  Current methods of chemical vapor deposition (CVD) of graphene on copper are
complicated by multiple processing steps and by high temperatures required in
both preparing the copper and inducing subsequent film growth. Here we
demonstrate a plasma-enhanced CVD chemistry that enables the entire process to
take place in a single step, at reduced temperatures (< 420 C), and in a matter
of minutes. Growth on copper foils is found to nucleate from arrays of
well-aligned domains, and the ensuing films possess sub-nanometre smoothness,
excellent crystalline quality, low strain, few defects and room temperature
electrical mobility up to (6.0 +- 1.0) x 10^{4} cm^{2}V^{-1}s^{-1}, better than
that of large, single-crystalline graphene derived from thermal CVD growth.
These results indicate that elevated temperatures and crystalline substrates
are not necessary for synthesizing high-quality graphene.
