Ultraviolet electroluminescence from controlled arsenic-doped ZnO nanowire homojunctions

ZnO nanowire arrays were grown on semi-insulating intrinsic GaAs substrates, and controlled arsenic-doping process was carried out to realize the n-ZnO∕p-ZnO nanowire array/GaAs structures. The constructed ZnO nanowire homojunctions demonstrated a clear rectifying behavior and the turn-on voltage was above 4.0V. The corresponding ultraviolet electroluminescence spectra were obtained for the applied forward voltage above 30V (20mA). The distinct ultraviolet electroluminescence peak, centered at 382nm, is nonlinearly enhanced with an increase in the applied forward voltage. The origin of the strong ultraviolet electroluminescence was discussed in terms of the controlled arsenic-doping process.