Phonons in epitaxially grown agr;hyphen;Sn1minus;xGexalloys

摘要

We present a Raman scattering study of optical phonons in agr;hyphen;Sn1minus;xGexalloys (xle;0.08) grown by molecular beam epitaxy on CdTethinsp;(100) substrates. The Raman spectra provide strong evidence for the growth of high quality films in the diamondhyphen;structure phase. The composition dependence of the Raman modes shows some qualitative differences with results from the isomorphic Ge1minus;xSixsystem. We show that these differences can be understood in terms of a simple model that considers confinement and strain effects.