Tuning the carrier scattering mechanism to effectively improve the thermoelectric properties

Jing Shuai; Jun Mao; Shaowei Song; Qing Zhu; Jifeng Sun; Yumei Wang; Ran He; Jiawei Zhou; Gang Chen; David J. Singh; Zhifeng Ren

doi:10.1039/C7EE00098G

Tuning the carrier scattering mechanism to effectively improve the thermoelectric properties†

Jing Shuai,‡^a Jun Mao,

‡^a Shaowei Song,^a Qing Zhu,^a Jifeng Sun,^b Yumei Wang,^a Ran He,^a Jiawei Zhou,^c Gang Chen,*^c David J. Singh*^b and Zhifeng Ren

*^a

Author affiliations

* Corresponding authors

^a Department of Physics and TcSUH, University of Houston, Houston, TX 77204, USA
E-mail: zren@uh.edu

^b Department of Physics and Astronomy, University of Missouri-Columbia, Columbia, MO 65211, USA
E-mail: singhdj@missouri.edu

^c Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
E-mail: gchen2@mit.edu

Abstract

A high thermoelectric power factor not only enables a potentially high figure of merit ZT but also leads to a large output power density, and hence it is pivotal to find an effective route to improve the power factor. Previous reports on the manipulation of carrier scattering mechanisms (e.g. ionization scattering) were mainly focused on enhancing the Seebeck coefficient. In contrast, here we demonstrate that by tuning the carrier scattering mechanism in n-type Mg₃Sb₂-based materials, it is possible to noticeably improve the Hall mobility, from ∼19 to ∼77 cm² V⁻¹ s⁻¹, and hence substantially increase the power factor by a factor of 3, from ∼5 to ∼15 μW cm⁻¹ K⁻². The enhancement in mobility is mainly due to the reason that ionization scattering has been converted into mixed scattering between ionization and acoustic phonon scattering, which less effectively scatters the carriers. The strategy of tuning the carrier scattering mechanism to improve the mobility should be widely applicable to various material systems for achieving better thermoelectric performance.

Energy & Environmental Science

Tuning the carrier scattering mechanism to effectively improve the thermoelectric properties†

Abstract

Supplementary files

Article information

Download Citation

Permissions

Tuning the carrier scattering mechanism to effectively improve the thermoelectric properties

Social activity

Search articles by author

Spotlight

Advertisements