Hybrid Cavity–Plasmonic Germanium Photodetector Architecture for High-Responsivity Near-Infrared Detection

Hybrid Cavity–Plasmonic Germanium Photodetector Architecture for High-Responsivity Near-Infrared Detection | 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 Research Article Hybrid Cavity–Plasmonic Germanium Photodetector Architecture for High-Responsivity Near-Infrared Detection Mohammad Abbaszadeh, Saeed Golmohammadi, Hamed Baghban This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9057778/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 4 You are reading this latest preprint version Abstract High-speed germanium photodetectors are essential for silicon photonics, but thin germanium absorbers typically exhibit limited absorption at 1550 nm. This work studies a resonant-cavity-enhanced germanium-on-silicon photodetector that combines dielectric cavity confinement, plasmonic near-field localization, and a transparent electrode to improve telecom-band detection. Alternating silicon dioxide and titanium dioxide multilayers form a bottom distributed Bragg reflector and a top anti-reflection coating, creating an optical cavity that boosts field intensity in the absorber. Plasmonic enhancement is achieved by embedding gold nanoparticles inside the germanium layer, with nanoparticle diameter and embedding depth optimized for strong optical localization. A graphene layer is integrated as a low-loss transparent electrode to support carrier extraction while preserving cavity response. Three-dimensional finite-difference time-domain simulations show that optimized structures achieve 0.78 - 0.8 absorption at 1550 nm for both symmetric and simple cavity designs. Photovoltaic operation is evaluated under 1550 nm illumination at 0.5 mW incident optical power. The symmetric cavity delivers 0.78 mA short-circuit current, 0.68 V open-circuit voltage, and 0.40 mW maximum electrical power at 0.58 V, corresponding to 1.56 A/W responsivity at zero bias. The simple cavity yields 0.52 mA, 0.65 V, and 0.225 mW at 0.52 V, corresponding to 1.04 A/W. These results demonstrate a scalable path to high-efficiency self-powered germanium photodetectors for silicon photonics receivers and infrared sensing. Germanium photodetector resonant-cavity-enhanced photodetector distributed Bragg reflector (DBR) anti-reflection coating (ARC) near-infrared (NIR) photodetection Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Reviewers invited by journal 06 Apr, 2026 Editor assigned by journal 07 Mar, 2026 Submission checks completed at journal 07 Mar, 2026 First submitted to journal 07 Mar, 2026 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-9057778","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":618125886,"identity":"90aa0395-7e45-4602-a923-22aeef43c5d4","order_by":0,"name":"Mohammad Abbaszadeh","email":"","orcid":"","institution":"University of Tabriz","correspondingAuthor":false,"prefix":"","firstName":"Mohammad","middleName":"","lastName":"Abbaszadeh","suffix":""},{"id":618125887,"identity":"af3d9888-9cbf-4645-b6b8-7f45d167af7e","order_by":1,"name":"Saeed Golmohammadi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABGUlEQVRIiWNgGAWjYHACxgMMDAfALImECgYGAwbGBogEM249SFrOGJCqhbENpIUAkO9ffODQjYo78rrTDj+88XDeH3lz6cPNn3kY7OQZ2HkfYNNicONZwuGcM88Mt91OM7ZI3GZguLMvscGYhyHZsIGZHauNBhJnDA7nth1m3HY7wUwCqIVxwxnGhmQeBuYEBmY27A6bAdFiv+12+jeJxDkG9iAth3kY6nFqYTjfA9aSuO12DtCWBoNEoJbGZh6Gwzi1GNxgA/nlcDJQS7FFwjHj5J09jM2McwyOG7bhclj/4YOPcyoO2wIdtvHmjxo52+087I8/vKmolufnP4bdYRIJ2G1nYMDhEwYG/gO4ZEbBKBgFo2AUQAEAY59l+sUwDIsAAAAASUVORK5CYII=","orcid":"","institution":"University of Tabriz","correspondingAuthor":true,"prefix":"","firstName":"Saeed","middleName":"","lastName":"Golmohammadi","suffix":""},{"id":618125891,"identity":"fbcae2c6-9749-4f9c-81c3-5015aea0842e","order_by":2,"name":"Hamed Baghban","email":"","orcid":"","institution":"University of Tabriz","correspondingAuthor":false,"prefix":"","firstName":"Hamed","middleName":"","lastName":"Baghban","suffix":""}],"badges":[],"createdAt":"2026-03-07 10:53:34","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9057778/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9057778/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106727207,"identity":"cd2bbc9a-0103-46c5-bb66-e3b3440c953b","added_by":"auto","created_at":"2026-04-12 18:38:17","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6311149,"visible":true,"origin":"","legend":"","description":"","filename":"OpticalandQuantumElectronics.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9057778/v1_covered_d8a586d4-b118-42fe-8f9d-36059ff5ec7a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Hybrid Cavity–Plasmonic Germanium Photodetector Architecture for High-Responsivity Near-Infrared Detection","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"optical-and-quantum-electronics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"oqel","sideBox":"Learn more about [Optical and Quantum Electronics](https://www.springer.com/journal/11082)","snPcode":"11082","submissionUrl":"https://submission.nature.com/new-submission/11082/3","title":"Optical and Quantum Electronics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Germanium photodetector, resonant-cavity-enhanced photodetector, distributed Bragg reflector (DBR), anti-reflection coating (ARC), near-infrared (NIR) photodetection","lastPublishedDoi":"10.21203/rs.3.rs-9057778/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9057778/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eHigh-speed germanium photodetectors are essential for silicon photonics, but thin germanium absorbers typically exhibit limited absorption at 1550 nm. 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