Temperature dependence of the Raman spectrum in Ge1−ySnyand Ge1−x−ySixSnyalloys

Abstract

The temperature dependence of the Raman spectrum of Ge-rich Ge${}_{1\ensuremath{-}y}$Sn${}_{y}$ and Ge${}_{1\ensuremath{-}x\ensuremath{-}y}$Si${}_{x}$Sn${}_{y}$ alloys has been determined in the 10- to 400-K range. The Raman line shift and width changes as a function of temperature are found to be virtually identical to those observed in bulk Ge. This result shows that the anharmonic decay process responsible for the temperature dependence is extremely robust against the alloy perturbation, so that the expected relaxation of the wave vector conservation rule does not affect the decay in any noticeable way.