Oxygen pressure and measurement temperature dependence of defects related bands in zinc oxide films

The ZnO films were fabricated by pulsed laser deposition at various oxygen pressure on single crystal silicon substrate. The structural and optical properties were investigated at various measurement temperature. The results showed that all the films have good c-axis preferred orientation. The different defects in films were fabricated which can be caused by various oxygen pressure. The films deposited at 1 Pa oxygen pressure have the most intense and narrow UV emission, and did not exhibit the deep band emission at the various measurement temperature. With the decrease of measurement temperature, the VO-, Oi- and OZn-related band energy decreases, which is opposed to the VZn-related defects, meanwhile, the intensity of Oi-related emission peak has a sharp increase.