ELECTRONIC PROPERTIES OF HgTe WITHIN DIFFERENT STRUCTURES

We present the results of a density functional theory study of high-pressure structures of HgTe up to bcc structure, which is the highest-pressure structure that has been fully characterized in experiments in the compounds. We investigated the different structures of HgTe and studied the semimetal → semiconductor → conductor transition in detail. We found, in the mechanism for the semimetal → semiconductor transition, the local structure plays a very important role. Change in local structure leads to the change in hybridization of bonding, sp3 →sp3d2 and led to the change from semiconductor to conductor. In addition, we focused on the special transition of semimetal → semiconductor. The tiny change of bond angle reduces the p–d repulsion interaction in the compound and a band gap is open up, which indicates the semiconductor property.