First principle study of the atomic and electronic structure of the polar CdTe(111)A surface

Abstract

For the first time ab initio calculations of the electronic structure of four variants of the polar surface Cd–terminated СdTe(111)А–(2 х 2): ideal, relaxed, reconstructed and reconstructed with the subsequent relaxation have been performed. In the approximation of a layered superlattice the surface is simulated as a film with a thickness of 12 atomic layers and a vacuum gap ~16 nm. The backside of the surface, which is not of interest, is terminated by 4 fictitious hydrogen atoms with a charge of 0,5 electron each to prevent the Te-dangling-bond effect. Ab initio calculations have been performed using the program QUANTUM ESPRESSO based on the density functional theory. The relaxation has been shown to result in splitting of layers. Band structures as well as full and layered electronic densities of states have been calculated and analyzed for 4 surface variants.