Topological quantum materials (TQMs), characterized by their nontrivial electronic band structure, represent a paradigm shift in our understanding of electronic structure, and band topology and reshaping modern condensed matter physics and solid-state chemistry. TQMs are rapidly emerging as promising candidates for next-generation sustainable energy conversion technologies. Their nontrivial band topology and symmetry-protected surface or interface states give rise to electronic and transport properties that are fundamentally distinct from those of conventional materials and have positioned TQMs at the forefront of research in electronics, spintronics,  and optoelectronics. More recently, the discovery of diverse classes of TQMs with unconventional electronic structures and properties has attracted significant interest from the chemistry and materials communities, particularly for their potential roles in sustainable energy technologies. In our group, we explore diffrenet TQMs for emerging applications including thermoelectrics, hydrogen evolution reaction (HER), oxygen evolution reaction (OER),  CO2 reduction reaction (CO2RR), and chiral catalysis (S. Dey, T. Ghosh, M. Samanta.* Small, 2026, e14986, https://doi.org/10.1002/smll.202514986).

Thermoelectrics (TE), “magic materials” which can convert the waste heat into electricity based on “Seebeck Effect”, hence provide total-package solution to mitigate environmental crisis and global energy dilemma. Hence, TE is foreseen as a potential front-runner for future energy management. TE figure of merit,   zT=σS^2 T/κ estimates the performance of a TE materials (Science 2021, 371, 722-727). Numerator of the equation is governed by electronic transport properties (electrical conductivity  and Seebeck coefficient, S) of materials. Denominator of zT is dictated by the phonon transport of the materials (total thermal conductivity, κ). In crystalline solids, heat is generally carried by either charge carriers (electronic thermal conductivity, κel)  ) or lattice vibrations (lattice thermal conductivity, κlat), commonly known as phonons. Main challenge to improve zT is the intertwined correlation between the TE parameters (S, σ and ) by the Wiedemann-Franz law (  where L is the temperature-dependent Lorentz number), imposing a fundamental limitation on the maximum attainable zT for a given material. However,   κlat is the only thermoelectric parameter which can be independently tuned without affecting the other parameters, thereof the parameter of interest in our studies. 

Topological quantum materials, TQM with unique/layered crystal structures offer excellent podium to explore and design high-performance thermoeletric materials (M. Samanta et al., J. Am. Chem. Soc., 2018, 140, 5866; M. Samanta et al., Angew. Chemie. Int. Ed., 2020, 59, 4822; M. Samanta et al., Chem. Mater. 2020, 32, 8819). Underlying reason for TQM being a source of potential candidates for TE is ascribed to the fact that both TQM and TE materials demand similar material features such as the presence of heavy constituent elements, narrow band gap and strong SOC (J. Solid State Chem., 2019, 275, 103-123). Exceptional electronic properties such as high carrier mobility and unique band structure of TQM make them appealing for thermoelectric applications. In our group, we explore TQM with unique crystal structures which hosts high degree of lattice anharmonicity and/or bonding hierarchy; might exhibit low κlat and can serve as excellent candidates for thermoelectrics.