituent.
• One additional condition is that the compound has a structure represented by the above general formula (2).
• One additional condition is that the compound has a structure represented by the above general formula (3).
• a group of compounds 2 in which R 1 is a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent there can be mentioned a group of compounds 2 in which R 1 is a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent.
• the group of compounds 2 includes a group of compounds 2a in which R 1 is an unsubstituted phenyl group, a group of compounds 2b in which R 1 is a substituted phenyl group, a group of compounds 2c in which R 1 is an unsubstituted condensed aromatic hydrocarbon group, and a group of compounds 2d in which R 1 is a condensed aromatic hydrocarbon group having a substituent.
• the substituents of the groups of compounds 2b and 2d are selected from the above-mentioned group of substituents A.
• the substituents of the groups of compounds 2b and 2d are an alkyl group or an aryl group.
• the groups of compounds 2a to 2d can each further satisfy at least one additional condition described in the description of the group of compounds 1.
• a group of compounds 3 in which R 1 is an amino group having 0 to 60 carbon atoms which may have a substituent there can be mentioned a group of compounds 3 in which R 1 is an amino group having 0 to 60 carbon atoms which may have a substituent.
• the group of compounds 3 includes a group of compounds 3a in which R 1 is an unsubstituted amino group, a group of compounds 3b in which R 1 is a monosubstituted amino group, a group of compounds 3c in which R 1 is a diarylamino group which may have a substituent, and a group of compounds 3d in which R 1 is a dialkylamino group which may have a substituent.
• the substituents of the groups of compounds 3b to 3d are selected from the above-mentioned group of substituents A.
• the substituents of the groups of compounds 3b to 3d are an alkyl group or an aryl group.
• the groups of compounds 3a to 3d can each further satisfy at least one
• Compound group 4 in which R 1 is a halogen atom, can be given as an example of the compound group represented by general formula (1).
• Compound group 4 includes compound group 4a, in which R 1 is a fluorine atom, compound group 4b, in which R 1 is a chlorine atom, compound group 4c, in which R 1 is a bromine atom, and compound group 4d, in which R 1 is an iodine atom.
• Compound groups 4a to 4d each can further satisfy at least one additional condition described in the description of compound group 1.
• a group of compounds represented by the general formula (1) there can be mentioned a group 5 of compounds in which R 1 is a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent.
• a group of compounds represented by the general formula (1) there can be mentioned a group 6 of compounds in which R 1 is a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent.
• a group of compounds represented by the general formula (1) there can be mentioned a group of compounds 7 in which R 1 is a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent.
• a group of compounds represented by the general formula (1) there can be mentioned a group of compounds 8 in which R 1 is an aryloxy group having 6 to 30 carbon atoms which may have a substituent.
• a group of compounds represented by the general formula (1) there can be mentioned a group of compounds 9 in which R 1 is a thio group having 0 to 20 carbon atoms which may have a substituent.
• Compounds represented by the general formula (1) include compound group 10 in which R 1 is a hydrogen atom.
• a group of compounds represented by the general formula (1) there can be mentioned a group of compounds 11 in which R 1 is a hydroxyl group.
• Compound groups 5-11 may each further satisfy at least one additional condition described in the description of compound group 1.
• the compounds of the present invention represented by the general formula (1) can be synthesized by known methods.
• the compounds represented by the general formula (2) and the compounds represented by the general formula (3) can be synthesized by, for example, the methods described below.
• the compound of general formula (2) can be synthesized by a nucleophilic substitution reaction between cyanuric acid chloride or a 2,4-dichloro-1,3,5-triazine derivative and a 3,6-triarylamino-substituted carbazole represented by the following general formula (4).
• R 2 to R 29 in the above general formula (4) are defined the same as R 2 to R 29 in the above general formula (1).
• the compound of general formula (3) can be synthesized by a nucleophilic substitution reaction between cyanuric acid chloride or a 2,4-dichloro-1,3,5-triazine derivative and a 2,7-triarylamino-substituted carbazole represented by the following general formula (5).
• R 2 to R 29 in the above general formula (5) are defined the same as R 2 to R 29 in the above general formula (1).
• the compound represented by the general formula (1) of the present invention can be purified by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using a solvent, etc. Alternatively, it is effective to use a compound with increased purity by using these methods in combination. In addition, these compounds can be identified by nuclear magnetic resonance analysis (NMR).
