Rational Synthesis of Ultrathin n-Type Bi2Te3 Nanowires with Enhanced Thermoelectric Properties

• Published in: Nano letters 2012-01, Vol.12 (1), p.56-60
• Main Authors: Zhang, Genqiang, Kirk, Benjamin, Jauregui, Luis A, Yang, Haoran, Xu, Xianfan, Chen, Yong P, Wu, Yue
• Format: Article
• Language: English
• Subjects: Applied sciences; Bismuth - chemistry; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystallization - methods; Electric Conductivity; Electronics; Exact sciences and technology; Macromolecular Substances - chemistry; Materials science; Materials Testing; Molecular Conformation; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotubes - chemistry; Nanotubes - ultrastructure; Particle Size; Physics; Quantum wires; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Surface Properties; Tellurium - chemistry; Thermal Conductivity; Thermal properties of condensed matter; Thermal properties of small particles, nanocrystals, nanotubes
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl202935k

A rational yet scalable solution phase method has been established, for the first time, to obtain n-type Bi2Te3 ultrathin nanowires with an average diameter of 8 nm in high yield (up to 93%). Thermoelectric properties of bulk pellets fabricated by compressing the nanowire powder through spark plasma sintering have been investigated. Compared to the current commercial n-type Bi2Te3-based bulk materials, our nanowire devices exhibit an enhanced ZT of 0.96 peaked at 380 K due to a significant reduction of thermal conductivity derived from phonon scattering at the nanoscale interfaces in the bulk pellets, which corresponds to a 13% enhancement compared to that of the best n-type commercial Bi2Te2.7Se0.3 single crystals (∼0.85) and is comparable to the best reported result of n-type Bi2Te2.7Se0.3 sample (ZT = 1.04) fabricated by the hot pressing of ball-milled powder. The uniformity and high yield of the nanowires provide a promising route to make significant contributions to the manufacture of nanotechnology-based thermoelectric power generation and solid-state cooling devices with superior performance in a reliable and a reproducible way.