Electronic Topological Transition as a Route to Improve Thermoelectric Performance in Bi0.5Sb1.5Te3. Issue 14 (15th March 2022)

• Record Type: Journal Article
• Authors: Bai, Feng‐Xian; Yu, Hao; Peng, Ya‐Kang; Li, Shan; Yin, Li; Huang, Ge; Chen, Liu‐Cheng; Goncharov, Alexander F.; Sui, Jie‐He; Cao, Feng; Mao, Jun; Zhang, Qian; Chen, Xiao‐Jia
• Is Part Of: Advanced science. Volume 9:Issue 14(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-15
• Subjects: Bi0.5Sb1.5Te3 -- electronic topological transition -- pressure -- thermoelectric materials; Science -- Periodicals; 505
• DOI: 10.1002/advs.202105709
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: The electronic structure near the Fermi surface determines the electrical properties of the materials, which can be effectively tuned by external pressure. Bi0.5 Sb1.5 Te3 is a p‐type thermoelectric material which holds the record high figure of merit at room temperature. Here it is examined whether the figure of merit of this model system can be further enhanced through some external parameter. With the application of pressure, it is surprisingly found that the power factor of this material exhibits λ behavior with a high value of 4.8 mW m −1 K −2 at pressure of 1.8 GPa. Such an enhancement is found to be driven by pressure‐induced electronic topological transition, which is revealed by multiple techniques. Together with a low thermal conductivity of about 0.89 W m −1 K −1 at the same pressure, a figure of merit of 1.6 is achieved at room temperature. The results and findings highlight the electronic topological transition as a new route for improving the thermoelectric properties. Abstract : This paper reports the pressure‐induced electronic topological transition as a novel route for improving thermoelectric performance. With the application of high pressure, the room‐temperature zT of Bi0.5 Sb1.5 Te3 exhibits a λ behavior, and the maximum zT value is as high as 1.6 around the vicinity of the electronic topological transition.