Reflectivity Study of the Zn$\text{}_{1-x}$Co$\text{}_{x}$Se Crystals

The room temperature reflectivity spectra of the Zn$\text{}_{1-x}$Co$\text{}_{x}$Se (x = 0, 0.03, 0.05) crystals have been measured in the visible and ultraviolet range from 1.7 to 12 eV. The structure of the spectra was interpreted in terms of the electronic band structure of the binary material (ŻnSe). The experimental results were compared with the reflectivity spectra of the Fe-based semi magnetic semiconductors [1], and the interpretation was confronted with the conclusions derived from the photoemission experiments performed for Cd$\text{}_{1-x}$Co$\text{}_{x}$Se [2] and the tight-binding CPA calculations of the band structure of Zn$\text{}_{1-x}$Co$\text{}_{x}$Se [3].