Effects of heat-treatment and hydrogen adsorption on Graphene grown on Cu foil

Graphene has recently been a subject of intense research efforts due to its remarkable physical properties as an ideal two-dimensional material. While numerous different methods for graphene synthesis are being explored, CVD-grown graphene on Cu foil presents the possibility of a large-scale and high-quality synthesis of graphene. [1] To improve the quality of graphene films on Cu foil prepared by CVD and better understand its microscopic growth, atomic-scale characterization becomes of great importance. We have investigated the effects of thermal annealing and hydrogen adsorption/desorption on \textit{ex-situ} CVD-grown monolayer graphene on polycrystalline Cu foil at the atomic-scale using ultrahigh vacuum scanning tunneling microscopy, and we will report on these studies. \\[4pt] [1] Li et al, Science \textbf{324}, 1312 (2009).