Fabrication and performance of N-doped ZnO UV photoconductive detector

We report study on the fabrication and characterization of an ultraviolet (UV) photodetectors based on N-doped ZnO films. The N-doped ZnO films with 10 at% N doping are spray deposited on to alumina substrates. The photoconductive UV detector based on N-doped ZnO thin films, having a metal-semiconductor-metal (MSM) configuration are fabricated using Al as a contact metal. The dependence of I-V characteristic under dark and illumination, spectral and transient photoresponse of the detector are investigated. The linear current-voltage (I-V) characteristics under forward bias exhibit ohmic metal-semiconductor contact. The UV photoconductive effect is observed showing fast response with switching on/off UV light illumination. The neutralization of photogenerated holes by negatively charged oxygen ion plays a key role in the photoconductive characteristics of N-doped ZnO polycrystalline films. (C) 2012 Elsevier B. V. All rights reserved.