Complex optical studies on a semiconducting derivative of polyindole as-synthesized through a chemical route

Complex optical studies on a semiconducting derivative of polyindole as-synthesized through a chemical route | 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 Complex optical studies on a semiconducting derivative of polyindole as-synthesized through a chemical route M. A. Attallah, Rasha A. Baseer, Reda Khalil This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6766972/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Dec, 2025 Read the published version in Polymer Bulletin → Version 1 posted 9 You are reading this latest preprint version Abstract Semiconducting polymers have become a significant area of research, as their electrical and electrochemical properties suggest a wide range of potential applications, including transistors, Schottky diodes, light-emitting diodes, and rechargeable batteries. This study aims to explore the novel optical characteristics of as-synthesized semiconducting poly(2-amino-5-(1H-indolyl)-5H-thiazolo[4,3-b]-1,3,4-thiadiazole) (PAITTD) and its N-substituted indole derivatives, which include a side chain containing chlorobenzene (PACBITTD) and bromobenzene (PABBSITTD). Several optical parameters, including the refractive index n(λ), optical conductivity (σ opt ), extinction coefficient (k), dissipation factor (tan δ), and relaxation time (τ) are calculated from the absorpance spectrum A(λ) recorded in the range of 200 to 1200 nm. The synthesized polymer samples demonstrated absorption in the range of 250 to 1000 nm. The absorption spectra are analyzed using multiple peak analysis techniques. The evaluated optical gaps (E g = 1.53-2.05 eV) are confirmed through various methods. It calculated from the intersections of the linear plot (αh ν ) 2 with the h ν -axis, the extrapolation of the straight line of the e' and e" curves of the dielectric constant to the abscissa-axis (photon energy), the intercept of the dielectric relaxation time and hν and the cross-point between the curves of σ opt and σ e . Notably, the optimized polyindole derivatives exhibited a reduced optical band gap of 1.53 eV in the visible region. This estimated optical band gap indicates that these materials have considerable potential for applications in photocatalysts and optoelectronic devices. Polyindole Optical properties Energy band gap-Thermal analysis relaxation time-semiconductor polymer Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 29 Dec, 2025 Read the published version in Polymer Bulletin → Version 1 posted Editorial decision: Revision requested 06 Sep, 2025 Reviews received at journal 30 Aug, 2025 Reviewers agreed at journal 16 Aug, 2025 Reviews received at journal 14 Aug, 2025 Reviewers agreed at journal 09 Aug, 2025 Reviewers invited by journal 13 Jun, 2025 Editor assigned by journal 01 Jun, 2025 Submission checks completed at journal 30 May, 2025 First submitted to journal 28 May, 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. 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-6766972","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":470791772,"identity":"73c549a8-61af-486b-86e7-3ccc12026b9e","order_by":0,"name":"M. A. 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This study aims to explore the novel optical characteristics of as-synthesized semiconducting poly(2-amino-5-(1H-indolyl)-5H-thiazolo[4,3-b]-1,3,4-thiadiazole) (PAITTD) and its N-substituted indole derivatives, which include a side chain containing chlorobenzene (PACBITTD) and bromobenzene (PABBSITTD). Several optical parameters, including the refractive index n(λ), optical conductivity (σ\u003csub\u003eopt\u003c/sub\u003e), extinction coefficient (k), dissipation factor (tan δ), and relaxation time (τ) are calculated from the absorpance spectrum A(λ) recorded in the range of 200 to 1200 nm. The synthesized polymer samples demonstrated absorption in the range of 250 to 1000 nm. The absorption spectra are analyzed using multiple peak analysis techniques. The evaluated optical gaps (E\u003csub\u003eg\u003c/sub\u003e = 1.53-2.05 eV) are confirmed through various methods.\u0026nbsp; It calculated from the intersections of the linear plot (αh\u003cem\u003eν\u003c/em\u003e)\u003csup\u003e2\u003c/sup\u003e with the h\u003cem\u003eν\u003c/em\u003e-axis, the extrapolation of the straight line of the e' and e\" curves of the dielectric constant to the abscissa-axis (photon energy), the intercept of the dielectric relaxation time and hν and the cross-point between the curves of σ\u003csub\u003eopt\u003c/sub\u003e and σ\u003csub\u003ee\u003c/sub\u003e.\u0026nbsp; Notably, the optimized polyindole derivatives exhibited a reduced optical band gap of 1.53 eV in the visible region. 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