Spatially Resolved Electronic Properties of Single-Layer WS${}_2$ on Transition Metal Oxides

Abstract

There is a substantial interest in the heterostructures of semiconducting transition metal dichalcogenides (TMDCs) amongst each other or with arbitrary materials, through which the control of the chemical, structural, electronic, spintronic, and optical properties can lead to a change in device paradigms. A critical need is to understand the interface between TMDCs and insulating substrates, for example high-$\kappa$ dielectrics, which can strongly impact the electronic properties such as the optical gap. Here we show that the chemical and electronic properties of the single-layer (SL) TMDC, WS${}_2$, can be transferred onto high-$\kappa$ transition metal oxide substrates TiO${}_2$ and SrTiO${}_3$. The resulting samples are much more suitable for measuring their electronic and chemical structures with angle-resolved photoemission than their native-grown SiO${}_2$ substrates. We probe the WS${}_2$ on the micron scale across 100-micron flakes, and find that the occupied electronic structure is exactly as predicted for freestanding SL WS${}_2$ with a strong spin-orbit splitting of 420~meV and a direct band gap at the valence band maximum. Our results suggest that TMDCs can be combined with arbitrary multi-functional oxides, which may introduce alternative means of controlling the optoelectronic properties of such materials.

arXiv comment28 pages, 5 figures

References in corpus (28)

• Atomically thin MoS2: A new direct-gap semiconductor
• Two Dimensional Atomic Crystals
• Van der Waals heterostructures
• Emerging Device Applications for Semiconducting Two-Dimensional Transition Metal Dichalcogenides
• Ultrafast Charge Transfer in Atomically Thin MoS2/WS2 Heterostructures
• Evolution of Electronic Structure in Atomically Thin Sheets of WS2 and WSe2
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Extraordinary room-temperature photoluminescence in WS2 monolayers
• Mixed-Dimensional van der Waals Heterostructures
• Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• Quasiparticle band structures and optical properties of strained monolayer MoS2 and WS2
• Two dimensional semiconductors with possible high room temperature mobility
• Electrical Transport Properties of Single-Layer WS2
• Band-Like Transport in High Mobility Unencapsulated Single-Layer MoS2 Transistors
• Fast pick up technique for high quality heterostructures of bilayer graphene and hexagonal boron nitride
• Excitons in van der Waals heterostructures: The important role of dielectric screening
• High-Performance Monolayer WS2 Field-effect Transistors on High-k Dielectrics
• Synthesis of Large-Area WS2 monolayers with Exceptional Photoluminescence
• Electronic Structure, Surface Doping, and Optical Response in Epitaxial WSe2 Thin Films
• Electronic Structure of Epitaxial Single-Layer MoS${}_2$
• Observation of Ultrafast Free Carrier Dynamics in Single Layer MoS${}_2$
• Single-layer MoS${}_2$ on Au(111): band gap renormalization and substrate interaction
• In situ observation of stress relaxation in epitaxial graphene
• Growth and electronic structure of epitaxial single-layer WS${}_2$ on Au(111)
• Tuning the Electronic Structure of Monolayer Graphene/MoS2 van der Waals Heterostructures via Interlayer Twist
• Angle-resolved X-ray photoemission electron microscopy

Cited by in corpus (16)

• Giant spin-splitting and gap renormalization driven by trions in single-layer WS${}_2$/h-BN heterostructures
• Electronic band structure of Two-Dimensional WS2/Graphene van der Waals Heterostructures
• Shubnikov-de Haas oscillations in optical conductivity of monolayer MoSe${}_2$
• Understanding Variations in Circularly Polarized Photoluminescence in Monolayer Transition Metal Dichalcogenides
• Direct observation of minibands in twisted heterobilayers
• Contact-Induced Semiconductor-to-Metal Transition in Single-Layer WS${}_2$
• Spin structure of K valleys in single-layer WS${}_2$ on Au(111)
• Nanoscale patterning of quasiparticle band alignment
• Electronic Structure of Exfoliated and Epitaxial Hexagonal Boron Nitride
• Imaging microscopic electronic contrasts at the interface of single-layer WS${}_2$ with oxide and boron nitride substrates
• Benchmarking exchange-correlation potentials with the mstar60 dataset: Importance of the nonlocal exchange potential for effective mass calculations in semiconductors
• Berry Curvature Signatures in Chiroptical Excitonic Transitions
• Quasi-free-standing single-layer WS2 achieved by intercalation
• Exchange-enhanced spin-orbit splitting and its density dependence for electrons in monolayer transition metal dichalcogenides
• Laser-patterned submicron Bi2Se3-WS2 pixels with tunable circular polarization at room temperature
• Exchange-Correlation Functionals in 2D Materials: Applications, Challenges, and Limitations