Speaker and Affliation:
Dr. Bhuvanesh Srinivasan
National Institute for Materials Science (NIMS),
10th December, 2021 (Friday), 02:30 PM (India Standard Time)
The exploitation of new types of clean energy has become paramount due to the severe depletion of non‐renewable energy resources and the deterioration of the environment caused by human energy consumption. In this regard, thermoelectric materials and devices have drawn increasing interest and attention due to their potential to convert waste heat into fruitful electricity.  A dimensionless figure of merit quantifies the thermoelectric material’s efficiency, zT = S 2σT/k where S, σ, T and k are Seebeck coefficient, electrical conductivity, temperature and total thermal conductivity (sum of the electronic part, ke and the lattice part, klatt) respectively. The fact that these thermoelectric transport properties are highly interrelated throws a more significant challenge in enhancing zT. However, advances in recent times show that it is feasible to improve zT by a number of approaches: electronic band convergence, fostering resonance states near the Fermi level, quantum confinement of charge carriers, nestification, electron filtering effect, dimensionality reduction, modulating light bands with a low effective mass, deformation potential coefficient, and nanostructuring, which includes the engineering of nanoscale defects (dislocations, stacking faults, point defects, and nanopores), and multiscale hierarchical architecting, imparting rattling impurities, intrinsic bond/strong lattice anharmonicities, etc. The presentation shall highlight some of these approaches that we have effectively applied on various kinds of materials, ranging from glasses and ceramics to several types of polycrystalline compounds (materials based on tellurides, sulfides, and oxides); different synthesis and processing techniques, right from traditional melt processing to advanced flash-spark plasma sintering; distinct approaches like dopant induced glass crystallization, composition engineering, nanostructuring, electronic band structure engineering, lattice softening, etc., to enhance the thermoelectric performance.[3–8] The presentation shall also touch upon our attempts to find thermoelectric materials for potential application at different operating ranges of temperature.
 L. E. Bell, Science 2008, 321, 1457.  J. R. Sootsman, D. Y. Chung, M. G. Kanatzidis, Angew. Chem. Int. Ed. 2009, 48, 8616.  B. Srinivasan, S. Cui, C. Prestipino, A. Gellé, C. Boussard-Pledel, S. Ababou-Girard, A. Trapananti, B. Bureau, S. Di Matteo, J. Phys. Chem. C 2017, 121, 14045.  B. Srinivasan, B. Fontaine, F. Gucci, V. Dorcet, T. G. Saunders, M. Yu, F. Cheviré, C. Boussard-Pledel, J.-F. Halet, R. Gautier, M. J. Reece, B. Bureau, Inorg. Chem. 2018, 57, 12976.  B. Srinivasan, A. Gellé, F. Gucci, C. Boussard-Pledel, B. Fontaine, R. Gautier, J.-F. Halet, M. J. Reece, B. Bureau, Inorg. Chem. Front. 2019, 6, 63.  A. R. Muchtar, B. Srinivasan, S. L. Tonquesse, S. Singh, N. Soelami, B. Yuliarto, D. Berthebaud, T. Mori, Adv. Energy Mater. 2021, 11, 2101122.  C. Bourgès, B. Srinivasan, B. Fontaine, P. Sauerschnig, A. Minard, J.-F. Halet, Y. Miyazaki, D. Berthebaud, T. Mori, J. Mater. Chem. C 2020, 8, 16368.  B. Srinivasan, S. L. Tonquesse, A. Gellé, C. Bourgès, L. Monier, I. Ohkubo, J.-F. Halet, D. Berthebaud, T. Mori, J. Mater. Chem. A 2020, 8, 19805.