The strain dependence of Ge1 - xsnx (x = 0.083) Raman shift
Journal
Thin Solid Films
Journal Volume
593
Pages
40-43
Date Issued
2015
Author(s)
Chang, C.
Li, H.
Chen, T.-P.
Tseng, W.-K.
Cheng, H.
Ko, C.-T.
Hsieh, C.-Y.
Chen, M.-J.
Sun, G.
Abstract
We report an investigation of strain-dependent Raman frequency shift in Ge0.917Sn0.083 epilayer where the Sn composition is near the indirect-to-direct band gap transition point. The strain is modulated by ex-situ rapid thermal annealing and the amount of strain relaxation is determined by X-ray diffraction measurement. The results show that the Raman shift of Ge-Ge longitudinal optical phonon is linearly dependent on the in-plane strain of the GeSn layers with a coefficient b = - 299.3 cm- 1. Such a relationship enables characterization of GeSn epilayers using the readily accessible Raman spectroscopy.
Type
journal article