Publication Date:
2015-02-03
Description:
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 2 V −1 s −1 to ∼600 cm 2 V −1 s −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 2 Se 3 at T = ∼570 K.
Print ISSN:
0003-6951
Electronic ISSN:
1077-3118
Topics:
Physics
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