Enhancement of power factor by energy filtering effect in hierarchical BiSbTe3 nanostructures for thermoelectric applications

The bismuth antimony telluride hierarchical nanostructures were synthesized by hydrothermal method using dodecanethiol as a capping agent. The flower like nanosheets with the length of 500-600 nm and thickness about 60-70 nm were obtained. XRD pattern confirmed that the formation of single phase BiSbTe3. The Raman spectroscopy measurement clearly revealed the vibration modes of BiSbTe3. The composition of synthesized compounds were homogeneous and it confirmed by energy dispersive X-ray spectroscopy (EDS). The maximum value of Seebeck coefficient and power factor were 171 μV/K and 74.78 μW/mK2, respectively for nanosheets which contains spherical shaped morphology at room temperature. The enhancement of Seebeck coefficient was due to energy dependent scattering of the charge carriers at the nanograin interfaces.