Boron arsenide heterostructures: lattice-matched heterointerfaces and strain effects on band alignments and mobility

• Published in: npj computational materials Vol. 6; no. 1
• Main Authors: Bushick, Kyle, Chae, Sieun, Deng, Zihao, Heron, John T., Kioupakis, Emmanouil
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 16.01.2020; Nature Publishing Group
• Subjects: 639/301/1005/1007; 639/301/1034/1035; Alignment; Arsenides; Boron; Carrier mobility; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computational Intelligence; Electronic devices; Electronic properties; Electrons; Heat conductivity; Heat transfer; Heterostructures; Indium gallium nitrides; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Lattice matching; MATERIALS SCIENCE; Mathematical and Computational Engineering; Mathematical and Computational Physics; Mathematical Modeling and Industrial Mathematics; Mobility; Offsets; Optoelectronic devices; Photonic band gaps; Plane strain; Substrates; Tensile strain; Theoretical; Thermal conductivity; Thin films
• ISSN: 2057-3960; 2057-3960
• DOI: 10.1038/s41524-019-0270-4

BAs is a 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 isotropic biaxial in-plane strain decreases the band gap independent of sign or direction. In addition, 1% biaxial tensile strain increases the in-plane electron and hole mobilities at 300 K by >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 ZnSnN 2 , 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 ZnSnN 2 demonstrate the potential of BAs heterostructures for electronic and optoelectronic devices.