Vertically aligned ZnO nanorod array/CuO heterojunction for UV detector application

Abstract

Vertically aligned ZnO nanorod array (ZNA) was deposited by electrodeposition technique over glass substrate coated with Al doped ZnO (AZO). The photo-luminescence spectrum of the ZNA showed a near band edge emission and deep level emission (DLE). The resolved DLE spectrum indicates the formation of various defect levels within the band gap of ZnO. P-type CuO was deposited on ZNA to form ZNA/CuO heterojunction. The voltage-current (V-I) characteristics show a turn on voltage of 0.65V. The device showed good rectification behavior and a rectification ratio of 50 at 1V. The heterojunction with a device structure AZO/ZNA/CuO/Au showed good response on ultra violet (UV) illumination. The device has stability even after long exposures to atmospheric conditions and UV light.