Characterization of Te-antisite-related defects in HgCdTe

Te-antisite-related defects in Hg1 − xCdxTe were considered as deep-level-suppliers and responsible for inferior device performance, but the underlying mechanism is still unclear. Here, the Te-antisite-related native defects were investigated using first-principles calculations. A novel defect complex with a “double-broken-bond” structure through antisite-vacancy coupling was found, and the geometrical and electronic structures of different antisite-vacancy coupling configurations were characterized. The split of antisite-Te−5p state within different crystal-fields is found to be the origin of different recombination/trap levels. To annihilate the recombination centers, a two-stage annealing procedure under Hg-rich conditions should be an effective way according to the formation energy calculations.