Tight-binding model for electronic structure of hexagonal boron phosphide monolayer and bilayer

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Physics

Background:

• Graphene-like hexagonal boron phosphide (h-BP) is a promising material for electronics and optoelectronics due to its moderate band gap and high carrier mobility.
• Accurate theoretical models are crucial for understanding and predicting the electronic properties of novel materials like h-BP.

Purpose of the Study:

• To derive and validate a tight-binding Hamiltonian for hexagonal boron phosphide (h-BP) monolayer and bilayer systems.
• To investigate the electronic band structure and identify key electronic transitions in h-BP.
• To elucidate the mechanism behind the observed pseudo-Lifshitz transition in h-BP bilayers.

Main Methods:

• Derivation of the tight-binding Hamiltonian for h-BP monolayer and bilayer, including up to fifth-nearest-neighbor in-plane and next-nearest-neighbor interlayer hoppings.
• Comparison of tight-binding band structure with first-principle calculations (screened Heyd-Scuseria-Ernzerhof hybrid functional).
• Analysis of the low-energy effective Hamiltonian and band structure near the K point to study electronic transitions.

Main Results:

• The tight-binding model accurately reproduces first-principle band structures for h-BP monolayer and bilayer with minimal band gap deviation (2 meV).
• A pseudo-Lifshitz transition of iso-energetic lines for the maximum valence band near the K point was observed when transitioning from monolayer to bilayer h-BP.
• The pseudo-Lifshitz transition is attributed to the influence of two interlayer hopping parameters, rather than a single one.

Conclusions:

• The developed tight-binding model provides a reliable and computationally efficient method for studying h-BP electronic properties.
• The discovery of a pseudo-Lifshitz transition in h-BP bilayers highlights unique electronic behaviors influenced by interlayer interactions.
• This work contributes to the fundamental understanding of h-BP, paving the way for its application in advanced electronic devices.