The Effect of Pressure on the Growth of Single-Layer Graphene on Copper Sheets by Chemical Vapor Deposition Methods

Chemical Vapor Deposition (CVD) is an effective method for large-scale graphene growth, but the growth of single-layer graphene using this process is relatively difficult. In this study, the morphological and structural properties of graphene grown by CVD on a copper substrate were investigated at four pressures: 5, 50, 100, and 1000 mbar. The formation mechanism is such that methane gas molecules collide with the copper surface after breaking their own bonds and are absorbed onto the copper surface. Based on Field Emission Scanning Electron Microscopy images, the graphene grown at 5 mbar pressure was a single-layer graphene without wrinkles, while wrinkles were observed at higher pressures due to the high gas density. In addition, according to the Raman results, the number of graphene layers grown increased with increasing pressure, leading to a decrease in the I-2D/I-G ratio from 2.07 to 0.5 cm(-1).