Abstract: | Wavelength-modulation spectroscopy is used to obtain the temperature dependence of the near band gap reflectivity spectrum Eo of MgxZn1?xTe ternary semiconducting alloys. Results are given in the range 80–100 K for the cubic materials: 0〈x〈0.5. The analysis of the line shapes as a function of x and T confirms the hypothesis of an exciton bound to the complex defect associated with zinc vacancy, as ZnTe. The Eo(x) curve is parabolic. The bowing parameter is C=0.45 ± 0.1 eV at 80 K, C=0.6 ± 0.1 eV at 300 K. Within experimental scattering the temperature coefficient dE0dT is nearly constant with x:-4.5±0.3 × 10?4eVK?1. This data is smaller than the value calculated in the literature for ZnTe from pseudo potential method. |