Ultrahigh thermoelectric figure of merit in n-type TiS2 thin films via hybrid superlattice with nanocrystal-amorphous composites

Abstract

Achieving high thermoelectric efficiency requires optimizing both the power factor and thermal conductivity. In this study, we introduce a novel approach to significantly enhance the thermoelectric performance of TiS<inf>2</inf> by incorporating nanocrystal-amorphous composite nanolayers within an organic–inorganic hybrid superlattice. While the suppression of lattice thermal conductivity through enhanced phonon scattering in the superlattice structure is well established, this work uniquely demonstrates a substantial improvement in the Seebeck coefficient, driven by the nanocrystal-amorphous composite. This architecture not only doubles the power factor but also effectively reduces lattice thermal conductivity, resulting in a synergistic effect that achieves a record-breaking figure of merit (ZT) of 2.95 at 235 °C. These results surpass previous TiS<inf>2</inf>-based thermoelectric benchmarks and highlight the potential of this innovative approach to advance the development of highly efficient thermoelectric materials for energy conversion applications