Effects of induced strain on the Raman spectra of AlxGa1−xAs compounds

Abstract

In this work we study the nuances of composition determination of AlxGa1−xAs alloys by Raman spectroscopy. We mainly focus on understanding the effect of induced strain on the frequency of the optical phonons, a possible source of the dispersion in the calibration curves found in the literature. We conclude that while GaAs-like and AlAs-like Raman peaks may show a wide dispersion across samples of the same composition, aluminum concentration can still be accurately determined via Raman spectroscopy, provided that the difference between the GaAs-like and AlAs-like longitudinal optical modes is used, regardless of residual strain present.