Raman scattering from in1-x-yGaxAlyas quaternary alloys

Abstract

Raman scattering studies were reported of In1-x-yGaxAlyAs/InP lattice matched quaternary alloys. The quaternary alloys were grown on (100) oriented InP substrates by MBE method. The composition and intensitiy dependence of optical phonon mode frequencies show that the quaternary alloys exhibit three-mode behavior, i. e. InAs-like, GaAs-like and AlAs-like modes. Polarization analysis of the Raman spectra shows that the LO phonon modes are Raman active in the depolarized configuration and Raman inactive in the polarized configuration. TO phonon modes were also observed due to disorder effects, resulting in the asymmetrical shapes of the Raman peaks of the optical phonons.