Tetragonal and trigonal deformations in zinc-blende semiconductors : a tight-binding point of view

TL;DR

This paper re-examines deformation potentials in cubic semiconductors using an extended tight-binding model, successfully addressing previous inaccuracies in trigonal deformation predictions and achieving excellent agreement with experimental and ab-initio data.

Contribution

It introduces a refined tight-binding approach that accurately captures trigonal deformations and improves the prediction of deformation potentials in zinc-blende semiconductors.

Findings

Corrected sign of shear deformation potential d

Achieved agreement with experimental data

Highlighted importance of on-site energy shifts

Abstract

The deformation potentials of cubic semiconductors are re-examined from the point of view of the extended-basis $sp^3d^5s^*$ tight-binding model. Previous parametrizations had failed to account properly for trigonal deformations, even leading to incorrect sign of the acoustic component of the shear deformation potential {\it d}. The strain-induced shifts and splittings of the on-site energies of the p- and d-orbitals are shown to play a prominent role in obtaining satisfactory values of deformation potentials both at the zone center and zone extrema. The present approach results in excellent agreement with available experimental data and ab-initio calculations.