Photochemical doping of graphene oxide thin films with nitrogen for electrical conductivity improvement

By using simple irradiation of graphene oxide (GO) thin films in NH3 atmosphere, nitrogen-doped GO (NGO) thin films had been successfully synthesized. It is notable that the reduction and nitrogen doping of graphene are simultaneously achieved by irradiation, and the nitrogen content of NGO could reach as high as 12.34 at.% within only 5 min. With further prolonging the irradiation time to 120 min, it could reach a very high value of 17.21 at.%. The electrical properties of NGO thin films were investigated. The results showed that, compared to irradiation of GO films in Ar atmosphere, irradiation in NH3 atmosphere is much more effective to improve the electrical conductivity. It may attribute to the nitrogen doping and oxygen reduction, both of which can effectively enhance the electrical conductivity.