Synthesis of the Nitrogen-doped CVD Graphene through Triazine

Abstract

Nitrogen-doped graphene (N-graphene) was prepared via molecular doping from symTriazine molecules at low temperature. The phase structure, morphology and electrical property were characterized by Raman spectroscopy (Raman), X-ray photoelectron spectroscope(XPS), atomic force microscope (AFM), ultraviolet spectrophotometer(UV), and Hall tester. Here the method provides a simple and safe process to grow N-graphene. The morphology of N-graphene retains good uniformity, and the transmittance of the graphene is 95% in the range from 300 nm to 800 nm. The typical graphene peaks G-band and 2D-band both upshift after doping. The hole-carrier concentration is decreased immediately after Triazine decoration. After exposure to Triazine for 3 h, the charge-carrier concentration of N-graphene remains as high as 4×1012/cm2, which approaching the pristine Chemical Vapor Deposition (CVD) graphene's carrier concentration due to the abundant molecular doping. After N-graphene annealed at 450℃, a hole-carrier concentration of ~8×1012/cm2 can be regenerated. The sheet resistance of N-graphene can stay steady at 300℃. The mechanism of Triazine doping is that Triazine is an electron-rich aromatic molecule due to the incorporation of N atoms in the aromatic ring, and some negative charges are expected to transfer onto the graphene. This research provides a simple method to obtain N-graphene doping for future application in electrical devices.