The influence of post-growth annealing on optical and electrical properties of p-type ZnO films

In this study, p-type ZnO films with excellent electrical properties were prepared by ultrasonic spray pyrolysis (USP) combined with a N–Al co-doping technique. The influence of post-growth annealing conditions, i.e., annealing ambient and temperature, on optical and electrical properties of p-type ZnO films was investigated. The dependence of the intensity of the green emission on the annealing ambient indicates that the green emission might originate from the donor defect, oxygen vacancy. The effect of the annealing temperature on electrical properties of ZnO-based films affirms the prominent action of hydrogen in the conductivity and acceptor doping of ZnO films.