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Title: Enhanced thermoelectric performance of nanostructured topological insulator Bi{sub 2}Se{sub 3}

To enhance thermoelectric performance by utilizing topological properties of topological insulators has attracted increasing attention. Here, we show that as grain size decreases from microns to ∼80 nm in thickness, the electron mobility μ increases steeply from 12–15 cm{sup 2} V{sup −1} s{sup −1} to ∼600 cm{sup 2} V{sup −1} s{sup −1}, owing to the contribution of increased topologically protected conducting surfaces. Simultaneously, its lattice thermal conductivity is lowered by ∼30%–50% due to enhanced phonon scattering from the increased grain boundaries. As a result, thermoelectric figure of merit, ZT, of all the fine-grained samples is improved. Specifically, a maximum value of ZT = ∼0.63 is achieved for Bi{sub 2}Se{sub 3} at T = ∼570 K.
Authors:
 [1] ;  [2] ; ; ; ; ; ; ; ; ;  [1]
  1. Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, 230031 Hefei (China)
  2. (China)
Publication Date:
OSTI Identifier:
22420261
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BISMUTH SELENIDES; ELECTRICAL INSULATORS; ELECTRON MOBILITY; GRAIN BOUNDARIES; GRAIN SIZE; NANOSTRUCTURES; PERFORMANCE; PHONONS; TEMPERATURE RANGE 0400-1000 K; THERMAL CONDUCTIVITY