Fabrication and photoresponse of a pn-heterojunction diode composed of transparent oxide semiconductors, p-NiO and n-ZnO

Transparent trilayered oxide films of ZnO/NiO/indium tin oxide were heteroepitaxially grown on a YSZ (111) substrate by pulsed-laser deposition combined with a solid-phase-epitaxy technique, and were processed to fabricate a p-NiO/n-ZnO diode. The diode exhibited a clear rectifying I-V characteristic with an ideality factor of similar to2 and a forward threshold voltage of similar to1 V. Although the photoresponsivity was fairly weak at the zero-bias voltage, it was enhanced up to similar to0.3 A W-1 through the application of a reverse bias of -6 V under the irradiation of 360 nm light, a value comparable to that of commercial devices. (C) 2003 American Institute of Physics.