Relaxations and bonding mechanism of arsenic in-situ impurities in MCT： first-principles study

The structural and electronic properties of the arsenic in-situ impurity in Hg1-xCdxTe（MCT） were studied by combining the full-potential linear augmented plane wave （FP-LAPW） and plane-wave pseudopotential methods base on the density functional theory. Structural relaxations, local charge density, densities of states are computed to investigate the effects of the impurity on the electronic structure. The bonding characteristics between the impurity and the host atoms are discussed by analysis of the valence charge density and the bonding charge density. The amphoteric behavior of arsenic impurity in MCT has been shown. The defect levels introduced by the in-situ arsenic impurities are determined by the single-particle electron energy calculations, which are in good agreement with the experimental results.