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Communication Dans Un Congrès Année : 2017

Development of thermoelectric metal oxides : the case of doped TiO2

A. Verchere
  • Fonction : Orateur
  • PersonId : 1032804
S. Mishra
S. Le Floch
Gilbert Fantozzi
  • Fonction : Auteur
  • PersonId : 883180
C. Adessi
  • Fonction : Auteur
G. Bouzerar
S. Daniele
S. Pailhès

Résumé

High-efficiency thermoelectric (TE) materials are important for power-generation devices that are designed to convert waste heat into electrical energy or to use in solid-state refrigeration. These applications require innovative materials which not only possess high conversion efficiency but should also be no toxic and have high chemical stability in air, over a wide temperature range such as oxide materials. The latter efficiency is related to high dimensionless number called figure of merit, “ZT” which is a combination of three material properties: Seebeck coefficient, electrical conductivity and thermal conductivity), The advent of nanotechnology has had a dramatic effect on thermoelectric material development and has resulted in the synthesis of nanostructured materials whose thermoelectric properties surpass the best performance of conventional materials mainly because of the reduction if the lattice thermal conductivity. In the context of this PhD, we are exploring the effects of resonant levels on the thermoelectric power factor of TiO2 on the basis of our recent theoretical developments [1-2] together with the effects of the nano-structration. Indeed, while TiO2 is a cheap, chemically stable and not toxic material, its poor electronical conduction remains a technological limitation to meet the requirements for thermoelectric applications as for other metal oxides. In this preliminary communication, we will first present a new approach combining the sol-gel process with spark plasma sintering (SPS) to yield functional doped nano-TiO2 dense ceramic. Impact of the temperature of SPS process onto the densification, the nano-structuration and the dopant distribution will be addressed as well as the oxygen reduction after sintering. Then, the thermoelectric properties of doped Nb-TiO2 will be presented. [1] “Unified modelling of the thermoelectric properties in SrTiO3” G. Bouzerar, S. Thébaud, Ch. Adessi, R. Debord, M. Apreutezei, R. Bachelet and S. Pailhès, EPL 118, 6 (2017) [2] “Boosting the power factor with resonant states: A model study” S. Thébaud, Ch. Adessi, S. Pailhès et G. Bouzerar, Phys. Rev. B 96, 075201(2017)
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Dates et versions

hal-01817445 , version 1 (18-06-2018)

Identifiants

  • HAL Id : hal-01817445 , version 1

Citer

A. Verchere, S. Mishra, S. Le Floch, Gilbert Fantozzi, C. Adessi, et al.. Development of thermoelectric metal oxides : the case of doped TiO2. Journée de la thermoélectricité 2017, Dec 2017, Montpellier, France. ⟨hal-01817445⟩
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