Ab-Initio Study of Structural and Electronic Properties of HgTe in Different Phases

In this work, the structural and electronic properties of Mercury Telluride (HgTe) in the stable zinc blend phase and high-pressure phases such as hexagonal, rocksalt, orthorhombic, and CSCl have been investigated. The calculations have been performed with the pseudopotential method in the density functional theory framework by using the Quantum-Espresso package. In order to investigate the effect of spin-orbit coupling, full relativistic calculations were performed in the ZincBlend and hexagonal phases. Energy-Volume curves indicate that the HgTe compound makes the transition from stable ZincBlend phase to hexagonal phase, as the pressure increased and Further increase in pressure leads to a transition to the rocksalt, orthorhombic, and CsCl structural phases, respectively. The calculations of band structure show that this compound is a semiconductor with zero bandgaps in the stable ZincBlend phase and indirect bandgap in the Hexagonal phase. Furthermore, by some calculations, the electronic properties of high-pressure rocksalt, orthorhombic, and CsCl phases are revealed to have metallic characters. The electronic density plot of mercury telluride shows the presence of strong covalent bonds among atoms of this compound.