• NMR nuclear magnetic resonance analysis
• the photoelectric conversion element of the present invention is characterized by having a hole transport layer containing a compound represented by general formula (1).
• a compound represented by general formula (1) the description in the above column "Compound represented by general formula (1)” can be referred to.
• the compound represented by general formula (1) has excellent hole transport properties and electron blocking properties, and therefore can be effectively used as a material for the hole transport layer of the photoelectric conversion element.
• the photoelectric conversion element has a conductive support 1, an electron transport layer 2, a photoelectric conversion layer 3, a hole transport layer 4, and a counter electrode 5 in this order, and the hole transport layer 4 contains a compound represented by general formula (1).
• the photoelectric conversion element has a conductive support, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a counter electrode in this order, and the hole transport layer contains a compound represented by general formula (1).
• the photoelectric conversion layer contains, for example, a perovskite compound.
• the photoelectric conversion element is, for example, a photoelectric conversion element used in a solar cell.
• each member and each layer of the photoelectric conversion element will be described using the photoelectric conversion element shown in FIG. 1 as an example.
• the conductive support 1 functions as a cathode that extracts electrons transported from the photoelectric conversion layer 3 via the electron transport layer 2.
• the conductive support 1 is a conductive support having translucency that allows light to pass through the conductive support, and is, for example, a conductive substrate in which a film of a conductive material is formed on a translucent substrate.
• the conductive material used for the conductive support include conductive transparent oxide semiconductors such as tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), tungsten-doped indium oxide (IWO), zinc aluminum oxide (AZO), fluorine-doped tin oxide (FTO), indium oxide (In 2 O 3 ), and indium-tin composite oxide, and it is preferable to use tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), etc.
• ITO tin-doped indium oxide
• IZO zinc-doped indium oxide
• IWO tungsten-doped indium oxide
• AZO zinc aluminum oxide
• FTO fluorine-doped tin oxide
• ITO indium oxide
• FTO fluorine-doped tin oxide
• the electron transport layer 2 is a layer containing a material (electron transport material) having a function of transporting electrons, and is disposed between the conductive support 1 and the photoelectric conversion layer 3, and has a function of transporting electrons generated in the photoelectric conversion layer 3 to the conductive support 1 side. This can improve the efficiency of electron migration from the photoelectric conversion layer to the conductive support.
• the electron transport layer may have a function of suppressing hole injection from the conductive support.
• the electron transport layer 2 may be formed adjacent to the conductive support 1, or another layer may be interposed between the conductive support 1 and the electron transport layer 2.
• semiconductor materials used in the electron transport layer include metal oxides such as tin oxide (SnO, SnO2 , SnO3, etc.), titanium oxide (TiO2 , etc.), tungsten oxide ( WO2 , WO3 , W2O3 , etc. ), zinc oxide (ZnO), niobium oxide ( Nb2O5, etc.), tantalum oxide (Ta2O5 , etc. ) , yttrium oxide ( Y2O3 , etc. ), and strontium titanate (SrTiO3 , etc.
• metal oxides such as tin oxide (SnO, SnO2 , SnO3, etc.), titanium oxide (TiO2 , etc.), tungsten oxide ( WO2 , WO3 , W2O3 , etc. ), zinc oxide (ZnO), niobium oxide ( Nb2O5, etc.), tantalum oxide (Ta2O5 , etc. ) ,
• metal sulfides such as titanium sulfide, zinc sulfide, zirconium sulfide, copper sulfide, tin sulfide, indium sulfide, tungsten sulfide, cadmium sulfide, and silver sulfide; metal selenides such as titanium selenide, zirconium selenide, indium selenide, and tungsten selenide; and elemental semiconductors such as silicon and germanium. These semiconductor materials may be used alone or in combination of two or more. Preferred examples of the semiconductor material used in the electron transport layer include one or a combination of two or more selected from tin oxide, titanium oxide, and zinc oxide.
• a paste containing fine particles of the semiconductor material can be mentioned.
• the semiconductor paste may be a commercially available product, or may be a preparation prepared by dispersing fine powder of the semiconductor material in a solvent.
• solvents used in preparing the semiconductor paste include, but are not limited to, water; alcohol-based solvents such as methanol, ethanol, and isopropyl alcohol; ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and hydrocarbon-based solvents such as n-hexane, cyclohexane, benzene, and toluene. These solvents may be used alone or as a mixed solvent of two or more types.
