Tunable optical properties of OH-functionalised graphene quantum dots

Graphene oxide quantum dots (GO-QDs) have distinct optoelectronic properties for their application in bio-imaging, drug delivery and photovoltaics. Herein, the effect of OH functionalisation on the optical properties of GO-QDs is studied based on state-of-the-art theoretical simulations. Our calculations predict the effect of OH groups on ionisation potentials, light absorption and emission properties. The mechanism of fluorescence is analysed considering the role of geometry distortion and charge transfer. Moreover, selective functionalisation of positions with large electron-hole separation offers a strategy to tune the optical gap and photoluminescence properties. These results open up new opportunities for the design of GO-QDs for a wide range of applications.