Raman and optical characterization of multilayer turbostratic graphene grown via chemical vapor deposition

We synthesize large-area graphene via atmospheic-pressure (AP) chemical vapor deposition (CVD) on copper, and transfer to SiO(2) wafers. In contrast to low-pressure CVD on copper, optical contrast and atomic force microscopy measurements show AP-CVD graphene contains significant multi-layer areas. Raman spectroscopy always shows a single Lorentzian 2D peak, however systematic differences are observed in the 2D peak energy, width, and intensity for single-and multi-layer regions. We conclude that graphene multi-layers grown by AP-CVD on Cu are rotationally disordered. (C) 2011 American Institute of Physics. [doi:10.1063/1.3605545]