Structural and electrical properties of p-type ZnO films prepared by Ultrasonic Spray Pyrolysis

Effects of atomic ratio of Zn:N:Al and solution concentration on the structural and electrical characteristic of ZnO films deposited by Ultrasonic Spray Pyrolysis using N-Al co-doping technique were investigated. Hall measurement indicated that with increasing Al doping, conductive type of ZnO thin films changed from n-type to p-type and then to n-type again. However, the solution concentration almost has no effect on the structural and electrical properties of p-type ZnO films. X-ray Photoelectron Spectroscopy indicated that the presence of Al indeed facilitates the incorporation of N through the formation of N-Al bonds in co-doped ZnO films. In addition, Photoluminescence spectra showed p-type ZnO films with a low density of native defects.