Strain-controlled fundamental gap and structure of bulk black phosphorus

TL;DR

This study uses advanced computational methods to analyze how in-layer strain affects the structure and electronic properties of bulk black phosphorus, revealing strain-induced band gap tuning and potential device applications.

Contribution

It provides a detailed theoretical analysis of strain effects on black phosphorus using GW calculations, improving upon previous DFT studies.

Findings

Band gap varies significantly with in-layer strain

Band gap can close at around 2% compressive strain

Anisotropic response of structure and energy to strain

Abstract

We study theoretically the structural and electronic response of layered bulk black phosphorus to in-layer strain. Ab initio density functional theory (DFT) calculations reveal that the strain energy and interlayer spacing display a strong anisotropy with respect to the uniaxial strain direction. To correctly describe the dependence of the fundamental band gap on strain, we used the computationally more involved GW quasiparticle approach that is free of parameters and superior to DFT studies, which are known to underestimate gap energies. We find that the band gap depends sensitively on the in-layer strain and even vanishes at compressive strain values exceeding about 2%, thus suggesting a possible application of black P in strain-controlled infrared devices.