High-temperature photoluminescence properties of various defects in hydrothermally grown ZnO microrods

High-temperature photoluminescence properties of hydrothermally grown ZnO microrods were reported. Photoluminescence spectra of ZnO microrods deconvoluted into three Gaussian components: near band edge (NBE) emission, Violet emission (VL) and Yellow emission (YL) peaks corresponding to free excitons, zinc vacancies and interstitial oxygen atoms, respectively. Increasing the temperature caused a redshift of the energy position of the NBE and VL peaks and a blueshift of the energy position of the YL peak were observed. In the temperature range from 300K to 473K, the intensities of the NBE and VL bands varied based on a nonlinear pattern. Intensity of these emission bands decreases from temperature 473K-673K. As the temperature increases, changes in the energy and crystal structures of the material due to decrease in the concentration of defects cause a blueshift of the emission bands related to interstitial atoms, and a redshift of the emission bands related to vacancies.