Abstract Thermoelectric GeTe alloys have recently attracted renewed interests due to the extraordinary performance. It is particularly interesting in the low-symmetry structure, where the symmetry-breaking induced diversity in the arrangement in energy of split valence bands might enable an optimal band convergence for thermoelectric enhancements. This in principle leads to an extra degree of freedom for advancing GeTe thermoelectrics though a control of the degree of rhombohedral-distortion in the structure. Here we demonstrate this concept and realize its extraordinariness near room temperature, an extremely important temperature range for thermoelectric power generation/cooling applications in which very few options on materials other than conventional Bi2Te3 are currently available. This is enabled by a continuous manipulation of the rhombohedral-distortion in simple Ge1-xPbxTe solid solutions quenched from the high-temperature single phase region, a simultaneous optimization of carrier concentration and a reduction in lattice thermal conductivity due to PbTe-alloying. The resultant figure of merit, zT, at 200–350 K, is highly competitive to that of commercially available p-type Bi2Te3 alloys and higher than that of other known p-type thermoelectrics.

中文翻译：

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近室温菱形 Ge1-Pb Te 热电材料

摘要 热电 GeTe 合金由于其非凡的性能最近重新引起了人们的兴趣。在低对称性结构中特别有趣，其中分裂价带能量排列中的对称破坏引起的多样性可能使热电增强的最佳带收敛成为可能。这原则上通过控制结构中的菱形扭曲程度为推进 GeTe 热电提供了额外的自由度。在这里，我们展示了这一概念并实现了其在室温附近的非凡性能，这是热电发电/冷却应用的一个极其重要的温度范围，其中除了传统的 Bi2Te3 之外，目前几乎没有其他材料可供选择。这是通过连续操纵从高温单相区域淬火的简单 Ge1-xPbxTe 固溶体中的菱形畸变、同时优化载流子浓度和由于 PbTe 合金化而降低晶格热导率来实现的。由此产生的品质因数 zT，在 200-350 K，与市售的 p 型 Bi2Te3 合金相比具有很强的竞争力，并且高于其他已知的 p 型热电材料。