Great enhancements in the thermoelectric power factor of BiSbTe nanostructured films with well-ordered interfaces

Abstract

An innovative concept of twin-enhanced thermoelectricity was proposed to fundamentally resolve the high electrical resistance while not degrading the phonon scattering of the thermoelectric nanoassemblies. Under this frame, a variety of highly oriented and twinned bismuth antimony telluride (Bi_xSb_2−xTe₃) nanocrystals were successfully fabricated by a large-area pulsed-laser deposition (PLD) technique on insulated silicon substrates at various deposition temperatures. The significant presence of the nonbasal- and basal-plane twins across the hexagonal BiSbTe nanocrystals, which were experimentally and systematically observed for the first time, evidently contributes to the unusually high electrical conductivity of ∼2700 S cm⁻¹ and the power factor of ∼25 μW cm⁻¹ K⁻² as well as the relatively low thermal conductivity of ∼1.1 W m⁻¹ K⁻¹ found in these nanostructured films.