Abstract
Based on first-principles calculations, a model for large-size-mismatched group-V dopants in ZnO is proposed. The dopants do not occupy the O sites as is widely perceived, but rather the Zn sites: each forms a complex with two spontaneously induced Zn vacancies in a process that involves fivefold As coordination. Moreover, an complex may have lower formation energy than any of the parent defects. Our model agrees with the recent observations that both As and Sb have low acceptor-ionization energies and that to obtain -type ZnO requires O-rich growth or annealing conditions.
- Received 12 September 2003
DOI:https://doi.org/10.1103/PhysRevLett.92.155504
©2004 American Physical Society