Ultraviolet-light-emitting ZnO nanosheets prepared by a chemical bath deposition method

Two-dimensional polar-surface-dominated ZnO nanosheets (nanodiscs) with dimensions of several microns and thickness of tens of nanometres were synthesized in bulk quantity at low temperature (∼70 °C) by a simple and environmentally benign chemical bath deposition (CBD) method. These ZnO nanosheets are of single-crystal wurtzite structure; they grow along the crystallographic directions within polar 0001 planes. This is different from previous reported films or nanowire arrays prepared by the CBD method. Raman scattering spectrum studies confirm that the as-synthesized nanosheets are of high crystal quality and indicate an optical phonon confinement effect in such ZnO nanosheets. These nanosheets show a sharp intrinsic ultraviolet excitonic emission peak centred at 380 nm at room temperature, have large surface area exposed to the gaseous environment, and could be an ideal ultraviolet light source or objects for the fabrication of nanoscaled devices.