Abstract Thermoelectric devices convert thermal energy, i.e. heat, into electric energy. With no moving parts, the thermoelectric generator has demonstrated its advantage of long-duration operational reliability. The IV–VI compound semiconductor PbTe-based materials have been widely adopted for the thermoelectric applications in the medium temperature range of 350–650 °C. In most of the reports, thermoelectric materials were manufactured by a hot pressing or quench and annealing method. The recent advancements in the converting efficiency of thermoelectrics, including PbTe-based materials, have been attributed to the modification on material inhomogeneity of microstructures by hot pressing or simply cooling the melt to reduce the thermal conductivity. On the other hand, due to its time-consuming preparation/processing and unnecessary good crystalline quality (for thermoelectric applications), the processing of thermoelectric materials by crystal growth resulted in very few investigations. In this report, the design and growth of the PbTe-based materials solidified from the melt for thermoelectric applications as well as the results of their thermoelectric characterizations will be reviewed. It shows that, besides its Figure of Merit comparable to other processing methods, the melt grown PbTe material has several additional capabilities, including the reproducibility, thermal stability and the functional gradient characteristics from the variation of properties along the growth length.

中文翻译：

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PbTe 基热电材料的设计、生长和表征

摘要 热电器件将热能，即热量，转化为电能。由于没有移动部件，热电发电机显示了其长期运行可靠性的优势。IV-VI 化合物半导体 PbTe 基材料已广泛用于 350-650°C 中等温度范围内的热电应用。在大多数报道中，热电材料是通过热压或淬火和退火方法制造的。热电材料（包括 PbTe 基材料）的转换效率的最新进展归因于通过热压或简单地冷却熔体以降低热导率来改变微观结构的材料不均匀性。另一方面，由于其耗时的制备/加工和不必要的良好结晶质量（用于热电应用），通过晶体生长加工热电材料导致很少有研究。在本报告中，将回顾用于热电应用的从熔体中固化的 PbTe 基材料的设计和生长，以及它们的热电表征结果。它表明，除了与其他加工方法相比的品质因数之外，熔体生长的 PbTe 材料还具有一些额外的能力，包括再现性、热稳定性和沿生长长度特性变化的功能梯度特性。通过晶体生长加工热电材料的研究很少。在本报告中，将回顾用于热电应用的从熔体中固化的 PbTe 基材料的设计和生长，以及它们的热电表征结果。它表明，除了与其他加工方法相比的品质因数之外，熔体生长的 PbTe 材料还具有一些额外的能力，包括再现性、热稳定性和沿生长长度特性变化的功能梯度特性。通过晶体生长加工热电材料的研究很少。在本报告中，将回顾用于热电应用的从熔体中固化的 PbTe 基材料的设计和生长，以及它们的热电表征结果。它表明，除了与其他加工方法相比的品质因数外，熔体生长的 PbTe 材料还具有多种附加功能，包括再现性、热稳定性和沿生长长度特性变化的功能梯度特性。