Electronic properties of single-layer and multilayer transition metal dichalcogenides $M{X}_2$ ($M=$ Mo, W and $X=$ S, Se)

Abstract

Single- and few-layer transition metal dichalcogenides have recently emerged as a new family of layered crystals with great interest, not only from the fundamental point of view, but also because of their potential application in ultrathin devices. Here we review the electronic properties of semiconducting $M{X}_2$, where $M=$Mo or W and $X=$ S or Se. Based on of density functional theory calculations, which include the effect of spin-orbit interaction, we discuss the band structure of single-layer, bilayer and bulk compounds. The band structure of these compounds is highly sensitive to elastic deformations, and we review how strain engineering can be used to manipulate and tune the electronic and optical properties of those materials. We further discuss the effect of disorder and imperfections in the lattice structure and their effect on the optical and transport properties of $M{X}_2$. The superconducting transition in these compounds, which has been observed experimentally, is analyzed, as well as the different mechanisms proposed so far to explain the pairing. Finally, we include a discussion on the excitonic effects which are present in these systems.

9 pages, 4 figures. Short review article for special issue of Ann. Phys. on "Two-dimensional materials"

References in corpus (14)

• The electronic properties of graphene
• Two Dimensional Atomic Crystals
• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Valley polarization in MoS2 monolayers by optical pumping
• Elastic properties of freely suspended MoS2 nanosheets
• Optical signature of symmetry variations and spin-valley coupling in atomically thin tungsten dichalcogenides
• Quasiparticle band structures and optical properties of strained monolayer MoS2 and WS2
• Anomalous Raman Spectra and Thickness Dependent Electronic properties of WSe2
• Robust optical emission polarization in MoS2 monolayers through selective valley excitation
• Intrinsic spin Hall effect in monolayers of group-VI dichalcogenides: A first-principles study
• Phonon Softening and Direct to Indirect Bandgap Crossover in Strained Single Layer MoSe2
• Intervalley Scattering and Localization Behaviors of Spin-Valley Coupled Dirac Fermions
• Electric field screening in atomically thin layers of MoS2: the role of interlayer coupling
• Effect of Point Defects on the Optical and Transport Properties of MoS2 and WS2

Cited by in corpus (14)

• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• First-principles theory of field-effect doping in transition-metal dichalcogenides: Structural properties, electronic structure, Hall coefficient, and electrical conductivity
• Hybridized intervalley moiré excitons and flat bands in twisted WSe${}_2$ bilayers
• Electronic Band Structure of Transition Metal Dichalcogenides from Ab Initio and Slater-Koster Tight-Binding Model
• Electronic localization in twisted bilayer MoS${}_2$ with small rotation angle
• Spin-valley relaxation and quantum transport regimes in two-dimensional transition metal dichalcogenides
• Phonon-assisted inter-valley scattering determines ultrafast exciton dynamics in MoSe${}_2$ bilayers
• Layer degree of freedom for excitons in transition metal dichalcogenides
• Symmetry-forbidden intervalley scattering by atomic defects in monolayer transition-metal dichalcogenides
• Emergence of large non-adiabatic effects induced by the electron-phonon interaction on the complex vibrational quasi-particle spectrum of the doped monolayer MoS${}_2$
• Ultrafast Hidden Spin Polarization Dynamics of Bright and Dark Excitons in 2H-WSe${}_2$
• Determination of interatomic coupling between two-dimensional crystals using angle-resolved photoemission spectroscopy
• Dark exciton energy splitting in monolayer WSe2: insights from time-dependent density-functional theory
• Strong band-filling-dependence of the scattering lifetime in gated MoS2 nanolayers induced by the opening of intervalley scattering channels