Monolayer WS${}_2$ electro- and photo-luminescence enhancement by TFSI treatment

Abstract

Layered material heterostructures (LMHs) can be used to fabricate electroluminescent devices operating in the visible spectral region. A major advantage of LMH-light emitting diodes (LEDs) is that electroluminescence (EL) emission can be tuned across that of different exciton complexes (e.g. biexcitons, trions, quintons) by controlling the charge density. However, these devices have an EL quantum efficiency as low as$\sim$10${}^{-4}$\%. Here, we show that the superacid bis-(triuoromethane)sulfonimide (TFSI) treatment of monolayer WS${}_2$-LEDs boosts EL quantum efficiency by over one order of magnitude at room temperature. Non-treated devices emit light mainly from negatively charged excitons, while the emission in treated ones predominantly involves radiative recombination of neutral excitons. This paves the way to tunable and efficient LMH-LEDs

References in corpus (27)

• The Raman Fingerprint of Graphene
• Two Dimensional Atomic Crystals
• Universal Dynamic Conductivity and Quantized Visible Opacity of Suspended Graphene
• Electrochemically Top Gated Graphene: Monitoring Dopants by Raman Scattering
• Uniaxial Strain in Graphene by Raman Spectroscopy: G peak splitting, Gruneisen Parameters and Sample Orientation
• Light-emitting diodes by bandstructure engineering in van der Waals heterostructures
• Strong light-matter coupling in two-dimensional atomic crystals
• Symmetry-dependent phonon renormalization in monolayer MoS2 transistor
• Exciton Binding Energy of Monolayer WS2
• Ultrafast Dynamics of Defect-Assisted Electron-Hole Recombination in Monolayer MoS2
• Rayleigh Imaging of Graphene and Graphene Layers
• Spectroscopic ellipsometry of graphene and an exciton-shifted van Hove peak in absorption
• Mono- and Bilayer WS2 Light-Emitting Transistors
• Electrical suppression of all nonradiative recombination pathways in monolayer semiconductors
• Graphene-Based Integrated Photonics For Next-Generation Datacom And Telecom
• Raman Signature and Phonon Dispersion of Atomically Thin Boron Nitride
• Anomalous excitonic resonance Raman effects in few-layer MoS2
• Optical properties of charged excitons in two-dimensional semiconductors
• The bright side of defects in MoS${}_2$ and WS${}_2$ and a generalizable chemical treatment protocol for defect passivation
• Exciton Trapping Is Responsible for the Long Apparent Lifetime in Acid-Treated MoS2
• Thermoelectric graphene photodetectors with sub-nanosecond response times at Terahertz frequencies
• Photonic crystals to enhance light extraction from 2D materials
• Efficient phonon cascades in hot photoluminescence of WSe${}_2$ monolayers
• Shear and breathing modes of layered materials
• Mechanistic Insight to the Chemical Treatments of Monolayer Transition Metal Disulfides for Photoluminescence Enhancement
• Tunneling-current-induced local excitonic luminescence in p-doped WSe${}_2$ monolayers
• Exploring the structural and optoelectronic properties of natural insulating phlogopite in van der Waals heterostructures