Abstract
The atomic and electronic structures of ternary chalcogenides (, and Bi, and , Se, and S) have been studied using ab initio electronic structure calculations. Most of these compounds are found to take rhombohedral structures as their lowest energy structures (except for , which takes a triclinic structure), in agreement with experiments. There is a disagreement between theory and experiment in the case of , wherein our calculations identify a rhombohedral structure (as yet hypothetical), which has lower energy than a monoclinic one (given by experiment). Band-gap formation in these ternaries are controlled by a highly directional hybridization between the cation (Sb, Bi), anion (S, Se, Te), and states, and the electronic structure near the Fermi level is sensitive to the ordering on the cation sublattice.
- Received 12 February 2008
DOI:https://doi.org/10.1103/PhysRevB.77.205107
©2008 American Physical Society