Withers, F., Del Pozo-Zamudio, O., Schwarz, S. et al. (15 more authors) (2015) WSe2 Light-Emitting Tunneling Transistors with Enhanced Brightness at Room Temperature. Nano Letters, 15 (12). pp. 8223-8228. ISSN 1530-6984
Abstract
Monolayers of molybdenum and tungsten dichalcogenides are direct bandgap semiconductors, which makes them promising for optoelectronic applications. In particular, van der Waals heterostructures consisting of monolayers of MoS2 sandwiched between atomically thin hexagonal boron nitride (hBN) and graphene electrodes allows one to obtain light emitting quantum wells (LEQWs) with low-temperature external quantum efficiency (EQE) of 1%. However, the EQE of MoS2- and MoSe2-based LEQWs shows behavior common for many other materials: it decreases fast from cryogenic conditions to room temperature, undermining their practical applications. Here we compare MoSe2 and WSe2 LEQWs. We show that the EQE of WSe2 devices grows with temperature, with room temperature EQE reaching 5%, which is 250× more than the previous best performance of MoS2 and MoSe2 quantum wells in ambient conditions. We attribute such different temperature dependences to the inverted sign of spin–orbit splitting of conduction band states in tungsten and molybdenum dichalcogenides, which makes the lowest-energy exciton in WSe2 dark.
Metadata
Item Type: | Article |
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Authors/Creators: | This paper has 18 authors. You can scroll the list below to see them all or them all.
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Copyright, Publisher and Additional Information: | © 2015 American Chemical Society. This is an author produced version of a paper subsequently published in Nano Letters . Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Electroluminescence; photoluminescence; transition metal dichalcogenides; tungsten diselenide; hexagonal boron nitride; graphene; van der Waals heterostructure |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number EUROPEAN COMMISSION - FP6/FP7 604391 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 26 Jan 2016 12:19 |
Last Modified: | 15 Nov 2016 20:17 |
Published Version: | http://dx.doi.org/10.1021/acs.nanolett.5b03740 |
Status: | Published |
Publisher: | American Chemical Society |
Refereed: | Yes |
Identification Number: | 10.1021/acs.nanolett.5b03740 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:94114 |