Effective bond-orbital model of III-nitride wurtzite structures based on modified interaction parameters of zinc-blende structures

TL;DR

This paper introduces a simplified semi-empirical bond-orbital model for III-nitride wurtzite semiconductors, using modified zinc-blende parameters and fitting techniques to accurately predict electronic band structures.

Contribution

It presents a novel method to derive the effective bond-orbital model for WZ structures from ZB parameters, incorporating three-center effects and optimization via genetic algorithms.

Findings

Accurate band structures for AlN, GaN, InN WZ semiconductors.

Effective masses near the zone center match experimental and other theoretical results.

Model outperforms basic approaches by including three-center integrals and optimization.

Abstract

A simple theoretical method for deducing the effective bond-orbital model (EBOM) of III-nitride wurtzite (WZ) semiconductors is presented. In this model, the interaction parameters for zinc-blende (ZB) structures are used as an initial guess for WZ structure based on the two-center approximation. The electronic band structure of III-nitride WZ semiconductors can hence be produced by utilizing this set of parameters modified to include effects due to three-center integrals and fitting with first-principles calculations. Details of the semi-empirical fitting procedure for constructing the EBOM Hamiltonian for bulk III-nitride WZ semiconductors are presented. The electronic band structure of bulk AlN, GaN, and InN with WZ structure calculated by EBOM with modified interaction parameters are shown and compared to the results obtained from density functional (DFT) theory with meta-generalized gradient approximation (mGGA). The set of parameters are further optimized by using a genetic algorithm. In the end, electronic band structures and electron (hole) effective masses near the zone center calculated by the proposed model with best fitting parameters are analyzed and compared with the $\mathbf{k}\cdot \mathbf{p}$ model.