Determination of the dispersion of the index of refraction and the elastic moduli for molecular-beam-epitaxy-grown Zn1−xBexSe alloys

The prism coupler technique, together with reflectivity channeled spectra, were used to determine the dispersion of the indices of refraction for a series of ternary alloys of Zn1−xBexSe grown by molecular-beam epitaxy on GaAs substrates. The measurements covered the wavelength range of 400–1300 nm, and the entire Be concentration range, from x=0 to 1.00. The availability of accurate values of the index-of-refraction then enabled us to determine the elastic moduli c11 for the Zn1−xBexSe and its dependence on the Be concentration x from frequency shifts in Brillouin scattering spectra observed on the epilayers of these ternary alloys. The c11 results clearly indicate that the bonding in Zn1−xBexSe becomes more robust as the Be concentration increases.