Disclosed are soluble diarylmethanofullerene derivatives that are effective as acceptors for organic thin-film solar batteries. They help to constitute effective organic thin-film solar batteries.
A number of diarylmethanofullerene derivatives were synthesized. The cyclopropane ring of the derivatives has two aryl groups substituted with electron-withdrawing and -donating groups, the latter with long alkylchains to improve solubility in organic solvents, an important property in processing cells. First reduction potentials of most derivatives were less negative than that of [6,6]-phenyl-C61-butyric