Defect complexes induced by diffusion of group I acceptors into CdTe

Abstract

The formation of defects following the diffusion of the group I acceptors Cu, Ag, or Au into CdTe was investigated by perturbed γγ-angular correlation (PAC) using the radioactive donor 111InCd. The formation of A-centres (InCd–VCd pairs) with the donor 111InCd was observed, indicating that the incorporation of the group I acceptors Cu, Ag, or Au is accompanied by the generation of cation vacancies. In addition, the formation of InCd–AgCd or InCd–AuCd pairs was observed in CdTe. The concentration of cation vacancies formed after diffusion of Cu, Ag, or Au was found to depend only weakly on the respective group I element. In contrast, the migration energy of the cation vacancy was observed to be different in CdTe crystals doped with Ag or Au, yielding 0.76 (3)eV and 0.84 (3)eV, respectively. In Ag-doped CdTe the binding energies of the InCd–VCd pair and the InCd–AgCd pair were determined to 0.18 (2)eV and 0.19 (2)eV, respectively.