Electronic band structure of cubic solid-state CdTe_1�xSe_x solutions

Abstract

We report on the electronic band structure of solid-state solutions CdTe 1-x Se x (CTS, 0 < x ≤ 5/16) calculated in the framework of density functional theory. The structure of CTS is calculated following from the 'parent' binary compound CdTe, which is crystallized in a cubic phase. The bandgap of CTS is found to be of a direct type for all of the solid-state solutions under test. A decrease in the bandgap E g is found with increasing selenium content x. The E g (x) dependence reveals some deviations from a simple linear function. The free-carrier concentration increases with increasing selenium content. It is shown that interaction among the atoms of host matrix (CdTe) and substitution selenium atoms causes splitting of the valence bands into heavy-hole and light-hole subbands and spin-orbit splitting, while the conduction bands remain unaffected. The dependence of refractive index on the selenium content is obtained.

Optical properties of CdTe thin film obtained by high-frequency magnetron sputtering method

“…where the normal conditions are assumed, the bandgap units are eV, and the n's subscripts abbreviate the authors mentioned above. In equation ( 3), we have C = 95 eV, a = 4.084 eV, b = 0.62 eV −1 , A = 13.6 eV, B = 3.47 eV, n 0 = 1.73, a = 1.901 7 and b = 0.539 eV −1 [10][11][12][13]. Depending on the material studied, these different empirical relations (3) may be applied to the experimental values n and E g more or less successfully [13].…”