Photoluminescence Enhancement in Two-Dimensional Semiconductors via Spacer-Free Metallic Screening

Photoluminescence Enhancement in Two-Dimensional Semiconductors via Spacer-Free Metallic Screening | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Photoluminescence Enhancement in Two-Dimensional Semiconductors via Spacer-Free Metallic Screening Hafiz Muhammad Shakir, Abdulsalam Aji Suleiman, Kübra Nur Kalkan, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5636467/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 01 Jul, 2025 Read the published version in npj 2D Materials and Applications → Version 1 posted 11 You are reading this latest preprint version Abstract Coulomb-bound electron-hole pairs, namely the excitons, in monolayer transition metal dichalcogenides (TMDCs) present unique opportunities for optoelectronic and quantum photonic device applications. Due to their two-dimensional confinement, these excitons are highly sensitive to their environment, with electric field lines extending beyond the TMDC monolayer. This sensitivity allows for the engineering of screening effects to modulate exciton radiative recombination and photoluminescence (PL) intensity with the aim of enhancing device efficiency. While previous studies have explored modifying the dielectric environment and introducing metal surfaces separated from TMDCs by a dielectric spacer layer to influence screening effects and PL, the case where a metal layer is in contact with the TMDC monolayer by only a van der Waals gap—has not been demonstrated until now. In this study, we demonstrate that this limit can be achieved by vertically stacking metals with appropriate work functions either above or below a monolayer semiconducting TMDC. Our findings reveal that PL intensity can be increased by up to two orders of magnitude in such metal-semiconductor junctions, attributed to the suppression of exciton-exciton interactions due to the strong screening provided by the metallic layer in a dielectric spacer-free environment. The van der Waals gapped interface minimizes free carrier transfer from the metal to the TMDC. Time-resolved PL measurements further indicate that the observed PL enhancement is due to reduced exciton-exciton annihilation, even at high generation rates, facilitated by the strong screening effect of the metal. These results highlight the potential for engineering optical emission from TMDCs through direct metal interfacing. Physical sciences/Nanoscience and technology/Nanoscale materials Physical sciences/Nanoscience and technology/Nanoscale devices Physical sciences/Nanoscience and technology Physical sciences/Optics and photonics Physical sciences/Physics Physical sciences/Materials science/Nanoscale materials/Two dimensional materials Physical sciences/Materials science Physical sciences/Materials science/Materials for optics Physical sciences/Materials science/Nanoscale materials Full Text Additional Declarations No competing interests reported. Supplementary Files SIvf.docx Cite Share Download PDF Status: Published Journal Publication published 01 Jul, 2025 Read the published version in npj 2D Materials and Applications → Version 1 posted Editorial decision: Revision requested 11 Feb, 2025 Reviews received at journal 08 Feb, 2025 Reviews received at journal 06 Feb, 2025 Reviews received at journal 06 Feb, 2025 Reviewers agreed at journal 30 Jan, 2025 Reviewers agreed at journal 27 Jan, 2025 Reviewers agreed at journal 27 Jan, 2025 Reviewers invited by journal 27 Jan, 2025 Editor assigned by journal 07 Jan, 2025 Submission checks completed at journal 19 Dec, 2024 First submitted to journal 13 Dec, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5636467","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":392391851,"identity":"3f7fce28-bc60-4bd3-8ee8-4630dae13276","order_by":0,"name":"Hafiz Muhammad Shakir","email":"","orcid":"","institution":"Bilkent University","correspondingAuthor":false,"prefix":"","firstName":"Hafiz","middleName":"Muhammad","lastName":"Shakir","suffix":""},{"id":392391852,"identity":"359c7d81-e195-493d-a53c-b698a3990756","order_by":1,"name":"Abdulsalam Aji Suleiman","email":"","orcid":"","institution":"Bilkent University UNAM – Institute of Materials Science 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