Sensitivity of Co doped ZnO films to NH3 at room temperature - Influence of the deposition temperature

Abstract

The sensitivity was studied of undoped ZnO films and doped with Co (ZnO:Co) to exposure to NH3. The films were deposited by magnetron sputtering of a sintered ZnO target and co-sputtering of the ZnO target with Co chips on its surface. The influence of the substrate temperature, Ts, on the properties of the films was studied. The structural and optical properties of the undoped and Co doped ZnO films were studied by X-ray diffraction spectroscopy (XRD) and optical transmittance and reflectance. The optical band gap of the films was calculated. The variation of the sensitivity of films deposited at different Ts with the NH3 concentration is presented. The results demonstrate that the Co doped ZnO films have a higher sensitivity to ammonia and their sensitivity increases with Ts. © 2008 IOP Publishing Ltd.