The cation vacancy-iso-electronic O pair (VCd/Zn-OTe) was investigated in Cd1-xZnxTe crystals and compared to it was behavior in CdTe using thermo-electric effect spectroscopy and first-principles total-energy calculations. It was found that the thermal ionization energy E = Ev + 0.184eV and trapping cross section of 7 x 10–17cm2 of the (–/–2) transition for the VCd-OTe pair were identical to those found in CdTe. In addition the concentration of the pair was much smaller in Cd1-xZnxTe than in CdTe crystal for samples with the same nominal O concentration. Using first-principles total-energy calculations, it was found that under equilibrium growth conditions the lowest achievable formation energy of OTe was about 0.5eV higher in CdZnTe than in CdTe. This indicated that the addition of Zn to CdTe reduced the equilibrium substitutional O concentration that could bind with the cation vacancy to form VCd/Zn-OTe.

Effect of Zn on the Cation Vacancy–Iso-Electronic Oxygen Pair in Cd1–xZnxTe Crystals. S.A.Awadalla, K.G.Lynn, S.H.Wei, C.Szeles: Physical Review B, 2004, 70[24], 245213