Yang Guangsai, Sang Lina, Li Meng, Kazi Nazrul Islam Sheik Md, Yue Zengji, Liu Liqiang, Li Jianing, Mitchell David R G, Ye Ning, Wang Xiaolin
Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong, New South Wales 2500, Australia.
Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, PR China.
ACS Appl Mater Interfaces. 2020 Mar 18;12(11):12910-12918. doi: 10.1021/acsami.0c00873. Epub 2020 Mar 6.
Thermoelectric (TE) materials have attracted extensive interest because of their ability to achieve direct heat-to-electricity conversion. They provide an appealing renewable energy source in a variety of applications by harvesting waste heat. The record-breaking figure of merit reported for single crystal SnSe has stimulated related research on its polycrystalline counterpart. Boosting the TE conversion efficiency requires increases in the power factor and decreases in thermal conductivity. It is still a big challenge, however, to optimize these parameters independently because of their complex interrelationships. Herein, we propose an innovative approach to decouple electrical and thermal transport by incorporating carbon fiber (CF) into polycrystalline SnSe. We show that the incorporation of highly conductive CF can successfully enhance the electrical conductivity, while greatly reducing the thermal conductivity of polycrystalline SnSe. As a result, a high TE figure-of-merit () of 1.3 at 823 K is obtained in p-type SnSe/CF composite polycrystalline materials. Furthermore, SnSe samples incorporated with CFs exhibit superior mechanical properties, which are favorable for device fabrication applications. Our results indicate that the dispersion of CF can be a good way to greatly improve both TE and mechanical performance.
热电（TE）材料因其能够实现直接的热到电转换而引起了广泛关注。通过收集废热，它们在各种应用中提供了一种有吸引力的可再生能源。单晶SnSe报道的创纪录的品质因数激发了对其多晶对应物的相关研究。提高TE转换效率需要提高功率因数并降低热导率。然而，由于这些参数之间复杂的相互关系，独立优化这些参数仍然是一个巨大的挑战。在此，我们提出了一种创新方法，通过将碳纤维（CF）掺入多晶SnSe中来解耦电传输和热传输。我们表明，掺入高导电性的CF可以成功提高电导率，同时大大降低多晶SnSe的热导率。结果，在p型SnSe/CF复合多晶材料中，在823 K时获得了1.3的高TE品质因数（）。此外，掺入CF的SnSe样品表现出优异的机械性能，这有利于器件制造应用。我们的结果表明，CF的分散可以是大大提高TE和机械性能的好方法。
