Effect of UV light-induced nitrogen doping on the field effect transistor characteristics of graphene

Abstract

The effect of nitrogen doping on graphene was characterized without exposing the prepared specimen to the atmosphere. Nitrogen doping was done via a photochemical process at room temperature, in which graphene on SiO₂/Si was irradiated by UV light in ammonia. Field effect transistor measurements revealed that the UV-irradiation of graphene in NH₃ causes electron doping of ∼10¹² cm⁻² (∼0.01%) as a result of N-doping, which can be controlled by changing the irradiation time. Comparing the transfer characteristics and the Raman spectra, we discuss the structure of the graphene functionalized via photochemical reactions, and the corresponding electronic structure.