A study on near-UV blue photoluminescence in graphene oxide prepared by Langmuir-Blodgett method

The paper reports a study on a near-UV blue photoluminescence (PL) in graphene oxide (GO) films prepared by Langmuir-Blodgett (LB)-based method. GO films was reduced into reduced-graphene oxide (rGO) through thermal process at 800 °C. The surface morphology of both GO and rGO is characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). X-ray photoelectron spectroscopy (XPS) analysis shows the largely restoration of graphitic domains in GO after reduction. The photoluminescence (PL) of rGO shows the near-UV blue emission, which is blueshifted along with luminescent decreased as compared to GO. This blueshift and decrease in PL is mainly due to the newly formed sp2 clusters in rGO, which established percolation pathways between the sp2 clusters already present.