Abstract In recent years, GeTe has received tremendous attention from the research community owing to its favorable electronic and thermal properties which make it one of the best performing thermoelectric compounds. In many reports, high performance has often been achieved via various doping/alloying methods, which typically involve more than one type of dopants. In contrast to the widely used codoping strategies, this work only uses a minute amount of 1% doping, giving rise to one of the highest quality factor (1.30) at 673 K amongst GeTe, with a corresponding zT of 1.5. The high performance is attributed to simultaneously improved electronic properties via carrier concentration optimization, as well as reduced thermal conductivity via additional phonon scattering brought about by In-mass fluctuations. More importantly, we elucidate on the importance of preserving the high quality factor via choosing the right dopants to optimize the carrier concentration. Furthermore, we showed that the strategy of evaluating the quality factor can be applied to other material systems, serving as a general guideline for thermoelectric materials design. The quality factor of GeTe in this work is superior to most other high-performing chalcogenides such as PbTe, SnTe, and SnS, revealing the large space for further enhancing its zT.

中文翻译：

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在 GeTe 中实现高品质因数以实现高品质因数

摘要 近年来，GeTe 因其良好的电子和热性能而受到研究界的极大关注，使其成为性能最好的热电化合物之一。在许多报告中，高性能通常是通过各种掺杂/合金化方法实现的，这些方法通常涉及不止一种类型的掺杂剂。与广泛使用的共掺杂策略相比，这项工作仅使用了 1% 的微量掺杂，从而产生了 GeTe 中 673 K 的最高品质因子 (1.30) 之一，相应的 zT 为 1.5。高性能归因于通过载流子浓度优化同时改善的电子特性，以及通过质量内波动带来的额外声子散射降低热导率。更重要的是，我们阐明了通过选择正确的掺杂剂来优化载流子浓度来保持高质量因子的重要性。此外，我们表明评估品质因数的策略可以应用于其他材料系统，作为热电材料设计的一般指南。这项工作中 GeTe 的品质因数优于大多数其他高性能硫属元素化物，如 PbTe、SnTe 和 SnS，揭示了进一步提高其 zT 的巨大空间。