Optical properties of molecular beam epitaxy-grown Zn_1-xMn_xTe 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 Zn_1-xMn_xTe 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 Zn_1-xMn_xTe system, in contrast to most other zinc-blende semiconductor alloys. © 2003 American Institute of Physics.