The development of new routes for the production of thermoelectric materials with low-cost and high-performance characteristics has been one of the long-term strategies for saving and harvesting thermal energy. Herein, we report a new approach for improving thermoelectric properties by employing the intrinsically low thermal conductivity of a quasi-one-dimensional (quasi-1D) crystal structure and optimizing the power factor with aliovalent ion doping. As an example, we demonstrated that SbCrSe₃, in which two parallel chains of CrSe₆ octahedra are linked by antimony atoms, possesses a quasi-1D property that resulted in an ultra-low thermal conductivity of 0.56 W m⁻¹ K⁻¹ at 900 K. After maximizing the power factor by Pb doping, the peak ZT value of the optimized Pb-doped sample reached 0.46 at 900 K, which is an enhancement of 24 times that of the parent SbCrSe₃ structure. The mechanisms that lead to low thermal conductivity derive from anharmonic phonons with the presence of the lone-pair electrons of Sb atoms and weak bonds between the CrSe₆ double chains. These results shed new light on the design of new and high-performance thermoelectric materials.

开发具有低成本和高性能特征的热电材料的新途径的开发一直是节省和收集热能的长期策略之一。本文中，我们报告了一种通过采用准一维（quad-1D）晶体结构固有的低热导率并利用铝价离子掺杂优化功率因数来改善热电性能的新方法。例如，我们证明了SbCrSe ₃（其中CrSe ₆八面体的两条平行链通过锑原子连接）具有准1D性质，导致0.56 W m ^-1  K ^-1的超低导热率在900 K下达到最大功率因数后，优化的Pb掺杂样品的ZT峰值在900 K时达到0.46，是母SbCrSe ₃结构的24倍。导致低热导率的机理源于非谐声子，其中存在Sb原子的孤对电子和CrSe ₆双链之间的弱键。这些结果为新型高性能热电材料的设计提供了新的思路。