Extrinsic Localized Excitons in Patterned 2D Semiconductors
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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Date
2022-08
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en
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8
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Advanced Functional Materials, Volume 32, issue 31
Abstract
A new localized excitonic state is demonstrated in patterned monolayer 2D semiconductors. The signature of an exciton associated with that state is observed in the photoluminescence spectrum after electron beam exposure of several 2D semiconductors. The localized state, which is distinguished by non-linear power dependence, survives up to room temperature and is patternable down to 20 nm resolution. The response of the new exciton to the changes of electron beam energy, nanomechanical cleaning, and encapsulation via multiple microscopic, spectroscopic, and computational techniques is probed. All these approaches suggest that the state does not originate from irradiation-induced structural defects or spatially non-uniform strain, as commonly assumed. Instead, it is shown to be of extrinsic origin, likely a charge transfer exciton associated with the organic substance deposited onto the 2D semiconductor. By demonstrating that structural defects are not required for the formation of localized excitons, this work opens new possibilities for further understanding of localized excitons as well as their use in applications that are sensitive to the presence of defects, e.g. chemical sensing and quantum technologies.Description
Funding Information: The authors thank Benjamin I. Weintrub, Nele Stetzuhn, and Abhijeet Kumar for their great comments on the paper. The authors acknowledge the German Research Foundation (DFG) for financial support through the Collaborative Research Center TRR 227 Ultrafast Spin Dynamics (project B08), SfB 951 (projects A6, A12, B15, Z2). AVK further thanks DFG (projects KR 4866/6‐1 and SFB‐1415‐417590517) for support. The authors thank HRLS Stuttgart, Germany, and TU Dresden (Taurus cluster) for generous grants of computing time. Publisher Copyright: © 2022 The Authors. Advanced Functional Materials published by Wiley-VCH GmbH.
Keywords
charge transfer excitons, defects, electron beam lithography, single photon emitters, TMDs
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Yagodkin, D, Greben, K, Ascunce, A E, Kovalchuk, S, Ghorbani-Asl, M, Jain, M, Kretschmer, S, Severin, N, Rabe, J P, Krasheninnikov, A V, Koch, C T & Bolotin, K I 2022, ' Extrinsic Localized Excitons in Patterned 2D Semiconductors ', Advanced Functional Materials, vol. 32, no. 31, 2203060 . https://doi.org/10.1002/adfm.202203060