Effect of annealing temperature on the properties of Ag doped ZnO thin films

Abstract

ZnO-Ag thin layers were prepared by thermal evaporation under vacuum and then subjected to recrystallization annealing heat treatment under atmosphere at 300, 400 and 500 °C to ensure oxidation and crystallization of ZnO. The results showed the evolution of these properties as a function of the annealing temperature. XRD analysis indicate that the crystallization of ZnO increase with annealing temperatures. The same observation was underlined for the transmittance with annealing temperature. However, the samples without annealing and those annealed at 300 and 400 °C appeared to be conductive with a resistance of 1.1 Ω, 0.67 Ω and 2.1 Ω while the sample annealed at 500 °C have a resistance of 1.73.105 Ω which belongs to a semiconductor material. As recognized, the hardness of the deposited layers as a function of the grain size does not respect the Hall-Petch relationship because of the grains size lower than 100 nm.