The New Candidate Materials for Infrared Optical Devices

In this study, We propose the cubic Al
_x
B
_1-x
Bi ternary alloy as a promising infrared material. We used the full potential-linearized augmented plane wave (FP-LAPW) method within the Density Functional Theory (DFT) to predict the structural and electronic properties of the Al
_x
B
_1-x
Bi ternary alloys. The structural properties such as the equilibrium lattice parameter, bulk modulus, and its pressure derivative are investigated with the effect of the concentration variation of Al atom, x (x=0, 0.25, 0.50, 0.75 and 1). We found that the equilibrium lattice parameter of Al
_x
B
_1-x
Bi ternary alloys increases when increasing the doping concentration of the Al atom, while its bulk modulus decreases. The energy band gap of the Al
_x
B
_1-x
Bi ternary alloys decreases with the increase in the Al doping concentration. The Al
_x
B
_1-x
Bi alloys present a semi-metallic character for 0.50 and 0.75 concentrations and are semiconductors at the other compositions. Our results show the direct nature of the energy band gap of the ternary Al
_x
B
_1-x
Bi alloy for all composition of Al substitution. To our knowledge, this is the first theoretical study of this ternary alloy that needs eventual experimental data for confirmations.