• Methods for dispersing semiconductor fine powder in a solvent include grinding the powder in a mortar or the like as necessary, and then dispersing it in the solvent using a dispersing machine such as a ball mill, paint conditioner, vertical bead mill, horizontal bead mill, or attritor.
• a dispersing machine such as a ball mill, paint conditioner, vertical bead mill, horizontal bead mill, or attritor.
• a surfactant or the like to prevent the semiconductor fine particles from agglomerating
• a thickener such as polyethylene glycol
• the electron transport layer can be formed using a known film-forming method. That is, the electron transport layer can be formed using a coating method or a gas-phase process using a coating liquid containing a semiconductor material (for example, a coating liquid for the electron transport layer such as a semiconductor paste).
• a method of forming a film by applying a coating liquid for the electron transport layer to a conductive substrate by a wet coating method such as a spin coating method, an inkjet method, a doctor blade method, a drop casting method, a squeegee method, a screen printing method, a reverse roll coating method, a gravure coating method, a kiss coating method, a roll brush method, a spray coating method, an air knife coating method, a wire barber coating method, a pipe doctor method, an impregnation/coating method, or a curtain coating method, and then removing the solvent or additives by baking, or a method of forming a film of a semiconductor material by a gas-phase film-forming method such as a sputtering method, a vapor deposition method, an electrodeposition method, an electrodeposition method, or a microwave irradiation method.
• a gas-phase film-forming method such as a sputtering method, a vapor deposition method, an electrode
• a coating method in which the prepared coating liquid for the electron transport layer is applied by a spin coating method it is preferable to use a coating method in which the prepared coating liquid for the electron transport layer is applied by a spin coating method, but this is not limited to this.
• the conditions for spin coating can be set appropriately.
• the atmosphere in which the film is formed is not particularly limited, and may be air or an inert atmosphere.
• the thickness of the electron transport layer is, for example, 5 nm to 200 nm, and preferably 10 nm to 150 nm. Furthermore, when a dense electron transport layer is used, for example from the viewpoint of further improving photoelectric conversion efficiency, the thickness of the electron transport layer is usually preferably 5 nm to 100 nm, and more preferably 10 nm to 50 nm. In the present invention, when a porous (mesoporous) metal oxide is used in addition to the dense layer, the thickness is usually preferably 20 nm to 200 nm, and more preferably 50 nm to 150 nm.
• the photoelectric conversion layer 3 is a layer for converting light energy into electricity, more specifically, a layer in which a charge separation state occurs due to light energy to generate holes and electrons.
• the photoelectric conversion layer 3 is formed on the opposite side of the electron transport layer 2 to the conductive support 1.
• the photoelectric conversion layer is a layer (perovskite layer) formed of a perovskite material.
• the "perovskite material” means a material having a perovskite structure represented by the general formula ABX3 .
• A represents a monovalent organic cation or a monovalent metal cation
• B represents a divalent metal cation
• X represents a halogen ion.
• Examples of the divalent metal cation represented by B include Pb 2+ and Sn 2+ .
• Examples of the halogen ion represented by X include I - and Br - .
• perovskite materials include MAPbI 3 , FAPbI 3 , EAPbI 3 , CsPbI 3 , MASnI 3 , FASnI 3 , EASnI 3 , MAPbBr 3 , FAPbBr 3 , EAPbBr 3 , MASnBr 3 , FASnBr 3 , and EASnBr 3 , and further include mixed cation type and mixed anion type perovskite materials such as (FAMA)Pb(IBr) 3 , K(FAMA)Pb(IBr) 3 , Rb(FAMA)Pb(IBr) 3 , and Cs(FAMA)Pb(IBr) 3.
• the photoelectric conversion layer may contain only one type selected from these perovskite materials, or may contain two or more types.
• the photoelectric conversion layer may be composed of only the perovskite material, or may contain other materials in addition to the perovskite material. Examples of other materials include light absorbing agents.
• the perovskite layer can be formed by applying a solution of halide AX and metal halide BX2 (perovskite precursor solution) to form a precursor coating film, and drying the precursor coating film.
• AX and metal halide BX2 perovskite precursor solution
• A, B, and X the description of each ion constituting ABX3 above can be referred to.
• specific examples of the halide AX include methylammonium halide, formamidine halide, and cesium halide
• specific examples of the metal halide BX2 include lead halide and tin halide.
