Micro-Raman spectroscopy and electrical conductivity of graphene layer on SiO2 dielectric subjected to electron beam irradiation

Abstract

The effect of electron beam irradiation on the structure and doping of the graphene film located on the silicon dioxide substrate is investigated, and its influence on carrier transport mechanism is discussed. Local potential measurements have shown that the graphene layer synthesized by CVD method on Cu foil has a granular structure with the grain size of about 3–5 μm. Micro-Raman analysis along the graphene film between the metal contacts demonstrates that at low doses electron beam irradiation leads to the generation of an additional positive charge in the silicon dioxide layer, which results in fluctuations of the graphene film doping that, in turn, considerably decreases electrical conductivity of graphene. Further increase of electron beam irradiation dose leads to formation of structural defects directly in the graphene layer in addition to doping fluctuations.