A quasi-chemical formalism was used to calculate native point defect densities in Hg0.78Cd0.22Te and CdTe. The linearized muffin-tin orbital method, based upon the local density approximation and including gradient corrections, was used to calculate the electronic contribution to defect-reaction free energies. A valence force field model was used to calculate the changes in the vibration free energy which occurred when a defect was created. It was found that the double-acceptor Hg vacancy was the predominant defect. This was in agreement with previous interpretations of experiments. The Te antisite, which was a donor, was also found to be an important defect in this material. The Hg vacancy plus Te antisite pair was predicted to be well bound and was expected to be important in Te antisite diffusion. The possibility was considered that the Te antisite was the residual donor, and a Shockley-Read recombination center in HgCdTe. It was predicted that the Cd vacancy, a double acceptor, was the predominant defect at low Cd pressures, while the Cd interstitial (a double donor) predominated at high Cd pressures.

M.A.Berding, A.Sher, M.Van Schilfgaarde: Journal of Electronic Materials, 1995, 24[9], 1127-35