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arXiv · 2509.21977

Carrier-phonon decoupling via annealing enhances thermoelectric performance of Bi2(Te,Se)3

Xinxiu Cheng·Liqing Xu·Zhibin Gao·Wei Liu·Zhanxiang Yin·Xiangdong Ding·Yu Xiao
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Abstract

Thermoelectric cooling based on the Peltier effect requires high-performance materials near room temperature. In this work, Bi2Te2.6Se0.4 synthesized by melting-hot pressing followed by 100 h annealing (MT-HP-AN) at 723 K exhibits markedly improved performance. Annealing introduces cation vacancies via Te(Se) volatilization, lowering carrier density and enhancing mobility, while simultaneously increasing phonon scattering. A peak ZT of 1.06 at 373 K and an average ZT of 0.99 at 300-423 K are achieved. This MT-HP-AN approach offers a simple yet effective strategy to decouple carrier and phonon transport, advancing the potential of n-type BTS for thermo-electric cooling applications.

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Xinxiu Cheng, Liqing Xu, Zhibin Gao, Wei Liu, Zhanxiang Yin, Xiangdong Ding, Yu Xiao. 2025-09-26. Carrier-phonon decoupling via annealing enhances thermoelectric performance of Bi2(Te,Se)3. https://doi.org/10.1063/5.0293474

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