Material for photoelectric conversion elements for image pickup, and photoelectric conversion element for image pickup
Provided are a material that achieves higher sensitivity and higher resolution of a photoelectric conversion element for imaging, and a photoelectric conversion element for imaging using the above material. A material for a photoelectric conversion element for imaging, the material including a compound having a structure of the following general formula (1), wherein Ar 1 to Ar 3 represent an aromatic hydrocarbon group, an aromatic heterocyclic group, or a linked aromatic group in which two to six of these groups are linked, and at least two groups thereof have an aromatic ring structure represented by any of the following formulae (2) to (4). X represents O or S.
1 . A photoelectric conversion element for imaging, comprising a photoelectric conversion layer and an electron blocking layer between two electrodes, wherein at least one layer of the photoelectric conversion layer or the electron blocking layer contains a material for a photoelectric conversion element comprising a compound represented by the following formula (1);
wherein Ar 1 to Ar 3 each independently represent a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 carbon atoms, or a substituted or unsubstituted linked aromatic group in which two to six of the aromatic hydrocarbon group or the aromatic heterocyclic group are linked, at least two groups of Ar 1 to Ar 3 have an aromatic ring structure represented by any of the following formulae (2) to (4), and the aromatic ring structure optionally has a substituent,
wherein X represents O or S.
2 . The photoelectric conversion element for imaging, according to claim 1 , wherein the electron blocking layer contains the material for a photoelectric conversion element according to claim 1 .
3 . The photoelectric conversion element for imaging according to claim 1 , wherein the photoelectric conversion layer contains an electron transport material.
4 . The photoelectric conversion element for imaging according to claim 1 , wherein an energy level of the material of a highest occupied molecular orbital (HOMO) obtained by structural optimization calculation with a density functional calculation B3LYP/6-31G(d) is-4.5 eV or lower.
5 . The photoelectric conversion element for imaging according to claim 4 , wherein an energy level of the material of a lowest unoccupied molecular orbital (LUMO) obtained by the structural optimization calculation is −2.5 eV or higher.
6 . The photoelectric conversion element for imaging according to claim 1 , wherein the material has a hole mobility of 1×10 −6 cm 2 /Vs or more.
7 . The photoelectric conversion element for imaging according to claim 1 , wherein at least two groups of Ar 1 to Ar 3 of the compound represented by formula (1) has any one of the aromatic ring structure represented by formula (2) or (3).
8 . The photoelectric conversion element for imaging according to claim 1 , wherein at least two groups of Ar 1 to Ar 3 of the compound represented by formula (1) has any one of the aromatic ring structure represented by formula (2) or (4).
9 . The photoelectric conversion element for imaging according to claim 1 , wherein at least one group of Ar 1 to Ar 3 of the compound represented by formula (1) is the aromatic ring structure represented by formula (2), and at least another group of Ar 1 to Ar 3 has any one of the aromatic ring structure represented by formula (2) or (4).
10 . The photoelectric conversion element for imaging according to claim 1 , wherein the material is amorphous.
11 . The photoelectric conversion element for imaging according to claim 1 , wherein the material is used as a hole transport material.