pubmed-article:21631285 | pubmed:abstractText | Space radiation damage in ZnO induced by subthreshold electrons was studied through reflectance spectra, electron paramagnetic resonance, and photoluminescence. Owing to the vacuum freezing treatment, perturbed singly ionized zinc vacancies (V'(Zn)?), chemisorbed species, and electrons in the conduction band and/or bound to shallow donor levels were observed. V'(Zn)? is due to the ionization and the ionization-induced diffusion processes and is most likely responsible for the 420-nm absorption band. These results also support that the green luminescence in ZnO is related to zinc vacancies. | lld:pubmed |