Empirical Tight-Binding Parameters for Wurtzite group III-V(non-Nitride) and IV Materials

TL;DR

This paper develops empirically fitted tight-binding parameters for hexagonal non-nitride III-V and group V semiconductors, improving transferability and accuracy of electronic structure modeling across different crystal phases.

Contribution

It introduces a new set of spds* tight-binding parameters for hexagonal phases, constrained to be close to cubic parameters for better transferability.

Findings

Parameters fit to experimental and pseudopotential data.

Enhanced accuracy in bandgap predictions for hexagonal phases.

Model supports heterostructure simulations with mixed phases.

Abstract

Many commonly used nearest neighbor tight binding models for cubic semiconductors often result in inaccurate band structures when transferred to hexagonal polytypes. The resulting bandgaps are systematically too small, and in some cases calculations may erroneously predict a metal for the wurtzite polytype. We have calculated a set of $\rm spds^*$ tight binding parameters for the hexagonal phases of non-nitride III-V and group V semiconductors fit to experimental data and empirical pseudopotential calculations. Our fitting procedure constrains the parameters to be as close as possible to those for the cubic polytype so as to make the the parameters maximally transferable. Our parameters, when combined with the existing cubic parameters, provide a model suitable for modeling the electronic structure of polytypic heterostructures containing both the wurtzite and zincblende crystal phases.