Applied Physics Letters · 2015 · 58 citations · 17 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsMaterials PhysicsSolid State PhysicsElectron-phonon InteractionsSemiconductor NanomaterialsThermal Properties Of MaterialsThermal Properties Of SemiconductorsThermoelectric MaterialsTopological MaterialsElectron MobilityGrain BoundariesLattice Thermal ConductivityLattice Thermal TransportThermal ConductivityThermoelectric Figure Of MeritThermoelectric PropertiesTopological Insulators
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 cm2 V−1 s−1 to ∼600 cm2 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 Bi2Se3 at T = ∼570 K.
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Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface
Haijun Zhang, Chao‐Xing Liu, Xiao‐Liang Qi et al. · Nature Physics · 2009 · 6.3K citations