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Keynote Lecture

WEB Thermoelectric Material Synthesis - From Nanoparticles to Epitaxial Thin Films

Friday (25.09.2020)
12:50 - 13:20 F: Functional Materials, Surfaces, and Devices 1
Part of:


The development of efficient thermoelectric generators TEG and thermoelectric coolers have attracted considerable attention in recent years. Radioisotope thermoelectric generators (RTG) are known since the 1950´s, but their low thermoelectric efficiency as given by the dimensionless figure of merit ZT= (α2σ/λ)T (α = Seebeck coefficient, σ = specific electrical conductivity, λ = thermal conductivity = sum of electronic λel and lattice λla contribution, T = absolute temperature [K]) inhibited their broad technical application. Nanostructuring has been proven to be a promising method for increasing the thermoelectric efficiency (zT) of a given material due to an efficient phonon scattering at boundaries and interfaces, resulting in a decreased thermal conductivity, and a simultaneously increased Seebeck coefficient due to both quantum confinement effects and the modification of the electronic band structure.

We will report on the synthesis of tetradymite-type - Sb2Te3, Bi2Te3, (BixSb1−x)2Te3 - nanoparticles[1] and thin films[2] by use of different solution-based and gas phase-based processes as well as on their thermoelectric properties. The role of the synthesis pathway, material composition and material processing of the resulting properties is discussed.

[1] J. Schaumann, M. Loor, D. Ünal, A. Mudring, S. Heimann, U. Hagemann, S. Schulz, F. Maculewicz, G. Schierning, Improving the zT value of thermoelectrics by nanostructuring: Tuning the nanoparticle morphology of Sb2Te3 by ionic liquids, Dalton Trans. 46, 656 (2017).

[2] G. Bendt, K. Kaiser, A. Heckel, F. Rieger, D. Oing, A. Lorke, N. Perez Rodriguez, G. Schierning, C. Jooss, S. Schulz, Structural and thermoelectrical characterization of epitaxial Sb2Te3 high quality thin films grown by thermal evaporation, Semicond. Sci. Technol. 33, 105002 (2018).

[3] F. Rieger, K. Kaiser, G. Bendt, V. Roddatis, S. Schulz, C. Jooss, Low intrinsic c-axis thermal conductivity in PVD grown epitaxial Sb2Te3 films, J. Appl. Phys. 123, 175108 (2018).

Speaker:
Prof. Dr. Stephan Schulz
University of Duisburg-Essen
Additional Authors:
  • Dr. Georg Bendt
    Universität Duisburg-Essen
  • Sarah Salloum
    Universität Duisburg-Essen
  • Kevin Kaiser
    Universität Duisburg-Essen

Dateien

Category Short file description File description File Size
Extended Abstract Abstract Abstract including several figures 333 KB Download