Boron Arsenide Heterostructures: Lattice-Matched Heterointerfaces, and Strain Effects on Band Alignments and Mobility

TL;DR

This study uses atomistic calculations to explore boron arsenide heterostructures, revealing strain effects on band gaps and mobility, and identifying its compatibility with key optoelectronic materials for advanced device applications.

Contribution

It provides the first detailed analysis of strain effects on BAs heterostructures, including band alignments and mobility, and identifies lattice-matched materials with potential for electronic and optoelectronic devices.

Findings

Strain reduces the band gap regardless of sign or direction.

Biaxial tensile strain increases electron and hole mobilities by over 60%.

BAs is nearly lattice-matched with InGaN and ZnSnN2, with type-II band alignments.

Abstract

BAs is III-V semiconductor with ultra-high thermal conductivity, but many of its electronic properties are unknown. This work applies predictive atomistic calculations to investigate the properties of BAs heterostructures, such as strain effects on band alignments and carrier mobility, considering BAs as both a thin film and a substrate for lattice-matched materials. The results show that strain decreases the band gap independent of sign or direction. In addition, biaxial tensile strain increases the in-plane electron and hole mobilities by more than 60% compared to the unstrained values due to a reduction of the electron effective mass and of hole interband scattering. Moreover, BAs is shown to be nearly lattice-matched with InGaN and ZnSnN2, two important optoelectronic semiconductors with tunable band gaps by alloying and cation disorder, respectively. The results predict type-II band alignments and determine the absolute band offsets of these two materials with BAs. The combination of the ultra-high thermal conductivity and intrinsic p-type character of BAs, with its high electron and hole mobilities that can be further increased by tensile strain, as well as the lattice-match and the type-II band alignment with intrinsically n-type InGaN and ZnSnN2 demonstrate the potential of BAs heterostructures for electronic and optoelectronic devices.