| abstract |
An electron donating organic material includes a benzothiadiazole compound including (a) a benzothiadiazole skeleton and (b) an oligothiophene skeleton, and having a band gap (Eg) of 1.8 eV or less, and a level of highest occupied molecular orbital (HOMO) of −4.8 eV or less, wherein said benzothiadiazole compound is formed by covalently combining the benzothiadiazole skeleton and the oligothiophene skeleton alternately, a proportion between the benzothiadiazole skeleton and the oligothiophene skeleton is within a range of 1:1 to 1:2 (however, excluding 1:1), and the number of thiophene rings contained in an oligothiophene skeleton is 3 or more and 12 or less. |