Decoupling Carrier-Phonon Scattering Boosts the Thermoelectric Performance of n-Type GeTe-Based Materials

De-Zhuang Wang; Wei-Di Liu; Yuanqing Mao; Shuai Li; Liang-Cao Yin; Hao Wu; Meng Li; Yifeng Wang; Xiao-Lei Shi; Xiaoning Yang; Qingfeng Liu; Zhi-Gang Chen

doi:10.1021/jacs.3c12546

Decoupling Carrier-Phonon Scattering Boosts the Thermoelectric Performance of n-Type GeTe-Based Materials

J Am Chem Soc. 2024 Jan 17;146(2):1681-1689. doi: 10.1021/jacs.3c12546. Epub 2024 Jan 4.

Authors

De-Zhuang Wang¹, Wei-Di Liu^{2

3}, Yuanqing Mao^{4

5}, Shuai Li¹, Liang-Cao Yin¹, Hao Wu¹, Meng Li³, Yifeng Wang⁶, Xiao-Lei Shi³, Xiaoning Yang¹, Qingfeng Liu¹, Zhi-Gang Chen³

Affiliations

¹ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
² Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland 4072, Australia.
³ School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology, Brisbane, Queensland 4000, Australia.
⁴ School of Mechanical and Mining Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia.
⁵ Department of Physics and Guangdong Provincial Key Laboratory of Computational Science and Material Design, Southern University of Science and Technology, Shenzhen 518055, China.
⁶ College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China.

PMID: 38178655
DOI: 10.1021/jacs.3c12546

Abstract

The coupled relationship between carrier and phonon scattering severely limits the thermoelectric performance of n-type GeTe materials. Here, we provide an efficient strategy to enlarge grains and induce vacancy clusters for decoupling carrier-phonon scattering through the annealing optimization of n-type GeTe-based materials. Specifically, boundary migration is used to enlarge grains by optimizing the annealing time, while vacancy clusters are induced through the aggregation of Ge vacancies during annealing. Such enlarged grains can weaken carrier scattering, while vacancy clusters can strengthen phonon scattering, leading to decoupled carrier-phonon scattering. As a result, a ratio between carrier mobility and lattice thermal conductivity of ∼492.8 cm³ V^-1 s^-1 W^-1 K and a peak ZT of ∼0.4 at 473 K are achieved in Ge_0.67Pb_0.13Bi_0.2Te. This work reveals the critical roles of enlarged grains and induced vacancy clusters in decoupling carrier-phonon scattering and demonstrates the viability of fabricating high-performance n-type GeTe materials via annealing optimization.