Raman-scattering probe of anharmonic effects due to temperature and compositional disorder in III-V binary and ternary alloy semiconductors

Abstract

Anharmonicity due to temperature and compositional fluctuations in ternary alloy semiconductors has been investigated. A comparative Raman-scattering study of temperature and compositional-fluctuation-induced anharmonic effects for various phonon modes in GaP, ${\mathrm{GaAs}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{P}}_{\mathit{x}}$, and ${\mathrm{In}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As is presented. In binary semiconductors, anharmonicity is found to increase with increasing temperature, whereas, in ternary alloys, it is found to increase with increasing compositional fluctuations and increasing temperature. Temperature-induced anharmonicity introduces changes in the linewidth and line center position, while compositional-fluctuation-induced anharmonicity, not only introduces changes in the linewidth and line center position, but also changes the line shape. © 1996 The American Physical Society.