The variation of energy gap with composition in ZnS-Te alloys

Abstract

Thin films of ZnSxTe1-x have been grown in the composition range 0<x<1. The optical energy gap and the lattice parameters of these alloys have been measured, and the energy gap bowing is compared with previous theoretical estimates. The bowings estimated from the dielectric model of Van Vechten are recalculated, and it is shown that disorder is unimportant. The dependence of the bowing on lattice constant is investigated, and is shown to be consistent with pseudopotential theory.