The formation and evolution of O vacancies in ZnO white paint during <200keV protons exposure was investigated using photoluminescence spectroscopy. After irradiation, the shape of photoluminescence spectra changes little, but the peak height decreased. With increasing fluence, the amount of doubly ionized O vacancies decreased, while that for the singly ionized O vacancies increased. The former could trap electrons in the conduction bands to become the singly ionized O vacancies, leading to that the latter gradually becoming the major defects induced by irradiation. The increase in content of singly ionized O vacancies due to the irradiation could also promote an increase in the amount of absorbed O in the paint, enhancing the quenching effect of photoluminescence and thus decreasing the photoluminescence peak.

Formation and Evolution of Oxygen Vacancies in ZnO White Paint during Proton Exposure. H.Xiao, M.Sun, C.Li, D.Yang, B.Han, S.He: Nuclear Instruments and Methods in Physics Research B, 2008, 266[14], 3275-80