HgTe-CdTe superlattice band-gap enhancement due to interdiffusion

Abstract

The effect of interdiffusion on the band gap of the HgTe-CdTe superlattice is calculated. Two simple models of the form of the interdiffusion are assumed: linear compositional grading, or shrinkage of HgTe layer widths due to Hg diffusion. A two-band model is used to solve for the electronic energy levels using parameters obtained from bulk data. Comparison with tentative experimental data implies that some effective shrinkage of the HgTe layers occurs.