In this paper we present a comprehensive study of the tetrahedral semiconductor ZnSe crystallizing in the zincblende structure. The electronic structure of ZnSe has been determined first using the ab initio self-consistent linear muffin-tin orbital method with a local-density form of the exchange-correlation functional. Then it has been adjusted to reproduce the experimental energy positions of the Zn 3d bands and of the optical gap. The adjusted electronic structure, densities of states and interband optical properties are presented and compared with previous calculations. Good agreement with experimental photoemission and bremsstrahlung isochromat measurements was found after including an energy-dependent lifetime broadening. We measured the reflectivity of ZnSe with high resolution from 4 to 30 eV and the high-energy region of the spectra has been interpreted on the basis of the present calculation.

Self-consistent semi-relativistic linear muffin-tin orbital calculations of the band structures are used in conjunction with the local-density-approximation to derive the complex dielectric function, epsilon ( omega )= epsilon 1( omega )+i epsilon 2( omega ), and the reflectivity spectrum R( omega ) up to 20 eV for the three most common II-VI semiconducting compounds ZnTe, CdTe and HgTe. The authors have interpreted the sharp structures above approximately 9 eV as transitions originating in the metal d levels. It is shown that a very significant contribution to the reflectivity spectrum in the UV energy range arises from the transitions originating in the upper part of the valence band to the higher conduction bands.

In this paper we present partial densities of states for spin-polarized antiferromagnetic phase of Zn0.5 Co0.5 Se as well as schematic layouts of the bands, obtained using the ab initio self-consistent semi-relativistic linear muffin tin orbital method. We also present, from theoretical point of view, the analysis of influence of the transition metal cobalt on the electronic structure of a pure ZnSe.

A self-consistent semirelativistic linear muffin-tin orbital calculation of the band structure is used in conjunction with the local-density approximation to derive the density of states and the direct interband contribution to the joint density ofstates for CdTe. The imaginary part of the dielectric function, E?("). is calculated with inclusion of the dipole transition matrix elements. A comparison is made with other theoretical and experimental results and an interpretation oi the sharp structures in the absorption spectrum in the ultraviolet (uv) range is presented. The importance of the transitions from the Cd 4d states is careiully evaluated. It is shown that a very significant contribution to the imaginary part of the dielectric function in the uv range arises from the transitions originating in the upper part of the valence band to the higher conduction bands.