Applied Physics Letters · 2010 · 183 citations · 20 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsHeat TransferThin FilmsHeat ConductionThermal Properties Of MaterialsThermoelectric MaterialsThin Film Electrical PropertiesThin Film Thermal PropertiesTopological MaterialsElectrical PropertiesExfoliationFermi LevelThermal ConductivityThermoelectric Figure Of MeritThermoelectric PropertiesThermoelectric TransportTopological Insulators
The authors report on “graphene-like” mechanical exfoliation of single-crystal Bi2Te3 films and thermoelectric characterization of the stacks of such films. Thermal conductivity of the resulting “pseudosuperlattices” was measured by the “hot disk” and “laser flash” techniques. The room temperature in-plane (cross-plane) thermal conductivity of the stacks decreases by a factor of ∼2.4 (3.5) as compared to bulk. The thermal conductivity reduction with preserved electrical properties leads to strong increase in the thermoelectric figure of merit. It is suggested that the film thinning to few-quintuples and tuning of the Fermi level can help in achieving the topological-insulator surface transport regime with an extraordinary thermoelectric efficiency.
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