Visual-infrared electroluminescence emission from ZnO∕GaAs heterojunctions grown by metal-organic chemical vapor deposition

The light-emitting diode of p-ZnO∕n-GaAs heterojunction was grown by metal-organic chemical vapor deposition. The p-ZnO films have been formed by the doping As atoms which diffuse into ZnO film from GaAs substrate. The p-type behavior of As-doped ZnO films based on As-doped p-ZnO∕n-GaAs, p-ZnO∕p-GaAs heterojunction was studied by carrying out I-V measurements and x-ray photoelectron spectroscopy. The I-V characteristic of p-ZnO∕n-GaAs heterojunction showed characteristic of rectifying diode and visual-infrared electroluminescence emission under forward current injection at room temperature. The I-V of the heterounction had a threshold voltage of ∼2.5V.