Effects of substrate temperature on structural, electrical and optical properties of As-doped ZnO films

As-doped ZnO films were prepared by co-sputtering ZnO and Zn3As2 targets on glass substrates at various temperatures from 250 to 500 °C. The effects of substrate temperature on structural, electrical and optical properties of the films were investigated. The films grown at temperatures from 250 to 400 °C were c-axis oriented and those deposited above 400 °C exhibited poor crystallinity. Hall measurement showed that p-type ZnO:As films were prepared at different temperatures. With increasing the substrate temperature from 250 to 500 °C, the optical band gap (Eg) first decreased, and then increased. The Eg changes upon the substrate temperature were due to the effect of substrate temperature on the crystallinity of ZnO films.