Photochemical doping of graphene oxide thin film with nitrogen for photoconductivity enhancement

Abstract N-doped graphene oxide (NGO) thin film is synthesized by irradiation of graphene oxide (GO) thin film in NH 3 atmosphere. NGO thin film obtained by irradiation of GO thin film for 60 min has a high N-doping level of 12.69 at.%, and the amino-like N dominates the doping with the level of 7.90 at.%. The photoconductivity properties of NGO thin film under white-light illumination have been systematically examined. The results show that compared to reduced graphene oxide (rGO) thin film, NGO thin film exhibits significant photoconductivity enhancement with a high ratio of 2000%, and shows a faster photoresponse. The current responsivity and external quantum efficiency values for the NGO film reach ∼31 mA W −1 and ∼87% at 2 V, respectively. It may attribute to the high doping level of amino-like N on the basal plane and the pyridine-like N at the vacancy-site of graphene sheets, which can offer substantial photocarriers and the effective transfer to the electrodes.