Electronic structure and optic absorption of phosphorene under strain

TL;DR

This paper investigates how strain affects the electronic structure and optical absorption of phosphorene, revealing strain-induced band gap tuning, semi-Dirac transition, and polarization changes in optical properties.

Contribution

It provides a detailed analysis of strain effects on phosphorene's band structure and optical absorption, including the transition to semi-Dirac dispersion and polarization modifications.

Findings

Strain narrows the band gap and can close it, inducing semi-Dirac dispersion.

Optical absorption is polarized along the armchair direction and is affected by strain.

Vertical and in-plane strains differently influence effective mass and electronic properties.

Abstract

We studied the electronic structure and optic absorption of phosphorene (monolayer of black phosphorus) under strain. Strain was found to be a powerful tool for the band structure engineering. The in-plane strain in armchair or zigzag direction changes the effective masse components along both directions, while the vertical strain only has significant effect on the effective mass in the armchair direction. The band gap is narrowed by compressive in-plane strain and tensile vertical strain. Under certain strain configurations, the gap is closed and the energy band evolutes to the semi-Dirac type: the dispersion is linear in the armchair direction and is gapless quadratic in the zigzag direction. The band-edge optic absorption is completely polarized along the armchair direction, and the polarization rate is reduced when the photon energy increases. Strain not only changes the absorption edge, but also the absorption polarization.