Inverse Funnel Effect of Excitons in Strained Black Phosphorus

Abstract

We study the effects of strain on the properties and dynamics of Wannier excitons in monolayer (phosphorene) and few-layer black phosphorus (BP), a promising two-dimensional material for optoelectronic applications due to its high mobility, mechanical strength and strain-tuneable direct band gap. We compare the results to the case of molybdenum disulphide (MoS${}_2$) monolayers. We find that the so-called funnel effect, i.e. the possibility of controlling exciton motion by means of inhomogeneous strains, is much stronger in few-layer BP than in MoS${}_2$ monolayers and, crucially, is of opposite sign. Instead of excitons accumulating isotropically around regions of high tensile strain like in MoS${}_2$, excitons in BP are pushed away from said regions. This \emph{inverse} funnel effect is moreover highly anisotropic, with much larger funnel distances along the armchair crystallographic direction, leading to a directional focusing of exciton flow. A strong inverse funnel effect could enable simpler designs of funnel solar cells, and offer new possibilities for the manipulation and harvesting of light.

11 pages, 7 figures and 3 tables. Final published version

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Cited by in corpus (20)

• Strain-modulated Bandgap and Piezo-resistive Effect in Black Phosphorus Field-effect Transistors
• Tuning 2D hyperbolic plasmons in black phosphorus
• Electronic Structure Theory of Strained Two-Dimensional Materials with Hexagonal Symmetry
• Electronic Band Structure of Transition Metal Dichalcogenides from Ab Initio and Slater-Koster Tight-Binding Model
• Excitonic Stark effect in MoS${}_2$ monolayers
• Impact of strain on the optical fingerprint of monolayer transition metal dichalcogenides
• Excitonic structure of the optical conductivity in MoS${}_2$ monolayers
• Dielectric nano-antennas for strain engineering in atomically thin two-dimensional semiconductors
• Strain-induced bound states in transition-metal dichalcogenide bubbles
• Anisotropic effects in two-dimensional materials
• Nano-imaging of the edge-dependent optical polarization anisotropy of black phosphorus
• Strong Modulation of Optical Properties in Rippled 2D GaSe via Strain Engineering
• Modulation of trion and exciton formation in monolayer WS2 by dielectric and substrate engineering
• Multi-scale approach for strain-engineering of phosphorene
• Exciton routing in the heterostructure of TMD and paraelectrics
• Enhanced Spin-Flip Scattering by Surface Roughness in WS${}_2$ and MoS${}_2$ Armchair Nanoribbons
• Polariton Hall Effect in Transition-Metal Dichalcogenides
• Local tuning of WS2 photoluminescence using polymeric micro-actuators in a monolithic van der Waals heterostructure
• Probing the uniaxial strain-dependent valley drift and Berry curvature in monolayer MoSi${}_2$N${}_4$
• First principles investigation of pressure related quantum transport in pure black phosphorus devices