{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,20]],"date-time":"2026-02-20T22:34:18Z","timestamp":1771626858127,"version":"3.50.1"},"posted":{"date-parts":[[2026]]},"group-title":"SSRN","reference-count":51,"publisher":"Elsevier BV","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>High-temperature waste heat harvesting using thermoelectric technology requires the development of materials that combine high thermoelectric performance with stability under large thermal gradients. In this context, oxide-based thermoelectrics have emerged as promising candidates for high-temperature operations. Among these, SrTiO3 stands out as one of the most promising oxide system, combining high phase stability with tunable electrical and thermal transport properties. In this work, Sr1-xTi0.9Nb0.1O3 ceramics with varied nominal A-site deficiency (x = 0-0.07) were successfully processed using the laser floating zone (LFZ) technique under both air and H2-containing atmospheres. The LFZ process enabled rapid, crucible-free growth of mechanically robust samples while allowing controlled phases formation and cations distribution as a function of processing conditions and Sr deficiency. X-ray diffraction studies confirmed the predominance of the cubic perovskite phase in all compositions, while energy-dispersive X-ray spectroscopy revealed the presence of secondary TiO2 and Nb-rich phases depending on the growth atmosphere. The best thermoelectric performance was achieved for the sample Sr0.95Ti0.9Nb0.1O3 grown in H2\/N2 atmosphere and heat treated in reducing conditions (10% H2\/90% N2) atmosphere (0.95STNO_h2+tt) sample, which exhibited a high-power factor and a peak ZT of 0.36 at 1173 K. This enhancement is attributed to the combined effects of improved electrical conductivity and reduced lattice thermal conductivity, influenced by A-site deficiency, phonon scattering from point defects, and secondary-phase interfaces. A four-leg UNILEG-type thermoelectric module fabricated from this composition delivered a maximum power output of approximately 10 mW under a 248 K thermal gradient, with a hot-side temperature of 675 K. Although contact resistance remains a major limitation, this study highlights the potential of LFZ processing for tailoring microstructure, defect chemistry, and thermoelectric performance in SrTiO3-based materials.<\/jats:p>","DOI":"10.2139\/ssrn.6277637","type":"posted-content","created":{"date-parts":[[2026,2,20]],"date-time":"2026-02-20T21:41:21Z","timestamp":1771623681000},"source":"Crossref","is-referenced-by-count":0,"title":["A-Site deficiency- and redox-driven functional performance of Laser Floating Zone-processed SrTiO3-based thermoelectric ceramics"],"prefix":"10.2139","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1087-9990","authenticated-orcid":true,"given":"Diogo","family":"Lopes","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8497-9310","authenticated-orcid":true,"given":"Rodrigo  Miguel","family":"Santos","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4398-9256","authenticated-orcid":true,"given":"Nuno  M.","family":"Ferreira","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4014-7555","authenticated-orcid":true,"given":"Oscar  J.","family":"Dura","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1614-1962","authenticated-orcid":true,"given":"G.","family":"Constantinescu","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5452-8191","authenticated-orcid":true,"given":"Sergey  M.","family":"Mikhalev","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8729-714X","authenticated-orcid":true,"given":"Florinda  M.","family":"Costa","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5814-9797","authenticated-orcid":true,"given":"Andrei","family":"Kovalevsky","sequence":"additional","affiliation":[]}],"member":"78","reference":[{"key":"ref1","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.gr.2023.03.025","article-title":"The need for energy efficiency and economic prosperity in a sustainable environment","volume":"127","author":"W Chen","year":"2024","journal-title":"Gondwana Research"},{"key":"ref2","doi-asserted-by":"crossref","DOI":"10.1016\/j.energy.2025.135674","article-title":"Revisiting the thermodynamic mechanisms of thermoelectric energy conversion","volume":"322","author":"X Zhang","year":"2025","journal-title":"Energy"},{"key":"ref3","author":"R Singh","year":"2024","journal-title":"Advancements in thermoelectric materials for efficient waste heat recovery and renewable energy 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