High performance n-ZnO/p-metal-oxides UV detector grown in low-temperature aqueous solution bath

In this paper we report fabrication and characterization of ZnO based hetero-junctions by chemical bath deposition and study the structural properties and photo-detection of samples. Since the ZnO is intrinsically n-type, two different metal oxide thin films, NiO and CuO, are used to serve as p-layer and create ZnO/NiO(CuO) junctions to be used as photodetector. Results confirm photo-detectivity of samples however for ZnO/CuO/NiO junction higher photo/dark current ratio about 55 can be achieved in UV wavelengths and at room temperatures. The proposed detector exhibits very fast response when exposed to the light source however its current decreases slowly by turning the source off. Simplicity of growth beside high responsivity are important advantages of this type of UV photodetectors.