Studies on magnetron-sputtered V2O5/ZnO thin films

Abstract

Crystalline vanadium oxide (V2O5) thin films were grown over zinc oxide (ZnO) buffer layer-coated glass substrates at room temperature by magnetron sputtering technique. Initially, ZnO thin films have been formed by oxidizing sputtered zinc films at different annealing temperatures (300–500°C) in ambient air for 1 h. The influence of ZnO buffer layer on the structural, morphological, optical and electrical properties of the V2O5 films was studied using the X-ray diffraction (XRD), field-emission scanning electron microscopy, energy-dispersive analysis of X-rays, ultraviolet–visible spectrophotometry and four-point probe method. The thickness values of the deposited films were measured using the stylus probe profilometer. XRD patterns of the V2O5 deposited over ZnO (VZO) showed reflection planes corresponding to V2O5 and ZnO buffer layer. The optical studies showed the enhancement on the optical properties of V2O5 films deposited over ZnO buffer layer. The electrical studies of the VZO films showed that the resistivity of VZO films varied from 400 to 60 Ω cm. The enhancement in the optical and electrical properties may be due to the improvement in the crystallinity of the film because of ZnO buffer layer.