SnS纳米薄膜热电性能的厚度与温度依赖性研究

中文摘要 AI 辅助

SnS作为一种环境友好、成本低廉且地球储量丰富的窄带隙半导体材料，在中温热电转换领域展现出显著的应用潜力。然而，其块体材料的热电性能受到本征点缺陷（如空位）和材料特定能带结构的固有制约。低维工程已成为克服这些限制并提升热电性能的关键策略。在本工作中，我们系统研究了不同厚度（82 nm、199 nm、616 nm和813 nm）的SnS纳米薄膜在300-600 K温度范围内的热电性能。测量采用时域热反射（TDTR）技术和专用薄膜热电参数测试系统（ZEM-3）进行。我们的结果证实，低维化有效提升了SnS的热电性能，热电优值（ZT）对薄膜厚度和温度均表现出显著的依赖性。所有四种SnS薄膜的热电性能均明显优于块体SnS。这种增强主要归因于低维结构特征所引发的量子限域效应、能量过滤效应以及增强的声子散射。这项工作不仅为SnS纳米薄膜的性能优化提供了实验证据和理论见解，还为开发高效、环保的中温热电材料奠定了基础框架，因此具有重要的科学价值和实际应用意义。

英文摘要

SnS as an environmentally friendly, cost-effective, and earth-abundant narrow-bandgap semiconductor material, has demonstrated significant application potential in the field of medium-temperature thermoelectric conversion. However, the thermoelectric performance of its bulk counterpart is inherently constrained by intrinsic point defects (e.g., vacancies) and the material's specific band structure. Low-dimensional engineering has emerged as a pivotal strategy for overcoming these limitations and enhancing thermoelectric performance. In this work, we systematically investigate the thermoelectric properties of SnS nanofilms with distinct thicknesses (82 nm, 199 nm, 616 nm, and 813 nm) across a temperature range of 300-600 K. Measurements were conducted using time-domain thermoreflectance (TDTR) and a dedicated thin-film thermoelectric parameter test system (ZEM-3). Our results confirm that low-dimensionalization effectively boosts the thermoelectric performance of SnS, with the thermoelectric figure of merit (ZT) displaying a pronounced dependence on both film thickness and temperature. All four SnS thin films exhibit thermoelectric performance that is markedly superior to that of bulk SnS. This enhancement is primarily attributed to the quantum confinement effect, energy filtering effect, and intensified phonon scattering, all of which are induced by the low-dimensional structural characteristics. This work provides not only experimental evidence and theoretical insights for the performance optimization of SnS nanofilms but also establishes a foundational framework for the development of high-efficiency, eco-friendly medium-temperature thermoelectric materials, thereby holding significant scientific value and practical implications.

发表机构

• School of Energy and Power Engineering, Dalian University of Technology（大连理工大学能源与动力学院）
• Dalian University of Technology（大连理工大学）
• School of Physics and Technology, Nanjing Normal University（南京师范大学物理科学与技术学院）
• Nanjing Normal University（南京师范大学）

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