Realization of ultraviolet electroluminescence from ZnO homojunction with n-ZnO∕p-ZnO:As∕GaAs structure

ZnO homojunction light-emitting diode with n-ZnO∕p-ZnO:As∕GaAs structure is produced by metal organic chemical vapor deposition. The p-type ZnO:As film is obtained out of thermal diffusion of arsenic from GaAs substrate with subsequent thermal annealing at 550°C. The n-type layer is composed of unintentionally doped ZnO film. Desirable rectifying behavior is observed from the current-voltage curve of the ZnO p-n homojunction. Furthermore, two distinct electroluminescence bands centered at 3.2 and 2.5eV are obtained from the junction under forward bias at room temperature.