Preparation and characteristics of transparent p-type ZnO film by Al and N co-doping method

Al–N co-doped ZnO films were fabricated by gaseous ammonia annealing at various temperatures. The structure and the electrical properties of Al–N-doped ZnO films strongly depend on the annealing temperature. XRD and SEM analysis indicate that the ZnO films possess a good crystallinity with c-axis orientation, uniform thickness and dense surface. Optical transmission spectra show a high transmittance (∼85%) in the visible region. Hall measurement demonstrates that ZnO films have p-type conduction with high carrier concentration of 8.3 × 1018 cm−3 and low resistivity of 25.0 Ω cm when the annealing temperature is 700 °C. Also the growth process of Al–N co-doped at various temperatures is discussed in detail.