Direct growth of graphene on gallium nitride using C2H2 as carbon source

Growing graphene on gallium nitride (GaN) at temperatures greater than 900°C is a challenge that must be overcome to obtain high quality of GaN epi-layers. We successfully met this challenge using C₂H₂ as the carbon source. We demonstrated that graphene can be grown both on copper and directly on GaN epi-layers. The Raman spectra indicated that the graphene films were about 4–5 layers thick. Meanwhile, the effects of the growth temperature on the growth of the graphene films were systematically studied, and 830°C was found to be the optimum growth temperature. We successfully grew high-quality graphene films directly on gallium nitride.