About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
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Alloys and Compounds for Thermoelectric and Solar Cell Applications XIV
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| Presentation Title |
Investigating the Phase Stability and Mechanical Performance of Environment-Friendly Phonon-Glass Electron-Crystal Thermoelectric Materials Ag2Se |
| Author(s) |
I-Lun Jen, Li-Yan Lee, Kunag-Kuo Wang, Wan-Ting Chiu, Hsin-Jay Wu |
| On-Site Speaker (Planned) |
I-Lun Jen |
| Abstract Scope |
Ag2Se is an environmentally friendly thermoelectric (TE) material exhibiting a phonon-glass electron-crystal (PGEC) character, with inherently low lattice thermal conductivity. In this study, we systematically investigated the effects of compositional variations on the phase transition, thermoelectric transport, and mechanical properties of bulk Ag2Se-based alloys. Mechanical testing demonstrated significant strengthening and ductility enhancements for Ag<sub>2.02</sub>Se and Ag<sub>2</sub>Se<sub>1.04</sub> samples, achieving ultimate strengths of ~70 MPa and 45 MPa, respectively, compared to ~15 MPa for stoichiometric Ag2Se. Shape deformation strain as a function of temperature (S-T measurement) further showed that Se-enriched Ag<sub>2</sub>Se<sub>1.04</sub> exhibited markedly ductility in its high-temperature β-phase, while other specimens remained brittle. TE measurements showed that Ag<sub>2</sub>Se<sub>1.04</sub> exhibited a higher Seebeck coefficient (−139 μV K<sup>-1</sup>) and lower thermal conductivity (1.34 W m<sup>-1</sup> K<sup>-1</sup>), resulting in an improved zT of 0.84. These results underscore the importance of stoichiometry control in balancing transport properties and mechanical performance in Ag2Se-based TE materials. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Phase Transformations, Mechanical Properties, Electronic Materials |