High-performance thermoelectrics from cellular nanostructured Sb2Si2Te6

• Main Authors: Luo, Yubo, Cai, Songting, Hao, Shiqiang, Pielnhofer, Florian, Hadar, Ido, Luo, Zhong-Zhen, Xu, Jianwei, Wolverton, Chris, Dravid, Vinayak P., Pfitzner, Arno, Yan, Qingyu, Kanatzidis, Mercouri G.
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Materials::Energy materials; Sb2Si2Te6; Thermoelectric
• Online Access: https://hdl.handle.net/10356/143413
• Institution: Nanyang Technological University

Thermoelectric materials promise to create additional efficiencies in energy management by harvesting the energy of waste heat and converting it to electricity. We introduce 2D Sb2Si2Te6 as a promising new high-performance thermoelectric material. Sb2Si2Te6 exhibits an intrinsically high thermoelectric figure of merit ZT value of ∼1.08 at 823 K. We then devise a unique cellular nanostructure by a post-synthetic reaction strategy that forms in situ Si2Te3 nanosheets, which serve as an effective barrier to heat propagation, yielding an ∼40% reduction in the already very low lattice thermal conductivity to ∼0.29 Wm−1K−1 at 823 K. The cellular nanostructure enables a very high ZT value of ∼1.65 at 823 K for this new material and a high average ZT value of 0.98 (400–823 K). We describe the novel cellular nanostructure design and a single-step chemical route to achieve it, highlighting a potentially new and effective general design strategy for achieving high thermoelectric performance.