With the existence of depletion layer, the intrinsic donor defect structure of ZnO ceramics was investigated by broadband dielectric spectroscopy in a wide temperature range. Two loss peaks originating from electronic relaxation of O vacancy and Zn interstitial, respectively, were observed in ZnO ceramics simultaneously, implying the coexistence of these two intrinsic defects. The corresponding activation energy for electronic relaxation of Zn interstitial and O vacancy were 0.26 and 0.36eV, respectively, which was consistent with other reports

Characterization of Intrinsic Donor Defects in ZnO Ceramics by Dielectric Spectroscopy. Cheng, P., Li, S., Zhang, L., Li, J.: Applied Physics Letters, 2008, 93[1], 012902