Engineering of Neutral Excitons and Exciton Complexes in Transition Metal Dichalcogenide Monolayers through External Dielectric Screening

Abstract

In order to fully exploit the potential of transition metal dichalcogenide monolayers (TMD-MLs), the well-controlled creation of atomically sharp lateral heterojunctions within these materials is highly desirable. A promising approach to create such heterojunctions is the local modulation of the electronic structure of an intrinsic TMD-ML via dielectric screening induced by its surrounding materials. For the realization of this non-invasive approach, an in-depth understanding of such dielectric effects is required. We report on the modulations of excitonic transitions in TMD-MLs through the effect of dielectric environments including low-k and high-k dielectric materials. We present absolute tuning ranges as large as 37 meV for the optical band gaps of WSe 2 and MoSe 2 MLs and relative tuning ranges on the order of 30% for the binding energies of neutral excitons in WSe 2 MLs. The findings suggest the possibility to reduce the electronic band gap of WSe 2 MLs by 120 meV, paving the way towards dielectrically defined lateral heterojunctions.

arXiv comment11 pages + 6 pages supporting information

References in corpus (32)

• Electric Field Effect in Atomically Thin Carbon Films
• Atomically thin MoS2: A new direct-gap semiconductor
• Black phosphorus field-effect transistors
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Control of valley polarization in monolayer MoS2 by optical helicity
• MoS_2 as an ideal material for valleytronics: valley-selective circular dichroism and valley Hall effect
• Exciton Binding Energy and Nonhydrogenic Rydberg Series in Monolayer WS2
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Electrically Tunable Excitonic Light Emitting Diodes based on Monolayer WSe2 p-n Junctions
• Electrical Control of Two-Dimensional Neutral and Charged Excitons in a Monolayer Semiconductor
• Germanene: a novel two-dimensional Germanium allotrope akin to Graphene and Silicene
• Optical Generation of Excitonic Valley Coherence in Monolayer WSe2
• Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
• Tightly bound excitons in monolayer WSe2
• Computational 2D Materials Database: Electronic Structure of Transition-Metal Dichalcogenides and Oxides
• Cross-sectional imaging of individual layers and buried interfaces of graphene-based heterostructures and superlattices
• Experimental demonstration of continuous electronic structure tuning via strain in atomically thin MoS2
• Quasiparticle band structures and optical properties of strained monolayer MoS2 and WS2
• Excitonic linewidth approaching the homogeneous limit in MoS2 based van der Waals heterostructures : accessing spin-valley dynamics
• Non-linear Optical Spectroscopy of Excited Exciton States for Efficient Valley Coherence Generation in WSe2 Monolayers
• Band Gap Engineering with Ultralarge Biaxial Strains in Suspended Monolayer MoS2
• Valley dynamics probed through charged and neutral exciton emission in monolayer WSe2
• Identification of excitons, trions and biexcitons in single-layer WS2
• Binding energies of exciton complexes in transition metal dichalcogenides and effect of dielectric environment
• Excitons in van der Waals heterostructures: The important role of dielectric screening
• Probing the influence of dielectric environment on excitons in monolayer WSe2: Insight from high magnetic fields
• The dielectric genome of van der Waals heterostructures
• Optical investigation of the natural electron doping in thin MoS2 films deposited on dielectric substrates
• Unusual Exciton-Phonon Interactions at van der Waals Engineered Interfaces
• Exciton states in monolayer MoSe2: impact on interband transitions
• Impact of strain on the optical fingerprint of monolayer transition metal dichalcogenides
• Non-invasive control of excitons in two-dimensional materials

Cited by in corpus (28)

• The dielectric impact of layer distances on exciton and trion binding energies in van der Waals heterostructures
• The Coulomb interaction in monolayer transition-metal dichalcogenides
• Substrate screening effects on the quasiparticle band gap and defect charge transition levels in MoS${}_2$
• Collective Excitations in 2D Materials
• Dynamical screening in monolayer transition-metal dichalcogenides and its manifestations in the exciton spectrum
• Dependence of the hBN Layer Thickness on the Band Structure and Exciton Properties of Encapsulated WSe2 Monolayers
• Moiré-Bose-Hubbard model for interlayer excitons in twisted transition metal dichalcogenide heterostructures
• Dielectric Engineering of Electronic Correlations in a van der Waals Heterostructure
• Direct view of phonon dynamics in atomically thin MoS${}_2$
• Dark-exciton driven energy funneling into dielectric inhomogeneities in two-dimensional semiconductors
• Exposing the trion's fine structure by controlling the carrier concentration in hBN-encapsulated MoS${}_2$
• Coulomb-Engineered Heterojunctions and Dynamical Screening in Transition Metal Dichalcogenide Monolayers
• Manipulation of Exciton Dynamics in Single-Layer WSe2 Using a Toroidal Dielectric Metasurface
• Anomalous Non-Hydrogenic Exciton Series in 2D Materials on High-$\kappa$ Dielectric Substrates
• Schottky barrier lowering due to interface states in 2D heterophase devices
• Charged exctions in two-dimensional transition-metal dichalcogenides - semiclassical calculation of Berry-curvature effects
• Exciton routing in the heterostructure of TMD and paraelectrics
• Interplay of Excitonic Complexes in $p$-Doped WSe${}_2$ Monolayers
• Radially polarized light beams from spin-forbidden dark excitons and trions in monolayer WSe${}_2$
• Impacts of dielectric screening on the luminescence of monolayer WSe${}_2$
• Engineering 2D material exciton lineshape with graphene/h-BN encapsulation
• Coulomb Engineering of two-dimensional Mott materials
• Charge Density Wave Activated Excitons in TiSe${}_2$-MoSe${}_2$ Heterostructures
• Exciton-exciton Interaction in Monolayer MoSe${}_2$ from Mutual Screening of Coulomb Binding
• Reentrant Kondo effect in a quantum impurity coupled to a metal-semiconductor hybrid contact
• Quantized exciton-exciton annihilation in monolayer WS2 on SrTiO3 substrates with atomically flat terraces
• Resonant Raman scattering of surface phonon polaritons mediated by excitons in WSe${}_2$ films
• Tuning of exciton type by environmental screening