Chemical vapor deposition of graphene on large-domain ultra-flat copper

Copper foil is the most commonly used substrate for chemical vapor deposition (CVD) growth of graphene, despite the impact of its surface roughness and polycrystalline structure on the resulting graphene. Here we present a method of preparing thick, ultra-flat copper substrates for growing graphene by CVD. We demonstrate the growth of graphene on these substrates using the common Atmospheric Pressure CVD (APCVD) and Low Pressure CVD (LPCVD) methods. We show that compared to copper foil, graphene grown on these thick ultra-flat copper substrates by APCVD results in 50 times smoother graphene on copper. Furthermore, the thick copper substrates have at least 5 times larger copper domains, compared to conventionally prepared copper foil. The evolution of the surface roughness in each growth method is also presented.