Correlations between low temperature thermoluminescence and oxygen vacancies in ZnO crystals

Low temperature thermoluminescence spectra of zinc oxide single crystals are presented in this paper. The signals can be interpreted in terms of annealing and inter-conversion of oxygen vacancy sites. Minor differences between signals from different suppliers suggest such vacancies are perturbed by association with complexes and impurities. Significant changes of bulk signals result from high dose surface ion implantation. This is an important demonstration of extremely long range effects resulting from ion implantation into the surface layer. Such extensive changes have rarely been considered, or experimentally sought. It is therefore fortunate that for ZnO the thermoluminescence signals offer a sensitive probe to monitor this phenomenon. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3556743]