Guide to optical spectroscopy of layered semiconductors

Abstract

In this technical review we give an introduction to optical spectroscopy for layered materials as a powerful, non-invasive tool to access details of the electronic band structure and crystal quality. Potential applications in photonics and optoelectronics are based on our understanding of the light-matter interaction on an atomic monolayer scale. Here atomically thin transition metal dichalcogenides, such as MoS2 and WSe2, are model systems for layered semiconductors with a bandgap in the visible region of the optical spectrum. They can be assembled to form heterostructures and combine the unique properties of the constituent monolayers. We review the working principles of micro-photoluminescence spectroscopy and optical absorption experiments. We discuss the physical origin of the main absorption and emission features in the optical spectra and how they can be tuned. We explain key-aspects of practical set-ups for performing experiments in different conditions such as variable temperatures or in applied magnetic fields and how parameters such as detection spot size and excitation laser wavelength impact the optical spectra. We describe the important influence of the direct sample environment, such as substrates and encapsulation layers, on the emission and absorption mechanisms. A survey of optical techniques that probe the coupling between layers and analyse carrier polarisation dynamics for spin- and valleytronics is provided.

arXiv comment12 pages, 4 Figures, initial version

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Cited by in corpus (30)

• Enhanced Light-Matter Interaction in Two-Dimensional Transition Metal Dichalcogenides
• Interface engineering of charge-transfer excitons in 2D lateral heterostructures
• One pot chemical vapor deposition of high optical quality large area monolayer Janus transition metal dichalcogenides
• Second harmonic generation control in twisted bilayers of transition metal dichalcogenides
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• Tip-induced excitonic luminescence nanoscopy of an atomically-resolved van der Waals heterostructure
• Stacking-dependent exciton multiplicity in WSe${}_2$ bilayers
• Substrate influence on transition metal dichalcogenide monolayer exciton absorption linewidth broadening
• Raman Polarization Switching in CrSBr
• Charge Density Wave Activated Excitons in TiSe${}_2$-MoSe${}_2$ Heterostructures
• Room Temperature Micro-Photoluminescence Studies of Colloidal WS2 Nanosheets
• Nano-optics of transition metal dichalcogenides and their van der Waals heterostructures with electron spectroscopies
• Light sources with bias tunable spectrum based on van der Waals interface transistors
• Nonlinear spectroscopy of excitonic states in transition metal dichalcogenides
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• Probing the optical near-field interaction of Mie nanoresonators with atomically thin semiconductors
• Scalable transparent conductive thin films with electronically passive interfaces for direct chemical vapor deposition of 2D materials
• Effect of photoinduced screening on the spectroscopic signature of exciton-phonon coupling
• Tuning nanowire lasers via hybridization with two-dimensional materials
• The Importance of Pure Dephasing in the Optical Response of Excitons in High-quality van der Waals Heterostructures
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• Magnetic Correlation Spectroscopy in CrSBr
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• Spin dependent charge transfer in MoSe2/hBN/Ni hybrid structures
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