中国物理B ›› 2018, Vol. 27 ›› Issue (4): 47204-047204.doi: 10.1088/1674-1056/27/4/047204
所属专题: SPECIAL TOPIC — Recent advances in thermoelectric materials and devices
• TOPIC REVIEW—Thermal and thermoelectric properties of nano materials • 上一篇 下一篇
Xiaoman Shi(史晓曼), Guoyu Wang(王国玉), Ruifeng Wang(王瑞峰), Xiaoyuan Zhou(周小元), Jingtao Xu(徐静涛), Jun Tang(唐军), Ran Ang(昂然)
Xiaoman Shi(史晓曼)1, Guoyu Wang(王国玉)2,3, Ruifeng Wang(王瑞峰)2,3, Xiaoyuan Zhou(周小元)4, Jingtao Xu(徐静涛)5, Jun Tang(唐军)1,6, Ran Ang(昂然)1,6
摘要: Binary Cu-based chalcogenide thermoelectric materials have attracted a great deal of attention due to their outstanding physical properties and fascinating phase sequence. However, the relatively low figure of merit zT restricts their practical applications in power generation. A general approach to enhancing zT value is to produce nanostructured grains, while one disadvantage of such a method is the expansion of grain size in heating-up process. Here, we report a prominent improvement of zT in Cu2Te0.2Se0.8, which is several times larger than that of the matrix. This significant enhancement in thermoelectric performance is attributed to the formation of abundant porosity via cold press. These pores with nano-to micrometer size can manipulate phonon transport simultaneously, resulting in an apparent suppression of thermal conductivity. Moreover, the Se substitution triggers a rapid promotion of power factor, which compensates for the reduction of electrical properties due to carriers scattering by pores. Our strategy of porosity engineering by phonon scattering can also be highly applicable in enhancing the performances of other thermoelectric systems.
中图分类号: (Thermoelectric and thermomagnetic effects)