Deformation Potentials in IV-VI Quantum Wells

Abstract

To analyse the electronic properties of semiconductor superlattices (SLs) or quantum wells (QWs) it is necessary to know the basic parameters of the layers of which the structures are composed: the band gaps, effective masses parallel to the interfaces, etc. In turn, to determine those parameters properly, it is necessary to take into account the strains in the interfaces as well as in the bulk of the layers. The strain induced energy shifts are usually calculated from the corresponding deformation potentials (DPs). For SLs and QWs made of the IV—VI semiconducting materials, the strain induced shifts of energy levels are considered in Refs. [1-4]. It is commonly assumed that the DPs in QWs and SLs are the same as those in bulk crystals. For example, for the DPs of PbTe and SnTe SLs theoretical results of Refs. [5] and [6] are taken as a rule. The purpose of the present contribution is to consider the difference between DPs in QWs and bulk material. We show that such difference does exist for the case of narrow-gap materials with the interband k—p interaction. This is because of pronounced effect of the size quantization on energy levels in QWs made of the narrow-gap materials.