Retarding moisture-induced chemical degradation of Yttrium Tellurides by tailoring grain boundary chemistry
Abstract Grain boundary engineering has been extensively applied to improve thermoelectric performance, but its potential to enhance chemical stability remains underexplored. Here, we demonstrate that modifying grain boundary chemistry can effectively suppress the chemical degradation of Y 2 Te 3 under ambient conditions. Scanning transmission electron microscopy and atom probe tomography reveal that H 2 O preferentially infiltrates along grain boundaries, initiating oxidation of Y 2 Te 3 into Y–O–H phases and causing chemo-mechanical breakdown of the matrix. This process, remarkably, can be retarded by just 1 at.% of Bi incorporation due to its segregation along grain boundaries. Density functional theory calculations reveal the thermodynamic and kinetic origins of Bi segregation, and show how segregated Bi modifies the local electronic and chemical environment of grain boundaries, thereby linking GB chemistry to both chemical stability and thermoelectric performance. These findings establish multifunctional grain boundary engineering as a generalizable strategy for the design of next-generation thermoelectric materials.
Authors
- Kornelius Nielsch (ORCID: https://orcid.org/0000-0003-2271-7726)
- Ruben Bueno Villoro (ORCID: https://orcid.org/0000-0001-6398-8229)
- Su‐Hyun Yoo (ORCID: https://orcid.org/0000-0002-0933-6323)
- Pyuck‐Pa Choi (ORCID: https://orcid.org/0000-0001-9920-0755)
- Ran He (ORCID: https://orcid.org/0000-0002-0295-6837)
- Chanwon Jung (ORCID: https://orcid.org/0000-0002-9782-0261)
- Yonghyuk Lee (ORCID: https://orcid.org/0000-0001-8961-2254)
- Eric Woods (ORCID: https://orcid.org/0000-0002-1169-893X)
- Jamil Ur Rahman (ORCID: https://orcid.org/0000-0003-0185-043X)
- Christina Scheu (ORCID: https://orcid.org/0000-0001-7916-1533)
- Kyuseon Jang (ORCID: https://orcid.org/0000-0003-1826-7443)
- Siyuan Zhang (ORCID: https://orcid.org/0000-0001-7045-0865)
Institutions
- Korea Advanced Institute of Science and Technology (KR)
- Institute of Chemical Technology (IN)
- Dongguk University (KR)
- Leibniz Institute for Solid State and Materials Research (DE)
- Max-Planck-Institut für Nachhaltige Materialien (DE)
- Korea Research Institute of Chemical Technology (KR)
- Pukyong National University (KR)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-07-25
- DOI
- https://doi.org/10.1038/s41467-026-76056-8
- Primary Topic
- Advanced Thermoelectric Materials and Devices
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- European Commission
- National Research Foundation
- Deutsche Forschungsgemeinschaft
- Korea Research Institute of Chemical Technology
- National Research Foundation of Korea
- Ministry of Science and ICT, South Korea
- HORIZON EUROPE Framework Programme
- National Supercomputing Center, Korea Institute of Science and Technology Information