Off-Centering of Ge Atoms in GeBi2Te4 and Impact on Thermoelectric Performance

Off-Centering of Ge Atoms in GeBi2Te4 and Impact on Thermoelectric Performance

Advanced Functional Materials

10.1002/adfm.202314499

http://dx.doi.org/10.1002/adfm.202314499

Jinfeng Dong, Lei Hu, Jue Liu, Yukun Liu, Yilin Jiang, Zhiling Yu, Xian Yi Tan, Ady Suwardi, Qiang Zheng, Qian Li, Jing‐Feng Li, Vinayak P. Dravid, Qingyu Yan, Mercouri G. Kanatzidis

10 January 2024

Dong, J., Hu, L., Liu, J., Liu, Y., Jiang, Y., Yu, Z., Tan, X. Y., Suwardi, A., Zheng, Q., Li, Q., Li, J., Dravid, V. P., Yan, Q., & Kanatzidis, M. G. (2024). Off‐Centering of Ge Atoms in GeBi2Te4 and Impact on Thermoelectric Performance. Advanced Functional Materials, 34(18). Portico. https://doi.org/10.1002/adfm.202314499

AbstractThe crystal structure and transport properties of GeBi2Te4 are investigated as a layered compound with potential applications as thermoelectric materials. A disordered arrangement of Ge and Bi atoms in a septuple‐layer structure is discovered through synchrotron radiation X‐ray diffraction and transmission electron microscopy. Neutron pair distribution function analysis revealed the presence of discordant Ge atoms with an off‐centering distance of 0.12 Å at 300 K. The thermal conductivity of GeBi2Te4 is very low due to the strong phonon scattering. This is a result of the three Einstein local oscillators coupled with the disordered arrangement of atoms. This study also explores further the structural characteristics of these materials and their associated phonon scattering processes. The effect of Sb substitution for Ge on the electrical transport properties of the sample is profound, resulting in a change from p‐type to n‐type conduction. An enhanced thermoelectric figure of merit (ZT) of 0.45 at 523 K in the in‐plane direction is obtained. This research provides valuable insights into the crystal structure and transport properties of GeBi2Te4, showcasing its promising role as a thermoelectric material with potential for near‐room‐temperature applications.

Publisher Copyright

This research / project is supported by the Ministry of Education - ACRF Tier 1
Grant Reference no. : RG128/21

This research / project is supported by the Ministry of Education - ACRF Tier 1
Grant Reference no. : RT6/22

This is the peer reviewed version of the following article: Dong, J., Hu, L., Liu, J., Liu, Y., Jiang, Y., Yu, Z., Tan, X. Y., Suwardi, A., Zheng, Q., Li, Q., Li, J., Dravid, V. P., Yan, Q., & Kanatzidis, M. G. (2024). Off‐Centering of Ge Atoms in GeBi2Te4 and Impact on Thermoelectric Performance. Advanced Functional Materials, 34(18). Portico. https://doi.org/10.1002/adfm.202314499, which has been published in final form at doi.org/10.1002/adfm.202314499. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

https://oar.a-star.edu.sg/communities-collections/articles/20372

1616-3028
1616-301X

Institute of Materials Research and Engineering