Structural parameters, energy gaps and density of states of AlAs1−xBix semiconducting ternary alloys

Abstract

The alloying of Bi with III–V semiconductor compounds leads to the formation of an interesting new III–V ternary semiconducting alloys whose physical properties may be considerably modified. In this respect, the present contribution deals with the structural and electronic properties of AlAs1−xBix using full-potential linearized augmented plane wave method. The exchange-correlation potential is treated using the Wu-Cohen (WC) and Tran-Blaha modified Becke-Johnson (TB-mBJ) generalized gradient approximations (GGA). Our findings compare well with experiment and previous published theoretical data. The variation in the lattice constant versus Bi content does not show much deviation from Vegard’s law. The structural parameters are found to vary monotonically with the alloy concentration x. A non-linear behavior has been noticed for the energy band-gaps as a function of x. The absorption at the optical gaps suggests a transition from an indirect to direct band gap at x ∼ 0.039 when using WC-GGA and x ∼ 0.059 when using TB-mBJ-GGA. The information obtained in the present study could be desirable in optoelectronics for infrared/near infrared applications.