Andrey Sushko
;
Kristiaan De Greve
;
Madeleine Phillips
;
Bernhard Urbaszek
;
Andrew Y. Joe
;
Kenji Watanabe
(National Institute for Materials Science)
;
Takashi Taniguchi
(National Institute for Materials Science)
;
Alexander L. Efros
;
C. Stephen Hellberg
;
Hongkun Park
;
Philip Kim
;
Mikhail D. Lukin
Description:
(abstract)Transition metal dichalcogenide (TMD) semiconductor heterostructures are actively explored as a new platform for quantum optoelectronic systems. Most state of the art devices make use of insulating hexagonal boron nitride (hBN) that acts as a wide-bandgap dielectric encapsulating layer that also provides an atomically smooth and clean interface that is paramount for proper device operation. We report the observation of large, through-hBN photocurrents that are generated upon optical excitation of hBN encapsulated MoSe2 and WSe2 monolayer devices. We attribute these effects to Auger recombination in the TMDs, in combination with an asymmetric band offset between the TMD and the hBN. We present experimental investigation of these effects and compare our observations with detailed, ab-initio modeling. Our observations have important implications for the design of optoelectronic devices based on encapsulated TMD devices. In systems where precise charge-state control is desired, the out-of-plane current path presents both a challenge and an opportunity for optical doping control. Since the current directly depends on Auger recombination, it can act as a local, direct probe of both the efficiency of the Auger process as well as its dependence on the local density of states in integrated devices.
Rights:
Keyword: Transition metal dichalcogenides, heterostructures, photocurrents
Date published: 2020-12-04
Publisher: Walter de Gruyter GmbH
Journal:
Funding:
Manuscript type: Publisher's version (Version of record)
MDR DOI:
First published URL: https://doi.org/10.1515/nanoph-2020-0397
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Updated at: 2025-02-26 12:31:17 +0900
Published on MDR: 2025-02-26 12:31:17 +0900
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[21928614 - Nanophotonics] Asymmetric photoelectric effect Auger-assisted hot hole photocurrents in transition metal dichalcogenides.pdf
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