凭借对热能和电能直接转换的能力，热电材料及器件在废热发电和微区制冷等可持续发展领域具有广阔的应用前景。目前高能量密度的废热主要集中在中温区范围（500 ~ 873 K），顺利回收部分能量将对提高能源利用效率起到巨大作用。决定热电器件转换效率的主要因素有材料热电性能、器件结构设计和两端有效温差等，而通常情况下效率测量值低于利用材料热电优值ZT导出的结果，这很大程度上来源于界面问题带来的有效温差及功率损耗。本项目拟针对影响PbSe基中温同质热电器件输运性质的界面问题，分别从材料内部界面、热电模块与电极界面、热电模块与隔离层界面出发开展深入研究。利用有限元分析、数学建模与系统实验相结合的方法，揭示相关界面问题影响器件电热输运性质的作用机理，并在此基础上优化设计，以增大有效温差并降低功率损耗，提高热电器件转换效率。最终缓解或基本解决高性能PbSe基热电材料集成同质器件过程中的性能劣化问题。

Thermoelectric (TE) materials and devices, enabling direct conversions between heat energy and electricity, could play a pivotal role in new clean energy for sustainable future, e.g., waste heat recycling and micro-refrigeration. For waste heat produced during various processes, the section with high energy density mainly focuses on the mid-temperature range (500-873 K), and the recycling would contribute to the increase of energy efficiency for entire consumption. Factors consisting of TE performance for related materials, structural design, and effective temperature difference play the predominated roles in affecting the efficiency of TE devices, yet the value is typically smaller than that deduced from the dimensionless figure of merit (ZT) of related materials, which is probably due to the loss of effective temperature difference and power resulted from interface problems. In this study, we will focus on the interface problems affecting the transport properties of homogeneous PbSe-based TE devices used for mid-temperature range, including materials interior, the interface between TE modules and electrodes, and the interface between TE modules and isolation layer. Based on finite element method, numerical modeling, and systematic experimental data, the related mechanism of regulating the electrical and thermal transport properties of specific TE devices by using interface modulation would be investigated, further enhancing the efficiency by increasing the effective temperature difference and reduce power loss upon optimizing design. Ultimately, the performance degradation when using PbSe-based materials with high TE performance to assemble homogeneous devices can be improved to some extent.