Single crystalline indene-C-60 bisadduct: isolation and application in polymer solar cells

Six fractions of indene-C-60 bisadducts (IC60BAs) with two indene pendants located at different positions of the C-60 cage were isolated by using the HPLC technique, in which one enantiomeric mixture was purified and the structure was confirmed by single crystal XRD analysis. It was revealed that the isolated IC(60)BA isomers possess an elevated LUMO energy level and afford increased electron mobility, but the solar cells assembled by the isolated IC(60)BA isomers with P3HT did not show high performance due to a serious phase separation between them. The results suggest that for high performance polymer solar cells we should consider not only the energy level matching between the donor and acceptor materials, but also the structural matching between them.