Oxygen-Aided Synthesis of Polycrystalline Graphene on Silicon Dioxide Substrates

Abstract

We report the metal-catalyst-free synthesis of high-quality polycrystalline graphene on dielectric substrates [silicon dioxide (SiO₂) or quartz] using an oxygen-aided chemical vapor deposition (CVD) process. The growth was carried out using a CVD system at atmospheric pressure. After high-temperature activation of the growth substrates in air, high-quality polycrystalline graphene is subsequently grown on SiO₂ by utilizing the oxygen-based nucleation sites. The growth mechanism is analogous to that of growth for single-walled carbon nanotubes. Graphene-modified SiO₂ substrates can be directly used in transparent conducting films and field-effect devices. The carrier mobilities are about 531 cm² V^–1 s^–1 in air and 472 cm² V^–1 s^–1 in N₂, which are close to that of metal-catalyzed polycrystalline graphene. The method avoids the need for either a metal catalyst or a complicated and skilled postgrowth transfer process and is compatible with current silicon processing techniques.