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Rational Design of Bi2Te3 Polycrystalline Whiskers for Thermoelectric Applications
journal contribution
posted on 2015-01-14, 00:00 authored by Guang Han, Zhi-Gang Chen, Lei Yang, Min Hong, John Drennan, Jin ZouBi2Te3 polycrystalline
whiskers consisting of interconnected nanoplates have been synthesized
through chemical transformation from In2Te3 polycrystalline
whisker templates assembled by nanoparticles. The synthesized Bi2Te3 whiskers preserve the original one-dimensional
morphology of the In2Te3, while the In2Te3 nanoparticles can be transformed into the Bi2Te3 thin nanoplates, accompanied by the formation of high-density
interfaces between nanoplates. The hot-pressed nanostructures consolidated
from Bi2Te3 polycrystalline whiskers at 400
°C demonstrate a promising figure of merit (ZT) of 0.71 at 400 K, which can be attributed to their low thermal
conductivity and relatively high electrical conductivity. The small
nanoparticles inherited from the polycrystalline whiskers and high-density
nanoparticle interfaces in the hot-pressed nanostructures contribute
to the significant reduction of thermal conductivity. This study provides
a rational chemical transformation approach to design and synthesize
polycrystalline microstructures for enhanced thermoelectric performances.