• examples of the solvent for the perovskite precursor solution include, but are not limited to, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ⁇ -butyrolactone, etc. Furthermore, these solvents may be used alone or in combination of two or more.
• a preferred example of the solvent is a mixed solvent of N,N-dimethylformamide and dimethyl sulfoxide.
• the application process of the perovskite precursor solution is preferably carried out in a dry atmosphere, and more preferably in a dry inert gas atmosphere such as a glove box. This prevents moisture from being mixed into the perovskite layer, allowing highly efficient perovskite solar cells to be produced with good reproducibility.
• a dry atmosphere such as a glove box.
• the perovskite layer is formed by drying the precursor coating film thus formed.
• the precursor coating film may be dried naturally or by heating using a hot plate or the like.
• the temperature at which the precursor coating film is heated using a hot plate or the like is preferably 50 to 200°C, more preferably 70 to 150°C, from the viewpoint of producing a perovskite material from the precursor.
• the heating time is preferably about 10 to 90 minutes, more preferably about 10 to 60 minutes.
• the thickness of the photoelectric conversion layer is preferably 50 to 1000 nm, and more preferably 300 to 700 nm. This suppresses performance degradation due to defects or peeling in the photoelectric conversion layer, prevents the element resistance from becoming excessively high, and provides the photoelectric conversion layer with sufficient light absorption.
• the hole transport layer 4 is a layer containing a material (hole transport material) having a function of transporting holes, and is disposed between the photoelectric conversion layer 3 and the counter electrode 5 to transport holes generated in the photoelectric conversion layer 3 to the counter electrode 5. This can improve the efficiency of hole movement from the photoelectric conversion layer to the electrode.
• the hole transport layer may have a function of suppressing electron injection from the counter electrode.
• the hole transport layer contains a compound represented by general formula (1) as a hole transport material.
• the compound represented by general formula (1) contained in the hole transport layer may be one type or two or more types selected from the group of compounds represented by general formula (1).
• the hole transport layer can be made into a layer with high hole transport ability and excellent function of blocking electron movement from the counter electrode.
• the hole transport layer may contain, in addition to the compound represented by general formula (1), a hole transport material other than the compound represented by general formula (1) (hereinafter referred to as a "second hole transport material") or an additive.
• the second hole transport material may be an inorganic hole transport material or an organic hole transport material.
• inorganic hole transport materials include compound semiconductors containing monovalent copper, such as CuI, CuInSe 2 , and CuS, and compounds containing metals other than copper, such as GaP, NiO, CoO, FeO, Bi 2 O 3 , MoO 2 , and Cr 2 O 3 .
• organic hole transport materials include polythiophene derivatives such as poly-3-hexylthiophene (P3HT) and polyethylenedioxythiophene (PEDOT); fluorene derivatives such as 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (Spiro-OMeTAD); carbazole derivatives such as polyvinylcarbazole; triphenylamine derivatives such as poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA); diphenylamine derivatives; polysilane derivatives; and polyaniline derivatives.
• P3HT poly-3-hexylthiophene
• PEDOT polyethylenedioxythiophene
• fluorene derivatives such as 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9
• second hole transport materials may be mixed in the hole transport layer, or a hole transport layer containing the second hole transport material may be laminated on the hole transport layer containing the compound represented by the general formula (1).
• the hole transport layer is a single layer and contains only the compound represented by the general formula (1) as the hole transport material.
• the solvent used in the coating solution for the hole transport layer may be an aromatic organic solvent such as benzene, toluene, xylene, mesitylene, tetralin (1,2,3,4-tetrahydronaphthalene), monochlorobenzene (chlorobenzene), o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, or nitrobenzene; an alkyl halide organic solvent such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, or dichloromethane; a nitrile solvent such as benzonitrile or acetonitrile; or a tetrahydrofuran,
• aromatic organic solvent such as benzene, toluene, xylene, mesitylene, tetralin (1,2,3,4-tetrahydronaphthalene), monochlorobenz
• the solvent examples include, but are not limited to, ether solvents such as isopropyl ether, c-pentyl methyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate and propylene glycol monomethyl ether acetate; and alcohol solvents such as methanol, isopropanol, n-butanol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, cyclohexanol, and 2-n-butoxyethanol.
• ether solvents such as isopropyl ether, c-pentyl methyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol monomethyl ether
• ester solvents such as ethyl acetate and propy
• the atmosphere during the film formation of the hole transport layer is preferably a dry atmosphere.
