Influence of chirality on the cyclohexene-fused C60 fullerene derivatives as an accepter partner in a photovoltaic cell

Organic photovoltaic devices (OPVs) using chiral cyclohexene-fused [C-60]-fullerene derivatives that have (l)-menthyl ester moiety have been prepared and their properties evaluated as acceptor molecules with P3HT polymer: racemic cyclohexene-fused [C-60] fullenene, (RS )-(1R,2S,5R)-2a showed higher PCE (2.81%) than that of standard [C-60]-PCBM (2.64%) under the same analysis conditions. On the contrary, devices using chiral (R)-(1R,2S,5R)-2a and (S)-(1R,2S,5R)-2a, showed PCE as 1.08% and 1.10%, respectively. The main origin of the differences in PCE was found to be their poor J(SC) values. The results indicate that the aggregation state might influence the interaction state with P3HT and impact the results of the OPV properties, J(SC )values in particular. (C) 2016, Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.