Mono- and Bilayer WS2 Light-Emitting Transistors

Abstract

We have realized ambipolar ionic liquid gated field-effect transistors based on WS2 mono- and bilayers, and investigated their opto-electronic response. A thorough characterization of the transport properties demonstrates the high quality of these devices for both electron and hole accumulation, which enables the quantitative determination of the band gap (Δ1L = 2.14 eV for monolayers and Δ2L = 1.82 eV for bilayers). It also enables the operation of the transistors in the ambipolar injection regime with electrons and holes injected simultaneously at the two opposite contacts of the devices in which we observe light emission from the FET channel. A quantitative analysis of the spectral properties of the emitted light, together with a comparison with the band gap values obtained from transport, show the internal consistency of our results and allow a quantitative estimate of the excitonic binding energies to be made. Our results demonstrate the power of ionic liquid gating in combination with nanoelectronic systems, as well as the compatibility of this technique with optical measurements on semiconducting transition metal dichalcogenides. These findings further open the way to the investigation of the optical properties of these systems in a carrier density range much broader than that explored until now.

arXiv comment22 pages, 6 figures, Nano Letters (2014)

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Cited by in corpus (70)

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• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• Exciton physics and device application of two-dimensional transition metal dichalcogenide semiconductors
• Electrical Transport Properties of Single-Layer WS2
• Black phosphorus: narrow gap, wide applications
• Charge transport and mobility engineering in two-dimensional transition metal chalcogenide semiconductors
• Electron and Hole Mobilities in Single-Layer WSe2
• Atomically thin p-n junctions based on two-dimensional materials
• WSe2 light-emitting tunneling transistors with enhanced brightness at room temperature
• High-Performance Monolayer WS2 Field-effect Transistors on High-k Dielectrics
• The role of contact resistance in graphene field-effect devices
• Enhanced Light-Matter Interaction in Two-Dimensional Transition Metal Dichalcogenides
• Nanophotonics with 2D Transition Metal Dichalcogenides
• Electric field induced strong enhancement of electroluminescence in multi-Layer MoS2
• Electrostatically Induced Superconductivity at the Surface of WS${}_2$
• Valley Polarization by Spin Injection in a Light-Emitting van der Waals Heterojunction
• Molecular-beam epitaxy of monolayer and bilayer WSe2: A scanning tunneling microscopy/spectroscopy study and deduction of exciton binding energy
• Optimizing the Stability of FETs Based on Two-Dimensional Materials by Fermi Level Tuning
• Metal to insulator quantum-phase transition in few-layered ReS${}_2$
• Mobility of 2D materials from first principles in an accurate and automated framework
• Mid-infrared polarized emission from black phosphorus light-emitting diodes
• WS2-graphite dual-ion battery
• Ambipolar Light-Emitting Transistors on Chemical Vapor Deposited Monolayer MoS2
• Control of Valley Degeneracy in MoS2 by Layer Thickness and Electric Field and Its Effect on Thermoelectric Properties
• Charge transport in ion-gated mono-, bi-, and trilayer MoS2 field effect transistors
• Ferroelectric Domain Patterning Controlled Schottky Junction State in Monolayer MoS${}_2$
• Excitonic effects in the optical properties of 2D materials: An equation of motion approach
• Microscopic Origin of the Valley Hall Effect in Transition Metal Dichalcogenides Revealed by Wavelength Dependent Mapping
• Enhanced electron-phonon interaction in multi-valley materials
• Opportunities in Electrically Tunable 2D Materials Beyond Graphene: Recent Progress and Future Outlook
• Hole Transport in Exfoliated Monolayer MoS${}_2$
• Observation of excitonic resonances in the second harmonic spectrum of MoS${}_2$
• Thermal light emission from monolayer MoS2
• Band filling and cross quantum capacitance in ion gated semiconducting transition metal dichalcogenide monolayers
• Engineering polar discontinuities in honeycomb lattices
• Large Range Manipulation of Exciton Species in Monolayer WS2
• Tuning Conductivity Type in Monolayer WS2 and MoS2 by Sulfur Vacancies
• Temperature dependence of Coulomb oscillations in a few-layer two-dimensional WS2 quantum dot
• Quantum Transport in Two-Dimensional WS${}_2$ with High-Efficiency Carrier Injection Through Indium Alloy Contacts
• Spin-valley relaxation and quantum transport regimes in two-dimensional transition metal dichalcogenides
• Ionic Gate Spectroscopy of 2D Semiconductors
• Valley-engineering mobilities in two-dimensional materials
• Photodetecting and Light-Emitting Devices Based on Two Dimensional Materials
• Theory of Strain-Induced Confinement in Transition Metal Dichalcogenide Monolayers
• Ultrasensitive, Ultrafast and Gate-Tunable Two-Dimensional Photodetectors in Ternary Rhombohedral ZnIn2S4 for Optical Neural Networks
• Semiconducting van der Waals Interfaces as Artificial Semiconductors
• Broken adiabaticity induced by Lifshitz transition in MoS${}_2$ and WS${}_2$ single layers
• Percolative switching in transition metal dichalcogenide field-effect transistors at room temperature
• High-throughput screening of 2D materials identifies p-type monolayer WS${}_2$ as potential ultra-high mobility semiconductor
• Temperature induced modulation of resonant Raman scattering in bilayer 2H-MoS${}_2$
• Strong dopant dependence of electric transport in ion-gated MoS2
• RKKY interaction and intervalley processes in p-doped transition metal dichalcogenides
• Variation of photoluminescence spectral line shape of monolayer WS2
• Lithium-ion conducting glass ceramics for electrostatic gating
• Charting the low-loss region in Electron Energy Loss Spectroscopy with machine learning
• Strong two-dimensional plasmon in Li-intercalated hexagonal boron-nitride film with low damping
• Monolayer WS${}_2$ electro- and photo-luminescence enhancement by TFSI treatment
• Annihilation mechanism of excitons in a MoS2 monolayer through direct Förster-type energy transfer and multistep diffusion
• Full control of solid-state electrolytes for electrostatic gating
• Synthetic Semimetals with van der Waals Interfaces
• Strong In-plane Anisotropy in the Electronic Properties of Doped Transition Metal Dichalcogenides exhibited in W1-xNbxS2
• Light sources with bias tunable spectrum based on van der Waals interface transistors
• Gate-controlled valley transport and Goos-Hänchen effect in monolayer WS${}_2$
• UV active plasmons in alkali and alkaline earth intercalated graphene
• Retrieval of material properties of monolayer transition-metal dichalcogenides from magnetoexciton energy spectra
• Wafer-scale fabrication of 2D van der Waals heterojunctions for efficient and broadband photodetection
• Experimentally Measured Field Effect Mobilities for Few Layer van der Waals Materials
• High-Mobility and High-Optical Quality Atomically Thin WS2
• Thermal stability of monolayer $W{S}_2$ in BEOL conditions
• Ionic liquid gating of InAs nanowire-based field effect transistors