Influence of ambient conditions on the electronic structure of graphene/copper interface

Abstract

Graphene films grown on the copper foils using chemical vapor deposition have been emphasized in the previous scientific studies and technical applications because of the high quality/cost ratio. However, no enough attention has been paid to the fundamentally important issue on the stability of graphene/copper interface compared with quality of the grown graphene films, though the properties of graphene/metal interface largely affect the Ohmic contacts in graphene‐based electronics (e.g. high‐frequency graphene transistors). Here, we investigated the electronic structure of graphene/copper interface which has been stored in the ambient conditions for different periods. Raman and photoelectron spectroscopic data indicated that the oxygen species do not prefer to adsorb on the graphene surface but insert into the graphene/copper interface. This results in the p‐doping of graphene, formation of the surface positive dipole, and energy upshift of the graphene's Dirac point. Copyright © 2015 John Wiley & Sons, Ltd.