Low thermal conductivity and enhanced Seebeck coefficient in Antimony and Selenium co-doped PbTe Nanopowders

• Published in: Indian journal of physics 2021-10, Vol.95 (10), p.2035-2045
• Main Authors: Kungumadevi, L., Senthil, T. S., Sathyamoorthy, R., Bhatia, S. N.
• Format: Article
• Language: English
• Subjects: Antimony; Astrophysics and Astroparticles; Figure of merit; Heat conductivity; Heat transfer; Intermetallic compounds; Nanoparticles; Original Paper; Physics; Physics and Astronomy; Seebeck effect; Selenium; Thermal conductivity
• ISSN: 0973-1458; 0974-9845
• DOI: 10.1007/s12648-020-01849-6

We report a new method to synthesize Sb and Se co-doped PbTe nanopowders by a simple aqueous chemical method without the assistance of any surfactant or template. X-ray diffraction studies revealed that the prepared nanopowders are polycrystalline in nature and crystallize in the face-centered-cubic (fcc) PbTe structure. SEM and TEM studies reveal that Sb and Se co-doped PbTe nanopowders consist of an interconnected network of spherical nanoparticles with diameters around 12 nm. Seebeck coefficient of the undoped PbTe (436 µV/K at 301 K) and co-doped PbTe (627 µV/K at 301 K) is enhanced compared to that of the bulk PbTe (265 µV/K at 298 K) and the thermal conductivity is drastically decreased [undoped PbTe (0.265 W/m-K) and co-doped PbTe (0.525 W/m-K) at 378 K] compared with the value for the bulk PbTe (2.2 W/m-K at 300 K). The dimensionless figure of merit ZT attains its maximum value 0.055 at 378 K for undoped and 1.09 × 10 −5 at 352 K for co-doped PbTe. Graphic abstract