Intrinsic point defect balance in self-ion implanted ZnO

Abstract

The role of excess intrinsic atoms for residual point defect balance has been discriminated by implanting Zn or O ions into Li-containing ZnO and monitoring Li redistribution and electric resistivity after post-implant anneals. Strongly Li depleted regions were detected in the Zn implanted samples at depths beyond the projected range (Rp) upon annealing ≥ 600 ◦C, correlating with a resistivity decrease. In contrast, similar anneals of the O implanted samples resulted in Li accumulation at Rp and an increased resistivity. Control samples implanted with Ar or Ne ions, yielding similar defect production as for the Zn or O implants but with no surplus of intrinsic atoms, revealed no Li depletion. Thus, the depletion of Li shows evidence of excess Zn interstitials (ZnI) being released during annealing of the Zn implanted samples. These ZnI’s convert substitutional Li atoms (LiZn) into higly mobile interstitial ones leading to the strongly Li-depleted regions. In the O-implanted samples, the high resistivity provides evidence of stable OI-related acceptors.

2013 American Physical Society