Opto-electronic properties of graphene oxide

In this presentation, a solution based method that allows uniform and controllable deposition of reduced graphene oxide thin films with thicknesses ranging from a single monolayer up to several layers over large areas will be described. The oxidation treatment during synthesis of GO creates sp3 C-0 sites where oxygen atoms are bonded in the form of various functional groups. GO is therefore a two dimensional network of sp2 and sp3 bonded atoms, in contrast to an ideal graphene sheet which consists of 100% sp2 carbon atoms. This unique atomic and electronic structure of GO, consisting of variable spιlsp3 fraction, opens up possibilities for new functionalities. The most notable difference between GO and mechanically exfoliated graphene is the opto-electronic properties arising from the presence of finite band gap. In particular, the photoluminescence can be tuned from blue to red to IR emission. The atomic and electronic structure along with tunable photoluminescence of graphene oxide at various degrees of reduction will be described.