• a solvent that has been dehydrated so that the moisture content is 10 ppm or less in the coating solution.
• the thickness of the hole transport layer is preferably 5 nm to 500 nm, and more preferably 10 nm to 250 nm.
• additives that may be added to the hole transport layer include an oxidizing agent (dopant) and a basic compound (basic additive). By adding these additives to the hole transport layer, the carrier concentration of the hole transport layer is improved, and the photoelectric conversion efficiency of the photoelectric conversion element can be improved.
• the dopant include lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), silver bis(trifluoromethanesulfonyl)imide, zinc bis(trifluoromethanesulfonyl)imide (II), copper bis(trifluoromethanesulfonyl)imide (II), magnesium bis(trifluoromethanesulfonyl)imide (II), calcium bis(trifluoromethanesulfonyl)imide (II), tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III) tri[bis(trifluoromethane)sulfonimide] (FK209), NOSbF 6 , SbCl 5 , and SbF 5. Of these, it is preferable to use lithium bis(trifluoromethylsulfonyl)imide (LiTFSI).
• LiTFSI lithium bis(
• the concentration of the dopant in the hole transport layer is preferably 2.0 equivalents or less, more preferably 0.5 equivalents or less, relative to 1 equivalent of the hole transport material. While the inclusion of an additive in the hole transport layer leads to an improvement in the photoelectric conversion efficiency of the photoelectric conversion element, if the concentration of the dopant is too high, the durability of the photoelectric conversion element may be reduced.
• Specific examples of the basic additive include 4-tert-butylpyridine (tBP), 2-picoline, and 2,6-lutidine, and among these, it is preferable to use 4-tert-butylpyridine.
• the basic additive may be used in combination with a dopant.
• the concentration of the basic additive in the hole transport layer is preferably 5 equivalents or less, more preferably 3.5 equivalents or less, relative to 1 equivalent of the hole transport material.
• the counter electrode 5 is an electrode formed on the opposite side of the hole transport layer 4 to the photoelectric conversion layer 3, and is disposed opposite the conductive support 1 with the electron transport layer 2, the photoelectric conversion layer 3, and the hole transport layer 4 sandwiched therebetween.
• the counter electrode functions as an anode that extracts holes transported from the photoelectric conversion layer via the hole transport layer.
• the counter electrode 5 may be provided adjacent to the hole transport layer 4, or an electron blocking layer made of an organic material or an inorganic compound semiconductor may be interposed between the hole transport layer 4 and the counter electrode 5.
• the material constituting the counter electrode include metals such as platinum, titanium, stainless steel, aluminum, gold, silver, nickel, magnesium, chromium, cobalt, and copper, or alloys thereof.
• metals such as platinum, titanium, stainless steel, aluminum, gold, silver, nickel, magnesium, chromium, cobalt, and copper, or alloys thereof.
• gold, silver, or a silver alloy since it shows high electrical conductivity even in a thin film.
• silver alloys include silver-gold alloys, silver-copper alloys, silver-palladium alloys, silver-copper-palladium alloys, and silver-platinum alloys, since they are less susceptible to sulfurization or chlorination and have high stability as a thin film.
• the counter electrode is a material that can be formed by a gas phase process such as deposition.
• the thickness thereof is preferably 10 nm or more, and more preferably 50 nm or more, in order to obtain good electrical conductivity.
• the conductive support 1 serves as a cathode
• the counter electrode 5 serves as an anode. It is preferable to irradiate light such as sunlight (light used for photoelectric conversion) from the conductive support side.
• the photoelectric conversion layer absorbs the light and enters an excited state, generating electrons and holes. These electrons move to the conductive support via the electron transport layer, and the holes move to the counter electrode via the hole transport layer, causing a current to flow, and the element functions as a photoelectric conversion element.
• the photoelectric conversion element of the present invention may also have a conductive support, a hole transport layer, a photoelectric conversion layer, an electron transport layer and a counter electrode in this order.
• the conductive support functions as an anode and the counter electrode functions as a cathode, and electrons generated in the photoelectric conversion layer move to the counter electrode via the electron transport layer, and holes generated in the photoelectric conversion layer move to the conductive support via the hole transport layer. This allows current to be taken out to the outside.
• the corresponding descriptions of the photoelectric conversion element shown in FIG. 1 above can be referred to.
• the short circuit current density, open circuit voltage, fill factor, and photoelectric conversion efficiency are measured.
