DISORDER EFFECTS ON ELECTRONIC AND OPTICAL-PROPERTIES IN ZNSEXTE1-X

The electronic band structure of the semiconducting alloy ZnSexTe1-x i s calculated by the empirical pseudopotential method and by an extende d virtual crystal approximation. The effect of compositional disorder on the lowest direct energy gap is calculated. Various quantities incl uding the bowing parameters of fundamental gaps, the charge densities and the bonding character are given. The influence of positional disor der is also discussed. Our results for the most important structures i n the optical spectrum are in good agreement with experimental data ov er the full compositional range. (C) 1998 Elsevier Science B.V. All ri ghts reserved.