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DS: Fachverband Dünne Schichten

DS 11: Thermoelectric and Phase Change Materials

DS 11.2: Vortrag

Donnerstag, 20. März 2025, 15:15–15:30, H3

Enhancing mechanical flexibility and thermoelectric efficiency of amorphous TiNiSn — •Denis Music — Department of Materials Science and Applied Mathematics, Malmö University, SE-205 06 Malmö, Sweden

Thermoelectrics can convert heat to electricity without greenhouse gas emissions and hold significant potential as energy sources for wearable devices. Current research focuses on designing compounds that combine high conversion efficiency with mechanical flexibility. Half-Heusler phases, such as TiNiSn, demonstrate promising chemical stability and thermoelectric efficiency, but their inherent brittleness limits their application in flexible devices. To address this shortcoming, amorphous TiNiSn thin films were synthesized by sputtering on various substrates, such as Kapton, silk, and paper, to evaluate their bending response. These thin films show good adhesion to the substrates, as predicted by density functional theory, and do not delaminate under mechanical loading. Bending tests up to 154 degrees reveal minimal crack formation, indicating a high degree of flexibility. Consequently, amorphous TiNiSn is a promising candidate for flexible thermoelectric devices. To further enhance the thermoelectric efficiency of these devices, density functional theory and Boltzmann transport theory were employed to tune the electronic structure and identify suitable doping elements among 3d and 4d transition metals. Experiments were carried out to validate these predictions, yielding an order of magnitude increase in performance at room temperature.

Keywords: thermoelectric properties; half-Heusler alloys; thin films; density functional theory; amorphous