Strain-induced competition of thermoelectric parameters in monolayer HfS2

IF 3.6 2区物理与天体物理 Q2 PHYSICS, APPLIED

Applied Physics Letters Pub Date : 2025-10-13 DOI:10.1063/5.0287334

Yi-min Ding, Min Jiang, Yu Wu, Youyong Li

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引用次数: 0

Abstract

Band convergence strategy has been widely used to improve thermoelectric performance. However, the effect of intervalley scattering caused by band convergence on the electrical and thermal properties is usually neglected. In this work, we investigate the thermoelectric properties of monolayer HfS2 under different tensile strains. The valence band of HfS2 can realize convergence at 6% strain. In this case, the Seebeck coefficient S reaches the maximum due to the significant increase in the density of states. Furthermore, the carrier scattering channels increases due to the intervalley scattering, which makes the electrical conductivity σ drop sharply. The competition between Seebeck coefficient and electrical conductivity leads the power factor (S2σ) decreasing with strain. On the other hand, band convergence effectively reduces the lattice thermal conductivity by softening phonons and increasing the phonon scattering rate. Furthermore, it enhances phonon scattering through electron–phonon coupling. The lattice thermal conductivity leads the way in the competition between thermoelectric parameters, resulting in a significant increase in ZT following band convergence. Our work provides important insights into the modulation of thermoelectric performance through strain and band convergence strategy.

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应变诱导的单层HfS2热电参数竞争

波段收敛策略被广泛用于提高热电性能。然而，由于带辐合引起的谷间散射对材料电学和热性能的影响通常被忽略。在本工作中，我们研究了不同拉伸应变下单层HfS2的热电性能。HfS2的价带在6%应变下可以收敛。在这种情况下，由于态密度的显著增加，塞贝克系数S达到最大值。此外，由于谷间散射，载流子散射通道增加，使得电导率σ急剧下降。塞贝克系数和电导率之间的竞争导致功率因数（S2σ）随应变减小。另一方面，带辐合通过软化声子和增加声子散射率有效地降低了晶格热导率。此外，它通过电子-声子耦合增强声子散射。晶格热导率在热电参数之间的竞争中处于领先地位，导致带收敛后ZT显著增加。我们的工作为通过应变和带收敛策略调制热电性能提供了重要的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Applied Physics Letters 物理-物理：应用

CiteScore

6.40

自引率

10.00%

发文量

1821

审稿时长

1.6 months

期刊介绍： Applied Physics Letters (APL) features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, APL offers prompt publication of new experimental and theoretical papers reporting applications of physics phenomena to all branches of science, engineering, and modern technology. In addition to regular articles, the journal also publishes invited Fast Track, Perspectives, and in-depth Editorials which report on cutting-edge areas in applied physics. APL Perspectives are forward-looking invited letters which highlight recent developments or discoveries. Emphasis is placed on very recent developments, potentially disruptive technologies, open questions and possible solutions. They also include a mini-roadmap detailing where the community should direct efforts in order for the phenomena to be viable for application and the challenges associated with meeting that performance threshold. Perspectives are characterized by personal viewpoints and opinions of recognized experts in the field. Fast Track articles are invited original research articles that report results that are particularly novel and important or provide a significant advancement in an emerging field. Because of the urgency and scientific importance of the work, the peer review process is accelerated. If, during the review process, it becomes apparent that the paper does not meet the Fast Track criterion, it is returned to a normal track.