The effect of the incorporation of phosphor on the optoelectronic properties of InAs 0.75 Sb 0.250 ternary for optical telecommunications: DFT calculation

Abstract The super cell 16 atoms special quasi-random structures have been used, to investigate the structural, electronic and optical properties of InPxAsySb1−s−y quaternary alloys in zinc blende phase with a number of concentrations (1-x-y = 0.250) and x ranging from 0 to 0.750 in step of 0.125. The calculations were performed using density functional theory (DFT) as implemented under the full potential linearized augmented plane wave (FP-LAPW) method. We employed the local intensity (LDA) and generalized gradient approximation of Wu and Cohen (GGA-WC) to calculate the structural parameters. The two schemes (EV-GGA) and (TB-mBJ) were also used to describe the optoelectronic properties. The equilibrium structural parameters found are in good agreement with the previous results. Electronic results showed that InPxAsySb1−s−y quaternary alloys are a direct band gap semiconductor for all P concentrations. In addition, (TB-mBJ) results revealed that the increase in P content (x) did change the electronic band gap (Eg) from 0.475 eV for x = 0 to 1.106 eV for x = 0.750. The optical properties of InPxAsySb1−s−y quaternaries, including the dielectric function, optical conductivity, absorption coefficient and the complex refractive index were predicted and discussed in detail. The obtained results make these compounds very promising for optical telecommunications.