Nearly white light photoluminescence from ZnO/rGO nanocomposite prepared by a one-step hydrothermal method

Abstract

A zinc oxide (ZnO)/reduced graphene oxide (rGO) nanocomposite was prepared by a facile one-step hydrothermal method, i. e., the reduction from graphene oxide (GO) to rGO and the growing of ZnO nanocrystals on rGO were accomplished simultaneously. ZnO/rGO nanocomposite was proved to be made of flower-like ZnO nanocrystals enwrapped by rGO voiles. Under the excitation of ultraviolet light, the photoluminescence (PL) from ZnO/rGO exhibits a broad emission band spanned from ∼350 nm to ∼800 nm, and as an integral a nearly white light PL with a chromaticity coordinate of (∼0.25, ∼0.23) was obtained. Through Gaussian fitting process, the broad PL band was decomposed into six PL peaks, which were attributed to the radiative recombinations from ZnO and rGO, respectively. An analysis on the PL mechanism verified that the synergistic effect between the two constituent parts plays an important role in modulating the PL peak positions and intensities through enhancing or restraining the transport and transition process. Our experiments might provide an alternative path for preparing high-quality solid-state white light sources using ZnO/rGO as ultraviolet-activated phosphors.