Synthèse et caractérisation de matériaux oxydes et oxylfures pour applications thermoélectriques.

Abstract : The development of new thermoelectric materials with good performance and low cost is necessary to make this technology more accessible and thus achieve a significant environmental impact. The work presented in this thesis deals with the synthesis and the structural and physicochemical characterisation of inexpensive oxides, oxysulfides and sulfides compounds in order to study their thermoelectric properties.The first study investigates the influence of low indium contents on the structure and properties of zinc oxide. The characterization of the samples by transmission electron microscopy shows that the solubility of indium in ZnO is less than 0.5 at%. The bidimensional defects formed from low concentrations of indium greatly reduce the electrical resistivity and the thermal conductivity of the material. In parallel with this work, our interest focused on the thermoelectric performances of the oxysulfide BiCuOS through a substitution of Pb at the Bi site. The aliovalent substitution allows a decrease in the electrical resistivity of the material. However, the later remains too high due to a low solubility of the divalent cation in the BiCuOS phase. The last two chapters are dedicated to the study of sulfides compounds. During this work, the natural kiddcreekite mineral phase (Cu6SnWS8) is synthesized for the first time in a laboratory. The successive steps followed to increase the purity of the product is described while the thermoelectric performance of the material is evaluated. Finally, our attention focused on the compounds MnBi4S7 and FeBi4S7 whose crystalline structure seems compatible with a low lattice thermal conductivity. The measured electrical and thermal transport properties are correlated with the electronic structure and the vibrational properties calculated for the two phases. The compound MnBi4S7 thus appears as a promising n-type semiconductor for thermoelectric applications.
Document type :
Theses
Complete list of metadatas

Cited literature [134 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02156736
Contributor : Abes Star <>
Submitted on : Friday, June 14, 2019 - 4:14:58 PM
Last modification on : Saturday, June 15, 2019 - 1:34:23 AM

File

sygal_fusion_28206-labegorre-j...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02156736, version 1

Citation

Jean Baptiste Labegorre. Synthèse et caractérisation de matériaux oxydes et oxylfures pour applications thermoélectriques.. Chimie organique. Normandie Université, 2018. Français. ⟨NNT : 2018NORMC272⟩. ⟨tel-02156736⟩

Share

Metrics

Record views

722

Files downloads

188