Effective atomic interface engineering in Bi2Te2.7Se0.3 thermoelectric material by atomic-layer-deposition approach. (July 2018)

• Record Type: Journal Article
• Authors: Li, Shuankui; Liu, Yidong; Liu, Fusheng; He, Dongsheng; He, Jiaqing; Luo, Jun; Xiao, Yinguo; Pan, Feng
• Is Part Of: Nano energy. Volume 49(2018)
• Page Start: 257
• Page End: 266
• Publication Date: 2018-07
• Subjects: Thermoelectric -- Bi2Te3 -- Atomic-Layer-Deposition -- Nanocomposites -- Energy filtering; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2018.04.047
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Grain boundaries play a critical role in the carrier/phonon transport in thermoelectric materials. It remains a big challenge to control over both chemical composition and dimension of grain boundary precisely by traditional approaches. Herein, an bottom-up grain boundary engineering strategy based on atomic layer deposition (ALD) is first introduced to atomically control and modify the grain boundary of Bi2 Te3 -based thermoelectric materials. To demonstrate the effect of this strategy, ultrathin ZnO interlayer is deposited on the Bi2 Te2.7 Se0.3 (BTS) grain boundaries to optimize of the carrier/phonon transport for achieving high thermoelectric performance. In situ TEM experiments upon heating reveals that the ZnO interlayer will give rise to the precipitation of Te nanodot at ZnO/BTS interface, which can be atomically controlled by adjusting the thickness of ZnO layer. Benefited from the atomically precise modified grain boundary, a maximum ZT of 0.85 is obtained, approximately 1.8 times higher than that of the pure BTS. As a powerful interfacial modification strategy, ALD-based approach can be extended to other thermoelectric material system simply, which may contribute to the development of high performance thermoelectric material of great significance. Graphical abstract: We demonstrate that bottom-up grain boundary engineering strategies based on atomic layer deposition could be introduced to design and control grain boundary in atomic-level. As an initial attempt, ultrathin ZnO layer with precise controlled thickness was introduced at the BTS grain boundary to investigate the chemical composition and structure of grain boundary related electron/phonon transportation behavior.fx1 Highlights: A grain boundary engineering strategy based on atomic layer deposition (ALD) is first introduced to modify the grain boundary of Bi2 Te3 -based thermoelectric materials. The atom-level control over the chemical composition and structure of grain boundary could be achevied by adjusting ZnO layer thickness. Benefited from the modified grain boundary, a maximum ZT of 0.85 is obtained.