▎ 摘　　要

Large-area mono- and bilayer graphene films were synthesized on Cu foil (similar to 1 in.(2)) in about 1 min by a simple ethanol-chemical vapor deposition (CVD) technique. Raman spectroscopy and high resolution transmission electron microscopy revealed the synthesized graphene films to have polycrystalline structures with 2-5 nm individual crystallite size which is a function of temperature up to 1000 degrees C. X-ray photoelectron spectroscopy investigations showed about 3 at.% carboxylic (COOH) functional groups were formed during growth. The field-effect transistor devices fabricated using polycrystalline graphene as conducting channel (L(c) = 10 mu m; W(c) = 50 mu m) demonstrated a p-type semiconducting behavior with high drive current and Dirac point at similar to 35 V. This simple one-step method of growing large area polycrystalline graphene films with semiconductor properties and easily functionalizable groups should assist in the realization of potential of polycrystalline graphene for nanoelectronics, sensors and energy storage devices. (C) 2011 Elsevier Ltd. All rights reserved.