Chemical synthesis of anisotropic nanocrystalline Sb2Te3 and low thermal conductivity of the compacted dense bulk.

We describe a one-step, one-pot non-aqueous route for the synthesis of Sb2Te3 nanocrystals with hexagonal shape and highly anisotropic nanostructures. The as-prepared nanostructures were characterized by XRD, TEM and HRTEM. The effect of the stabilizers on the nanocrystal morphology has been discussed in detail. We have studied the thermal conductivity of the compacted bulk from the Sb2Te3 nanostructures. The results indicated that a very low thermal conductivity of about 1 W/mK at 300 K, comparing to 4.7 W/mK of the polycrystalline bulk, was achieved. The results indicated that nanostructured Sb2Te3 is potentially a good candidate for engineered nanocomposites that can lead to high thermoelectric figure-of-merit.