Determination of the dielectric functions of MBE‐grown Zn1−xMgxTe II‐VI semiconductor alloys
We have explored the dielectric functions of ternary Zn1−xMgxTe thin films using a variable angle spectroscopic ellipsometer for samples between x = 0 and x = 0.52. We obtained values for the complex dielectric function for Zn1−xMgxTe in both the transparent and absorption regions by incorporating a threelayer model to simulate the experimental data. To this end, we also used the previously published relations of the dispersion of the indices of refraction (in the transparent region) of Zn1−xMgxTe measured using a combination of prism coupler and reflectivity. We have fitted the second derivatives of both the real and the imaginary parts of the dielectric function to obtain the critical point parameters corresponding to the higher order electronic transitions in the lattice.
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