Anomalous Behaviors of Graphene Transparent Conductors in Graphene-Silicon Heterojunction Solar Cells

An unexpected behavior of graphene in graphene–silicon heterojunction junction solar cells when it is used as the window electrode is reported. Although the synthesized mono layer graphene exhibits better transparency and conductivity, the multilayer graphene enables much higher solar conversion ability of the solar cell. This surprising observation may be because the multilayer graphene can more effectively suppress charge recombination at the heterojunction interface, which increases the fill factor and enhances the cell performance.