Thermoelectric generators, capable of directly converting heat into electricity, hold great promise for tackling the ever-increasing energy sustainability issue. The thermoelectric energy conversion efficiency is heavily dependent upon the materials’ performance that is quantified by the dimensionless figure-of-merit (ZT). Therefore, the central issue in the research of thermoelectric materials lies in continuously boosting the ZT value. Although thermoelectric effects were discovered in the nineteenth century, it was only until the 1950s when classic materials like Bi2Te3 and PbTe were developed and basic science of thermoelectrics was established. However, the research of thermoelectrics did not take a smooth path but a rather tortuous one with ups and downs. After hiatus in the 1970s and 1980s, relentless efforts starting from the 1990s were devoted to understanding the transport and coupling of electrons and phonons, identifying strategies for improving the thermoelectric performance of existing materials, and discovering new promising compounds. Rewardingly, substantial improvements in materials’ performance have been achieved that broke the ZT limit of unity. Meanwhile, advancements in fundamental understanding related to thermoelectrics have also been made. In this Review, recent advances in the research of thermoelectric materials are overviewed. Herein, strategies for improving and decoupling the individual thermoelectric parameters are first reviewed, together with a discussion on open questions and distinctly different opinions. Recent advancements on a number of good thermoelectric materials are highlighted and several newly discovered promising compounds are discussed. Existing challenges in the research of thermoelectric materials are outlined and an outlook for the future thermoelectrics research is presented. The paper concludes with a discussion of topics in other fields but related to thermoelectricity.

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热电学的进展

热电发电机能够直接将热量转化为电能，有望解决日益严重的能源可持续性问题。热电能量转换效率在很大程度上取决于由无量纲品质因数 (ZT) 量化的材料性能。因此，热电材料研究的核心问题在于不断提高ZT值。虽然热电效应是在 19 世纪发现的，但直到 1950 年代，Bi2Te3 和 PbTe 等经典材料才被开发出来，热电基础科学才得以建立。然而，热电的研究并没有走上平坦的道路，而是一段曲折起伏的道路。在 1970 年代和 1980 年代中断之后，从 1990 年代开始，人们不懈努力，致力于了解电子和声子的传输和耦合，确定改善现有材料热电性能的策略，以及发现新的有前途的化合物。值得庆幸的是，材料性能的显着改进已经突破了 ZT 的统一限制。同时，与热电相关的基本理解也取得了进展。在这篇综述中，概述了热电材料研究的最新进展。在此，首先回顾了改进和解耦单个热电参数的策略，同时讨论了开放性问题和截然不同的意见。重点介绍了许多优良热电材料的最新进展，并讨论了几种新发现的有前景的化合物。概述了热电材料研究中存在的挑战，并对未来的热电研究提出了展望。本文最后讨论了其他领域但与热电相关的主题。