| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
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Alloys and Compounds for Thermoelectric and Solar Cell Applications XIII
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| Presentation Title |
Modulation of Crystal Structure and Thermoelectric Properties of Medium-Entropy GeTe-Based Compounds with Sb and Se Alloying |
| Author(s) |
Cheng-Ruei Wu, Chien-Neng Liao |
| On-Site Speaker (Planned) |
Cheng-Ruei Wu |
| Abstract Scope |
Germanium telluride (GeTe) is a promising thermoelectric material with tunable band structure and transport properties in the mid-high temperature regime. Nevertheless, its rhombohedral-to-cubic phase transition at ~700 K raises structural stability concerns for high-temperature thermoelectric modules. This study proposes entropy-engineering to stabilize the cubic structure of GeTe-based alloys at room temperature through substituting high fractions of Sb and Se. The synthesized GeSbSeTe (GSST-series) alloys exhibited a single-phase cubic structure, high Seebeck coefficients of 200 – 250 μV/K, and low thermal conductivities of 0.66 W/m·K. The cubic GSST alloy exhibited (zT)max of 1.24 at 623 K and (zT)average of 0.82 over the temperature range of 300 – 623 K, four times higher than pristine GeTe. The alloys achieve a maximum thermoelectric conversion efficiency (η)max of approximately 4.7% at a hot side temperature of 648 K. This work establishes an alternative strategy of manipulating crystal structure and thermoelectric properties of GeTe-based alloys. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Energy Conversion and Storage, Phase Transformations, High-Entropy Alloys |