Effect of crystal disorder on linewidth of the Raman modes in GaS1-xSex layered mixed crystals

The linewidths of Raman-active intralayer compressional modes in GaS1-xSex layered mixed crystals (0 less than or equal to x less than or equal to 1) have been measured in the 10-300 K temperature range to study the anharmonic effect as a function of compositional variation and temperature. It was found that the anharmonicity increases with an increase in substitutional disorder. The cubic (three-phonon) processes with energy conservation is responsible for the anharmonic contribution to the broadening of the intralayer phonon lines with temperature. (C) 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim