Stable interstitial dopant–vacancy complexes in ZnO

Using ab initio calculations, we have identified stable group-V dopant-vacancy complexes complexes in ZnO consisting of interstitial dopants surrounded by three VZn (DI-3VZn with D=P, As, or Sb). In contradiction with previous reports, our calculations show that the acceptor level of group-V dopant--vacancy complexes is too deep to be the shallow acceptor level identified experimentally as contributing to p-type conductivity in ZnO. The interstitial-vacancy complexes we have identified can be generalized to other compositions, dopants, and structures.