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Title: Opto-valleytronic imaging of atomically thin semiconductors

Journal Article · · Nature Nanotechnology

Transition metal dichalcogenide semiconductors represent elementary components of layered heterostructures for emergent technologies beyond conventional opto-electronics. In their monolayer form they host electrons with quantized circular motion and associated valley polarization and valley coherence as key elements of opto-valleytronic functionality. Here, we introduce two-dimensional polarimetry as means of direct imaging of the valley pseudospin degree of freedom in monolayer transition metal dichalcogenides. Using MoS2 as a representative material with valley-selective optical transitions, we establish quantitative image analysis for polarimetric maps of extended crystals, and identify valley polarization and valley coherence as sensitive probes of crystalline disorder. Moreover, we find site-dependent thermal and non-thermal regimes of valley-polarized excitons in perpendicular magnetic fields. Finally, we demonstrate the potential of widefield polarimetry for rapid inspection of opto-valleytronic devices based on atomically thin semiconductors and heterostructures.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC52-06NA25396
OSTI ID:
1375888
Report Number(s):
LA-UR-17-25599; TRN: US1702562
Journal Information:
Nature Nanotechnology, Vol. 12, Issue 4; ISSN 1748-3387
Publisher:
Nature Publishing GroupCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 50 works
Citation information provided by
Web of Science

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Cited By (18)

Highly Stable Field Emission from a Tungsten Diselenide Monolayer on Zinc Oxide Nanowire by Geometrically Modulating Hot Electrons journal June 2019
The role of momentum-dark excitons in the elementary optical response of bilayer WSe2 journal July 2018
Evidence for line width and carrier screening effects on excitonic valley relaxation in 2D semiconductors journal July 2018
Tuning the Fröhlich exciton-phonon scattering in monolayer MoS2 journal February 2019
Polariton hyperspectral imaging of two-dimensional semiconductor crystals journal September 2019
Electromagnetic plasmonic field of nanoparticles tune the band gap of two-dimensional semiconducting materials journal January 2019
Spectrally narrow exciton luminescence from monolayer MoS 2 and MoSe 2 exfoliated onto epitaxially grown hexagonal BN journal July 2018
Control of spin and valley Hall effects in monolayer transition metal dichalcogenides by magnetic proximity effect journal January 2020
Perfect absorption in transition metal dichalcogenides-based dielectric grating journal August 2018
Dark and bright exciton formation, thermalization, and photoluminescence in monolayer transition metal dichalcogenides journal May 2018
High optical quality of MoS 2 monolayers grown by chemical vapor deposition journal November 2019
Defect-Induced Modification of Low-Lying Excitons and Valley Selectivity in Monolayer Transition Metal Dichalcogenides journal October 2018
Excitonic Linewidth Approaching the Homogeneous Limit in MoS 2 -Based van der Waals Heterostructures journal May 2017
Colloquium : Excitons in atomically thin transition metal dichalcogenides journal April 2018
Giant Valley Coherence at Room Temperature in 3R WS 2 with Broken Inversion Symmetry journal October 2019
Polariton hyperspectral imaging of two-dimensional semiconductor crystals text January 2019
Defect-induced modification of low-lying excitons and valley selectivity in monolayer transition metal dichalcogenides text January 2018
Colloquium : Excitons in atomically thin transition metal dichalcogenides text January 2018

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