How Substitutional Point Defects in Two-Dimensional WS${}_2$ Induce Charge Localization, Spin-Orbit Splitting, and Strain

Abstract

Control of impurity concentrations in semiconducting materials is essential to device technology. Because of their intrinsic confinement, the properties of two-dimensional semiconductors such as transition metal dichalcogenides (TMDs) are more sensitive to defects than traditional bulk materials. The technological adoption of TMDs is dependent on the mitigation of deleterious defects and guided incorporation of functional foreign atoms. The first step towards impurity control is the identification of defects and assessment of their electronic properties. Here, we present a comprehensive study of point defects in monolayer tungsten disulfide (WS${}_2$) grown by chemical vapor deposition (CVD) using scanning tunneling microscopy/spectroscopy, CO-tip noncontact atomic force microscopy, Kelvin probe force spectroscopy, density functional theory, and tight-binding calculations. We observe four different substitutional defects: chromium (Cr${}_{\text{W}}$) and molybdenum (Mo${}_{\text{W}}$) at a tungsten site, oxygen at sulfur sites in both bottom and top layers (O${}_{\text{S}}$ top/bottom), as well as two negatively charged defects (CDs). Their electronic fingerprints unambiguously corroborate the defect assignment and reveal the presence or absence of in-gap defect states. The important role of charge localization, spin-orbit coupling, and strain for the formation of deep defect states observed at substitutional defects in WS${}_2$ as reported here will guide future efforts of targeted defect engineering and doping of TMDs.

References in corpus (35)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• 2D materials and van der Waals heterostructures
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Control of valley polarization in monolayer MoS2 by optical helicity
• Optimized norm-conserving Vanderbilt pseudopotentials
• Grains and grain boundaries in highly crystalline monolayer molybdenum disulfide
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Optical Spectrum of MoS${}_2$: Many-body Effects and Diversity of Exciton States
• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Hopping Transport through Defect-induced Localized States in Molybdenum Disulfide
• Two-dimensional transition metal dichalcogenides under electron irradiation: defect production and doping
• Quasi-free Standing Epitaxial Graphene on SiC by Hydrogen Intercalation
• The mechanism of high-resolution STM/AFM imaging with functionalized tips
• Tight-binding model and direct-gap/indirect-gap transition in single-layer and multi-layer MoS${}_2$
• Covalent Nitrogen Doping and Compressive Strain in MoS2 by Remote N2 Plasma Exposure
• Identifying substitutional oxygen as a prolific point defect in monolayer transition metal dichalcogenides with experiment and theory
• Observation of charge density wave order in 1D mirror twin boundaries of single-layer MoSe2
• Modeling electronic structure and transport properties of graphene with resonant scattering centers
• The origin of high-resolution IETS-STM images of organic molecules with functionalized tips
• A systematic study of structural, electronic and optical properties of atomic scale defects in 2D transition metal dichalcogenides MX${}_2$ (M = Mo,W; X = S, Se, Te)
• Atomistic defect states as quantum emitters in monolayer MoS${}_2$
• Large spin-orbit splitting of deep in-gap defect states of engineered sulfur vacancies in monolayer WS2
• Effect of Point Defects on the Optical and Transport Properties of MoS2 and WS2
• Point Defects and Grain Boundaries in Rotationally Commensurate MoS2 on Epitaxial Graphene
• Giant spin-orbit splitting of point defect states in monolayer WS${}_2$
• Optically discriminating carrier-induced quasiparticle band gap and exciton energy renormalization in monolayer MoS2
• Doping nature of native defects in 1T-TiSe2
• Substrate screening effects on the quasiparticle band gap and defect charge transition levels in MoS${}_2$
• Electronic and Optical Properties of Vacancy Defects in Transition Metal Dichalcogenides
• Robust valley polarization of helium ion modified atomically thin MoS${}_2$
• Spin-orbit dynamics of single acceptor atoms in silicon
• Nanoscale patterning of quasiparticle band alignment
• Apparent Reversal of Molecular Orbitals Reveals Entanglement
• Dimensionality-suppressed chemical doping in 2D semiconductors: the cases of phosphorene, MoS2, and ReS2 from first-principles

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• Tip-induced creation and Jahn-Teller distortions of sulfur vacancies in single-layer MoS${}_2$
• Doped Mott phase and charge correlations in monolayer 1T-NbSe${}_2$
• Qubit guidelines for solid-state spin defects
• Influence of surface relaxations on scanning probe microscopy images of the charge density wave material 2H-NbSe${}_2$
• Graphene-driven correlated electronic states in one dimensional defects within WS${}_2$
• Making atomistic materials calculations accessible with the AiiDAlab Quantum ESPRESSO app