Direct growth of large-area graphene films onto oxygen plasma-etched quartz for nitrogen dioxide gas detection

We report a simple oxygen plasma-etching of quartz substrates as an active surface for efficient growth of graphene films through a chemical vapour deposition process. The resulting graphene films prepared on the oxygen plasma-etched quartz surface exhibited a high optical transmittance of 95.3% coupled with a sheet resistance of similar to 4.6 k Omega sq(-1). We also demonstrated that the as-grown graphene films had a high sensitivity to NO2 at low parts-per-million level in air at room temperature. Our work suggested that the as-grown films on quartz can be used as chemoresistive sensors for transparent electronics applications.