Abstract
Thermoelectric materials are promising as they found numerous applications in electrical power generation and solid-state cooling. In the last decade, Lead Telluride (PbTe) has emerged as a potential thermoelectric candidate for electrical power generation in the medium temperature range. In the present work, we demonstrate nearly 78% enhancement in thermoelectric figure of merit (zT) of nanostructured PbTe compound through doping with bismuth and dispersing 50 nm SiC nanoparticles. Bismuth doping induces n-type conduction and improves the electrical conductivity, while the SiC nanoinclusions modulate the Seebeck coefficient by carrier energy filtering, in addition to suppressing the lattice thermal conductivity. The significant phonon scattering at multi-scale scattering centers resulted in a minimum lattice thermal conductivity (kappa(L)) of 0.69 W/m-K in Bi-0.02-Pb0.98Te-8% SiC nanocomposite sample. Finally, the reduced lattice thermal conductivity in conjunction with moderate electrical conductivity and high Seebeck coefficient leads to a zT(max) value of 0.32 at 590 K in the sample with 6% SiC content. Hence, the partial substitution of the host atom and the presence of a secondary phase can be another promising strategy to enhance the thermoelectric performance. (C) 2022 Elsevier B.V. All rights reserved.
NSTL
Elsevier