Fairly pure ultraviolet electroluminescence from ZnO-based light-emitting devices

Fairly pure ultraviolet (UV) electroluminescence (EL) was realized on a ZnO-based metal-insulator (SiOx,x <= 2)-semiconductor structure on a silicon substrate, which was easily fabricated by the reactive direct current sputtering and electron beam evaporation. The UV EL originated from the near-band-edge (NBE) emission of ZnO was achieved at room temperature when the device was under sufficient forward bias with the negative voltage applied on the silicon substrate. Moreover, the intermediate SiOx layer should be thick enough to confine the electrons in the conduction band of ZnO beneath the ZnO/SiOx interface, which is critical for generation of NBE emission from ZnO. (c) 2006 American Institute of Physics.