Realizing record high performance in n-type Bi2Te3-based thermoelectric materials

By B. Zhu, Xixi Liu, Qi Wang, Y. Qiu, Zhong Shu, Zuteng Guo, Yao Tong, Juan Cui, Meng Gu, Jiaqing He. 2020

243 citations recorded by the source corpus.

The application of Bi2Te3-based power generation is seriously hindered by the poor n-type samples, demonstrating a strong demand for high-performance n-type Bi2Te3-based thermoelectric (TE) materials. However, the strong relationship between thermal and electrical transport limits the improvement of the TE properties. Here, we propose a strategy to enhance the Seebeck coefficient while retaining a large electrical conductivity in n-type (Bi,Sb)2(Te,Se)3 materials through introducing electron transport potential wells and texturing. The thermal conductivity was also successfully decreased by constructing multi-scale phonon scattering structures. Consequently, a record maximum and average thermoelectric figure of merit (ZT) of ∼1.4 and ∼1.3 were achieved in the Bi1.8Sb0.2Te2.7Se0.3 + 15 wt% Te sample at a temperature of 300–575 K. A TE power generation module was fabricated with this n-type material and a home-made p-type Bi2Te3 sample. It demonstrated a record conversion efficiency of 6.6% at a temperature gradient of 235 K, representing about an 88% improvement compared with a commercial zone-melt Bi2Te3-based module.

Subfields: Civil and Structural Engineering, Materials Chemistry, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/3da38bb00cf6865a3dfd1aaae1bc6554d4d72eeb