Atomic and electronic structure of the CdTe(111)B–(2√3 × 4) orthogonal surface

详细

The atomic and electronic structure of four variants of Te-terminated CdTe(111)B–(2√3 × 4) orthogonal polar surface (ideal, relaxed, reconstructed, and reconstructed with subsequent relaxation) are calculated ab initio for the first time. The surface is modeled by a film composed of 12 atomic layers with a vacuum gap of ~16 Å in the layered superlattice approximation. To close Cd dangling bonds on the opposite side of the film, 24 fictitious hydrogen atoms with a charge of 1.5 electrons each are added. Ab initio calculations are performed using the Quantum Espresso program based on density functional theory. It is demonstrated that relaxation leads to splitting of the four upper layers. The band energy structures and total and layer-by-layer densities of electronic states for the four surface variants are calculated and analyzed.