Electronic and optical excitations of two-dimensional ZrS${}_2$ and HfS${}_2$ and their heterostructure

Abstract

In a first-principles study based on density-functional theory and many-body perturbation theory we investigate the electronic properties and the optical excitations of ZrS${}_2$ and HfS${}_2$ monolayers and their van der Waals heterostructure. Both materials have an indirect quasi-particle band gap, which amounts to about 2.8 eV in ZrS${}_2$ and to 2.6 eV in HfS${}_2$. In both systems the valence-band maximum is at $\Gamma$ and the conduction-band minimum at M. Spin-orbit coupling induces a splitting of about 100 meV at the $\Gamma$ point in the valence band, while it does not affect the conduction band. The optical absorption spectra are dominated by excitonic peaks, with binding energies between 0.6 eV and 0.8 eV. The ZrS${}_2$/HfS${}_2$ heterobilayer exhibits a peculiar type-I level alignment with a large degree of hybridization between the two monolayers in the valence band, while the conduction bands retain either ZrS${}_2$ or HfS${}_2$ character, respectively. As a consequence, both the electron and the hole components of the first exciton are localized in the ZrS${}_2$ monolayer with non-vanishing probability of finding the hole also in the HfS${}_2$ sheet.

References in corpus (29)

• Atomically thin MoS2: A new direct-gap semiconductor
• Van der Waals heterostructures
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Valley polarization in MoS2 monolayers by optical pumping
• Single-Layer MoS2 Phototransistors
• Exciton Binding Energy and Nonhydrogenic Rydberg Series in Monolayer WS2
• Atomically thin p-n junctions with van der Waals heterointerfaces
• Ultrafast Charge Transfer in Atomically Thin MoS2/WS2 Heterostructures
• Light-emitting diodes by bandstructure engineering in van der Waals heterostructures
• The Computational 2D Materials Database: High-Throughput Modeling and Discovery of Atomically Thin Crystals
• Computational 2D Materials Database: Electronic Structure of Transition-Metal Dichalcogenides and Oxides
• Theory of Neutral and Charged Excitons in Monolayer Transition Metal Dichalcogenides
• Two dimensional semiconductors with possible high room temperature mobility
• Band alignment of two-dimensional transition metal dichalcogenides: application in tunnel field effect transistors
• Dielectric screening in two-dimensional insulators: Implications for excitonic and impurity states in graphane
• Electronic properties of the MoS2-WS2 heterojunction
• Electronic structures and optical properties of realistic transition metal dichalcogenide heterostructures from first principles
• Quantum engineering of transistors based on 2D materials heterostructures
• Efficient Interlayer Relaxation and Transition of Excitons in Epitaxial and Non-epitaxial MoS2/WS2 Heterostructures
• Truncation of Periodic Image Interactions for Confined Systems
• How dielectric screening in two-dimensional crystals affects the convergence of excited-state calculations: Monolayer MoS${}_2$
• Absorption of Light by Excitons and Trions in Monolayers of Metal Dichalcogenide MoS${}_2$: Experiments and Theory
• Few Layer HfS2 FET
• Accurate all-electron $G_0{W}_0$ quasiparticle energies employing the full-potential augmented planewave method
• Ab initio Investigation of Structural Stability and Exfoliation Energies in Transition Metal Dichalcogenides based on Ti-, V-, and Mo-Group Elements
• Control of excitons in multi-layer van der Waals heterostructures
• Dimensionality of excitons in stacked van der Waals materials: The example of hexagonal boron nitride
• Enhanced Light-Matter Interaction in Graphene/h-BN van der Waals Heterostructures
• Understanding effects of packing and chemical terminations on the optical excitations of azobenzene-functionalized self-assembled monolayers

Cited by in corpus (8)

• MoS${}_2$ and Janus (MoSSe) Based 2D van der Waals heterostructures: Emerging Direct Z-scheme Photocatalysts
• A colloquium on the variational method applied to excitons in 2D materials
• MoTe2 as a natural hyperbolic material across the visible and the ultraviolet region
• Electronic structure and optical properties of Na${}_2$KSb and NaK${}_2$Sb from first-principles many-body theory
• Ultrafast charge transfer and vibronic coupling in a laser-excited hybrid inorganic/organic interface
• High-throughput characterization of transition metal dichalcogenide alloys: Thermodynamic stability and electronic band alignment
• Advancing excited-state properties of two-dimensional materials using a dielectric-dependent hybrid functional
• First-Principles Insights into Excitonic and Electron-Phonon Effects in van der Waals Heterostructures