Films which had been prepared at various temperatures, and annealed at 900C in O, were studied using photoluminescence and X-ray photo-electron spectroscopy. It was observed that, in the photoluminescence of as-grown films, the green luminescence and the yellow luminescence were related. After annealing, the green luminescence was restrained and the yellow luminescence was enhanced. The O 1s X-ray photo-electron spectroscopy results also revealed the coexistence of O vacancies (VO) and interstitial O (Oi) before annealing, and quenching of the VO after annealing. By combining the 2 results, it was deduced that the green and yellow luminescences were related to the VO and Oi defects, respectively.

Investigation of Oxygen Vacancy and Interstitial Oxygen Defects in ZnO Films by Photoluminescence and X-ray Photoelectron Spectroscopy. H.B.Fan, S.Y.Yang, P.F.Zhang, H.Y.Wei, X.L.Liu, C.M.Jiao, Q.S.Zhu, Y.H.Chen, Z.G.Wang: Chinese Physics Letters, 2007, 24[7], 2108-11