Relaxations and bonding mechanism inHg1−xCdxTewith mercury vacancy defect: First-principles study

Abstract

The structural and electronic properties of the mercury vacancy defect in ${\mathrm{Hg}}_{1\ensuremath{-}x}{\mathrm{Cd}}_{x}\mathrm{Te}$ have been studied by combining the full-potential linear augmented plane wave and plane-wave pseudopotential method base on the density functional theory. Structural relaxation, local charge density, and on-site and partial densities of states are computed to investigate the effects of the mercury vacancy on the electronic structure. The characteristics of dangling bond rehybridization due to the mercury vacancy are discussed by analysis of the valence charge density and the bonding charge density. We reveal upshift of the energy level for the $5s$ states of the nearest neighbor tellurium of the defect due to dangling bond rehybridization. The double acceptor levels introduced by the vacancy are determined by the single-particle electron energy calculations and the transition energy levels, which agree well with the experimental results.