Enhanced thermal stability of Bi2Te3-based alloys via interface engineering with atomic layer deposition. Issue 10 (August 2020)

• Record Type: Journal Article
• Authors: Lim, Sang-Soon; Kim, Kwang-Chon; Jeon, Hansol; Kim, Ju-Young; Kang, Jun-Yun; Park, Hyung-Ho; Baek, Seung-Hyub; Kim, Jin-Sang; Kim, Seong Keun
• Is Part Of: Journal of the European Ceramic Society. Volume 40:Issue 10(2020)
• Page Start: 3592
• Page End: 3599
• Publication Date: 2020-08
• Subjects: Thermal stability -- Bi2Te3 -- Atomic layer deposition -- Heterogeneous interfaces -- Te sublimation; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2020.04.013
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The ease of Te sublimation from Bi2 Te3 -based alloys significantly deteriorates thermoelectric and mechanical properties via the formation of voids. We propose a novel strategy based on atomic layer deposition (ALD) to improve the thermal stability of Bi2 Te3 -based alloys via the encapsulation of grains with a ZnO layer. Only a few cycles of ZnO ALD over the Bi2 Te2.7 Se0.3 powders resulted in significant suppression of the generation of pores in Bi2 Te2.7 Se0.3 extrudates and increased the density even after post-annealing at 500 °C. This is attributed to the suppression of Te sublimation from the extrudates. The ALD coating also enhanced grain refinement in Bi2 Te2.7 Se0.3 extrudates. Consequently, their mechanical properties were significantly improved by the encapsulation approach. Furthermore, the ALD approach yields a substantial improvement in the figure-of-merit after the post-annealing. Therefore, we believe the proposed approach using ALD will be useful for enhancing the mechanical properties of Bi2 Te3 -based alloys without sacrificing thermoelectric performance.