FIRST-PRINCIPLES STUDY OF DX-CENTERS IN CDTE, ZNTE, AND CDXZN1-X TE ALLOYS

Large lattice relaxation models for DX centers in CdTe, ZnTe, and CdxZn1-x Te alloys are examined through first-principles pseudopotential calculations. The calculated binding energies of DX centers for Al, Ga, In, Cl, Br, and I donor impurities in CdTe and their pressure and alloy dependence in CdxZn1-xTe are in good agreement with experimental data. Three distinct types of DX-like structures characterized by either bond rupture or bond compression are found for column VII donors. The relative stability of these structures is impurity and pressure dependent.