Graphene-Based Polymer Bulk Heterojunction Solar Cells

We propose and demonstrate BHJs that utilize pristine graphene in order to facilitate exciton dissociation and charge transfer in polymeric solar cells. Devices based on P3HT:PCBM:graphene were fabricated on patterned ITO glass, and the effect of graphene on performance was investigated. Various device parameters including short-circuit current density, open-circuit voltage, fill factor, power conversion efficiency, and external quantum efficiency are compared with traditional BHJs. Results are discussed in the context of the morphology of the active layer, and the distribution and orientation of graphene platelets, as characterized by GIXRD, and neutron reflectometry.