Gate-dependent photoresponse in self-assembled graphene p-n junctions

The intrinsic photocurrent generation mechanism of a self-assembled graphene p–n junction operating at 1.55 μ is investigated experimentally. It is concluded that both a photovoltage effect and a photothermoelectric effect contribute to the final photocurrent. The photocurrent signal at the p–n junction was found to be dominated by photothermoelectric current, arising from different self-assembled doping levels.