Sb₂Te₃ nanoparticles with enhanced seebeck coefficient and low thermal conductivity

Nanostructured thermoelectric semiconductors represent a promising new direction that can further increase energy conversion efficiency, which requires the realization of thermoelectric nanocrystals with size comparable to their de Broglie wavelength while maintaining a high electrical conductivity. Here, we demonstrate a new facile process to grow self-assembled Sb₂Te ₃ nanoparticles with controlled particle size and enhanced thermoelectric properties by using a catalyst-free vapor transport growth technique. The samples show much more enhanced Seebeck coefficients than that of bulk Sb₂Te₃ with similar charge carrier concentration. Meanwhile, the thermal conductivity measurements with pulse photothermal reflectance suggest that the these Sb₂Te₃ nanoparticle films show much reduced thermal conductivity as compared to that of bulk Sb ₂Te₃. The discussed approach is promising for realizing new types of highly efficient thermoelectric semiconductors.