Deng Tingting, Wei Tian-Ran, Song Qingfeng, Xu Qing, Ren Dudi, Qiu Pengfei, Shi Xun, Chen Lidong
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences Shanghai 200050 China
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences Beijing 100049 China.
RSC Adv. 2019 Mar 8;9(14):7826-7832. doi: 10.1039/c9ra00077a. eCollection 2019 Mar 6.
Copper-based chalcogenides have ultralow thermal conductivity and ultrahigh thermoelectric performance, but most of them are p-type semiconductors. It is urgent to develop n-type counterparts for high efficiency thermoelectric modules based on these copper based-chalcogenides. CuSnS is an intrinsically n-type semiconductor with complex crystal structure and low thermal conductivity. However, its thermoelectric properties have not been well studied when compared to the well-known n-type CuFeS. In this work, high-quality CuSnS-based compounds are fabricated and their thermoelectric properties are systematically studied. Using Ag and Sb as dopants, the carrier concentration is tuned over a wide range. The electrical transport properties can be well described by the single parabolic band model with carrier acoustic phonons scattering. It is revealed that CuSnS exhibits a low effective mass and relatively high mobility. The thermal conductivity is lower than 0.8 W m K from 300 to 700 K and shows a weak dependence on temperature. A maximum of 0.27 is obtained in CuAgSnS at 700 K. Further enhancement of thermoelectric performance is possible when a more efficient n-type dopant is used.
铜基硫族化合物具有超低的热导率和超高的热电性能，但它们大多是p型半导体。迫切需要开发基于这些铜基硫族化合物的n型对应物，以用于高效热电模块。CuSnS是一种本征n型半导体，具有复杂的晶体结构和低热导率。然而，与著名的n型CuFeS相比，其热电性能尚未得到充分研究。在这项工作中，制备了高质量的CuSnS基化合物，并对其热电性能进行了系统研究。使用Ag和Sb作为掺杂剂，在很宽的范围内调节载流子浓度。电输运性质可以用载流子声子散射的单抛物线带模型很好地描述。结果表明，CuSnS具有低有效质量和相对较高的迁移率。在300至700 K范围内，热导率低于0.8 W m K，且对温度的依赖性较弱。在700 K时，CuAgSnS的热电优值最高达到0.27。当使用更有效的n型掺杂剂时，热电性能有可能进一步提高。
