Electric- and magnetic-field dependence of the electronic and optical properties of phosphorene quantum dots

TL;DR

This study theoretically explores how in-plane electric and perpendicular magnetic fields affect the electronic and optical properties of rectangular phosphorene quantum dots, revealing distinct edge and bulk state behaviors and transitions.

Contribution

It introduces a numerical analysis of field-dependent electronic and optical properties of phosphorene quantum dots, highlighting the role of edge states and their influence on optical transitions.

Findings

Edge states exist within the band gap and are well separated from bulk states.

Electric and magnetic fields differently affect bulk and edge state transitions.

Multiple types of optical transitions are identified, including edge-to-edge and edge-to-bulk.

Abstract

Recently, black phosphorus quantum dots were fabricated experimentally. Motivated by these experiments, we theoretically investigate the electronic and optical properties of rectangular phosphorene quantum dots (RPQDs) in the presence of an in-plane electric field and a perpendicular magnetic field. The energy spectra and wave functions of RPQDs are obtained numerically using the tight-binding (TB) approach. We find edge states within the band gap of the RPQD which are well separated from the bulk states. In an undoped RPQD and for in-plane polarized light, due to the presence of well-defined edge states, we find three types of optical transitions which are between the bulk states, between the edge and bulk states, and between the edge states. The electric and magnetic fields influence the bulk-to-bulk, edge-to-bulk, and edge-to-edge transitions differently due to the different responses of bulk and edge states to these fields.