Making Graphene Luminescent by Oxygen Plasma Treatment

We show that strong photoluminescence (PL) can be induced in single-layer graphene using an oxygen plasma treatment. The PL is spatially uniform across the flakes and connected to elastic scattering spectra distinctly different from those of gapless pristine graphene. Oxygen plasma can be used to selectively convert the topmost layer when multilayer samples are treated.A.C.F., K.S.N., and A.K.G. thank the Royal Society and the European Research Council (Grants NANOPOTS and GRAPHENE), A.H. the Deutsche Forschungsgemeinschaft (DFG-grant HA4405/4-1) and Nanosystems Initiative Munich (NIM), A. L. from the University of Palermo, Italy