Long-wavelength lattice dynamics of Ga<i>x</i>In1−<i>x</i>As<i>y</i>Sb1−<i>y</i> quaternary alloys

Abstract

The quaternary semiconductor alloy GaxIn1−xAsySb1−y has been investigated using Raman scattering spectroscopy in the spectral region from 150 to 300 cm−1 at room temperature. The Raman spectra exhibit two- or three-mode behavior depending on the composition. A modified random-element isodisplacement model is used to describe the behavior of the optical phonons. The calculations of the dependence of the long-wavelength optical phonon frequencies on the composition are in good agreement with the experimental results.