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Updated: Nov 14, 2025
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Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating
Published on: April 12, 2018
11.8K
Excitonic Complexes in n-Doped WS2 Monolayer.
Małgorzata Zinkiewicz1, Tomasz Woźniak2, Tomasz Kazimierczuk1
1Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
Nano Letters
|March 8, 2021
Summary
This study reveals the origins of emission lines in n-doped tungsten disulfide (WS2) monolayers. Researchers identified bright and dark negative trions and their phonon replicas using magnetic fields and calculations.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Optics
Background:
- Low-temperature photoluminescence reveals complex emission spectra in n-doped transition metal dichalcogenides.
- Understanding exciton complexes in 2D materials is crucial for optoelectronic applications.
Purpose of the Study:
- To identify the origin of various emission lines in n-doped WS2 monolayer photoluminescence.
- To distinguish between different types of negatively charged excitons and their properties.
Main Methods:
- Low-temperature photoluminescence spectroscopy under external magnetic fields.
- First-principles calculations to model electronic and optical properties.
- Analysis of experimentally extracted and theoretically calculated g-factors.
Main Results:
- All observed emission lines, except the neutral A exciton, originate from negatively charged excitons.
- Identification of bright (singlet, triplet) and dark (spin- and momentum-forbidden) negative trions.
- Distinction between semidark trions and negative biexcitons based on g-factors.
Conclusions:
- Three distinct families of WS2 exciton complexes were identified: bright, intravalley dark, and intervalley dark.
- The g-factors of spin-split subbands in conduction and valence bands were determined.
- This work provides a comprehensive understanding of exciton physics in WS2 monolayers.
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