GaZn-VZn acceptor complex defect in Ga-doped ZnO

Abstract

Gallium (Ga)-doped ZnO is regarded as a promising plasmonic material with a wide range of applications in plasmonics. In this study, zinc self-diffusion experiments are adopted to disclose the nature of the dominant compensating defect in Ga-doped ZnO isotopic heterostructures. The (GaZn-VZn)− complex defect, instead of the isolated VZn2−, is identified as the predominant compensating acceptor center responsible for the low donor doping efficiency. The comparative diffusion experiments operated by the secondary ion mass spectrometry reveal a ~0.78 eV binding energy of this complex defect, which well matches the electrical activation energy derived from the temperature-dependent Hall effect measurements (~(0.82±0.02) eV). These findings contribute to an essential understanding of the (GaZn-VZn)− complex defect and the potential engineering routes of heavily Ga-doped ZnO.