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Improved Electrical, Thermal, and Thermoelectric Properties Through Sample‐to‐Sample Fluctuations in Near‐Percolation Threshold Composite Materials

Rösch, Andres Georg 1; Giunta, Fabian 1,2; Mallick, Md. Mofasser ORCID iD icon 1; Franke, Leonard 1; Gall, André 1; Aghassi-Hagmann, Jasmin ORCID iD icon 3; Schmalian, Jörg 2,4; Lemmer, Uli 1
1 Lichttechnisches Institut (LTI), Karlsruher Institut für Technologie (KIT)
2 Institut für Theorie der Kondensierten Materie (TKM), Karlsruher Institut für Technologie (KIT)
3 Institut für Nanotechnologie (INT), Karlsruher Institut für Technologie (KIT)
4 Institut für Quantenmaterialien und -technologien (IQMT), Karlsruher Institut für Technologie (KIT)

Abstract:

Effective medium theories (EMT) are powerful tools to calculate sample averaged thermoelectric material properties of composite materials. However, averaging over the heterogeneous spatial distribution of the phases can lead to incorrect estimates of the thermoelectric transport properties and the figure of merit ZT in compositions close to the percolation threshold. This is particularly true when the phases’ electronic properties are rather distinct leading to pronounced percolation effects. The authors propose an alternative model to calculate the thermoelectric properties of multi-phased materials that are based on an expanded nodal analysis of random resistor networks (RRN). This method conserves the information about the morphology of the individual phases, allowing the study of the current paths through the phases and the influence of heterogeneous charge transport and cluster formation on the effective material properties of the composite. The authors show that in composites with strongly differing phases close to the percolation threshold the thermoelectric properties and the ZT value are always dominated exclusively by one phase or the other and never by an average of both. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000131863
Veröffentlicht am 23.08.2021
Originalveröffentlichung
DOI: 10.1002/adts.202000284
Scopus
Zitationen: 4
Web of Science
Zitationen: 4
Dimensions
Zitationen: 4
Cover der Publikation
Zugehörige Institution(en) am KIT Graduiertenschule MERAGEM (MERAGEM)
Institut für Nanotechnologie (INT)
Institut für Quantenmaterialien und -technologien (IQMT)
Institut für Theorie der Kondensierten Materie (TKM)
Lichttechnisches Institut (LTI)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2021
Sprache Englisch
Identifikator ISSN: 2513-0390, 2513-0390
KITopen-ID: 1000131863
HGF-Programm 47.11.02 (POF IV, LK 01) Emergent Quantum Phenomena
Erschienen in Advanced theory and simulations
Verlag Wiley-VCH Verlag
Band 4
Heft 6
Seiten Art.-Nr.: 2000284
Vorab online veröffentlicht am 19.04.2021
Nachgewiesen in Scopus
Web of Science
Dimensions
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