Selective Dissolution-Derived Nanoporous Design of Impurity-Free Bi2 Te3 Alloys with High Thermoelectric Performance

Seunghyeok Lee; Sung-Jin Jung; Gwang Min Park; Min Young Na; Kwang-Chon Kim; Junpyo Hong; Albert S Lee; Seung-Hyub Baek; Heesuk Kim; Tae Joo Park; Jin-Sang Kim; Seong Keun Kim

doi:10.1002/smll.202205202

Selective Dissolution-Derived Nanoporous Design of Impurity-Free Bi₂ Te₃ Alloys with High Thermoelectric Performance

Small. 2023 Apr;19(14):e2205202. doi: 10.1002/smll.202205202. Epub 2023 Jan 12.

Authors

Seunghyeok Lee^{1

2}, Sung-Jin Jung¹, Gwang Min Park^{1

3}, Min Young Na⁴, Kwang-Chon Kim¹, Junpyo Hong^{5

6}, Albert S Lee^{5

6}, Seung-Hyub Baek^{1

7

8

9}, Heesuk Kim¹⁰, Tae Joo Park², Jin-Sang Kim¹¹, Seong Keun Kim^{1

3}

Affiliations

¹ Electronic Materials Research Center, Korea Institute of Science and Technology Seoul, Seoul, 02792, South Korea.
² Department of Materials Science and Chemical Engineering, Hanyang University, Ansan, 15588, South Korea.
³ KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, South Korea.
⁴ Advanced Analysis and Data Center, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
⁵ Materials Architecturing Research Center, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
⁶ Convergence Research Center for Solutions to Electromagnetic Interference in Future-mobility, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
⁷ Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, South Korea.
⁸ Yonsei-KIST Convergence Research Institute, Seoul, 02792, South Korea.
⁹ Nanomaterials Science & Engineering, KIST School, Korea University of Science and Technology, Seoul, 02792, South Korea.
¹⁰ Soft Hybrid Materials Research Center, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
¹¹ Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Wanju, 55324, South Korea.

PMID: 36634999
DOI: 10.1002/smll.202205202

Abstract

Thermoelectric technology, which has been receiving attention as a sustainable energy source, has limited applications because of its relatively low conversion efficiency. To broaden their application scope, thermoelectric materials require a high dimensionless figure of merit (ZT). Porous structuring of a thermoelectric material is a promising approach to enhance ZT by reducing its thermal conductivity. However, nanopores do not form in thermoelectric materials in a straightforward manner; impurities are also likely to be present in thermoelectric materials. Here, a simple but effective way to synthesize impurity-free nanoporous Bi_0.4 Sb_1.6 Te₃ via the use of nanoporous raw powder, which is scalably formed by the selective dissolution of KCl after collision between Bi_0.4 Sb_1.6 Te₃ and KCl powders, is proposed. This approach creates abundant nanopores, which effectively scatter phonons, thereby reducing the lattice thermal conductivity by 33% from 0.55 to 0.37 W m^-1 K^-1 . Benefitting from the optimized porous structure, porous Bi_0.4 Sb_1.6 Te₃ achieves a high ZT of 1.41 in the temperature range of 333-373 K, and an excellent average ZT of 1.34 over a wide temperature range of 298-473 K. This study provides a facile and scalable method for developing high thermoelectric performance Bi₂ Te₃ -based alloys that can be further applied to other thermoelectric materials.

Keywords: Bi 2Te 3; KCl; porous materials; selective dissolution; thermoelectrics.

Abstract

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