DX centers in CdTe: A density functional study

DX centers induced by both group-III and group-VII donors in CdTe are studied using density functional calculations. The results show that, for group-VII donors, the DX centers with a cation-cation bond (alpha- and beta-CCB-DX centers) are more stable than the previously proposed broken-bond DX (BB-DX) center and the beta-CCB-DX center is the most stable. The stability trend found for the CCB-DX centers for different donors in CdTe is consistent with that for GaAs and GaSb, which suggests a general rule that the CCB-DX centers are favored for small donor atoms on anion site especially for semiconductors with large anion size. (C) 2008 American Institute of Physics.