• the short circuit current density represents the current per 1 cm2 flowing between the output terminals when the output terminals are shorted
• the open circuit voltage represents the voltage between the output terminals when the output terminals are open.
• the fill factor is the maximum output (product of current and voltage) divided by the product of the short circuit current density and the open circuit voltage, and is mainly dependent on the internal resistance.
• the photoelectric conversion efficiency is calculated as a percentage value obtained by multiplying the maximum output (W) by the light intensity (W) per cm2 by 100. If the initial photoelectric conversion efficiency of the photoelectric conversion element in the element configuration of the present invention is 10% or more, it can be determined that the photoelectric conversion efficiency is good.
• the photoelectric conversion element of the present invention can be applied to solar cells, various optical sensors, and the like.
• the solar cell to which the photoelectric conversion element of the present invention is applied is preferably a perovskite solar cell.
• a solar cell can be obtained by arranging the required number of photoelectric conversion elements, each of which contains a compound represented by general formula (1) in the hole transport layer, into a module and providing the required electrical wiring.
• Synthesis Example 1 Synthesis of Compound (A-1) 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-9H-carbazole (336 mg, manufactured by Tokyo Chemical Industry Co., Ltd.), DMF (10 mL), and sodium hydride (19 mg, purity 55%, manufactured by Kanto Chemical Industry Co., Ltd.) were added to a reaction vessel and stirred in an ice bath for 30 minutes. Furthermore, cyanuric chloride (25 mg, manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred at room temperature for 1 hour. After completion of the reaction, water (20 mL) was added and the precipitated solid was collected by suction filtration.
• Synthesis Example 2 Synthesis of Compound (A-2) 2,7-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-9H-carbazole (168 mg, Tokyo Chemical Industry Co., Ltd.), DMF (3 mL), and sodium hydride (10 mg, purity 55%, Kanto Chemical Industry Co., Ltd.) were added to a reaction vessel and stirred in an ice bath for 30 minutes. Furthermore, cyanuric chloride (15 mg, Tokyo Chemical Industry Co., Ltd.) was added and stirred at room temperature for 1 hour. After completion of the reaction, water (20 mL) was added and the precipitated solid was collected by suction filtration.
• Synthesis Example 3 Synthesis of Compound (A-3) 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-9H-carbazole (143 mg, Tokyo Chemical Industry Co., Ltd.), DMF (3 mL), and sodium hydride (9 mg, purity 55%, Kanto Chemical Industry Co., Ltd.) were added to a reaction vessel and stirred in an ice bath for 30 minutes. Furthermore, 2,4-dichloro-6-phenyl-1,3,5-triazine (20 mg, Tokyo Chemical Industry Co., Ltd.) was added and stirred at room temperature for 30 minutes. After completion of the reaction, water (20 mL) was added and the precipitated solid was collected by suction filtration.
• Synthesis Example 4 Synthesis of Compound (A-4) 2,7-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-9H-carbazole (143 mg, Tokyo Chemical Industry Co., Ltd.), DMF (3 mL), and sodium hydride (10 mg, purity 55%, Kanto Chemical Industry Co., Ltd.) were added to a reaction vessel and stirred in an ice bath for 30 minutes. Furthermore, 2,4-dichloro-6-phenyl-1,3,5-triazine (20 mg, Tokyo Chemical Industry Co., Ltd.) was added and stirred at room temperature for 1.5 hours. After completion of the reaction, water (20 mL) was added and the precipitated solid was collected by suction filtration.
• Synthesis Example 5 Synthesis of Compound (A-5) 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-9H-carbazole (600 mg, Tokyo Chemical Industry Co., Ltd.), DMF (12 mL), and sodium hydride (34 mg, Kanto Chemical Industry Co., Ltd.) were added to a reaction vessel and stirred in an ice bath for 30 minutes. After the reaction system was cooled to -10°C, cyanuric chloride (23 mg, Tokyo Chemical Industry Co., Ltd.) was added and stirred at -10°C for 2 hours and at 0°C for 90 minutes. After the reaction was completed, water (50 mL) was added and the precipitated solid was collected by suction filtration.
• cyanuric chloride 23 mg, Tokyo Chemical Industry Co., Ltd.
