Defect complexes induced by diffusion of group I accepters into CdTe

The formation of defects following the diffusion of the group I accepters C u, Ag, or Au into CdTe was investigated by perturbed gamma gamma-angular co rrelation (PAC) using the radioactive donor In-111(Cd). The formation of A- centres (In-Cd-V-Cd pairs) with the donor In-111(Cd) was observed, indicati ng that the incorporation of the group I accepters Cu, Ag, or Au is accompa nied by the generation of cation vacancies. In addition, the formation of I n-Cd-Ag-Cd or In-Cd-Au-Cd pairs was observed in CdTe. The concentration of cation vacancies formed after diffusion of Cu, Ag, or Au was found to depen d 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. I n Ag-doped CdTe the binding energies of the In-Cd-V-Cd pair and the In-Cd-A g-Cd pair were determined to 0.18 (2) eV and 0.19 (2) eV, respectively. (C) 1999 Elsevier Science B.V. All rights reserved.