Microscopic Investigation and Analysis of the Optoelectronic and Electronic Structure Characteristics of OLED Materials with Various Derivatives

Microscopic Investigation and Analysis of the Optoelectronic and Electronic Structure Characteristics of OLED Materials with Various Derivatives | 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 Microscopic Investigation and Analysis of the Optoelectronic and Electronic Structure Characteristics of OLED Materials with Various Derivatives Huai-Wen Tsai This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9194108/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Context: Organic light-emitting materials based on tris(8-hydroxyquinoline) aluminum (Alq₃) and gallium (Gaq₃) remain benchmark emitters in OLED research due to stable emission behaviors. The present work is concerned with the molecular and optical characteristics of these compounds by introducing CH/N substitutions at different positions. A series of derivatives was constructed to evaluate the impact of structural modifications on absorption, emission, and Stokes shift. The results reveal that substitution position apparently affects electronic transitions and spectral behavior. Modifications on the pyridyl side tend to induce red shifts, whereas those on the phenoxide side result in blue shifts. Molecular orbital analyses further indicate that parent complexes exhibit multi-orbital excitations, whereas the 5n₂p derivatives show localized HOMO to LUMO + 1 transitions, leading to higher excitation energies and narrower Stokes shifts. Methods: GaussView was used to construct molecular structures, which were subsequently optimized using density functional theory (DFT) with the B3LYP functional and the 6-31G(d) basis set. Absorption and emission spectra were calculated from single-point time-dependent DFT calculations based on the optimized structures. The computed results have a good agreement with the experimental UV-vis and photoluminescence trends, providing confidence in the modeling approach. OLED Stokes shift Molecular Orbitals Density functional theory Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 30 Mar, 2026 Editor assigned by journal 29 Mar, 2026 Submission checks completed at journal 29 Mar, 2026 First submitted to journal 22 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. 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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-9194108","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":614347867,"identity":"0118fb2d-3133-4890-94e8-2dcf1a43edd1","order_by":0,"name":"Huai-Wen Tsai","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6klEQVRIiWNgGAWjYJCCw0DMA8SMDxgYDgDpBPzKeZC0MBvAtRwgoIUZymaTIEqLPf/hh4cL2+xkDI73HqvmqbnDwM+eY8D8sQ2PLRJpBodntiXzGJw5l3ab59gzBsmeNwYMB/FqYTA4zNvGzGN2I8fsNm/DYQaDGzlALdvwaOE//gGopZ7H7P4bs2KQFnuCWhhyQLYcBtrCY8YMtkWCkJYbOQWHec4d57E/k2MsOefYYR6JM88KDpz9h1sLe//xzZ95yqrtJdvPGH54U3NYjr89eeODijO4tWBxKQP+aBkFo2AUjIJRQAQAAFzRUuarXdayAAAAAElFTkSuQmCC","orcid":"","institution":"Chien Hsin University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Huai-Wen","middleName":"","lastName":"Tsai","suffix":""}],"badges":[],"createdAt":"2026-03-23 00:08:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9194108/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9194108/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107479284,"identity":"1a5b5ebd-86d0-4c82-b4db-cb5a1f45eb52","added_by":"auto","created_at":"2026-04-22 01:23:03","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1315170,"visible":true,"origin":"","legend":"","description":"","filename":"02Manuscript0326.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9194108/v1_covered_b1ae70fd-8e58-4894-92a8-bee0efde781c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Microscopic Investigation and Analysis of the Optoelectronic and Electronic Structure Characteristics of OLED Materials with Various Derivatives","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":"journal-of-molecular-modeling","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jmmo","sideBox":"Learn more about [Journal of Molecular Modeling](https://www.springer.com/journal/894)","snPcode":"894","submissionUrl":"https://submission.nature.com/new-submission/894/3","title":"Journal of Molecular Modeling","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"OLED, Stokes shift, Molecular Orbitals, Density functional theory","lastPublishedDoi":"10.21203/rs.3.rs-9194108/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9194108/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eContext:\u003c/h2\u003e \u003cp\u003eOrganic light-emitting materials based on tris(8-hydroxyquinoline) aluminum (Alq₃) and gallium (Gaq₃) remain benchmark emitters in OLED research due to stable emission behaviors. The present work is concerned with the molecular and optical characteristics of these compounds by introducing CH/N substitutions at different positions. A series of derivatives was constructed to evaluate the impact of structural modifications on absorption, emission, and Stokes shift. The results reveal that substitution position apparently affects electronic transitions and spectral behavior. Modifications on the pyridyl side tend to induce red shifts, whereas those on the phenoxide side result in blue shifts. 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