• Synthesis Example 6 Synthesis of Compound (A-16) 3,6-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-9H-carbazole (280 mg, manufactured by Tokyo Chemical Industry Co., Ltd.), DMF (5 mL), and sodium hydride (16 mg, manufactured by Kanto Chemical Industry Co., Ltd.) were added to a reaction vessel, and the mixture was stirred in an ice bath for 30 minutes. Furthermore, 2,4-dichloro-6-morpholino-1,3,5-triazine (40 mg, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the mixture was stirred at room temperature for 90 minutes.
• Example 1 Preparation of a photoelectric conversion element using compound (A-1)
• a glass with an ITO film conductive support 1, manufactured by Geomatec Co., Ltd.
• ITO film conductive support 1, manufactured by Geomatec Co., Ltd.
• a tin oxide colloidal solution tin(IV) oxide, 15% in H2O colloidal dispersion (manufactured by Alfa Aesar)
• purified water were mixed at a volume ratio of 1:1 to form a tin oxide dispersion (electron transport layer coating solution) on the ITO film.
• the ITO film was then heated on a hot plate at 150°C for 30 minutes to form a tin oxide layer (electron transport layer 2) with a thickness of about 20 nm.
• the cesium iodide solution was added in an amount such that the amount of cesium charged was 5% in terms of composition ratio.
• the prepared perovskite precursor solution was dropped onto the tin oxide layer, and spin-coated while dropping chlorobenzene (0.35 mL) to form a perovskite precursor coating film. Then, the film was heated on a hot plate at 100° C. for 1 hour to form a perovskite layer (photoelectric conversion layer 3) of Cs(MAFA)Pb(IBr) 3 with a thickness of about 500 nm.
• lithium bis(trifluoromethanesulfonyl)imide was dissolved in acetonitrile at a concentration of 1.8 M to prepare a dopant solution.
• compound (A-1) which is a hole transport material obtained in Synthesis Example 1
• compound (A-1) was dissolved in chlorobenzene at 70° C. at a concentration of 30 mM.
• 4-tert-butylpyridine was added thereto so that the amount was 3.3 equivalents relative to compound (A-1).
• the dopant solution was added so that the amount of lithium bis(trifluoromethanesulfonyl)imide was 0.5 equivalents relative to compound (A-1) to prepare a hole transport layer coating solution.
• a hole transport layer coating solution was spin-coated onto the Cs(MAFA)Pb(IBr) trilayer (photoelectric conversion layer 3) to form a hole transport layer 4 having a thickness of about 200 nm.
• a gold film of about 80 nm was formed by vacuum deposition at a degree of vacuum of about 1 ⁇ 10 ⁇ 4 Pa to form a gold electrode (counter electrode 5 ), thereby preparing a photoelectric conversion element.
• Example 2 Preparation of Photoelectric Conversion Element Using Compound (A-3)
• a photoelectric conversion element was prepared in the same manner as in Example 1, except that instead of compound (A-1), compound (A-3) was dissolved in chlorobenzene at room temperature at a concentration of 50 mM and spin-coated.
• Example 3 Preparation of photoelectric conversion element using compound (A-4) A photoelectric conversion element was prepared in the same manner as in Example 1, except that compound (A-4) was dissolved in chlorobenzene at room temperature at a concentration of 50 mM instead of compound (A-1), and the solution was spin-coated.
• Example 4 Preparation of Photoelectric Conversion Element Using Compound (A-5) A photoelectric conversion element was prepared in the same manner as in Example 1, except that instead of compound (A-1), compound (A-5) was dissolved in chlorobenzene at room temperature at a concentration of 27 mM and spin-coated.
• Comparative Example 1 Preparation of Photoelectric Conversion Element Using Comparative Compound (B-1)
• a photoelectric conversion element was prepared in the same manner as in Example 1, except that a standard hole transport material, Spiro-OMeTAD (manufactured by Sigma-Aldrich), represented by the following formula (B-1), was used in place of compound (A-1), by dissolving it in chlorobenzene at room temperature at a concentration of 70 mM.
• the sealed photoelectric conversion element was placed in a vacuum constant temperature dryer (VOS-310C, Tokyo Rikakikai Co., Ltd.) and stored at 85° C. for 1,000 hours, and the current-voltage characteristics were measured again under irradiation with simulated solar light to obtain the photoelectric conversion efficiency after 1,000 hours of heating.
• VOS-310C Tokyo Rikakikai Co., Ltd.
• the retention rate (%) was calculated according to the following formula (a-1).
• the present invention has a high industrial applicability.

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