Electron donating organic material, material for photovoltaic element, and photovoltaic element

Abstract

Disclosed is an electron donating organic material that can provide a photovoltaic element with a high photoelectric conversion efficiency. The electron donating organic material comprises a benzothiadiazole compound satisfying requirements that (a) a benzothiadiazole skeleton and an oligothiophene skeleton are contained, (b) the bandgap (Eg) is not more than 1.8 eV, and (c) the level of the highest occupied molecular orbital (HOMO) is not more than -4.8 eV. In the benzothiadiazole compound, the benzothiadiazole skeleton and the oligothiophene skeleton are alternately covalently bonded. The benzothiadiazole skeleton : oligothiophene skeleton ratio is in the range of 1 : 1 to 1 : 2 excluding 1 : 1. The number of thiophene rings contained in one oligothiophene skeleton is 3 or more and 12 or less.

Description

technical field

[0001] The present invention relates to an electron-donating organic material, a material for a photovoltaic element, and a photovoltaic element using the same. Background technique

[0002] A solar cell is attracting attention as an environmentally excellent electric energy source. Currently, inorganic substances such as single crystal silicon, polycrystalline silicon, amorphous silicon, and compound semiconductors are used as semiconductor raw materials for photovoltaic elements of solar cells. However, solar cells manufactured using inorganic semiconductors have not been widely used in ordinary households due to their high cost compared with thermal power generation, atomic power generation, and other power generation methods. The reason for the high cost is mainly due to the step of manufacturing the semiconductor thin film under vacuum and high temperature. Therefore, in order to simplify the manufacturing steps, organic solar cells using organic semic...

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