KP-approach for non-symmetric short-range defects: resonant states and alloy bandstructure

TL;DR

This paper investigates how non-symmetric short-range defects affect the electronic states and bandstructure of narrow-gap semiconductors using a KP-approach, including resonant states and a generalized virtual crystal approximation.

Contribution

It introduces a KP-based method accounting for matrix potential energy and analyzes non-symmetric defect effects on alloy bandstructure and resonant states.

Findings

Resonant states at single defects are characterized within the Koster-Slater approximation.

Bandstructure modifications due to non-symmetric impurities are discussed.

A generalized virtual crystal approximation is proposed for alloys with such defects.

Abstract

The short-range defect with reduced symmetry is studied in the framework of KP-approach taking into account a matrix structure of potential energy in the equations for envelope functions. The case of the narrow-gap semiconductor, with defects which are non-symmetric along the [001], [110], or [111] directions, is considered. Resonant state at a single defect is analyzed within the Koster-Slater approximation. The bandstructure modification of the alloy, formed by non-symmetric impurities, is discussed and a generalized virtual crystal approximation is introduced.