Design of van der Waals Interfaces for Broad-Spectrum Optoelectronics

Abstract

Van der Waals (vdW) materials offer new ways to assemble artificial electronic media with properties controlled at the design stage, by combining atomically defined layers into interfaces and heterostructures. Their potential for optoelectronics stems from the possibility to tailor the spectral response over a broad range by exploiting interlayer transitions between different compounds with an appropriate band-edge alignment. For the interlayer transitions to be radiative, however, a serious challenge comes from details of the materials --such as lattice mismatch or even a small misalignment of the constituent layers-- that can drastically suppress the electron-photon coupling. The problem was evidenced in recent studies of heterostructures of monolayer transition metal dichalcogenides, whose band edges are located at the K-point of reciprocal space. Here we demonstrate experimentally that the solution to the interlayer coupling problem is to engineer type-II interfaces by assembling atomically thin crystals that have the bottom of the conduction band and the top of the valence band at the $\Gamma$-point, thus avoiding any momentum mismatch. We find that this type of vdW interfaces exhibits radiative optical transition irrespective of lattice constant, rotational/translational alignment of the two layers, or whether the constituent materials are direct or indirect gap semiconductors. The result, which is robust and of general validity, drastically broadens the scope of future optoelectronics device applications based on 2D materials.

References in corpus (22)

• Van der Waals heterostructures
• 2D materials and van der Waals heterostructures
• Atomically thin p-n junctions with van der Waals heterointerfaces
• Evolution of Electronic Structure in Atomically Thin Sheets of WS2 and WSe2
• Observation of Long-Lived Interlayer Excitons in Monolayer MoSe2-WSe2 Heterostructures
• High Electron Mobility, Quantum Hall Effect and Anomalous Optical Response in Atomically Thin InSe
• Local strain engineering in atomically thin MoS2
• Strong interlayer coupling in van der Waals heterostructures built from single-layer chalcogenides
• Photovoltaic effect in an electrically tunable van der Waals heterojunction
• Origin of indirect optical transitions in few-layer MoS2, WS2 and WSe2
• Long-lived direct and indirect interlayer excitons in van der Waals heterostructures
• Interlayer Exciton Optoelectronics in a 2D Heterostructure p-n Junction
• Control of interlayer excitons in two-dimensional van der Waals heterostructures
• Anomalous light cones and valley optical selection rules of interlayer excitons in twisted heterobilayers
• Interfacial Charge Transfer Circumventing Momentum Mismatch at 2D van der Waals Heterojunctions
• Interlayer exciton dynamics in a dichalcogenide monolayer heterostructure
• Exciton correlations in coupled quantum wells and their luminescence blue shift
• Out-of-plane orientation of luminescent excitons in atomically thin indium selenide flakes
• Indirect to direct gap crossover in two-dimensional InSe revealed by ARPES
• Upconverted electroluminescence via Auger scattering of interlayer excitons in van der Waals heterostructures
• Infrared-to-violet tunable optical activity in atomic films of GaSe, InSe, and their heterostructures
• Semiconducting van der Waals Interfaces as Artificial Semiconductors

Cited by in corpus (22)

• Guide to optical spectroscopy of layered semiconductors
• Multifaceted moiré superlattice physics in twisted WSe${}_2$ bilayers
• The optical properties of few-layer InSe
• Tuning the electronic structure of α-antimonene monolayer through interface engineering
• Electrical detection of the flat band dispersion in van der Waals field-effect structures
• Momentum matching and band-alignment type in van der Waals heterostructures: Interfacial effects and materials screening
• Tunable spin-orbit coupling in two-dimensional InSe
• Band Gap Opening in Bilayer Graphene-CrCl${}_3$/CrBr${}_3$/CrI${}_3$ van der Waals Interfaces
• Thickness and twist angle dependent interlayer excitons in metal monochalcogenide heterostructures
• Crossover from weakly indirect to direct excitons in atomically thin films of InSe
• Room-temperature quantum emission from interface excitons in mixed-dimensional heterostructures
• Tunable Interband Transitions in Twisted h-BN/Graphene Heterostructures
• Light sources with bias tunable spectrum based on van der Waals interface transistors
• Terahertz control of photoluminescence emission in few-layer InSe
• Two dimensional semiconductors: optical and electronic properties
• Quantum Defects in 2D Transition Metal Dichalcogenides for Terahertz Technologies
• Electronic structure of 2D van der Waals crystals and heterostructures investigated by spatially- and angle-resolved photoemission
• Identifying atomically thin crystals with diffusively reflected light
• Electrical Control of Excitons in Bare-MoSe2 and MoSe2/NbSe2 Heterostructure
• Room-temperature tuning and probing of Fermi polarons in atomically thin semiconductors on a plasmonic metasurface
• Direct band gap and strong Rashba effect in van der Waals heterostructures of InSe and Sb single layers
• Subnanometric control of coupling between WS${}_2$ monolayers with a molecular spacer