Electronic properties and charge density of BexZn 1-xTe alloys

Abstract

Electronic band structure calculations are performed for the Be xZn1-xTe (0≤x≤1 in steps of 0.2) alloys following the empirical pseudopotential method. The alloying effects are modelled through the modified virtual crystal approximation. Throughout the composition, valence band maximum resides at the Γ point. The conduction band minimum, however, shifts from Γ to X point of symmetry when x = 0.27. The observed crossover from direct to indirect bandgap is well in accordance with the experimental observations. Effect of alloying on the density of states is also discussed. The charge density distribution along a few major planes is computed and discussed. The electronic band structure related parameters like bandwidths, bandgaps and ionicity are reported and compared with experimental data wherever available. We also give estimates of cohesive energy and bulk modulus for the alloys. © Indian Academy of Sciences.