Optical properties of molecular beam epitaxy-grown Zn1-xMnxTe thin films measured by complementary techniques

By using a combination of prism coupler, reflectivity, and spectroscopic ellipsometry techniques, we have determined the dielectric function of a series of molecular beam epitaxy-grown Zn1-xMnxTe thin films. These results have enabled us to determine the critical point parameters that correspond to the electronic transitions in the Brillouin zone for this particular alloy family. We find that, although the fundamental band gap E0 increases with x for this alloy, E1 and E1+Δ1 transition energies decrease with x for the Zn1-xMnxTe system, in contrast to most other zinc-blende semiconductor alloys