Probing the Role of Interlayer Coupling and Coulomb Interactions on Electronic Structure in Few-Layer MoSe2 Nanostructures

Abstract

Despite the weak nature of interlayer forces in transition metal dichalcogenide (TMD) materials, their properties are highly dependent on the number of layers in the few-layer two-dimensional (2D) limit. Here, we present a combined scanning tunneling microscopy/spectroscopy and GW theoretical study of the electronic structure of high quality single- and few-layer MoSe2 grown on bilayer graphene. We find that the electronic (quasiparticle) bandgap, a fundamental parameter for transport and optical phenomena, decreases by nearly one electronvolt when going from one layer to three due to interlayer coupling and screening effects. Our results paint a clear picture of the evolution of the electronic wave function hybridization in the valleys of both the valence and conduction bands as the number of layers is changed. This demonstrates the importance of layer number and electron-electron interactions on van der Waals heterostructures, and helps to clarify how their electronic properties might be tuned in future 2D nanodevices.

References in corpus (4)

• Valley polarization in MoS2 monolayers by optical pumping
• Atomically thin p-n junctions with van der Waals heterointerfaces
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Integrated Circuits Based on Bilayer MoS2 Transistors

Cited by in corpus (39)

• Excitons in atomically thin transition metal dichalcogenides
• Identifying substitutional oxygen as a prolific point defect in monolayer transition metal dichalcogenides with experiment and theory
• Optical properties of atomically thin transition metal dichalcogenides: Observations and puzzles
• Probing critical point energies of transition metal dichalcogenides: surprising indirect gap of single layer $SL-WS{e}_2$
• Large spin-orbit splitting of deep in-gap defect states of engineered sulfur vacancies in monolayer WS2
• Thickness dependence of work function, ionization energy, and electron affinity of Mo and W dichalcogenides from DFT and GW calculations
• Electronic Structure, Surface Doping, and Optical Response in Epitaxial WSe2 Thin Films
• Interlayer coupling in commensurate and incommensurate bilayer structures of transition metal dichalcogenides
• Defect-induced modification of low-lying excitons and valley selectivity in monolayer transition metal dichalcogenides
• 2D MoS2-Graphene-based multilayer van der Waals heterostructures: Enhanced charge transfer and optical absorption, and electric-field tunable Dirac point and band gap
• Single-layer MoS${}_2$ on Au(111): band gap renormalization and substrate interaction
• Resonance effects in the Raman scattering of mono- and few layers MoSe${}_2$
• Synthesis of Epitaxial Single-Layer MoS${}_2$ on Au(111)
• Tunable Quasiparticle Band Gap in Few Layer GaSe/graphene Van der Waals Heterostructures
• Davydov splitting and excitonic resonance effects in Raman spectra of few-Layer MoSe2
• Newly observed first-order resonant Raman modes in few-layer MoS${}_2$
• Highly-Oriented Atomically Thin Ambipolar MoSe${}_2$ Grown by Molecular Beam Epitaxy
• Twistronics: A turning point in 2D quantum materials
• Exciton states in monolayer MoSe2: impact on interband transitions
• Band gap measurements of monolayer h-BN and insights into carbon-related point defects
• Substrate screening effects on the quasiparticle band gap and defect charge transition levels in MoS${}_2$
• Band gap renormalization and work function tuning in MoSe2/hBN/Ru(0001) heterostructures
• Accelerating $GW$-Based Energy Level Alignment Calculations for Molecule-Metal Interfaces Using a Substrate Screening Approach
• Orbital symmetry and the optical response of single-layer monochalcogenides
• Band gap engineering of PtSe2
• Fine structure of $\mathrm{K}$-excitons in multilayers of transition metal dichalcogenides
• Hybrid k$\cdot$p tight-binding model for subbands and infrared intersubband optics in few-layer films of transition-metal dichalcogenides: MoS${}_2$, MoSe${}_2$, WS${}_2$ and WSe${}_2$
• Origin of layer dependence in band structures of two-dimensional materials
• Coulomb-Engineered Heterojunctions and Dynamical Screening in Transition Metal Dichalcogenide Monolayers
• Comprehensive tunneling spectroscopy of quasi-freestanding MoS${}_2$ on graphene on Ir(111)
• Solving the Bethe-Salpeter Equation on a Subspace: Approximations and Consequences for Low-dimensional Materials
• Non-invasive control of excitons in two-dimensional materials
• Computational methods for 2D materials modelling
• Substrate screening approach for quasiparticle energies of two-dimensional interfaces with lattice mismatch
• Quantum well confinement and competitive radiative pathways in the luminescence of black phosphorus layers
• Exciton Shift Currents: DC Conduction with Sub-bandgap Photo Excitations
• Waveguiding valley excitons in monolayer transition metal dicalcogenides by dielectric interfaces in the substrate
• Strong Effects of Interlayer Interaction on Valence-Band Splitting in Transition Metal Dichalcogenides
• Optical excitations in nanographenes from the Bethe-Salpeter equation and time-dependent density functional theory: absorption spectra and spatial descriptors