1? x Bi x bismide alloys for MID?infrared optical devices: A DFT + TB-mBJ study]]>

摘要

AbstractUsing full-potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT), we have studied the structural and opto-electronic properties of zinc blende InP1?xBixbismide alloys (0 ≤x≤ 0.5). The bowing lattice parameter exhibits a weak composition dependence on InP1?xBixalloys withb= 0.02834?. The band gap decreases with Bi composition by about 1.285meV forx= 0.25 covering the middle (MID) and far-wavelength infrared region [0.88?10.5μm]. From DOS, the decrease of band gap can be attributed to the both upper shifts of the valence band VB and the downward shifts of the conduction band CB, due to the resonance interaction of the Bi-porbitals at the top of the VB and hybridization of the occupieds/porbitals of In/P/Bi atoms at the bottom of the CB, with increasing Bi composition. The dielectric functions (ε1(ω),ε2(ω)) and optical constants such asn(ω),k(ω),α(ω) andR(ω) for InP1?xBix