Study of the Surface Morphology of Thermally Annealed Copper Foils and Various Transfer Methods for Graphene.

摘要

The surface morphology of thermally annealed copper foils utilized for graphene growth by chemical vapor deposition (CVD) has been studied by Optical microscopy, Scanning Electron Microscopy (SEM), and Scanning Tunneling Microscopy (STM) as a function of heat treatment. This study reports on the surface roughness and relative grain size before and after thermal annealing. The main results are that (a) the graphene covered foil exhibits reduced surface roughness, and (b) the graphene film preserves an imprint of the Cu grain structure. In the second part of the work, the transfer of CVD graphene is ex-perimentally investigated using Poly(methyl methacrylate) (PMMA), Polycarbonate (PC), and Polysty-rene (PS). Noticeable improvement to surface cleanness as well as electrical properties of graphene is observed after the ethanol treatment. Finally, Raman characterization showed apparent blue-shifts of the G and 2D bands suggesting that the graphene is heavily doped after the ethanol treatment.