Mn2+-Bonded Reduced Graphene Oxide with Strong Radiative Recombination in Broad Visible Range Caused by Resonant Energy Transfer

The photoluminescence (PL) characteristics of Mn2+-bonded reduced graphene oxide (rGO) are studied in details. The Mn2+-bonded rGO is synthesized using MnO2-decorated GO as the intermediate products and ideal tunable PL is obtained by enhancing the long-wavelength (450-550 nm) emission. The PL spectra excited by different wavelengths are analyzed to elucidate the mechanism, and the resonant energy transfer between Mn2+ and sp(2) clusters of the rGO appears to be responsible for the enhanced long-wavelength emission. To examine the effect of Mn2+ on the long-wavelength emission from the Mn2+-bonded rGO, the PL characteristics of Mn2+-bonded rGO with smaller Mn concentrations are studied and weaker emission is observed. Our theoretical calculation corroborates the experimental results.