Lattice-Constant and Band-Gap Tuning in Wurtzite and Zincblende BInGaN Alloys

TL;DR

This study uses computational methods to explore how BInGaN alloys can be optimized for LED applications by tuning lattice constants and band gaps, potentially improving efficiency and power output.

Contribution

It demonstrates that BInGaN alloys can be lattice-matched to GaN and have tunable band gaps, offering a promising alternative to InGaN for high-performance LEDs.

Findings

Wurtzite BInGaN is more stable than zincblende.

Lattice matching to GaN is possible up to ~30% boron content.

Band gaps remain tunable across the visible spectrum.

Abstract

InGaN light-emitting diodes (LEDs) are more efficient and cost effective than incandescent and fluorescent lighting, but lattice mismatch limits the thickness of InGaN layers that can be grown on GaN without performance-degrading dislocations. In this work, we apply hybrid density functional theory calculations to investigate the thermodynamic stability, lattice parameters, and band gaps of wurtzite and zincblende quaternary BInGaN alloys. We find that the wurtzite phase is more stable and can be lattice-matched to GaN for BInGaN compositions containing up to ~30% boron. The lattice match with GaN decreases strain and enables thicker active layers that mitigate Auger recombination and increase the efficiency of the LEDs. The band gap of the alloy remains tunable throughout the visible spectrum. Our results indicate that BInGaN alloys are promising alternatives to InGaN for high-efficiency, high-power LEDs.