Lateral optical anisotropy of type-II interfaces in the tight-binding approach

TL;DR

This paper develops a tight-binding model to analyze the electronic and optical properties of type-II heterostructures, revealing giant optical polarization effects consistent with experimental data.

Contribution

It introduces a detailed tight-binding approach including interface parameters to study optical anisotropy in type-II heterostructures, highlighting interface-localized hole states.

Findings

Giant optical polarization in type-II heterostructures

Interface-localized Tamm-like hole states identified

Model aligns with experimental polarization measurements

Abstract

We have developed the tight-binding theory to study electronic and optical properties of type-II heterostructures CA/C'A' grown from the zinc-blende semiconductors CA and C'A' along the crystallographic direction [001]. The sp^3s* nearest-neighbor tight-binding model with allowance for the spin-orbit interaction is used to calculate the energy states and the in-plane linear polarization of the spatially-indirect band-edge photoluminescence of InAs/AlSb and ZnSe/BeTe multi-layered structures. The interface parameters for a pair of the nonstandard planes C-A' or C'-A are considered as fitting variables. A wide range of these parameters are shown to allow Tamm-like hole states localized at the interfaces. The theory leads to giant values of the light polarization in the both type-II heterosystems in agreement with existing experimental findings.