The structure and electronic properties of InBixAs1-x alloy (0 ≤ x < 0.1) predicted by first-principles calculations

Abstract

The generalized gradient approximation (GGA) plus Hubbard U parameter method is adopted to made a research on the structure and electronic properties of the As-rich InBixAs1-x. It is found that the standard bowing equation is more suitable for giving a description for the lattice constant than the linear equation. The bowing coefficient for the lattice constant of InBixAs1-x is −0.022 Å. Based on the experimental lattice constant of InAs and the difference of the lattice constant between InAs and InBi acquired by the GGA method, the acquired lattice constant of InBi is 6.657 Å. It is also found that incorporating bismuth atoms in InAs can lower the bandgap energy quickly. The bandgap narrowing is on account of the ascending of the valence band maximum (VBM) and the descending of the conduction band minimum (CBM). For the sake of depicting the bandgap energy, the combination of the modified valence band anticrossing (MVBAC) model and a linear equation is employed. It is observed that the combination can give an accurate estimation. Besides, when the bismuth concentration reaches up to 0.105, the bandgap energy of InBixAs1-x can be lowered to 0 eV.