Enhanced Thermoelectric Performance of Bi2Te2.7Se0.3/Bi2S3 Synthesized by Anion Exchange Method. Issue 4 (14th January 2020)

• Record Type: Journal Article
• Authors: Chen, Xi; Cai, Fanggong; Liu, Chuanrong; Dong, Rong; Qiu, Lanxin; Jiang, Lili; Yuan, Guocai; Zhang, Qinyong
• Is Part Of: Physica status solidi. Volume 14:Issue 4(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-01-14
• Subjects: Bi2Te2.7Se0.3 -- Bi2Te2.7Se0.3/Bi2S3 -- heterostructures -- thermal conductivity -- thermoelectric materials; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.201900679
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Decoupling the electric conductivity, Seebeck coefficient, and thermal conductivity is a core issue to improve the properties of thermoelectric materials by tuning the electron and phonon transport properties. Herein, Bi2 Te2.7 Se0.3 /Bi2 S3 heterostructure is successfully synthesized by a simple anion exchange method with Bi2 Te2.7 Se0.3 as the starting material. The Bi2 Te2.7 Se0.3 /Bi2 S3 heterointerfaces can achieve an effective phonon scattering and significant decrease in thermal conductivity, while maintaining a high power factor, resulting in an enhanced figure of merit ( ZT ). By controlling the concentration of Bi2 Te2.7 Se0.3 /Bi2 S3 heterointerfaces, the carrier‐transporting and phonon‐scattering behaviors can be simultaneously optimized. A maximum ZT of 0.7 is obtained at 473 K, which is 23% higher than that of pure Bi2 Te2.7 Se0.3 . In addition, the average ZT at 300–548 K increases from 0.49 to 0.61, which is 25% higher than that of pure Bi2 Te2.7 Se0.3 . Abstract : Bi2 Te2.7 Se0.3 /Bi2 S3 heterostructure is successfully synthesized by a simple anion exchange method with Bi2 Te2.7 Se0.3 as the starting material. The heterostructure realizes the decoupling of electron–phonon interactions, resulting in better thermoelectric properties than for plain Bi2 Te2.7 Se0.3 . A high power factor is maintained, and thermal conductivity is decreased because of effective phonon scattering from Bi2 Te2.7 Se0.3 /Bi2 S3 heterointerfaces.