▎ 摘　　要

Continuous and uniform graphene films were directly grown on SiO2 substrates using a chemical vapor deposition system with two-temperature zones assembled. The carbon species from the high temperature zone nucleate in the low temperature zone, initiating the growing process of graphene. The films are predominantly single-layer graphene, with a small percentage of the area having a few layers, whose optical transmittance and electrical conductivity can be comparable with transferred metal-catalyzed graphene. This method avoids the need for either a metal catalyst or a complicated and skilled post growth transfer process and favors the application of graphene as a transparent electrode.