Sébastien Roux
;
Christophe Arnold
;
Etienne Carré
;
Alexandre Plaud
;
Lei Ren
;
Frédéric Fossard
;
Nicolas Horezan
;
Eli Janzen
;
James H. Edgar
;
Camille Maestre
;
Bérangère Toury
;
Catherine Journet
;
Vincent Garnier
;
Philippe Steyer
;
Takashi Taniguchi
(National Institute for Materials Science)
;
Kenji Watanabe
(National Institute for Materials Science)
;
Cédric Robert
;
Xavier Marie
;
François Ducastelle
;
Annick Loiseau
;
Julien Barjon
Description:
(abstract)One of the primary interests of 2D materials is that their atomic layers can be assembled with various degrees of freedom, allowing for tunable excitonic properties. Understanding how interlayer interfaces affect excitons is crucial. In this study, cathodoluminescence and time-resolved cathodoluminescence reveal how excitons interact with the interface between two twisted hexagonal boron nitride (h-BN) crystals at different angles. The interface efficiently captures free excitons, resulting in a population of long-lived, interface-localized (2D) excitons. Temperature-dependent measurements show that, at large twist angles, these interface-localized excitons undergo self-trapping caused by lattice distortion around the exciton. This exciton-interface interaction is responsible for the broad 4-eV optical emission of highly twisted h-BN/h-BN structures. Exciton self-trapping is discussed as a common trait in sp²-hybridized boron nitride polytypes and nanostructures, due to the ionic nature of the B–N bond and the small size of the excitons.
Rights:
Keyword: exciton self-trapping , twisted hexagonal boron nitride (h-BN) , cathodoluminescence
Date published: 2025-05-27
Publisher: American Physical Society (APS)
Journal:
Funding:
Manuscript type: Publisher's version (Version of record)
MDR DOI:
First published URL: https://doi.org/10.1103/physrevx.15.021067
Related item:
Other identifier(s):
Contact agent:
Updated at: 2026-02-17 12:30:31 +0900
Published on MDR: 2026-02-17 09:11:01 +0900
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