Impact of Substrates on the Electronic and Mechanical Properties of AlxIn1−xPySb1−y Alloys

The compositional dependence of electronic and mechanical properties of a Al x In 1−x P y Sb 1−y quaternary alloy in zinc-blende structure lattice-matched to GaSb , InAs, and InP substrates is studied. The calculations are done based on the empirical pseudopotential method modified with virtual crystal approximation. Our calculations are obtained for the energy band gaps, elastic constants, elastic moduli, bond stretching, bond bending forces, and internal strain parameter. The material system of interest is found to be a direct semiconductor within a small range of Al concentrations about 0 – 0.07 and an indirect one outside this region. The Debye temperature and the Fröhlich coupling constant have been determined at different values of composition lattice-matched to different substrates. The phonon frequencies and the sound velocity for different substrates at various compositions have been studied. There is a good agreement between our results and the experimental data for its constituent binary compounds, AlP, AlSb, InP, InSb, and ternary alloys, InPSb, AlPSb, which supports the calculated results of the studied Al x In 1−x P y Sb 1−y quaternary alloy. The studied properties for the considered alloy may be helpful for the fabrication of optoelectronic devices.