Enhancing the Open-circuit Voltage of Organic Thin Film Solar Cells by Modifying the Structure of Fullerene

Organic photovoltaic devices( OPVS) have attracted much attention due to their low cost,light weight,and flexible features. Fullerenes have been regarded as the best choice for the acceptors. Methyl[6,6]-phenyl-C61-butylate( [C60]- PCBM) is known to be the best blending material among these derivatives as acceptor,but the relatively low LUMO level has limited the further improvement of open-circuit voltages. Researches were done to change the structures of fullerenes to achieve high LUMO level and Voc. This review summarizes the methods to achieve high Voc by structure modifying of fullerene derivatives and expound structure-property relationship between the acceptors and photovoltaic devices,which could provide valuable information for future material exploitation.