Excitons and optical spectra of phosphorene nanoribbons

TL;DR

This study uses advanced many-body ab-initio calculations to analyze the electronic and optical properties of phosphorene nanoribbons, revealing strong excitonic effects and quantum confinement, with implications for optoelectronic applications.

Contribution

It provides a detailed theoretical analysis of excitonic properties and quantum confinement in phosphorene nanoribbons using G0W0 and Bethe-Salpeter methods, highlighting their optoelectronic potential.

Findings

Strong singlet-triplet exciton splitting in PNRs

Quantum confinement effects are more pronounced in zigzag PNRs

Size-dependent scaling laws for excitonic properties

Abstract

On the basis of many-body {\it ab-initio} calculations, using single-shot G$_0$W$_0$ method and Bethe-Salpeter equation, we study phosphorene nanoribbons (PNRs) in the two typical zigzag and armchair directions. The electronic structure, optical absorption, electron-hole (exciton) binding energy, exciton exchange splitting, and exciton wave functions are calculated for different size of PNRs. The typically strong splitting between singlet and triplet excitonic states make PNRs favorable systems for application in optoelectronic. Quantum confinement occurs in both kinds of PNRs, and it is stronger in the zPNRs, as behave like quasi-zero-dimensional systems. Scaling laws are investigated for the size-dependent behaviors of PNRs. The first bright excitonic state in PNRs is explored in detail.