  Sb-doped Bi2Te3 is known since the 1950s as the best thermoelectric material
for near-room temperature operation. Improvements in material performance are
expected from nanostructuring procedures. We present a straightforward and fast
method to synthesize already nanostructured pellets that show an enhanced ZT
due to a remarkably low thermal conductivity and unusually high Seebeck
coefficient for a nominal composition optimized for arc-melting:
Bi0.35Sb1.65Te3. We provide a detailed structural analysis of the Bi2-xSbxTe3
series based on neutron powder diffraction as a function of composition and
temperature that reveals the important role played by atomic vibrations.
Arc-melting produces layered platelets with less than 50 nm-thick sheets. The
low thermal conductivity is attributed to the phonon scattering at the grain
boundaries of the nanosheets. This is a fast and cost-effective production
method of highly efficient thermoelectric materials.
