White Light Electroluminescence from Zinc Oxide Nanowire Composites

We report the white light emission of the zinc oxide (ZnO) nanowires/insulator composite films by low-cost hydrothermal method. The hybrid composite film consists of ZnO nanowires and insulator materials of polymethyl methacrylate (PMMA) and spin-on-glass (SOG) respectively. The ZnO EL device with PMMA shows a peak at 595 nm and the one with SOG shows a peak at 560 nm under bias of 9 V. The above emissions are contributed by the high concentration of ZnO surface defects (oxygen vacancies). The bandwidth of the white light emission spans as wide as 400 nm, which is attributed to the interaction between the surface of ZnO nanowires and insulator components of the hybrid film. We further investigate the morphology of the hybrid film by field emission scanning electron microscope (FESEM).