Improving photovoltaic properties by incorporating graphene into P30T/PCBM photovoltaic devices

Summary form only given. We report the optoelectronic properties occurring in solution-processable functionalized graphene(SPFGraphene)-PCBM/poly(3-octylthiophene)(P3OT) composites. The structural configuration of devices is ITO/PEDOT:PSS/P3OT:PCBM-SPFGraphene/LiF/Al. The best results were obtained with a P3OT/PCBM (1:1) mixture with 8wt% of SPFGraphene is open-circuit voltage (Voc) of 0.65V, a short-circuit current density (Jsc) of 4.2mA/cm² and a FF of 0.35 which led to a power conversion efficiency of 0.95% at illumination at 100mW/cm² AM 1.5. In the P3OT:PCBM-SPFGraphene composite, the SPFGraphene acted as exciton dissociation sites and provided the transport pathway of LUMO-graphene-Al. Doping of SPFGraphene into P3OT resulted in appropriate energetic distance between HOMO and LUMO of the donor/acceptor for a high open circuit voltage and provided higher exciton dissociation volume mobility of carrier transport for a large short-circuit current density.