▎ 摘　　要

We investigated the effect of process parameters, such as the temperature, gas flow rates, and process time, on the number of graphene layers produced by atmospheric pressure chemical vapor deposition (APCVD). The objective was to obtain single-layer graphene. Single-layer graphene was synthesized on copper foils by APCVD under gas flow conditions of CH4:H-2:Ar = 1:90:1500 (sccm) at 975 degrees C. The number of graphene layers increased as the methane concentration increased. Single-layer graphene grains became hexagonal in shape and increased in area with higher ratios of hydrogen or methane in the mixture. The properties of graphene were analyzed by Raman spectroscopy and field emission-scanning electron microscopy. The number of graphene layers was evaluated by analyzing the Raman spectra and ultraviolet-visible transmittance.