Photoresponse in graphene induced by defect engineering

We present a photoresponse study on a lateral defect/pristine graphene junction device fabricated by a simple plasma irradiation method. The junction between pristine graphene and plasma-modified graphene was created by controlling the location of Ar+ plasma treatment. We found that a distinct photocurrent was generated at the junction by photocurrent line scanning measurements, and further analysis reveals that the photo-thermoelectric (PTE) effect, instead of the photovoltaic (PV) effect, dominates the photocurrent generation at the interface. Additionally, the obtained results suggest that tuning the defect density could be effective in modulating the optoelectronic performance of junctions in our device.