Abstract
The luminescence of ZnO exhibits a band-edge UV emission peak and a broad emission in the blue-green-red regions associated with the deep level defects as well as the oxygen vacancies and zinc interstitials in the discs. The mechanism of the defect is attributed to the electronic transitions from near conduction band-edge to the deep level acceptors and transitions from the deep donor levels to the valence band. In this study, post-growth annealing was conducted to investigate the mechanism involved in the visible luminescence of ZnO nanoparticle discs prepared. Post-growth thermal annealing can be applied as a new technique in controlling the optical properties of ZnO discs.