Raman scattering in Ge1-ySny alloys

V. R. D'Costa, J. Tolle, R. Roucka, C. D. Poweleit, John Kouvetakis, Jose Menendez

Research output: Contribution to journalArticle

70 Scopus citations

Abstract

The Raman spectrum of nearly relaxed Ge1-ySny alloys grown on Si substrates was investigated for Sn concentrations y < 0.2. The frequency dependence of the Ge-Ge Raman mode was re-evaluated by carrying out careful corrections for residual strain shifts. The Ge-Sn mode was observed for the first time in this type of samples. Its frequency appears to decrease monotonically as a function of the Sn concentration. This is very different from the behavior of the Si-Ge mode in Si1-yGey alloys, but a detailed analysis suggest that there is a scaling relationship between these modes that is the analog of the scaling relationship found earlier for the Ge-Ge mode. Raman activity is also found in the spectral range where Sn-Sn modes are expected, but the polarization properties of these features suggest an overlap with disorder-activated Ge-acoustic phonons. Additional features observed in "forbidden" scattering configurations are also assigned to disorder-activated Raman scattering.

Original languageEnglish (US)
Pages (from-to)240-244
Number of pages5
JournalSolid State Communications
Volume144
Issue number5-6
DOIs
StatePublished - Nov 1 2007

    Fingerprint

Keywords

  • A. Semiconductors
  • D. Raman scattering

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Materials Chemistry

Cite this