Facet dependent ultralow thermal conductivity of zinc oxide coated silver fabric for thermoelectric devices

Autor: M. Shalini, S. Nanthini, Pandiyarasan Veluswamy, Janith Weerasinghe, Igor Levchenko, Katia Alexander, Karthika Prasad, H. Shankar, Suhasini Sathiyamoothy
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Scientific Reports, Vol 14, Iss 1, Pp 1-11 (2024)
Druh dokumentu: article
ISSN: 2045-2322
DOI: 10.1038/s41598-024-73773-2
Popis: Abstract The conversion efficiency of a thermoelectric power generator depends on the dimensionless figure-of-merit (ZT) of the constituent thermoelectric materials, which is mainly determined by their Seebeck coefficient as well as the electrical and thermal conductivity. ZnO holds promise for thermoelectric applications, yet its use is currently limited by low electrical conductivity and high thermal conductivity. Herein, we demonstrate how thermal conductivity of ZnO can be significantly reduced by intelligently combining it with a cellulose-based Ag fabric using a one-step hydrothermal method, and how different ratios of zinc nitrate hexahydrate (ZNH) to hexamethylenetetramine (HMT) can be used to fine-tune the thermoelectric performance of the resulting composite. We show that as-prepared samples have a composite structure of Ag, Zn and O without any other impurity phases. We propose that the facet dependent crystal growth orientation, from the c-axis in (101) planes to the a-axis in (100) plane, amplify phonon scattering within the material, impeding effective heat transfer and thereby lowering overall thermal conductivity to 0.046 W/mK at room temperature for composites with a 1:1 ZNH to HMT ratio.
Databáze: Directory of Open Access Journals
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