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Two-Photon Absorption in Monolayer MXenes

Accepted version
Peer-reviewed

Type

Article

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Authors

Bennett, D 
Zhang, C 
Ó Coileáin, C 
Liang, M 

Abstract

jats:titleAbstract</jats:title>jats:pTwo‐photon absorption (2PA) is a nonlinear optical (NLO) effect that typically occurs in a conventional semiconductor whose bandgap is larger than the energy of one excited photon but smaller than the energy of two photons. In this work, the experimental observation of strong 2PA in gapless MXene monolayers is reported. This phenomenon is verified by a nonlinear transmission method and ultrafast dynamic studies based on a wavelength‐degenerate, non‐collinear pump‐probe technique. The unconventional 2PA is attributed to the structures of the MXene energy bands near the Fermi level, which favors two‐photon transitions and suppresses one‐photon transitions due to parallel band absorption effects. These results, as well as the measured NLO parameters including the 2PA coefficient, absorption cross‐section, excited carrier lifetimes, and third‐order NLO susceptibility, provide a systematic understanding of the unusual NLO effect in MXenes and may be applied in advanced photonic and optoelectronic devices.</jats:p>

Description

Keywords

monolayer, MXenes, nonlinear optics, two-photon absorption, ultrafast photonics

Journal Title

Advanced Optical Materials

Conference Name

Journal ISSN

2195-1071
2195-1071

Volume Title

8

Publisher

Wiley

Rights

All rights reserved
Sponsorship
Engineering and Physical Sciences Research Council (EP/L015552/1)