Optical and electrical properties of ZnO/Mo/ZnO multilayer films processed at different annealing temperatures

Abstract

ZnO/Mo/ZnO transparent conductive thin films are deposited on Corning glass substrates using an RF magnetron sputtering system. The optical and electrical properties of the thin films are then examined following annealing for 40 min at temperatures ranging from 200 to 450 °C. It is shown that the resistivity of the ZnO/Mo/ZnO films has a low and reducing value at annealing temperatures up to 300 °C. However, the resistivity increases dramatically as the annealing temperature is further increased to 450 °C. The average transmittance of the annealed films generally increases with an increasing annealing temperature as the result of a larger grain size. For an annealing temperature of 450 °C, the maximum transmittance is equal to approximately 85%. Overall, the results suggest that the optimal annealing temperature for the present ZnO/Mo/ZnO films is 300 °C, which results in an electrical resistivity of 6.44 × 10−3 Ω-cm and an optical transmittance of 80%.