MOCVD Growth of Covalent and 2D Ga–Se: A Raman Microscopy-Based Phase Validation

MOCVD Growth of Covalent and 2D Ga–Se: A Raman Microscopy-Based Phase Validation | 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 MOCVD Growth of Covalent and 2D Ga–Se: A Raman Microscopy-Based Phase Validation Nils Fritjof Langlotz, Robin Günkel, Dominik Muth, Imad Limame, and 8 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7318333/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Nov, 2025 Read the published version in npj 2D Materials and Applications → Version 1 posted 11 You are reading this latest preprint version Abstract Two-dimensional (2D) materials like gallium selenide (GaSe) hold great promise for optoelectronic devices. GaSe, in particular, features a thickness-dependent bandgap tunable from red to the ultraviolet region. Gallium sesquiselenide (Ga 2 Se 3 ), a related phase with a direct bandgap and a lattice constant closely matched to silicon, can also be grown, making it suitable for integration. To achieve phase-pure growth, constructing a detailed phase diagram is essential. We report wafer-scale synthesis of GaSe and Ga 2 Se 3 via metal-organic chemical vapor deposition (MOCVD), systematically varying growth temperature (450–600°C) and the selenium-to-gallium partial pressure ratio. Raman spectroscopy confirmed phase formation, while AFM, SEM, and HAADF-STEM revealed morphology and epitaxy. Ga 2 Se 3 formed micron-scale three-dimensional islands and epitaxial films with antiphase domains on GaP/Si, whereas GaSe grew as faceted ⟨111⟩-oriented sheets. Photoluminescence and cathodoluminescence showed direct transitions at 1.34 eV for Ga 2 Se 3 and 1.89 eV for GaSe. These results demonstrate controlled MOCVD synthesis of phase-pure GaSe and Ga 2 Se 3 , highlighting their potential for silicon-based optoelectronics. Physical sciences/Materials science Physical sciences/Nanoscience and technology Physical sciences/Optics and photonics Physical sciences/Physics MOCVD GaSe Ga2Se3 phase 2D material Raman microscopy Full Text Additional Declarations No competing interests reported. Supplementary Files GaSePhaseSIfinal.docx Cite Share Download PDF Status: Published Journal Publication published 28 Nov, 2025 Read the published version in npj 2D Materials and Applications → Version 1 posted Editorial decision: Revision requested 25 Aug, 2025 Reviews received at journal 23 Aug, 2025 Reviews received at journal 23 Aug, 2025 Reviews received at journal 19 Aug, 2025 Reviewers agreed at journal 14 Aug, 2025 Reviewers agreed at journal 14 Aug, 2025 Reviewers agreed at journal 13 Aug, 2025 Reviewers invited by journal 13 Aug, 2025 Editor assigned by journal 13 Aug, 2025 Submission checks completed at journal 11 Aug, 2025 First submitted to journal 07 Aug, 2025 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. 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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-7318333","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":502839032,"identity":"fa5345c5-4356-4f97-afde-6c67398c1f36","order_by":0,"name":"Nils Fritjof Langlotz","email":"","orcid":"","institution":"Philipps- Universität Marburg","correspondingAuthor":false,"prefix":"","firstName":"Nils","middleName":"Fritjof","lastName":"Langlotz","suffix":""},{"id":502839033,"identity":"57dedd8d-b4d8-4b5e-b534-d5fa09ecdf97","order_by":1,"name":"Robin Günkel","email":"","orcid":"","institution":"Philipps- Universität 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Validation","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"npj-2d-materials-and-applications","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"npj2dmaterials","sideBox":"Learn more about [npj 2D Materials and Applications](http://www.nature.com/npj2dmaterials/)","snPcode":"41699","submissionUrl":"https://submission.springernature.com/new-submission/41699/3","title":"npj 2D Materials and Applications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"MOCVD, GaSe, Ga2Se3, phase, 2D material, Raman microscopy","lastPublishedDoi":"10.21203/rs.3.rs-7318333/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7318333/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTwo-dimensional (2D) materials like gallium selenide (GaSe) hold great promise for optoelectronic devices. GaSe, in particular, features a thickness-dependent bandgap tunable from red to the ultraviolet region. Gallium sesquiselenide (Ga\u003csub\u003e2\u003c/sub\u003eSe\u003csub\u003e3\u003c/sub\u003e), a related phase with a direct bandgap and a lattice constant closely matched to silicon, can also be grown, making it suitable for integration. To achieve phase-pure growth, constructing a detailed phase diagram is essential. We report wafer-scale synthesis of GaSe and Ga\u003csub\u003e2\u003c/sub\u003eSe\u003csub\u003e3\u003c/sub\u003e via metal-organic chemical vapor deposition (MOCVD), systematically varying growth temperature (450\u0026ndash;600\u0026deg;C) and the selenium-to-gallium partial pressure ratio. Raman spectroscopy confirmed phase formation, while AFM, SEM, and HAADF-STEM revealed morphology and epitaxy. Ga\u003csub\u003e2\u003c/sub\u003eSe\u003csub\u003e3\u003c/sub\u003e formed micron-scale three-dimensional islands and epitaxial films with antiphase domains on GaP/Si, whereas GaSe grew as faceted ⟨111⟩-oriented sheets. Photoluminescence and cathodoluminescence showed direct transitions at 1.34 eV for Ga\u003csub\u003e2\u003c/sub\u003eSe\u003csub\u003e3\u003c/sub\u003e and 1.89 eV for GaSe. These results demonstrate controlled MOCVD synthesis of phase-pure GaSe and Ga\u003csub\u003e2\u003c/sub\u003eSe\u003csub\u003e3\u003c/sub\u003e, highlighting their potential for silicon-based optoelectronics.\u003c/p\u003e","manuscriptTitle":"MOCVD Growth of Covalent and 2D Ga–Se: A Raman Microscopy-Based Phase Validation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-21 12:04:47","doi":"10.21203/rs.3.rs-7318333/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-25T12:05:17+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-23T13:55:07+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-23T12:59:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-20T02:37:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"82103370571616251356724574361097029122","date":"2025-08-14T08:01:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"149444976440119682307881380607104591709","date":"2025-08-14T06:47:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"333154954405304385607161811831426445114","date":"2025-08-14T03:58:50+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-14T03:56:49+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-13T15:33:07+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-11T09:35:40+00:00","index":"","fulltext":""},{"type":"submitted","content":"npj 2D Materials and Applications","date":"2025-08-07T11:29:49+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"npj-2d-materials-and-applications","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"npj2dmaterials","sideBox":"Learn more about [npj 2D Materials and Applications](http://www.nature.com/npj2dmaterials/)","snPcode":"41699","submissionUrl":"https://submission.springernature.com/new-submission/41699/3","title":"npj 2D Materials and Applications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5543e05f-ac5d-4074-aece-971f5856b6de","owner":[],"postedDate":"August 21st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":53413147,"name":"Physical sciences/Materials science"},{"id":53413148,"name":"Physical sciences/Nanoscience and technology"},{"id":53413149,"name":"Physical sciences/Optics and photonics"},{"id":53413150,"name":"Physical sciences/Physics"}],"tags":[],"updatedAt":"2025-12-01T16:01:04+00:00","versionOfRecord":{"articleIdentity":"rs-7318333","link":"https://doi.org/10.1038/s41699-025-00635-4","journal":{"identity":"npj-2d-materials-and-applications","isVorOnly":false,"title":"npj 2D Materials and Applications"},"publishedOn":"2025-11-28 15:57:28","publishedOnDateReadable":"November 28th, 2025"},"versionCreatedAt":"2025-08-21 12:04:47","video":"","vorDoi":"10.1038/s41699-025-00635-4","vorDoiUrl":"https://doi.org/10.1038/s41699-025-00635-4","workflowStages":[]},"version":"v1","identity":"rs-7318333","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7318333","identity":"rs-7318333","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}