Magnetic resonance studies of defects in electron-irradiated ZnO substrates

Optical detection of magnetic resonance (ODMR) was used to study defects in electron-irradiated ZnO substrates. In addition to the shallow donor and the Zn vacancy, several ODMR centers with an effective electron spin <img src="http://ars.els-cdn.com/content/image/1-s2.0-S0921452607007685-si1.gif" data-loaded="true" data-inlimgeid="1-s2.0-S0921452607007685-si1.gif" /> were detected. Among these, the axial LU3 and non-axial LU4 centers are shown to be dominating recombination centers. The annealing behavior of radiation-induced defects was studied and possible defect models are discussed.