Organic-SnSe₂ Hybrid Superlattice toward Synergistic Electrical Transport Optimization and Thermal Conductance Suppression

Recently,layered SnSe2 has drawn broad research interestas a promising thermoelectric material that possesses great potentialfor application in energy conversion. However, extensive efforts havebeen devoted to optimizing the thermoelectric performance of SnSe2, but the ZT value is still far from satisfactory.Therefore, we developed an organic-inorganic superlattice hybridby intercalating organic cations into SnSe2 interlayersin an attempt to enhance the thermoelectric properties. Organic intercalantscan enlarge the basal spacing and decouple the SnSe2 layers,bringing about synergistic electrical transport modification and phononsoftening. Thus, by simultaneously improving the electrical conductivityand reducing the thermal conductivity, a ZT valueof 0.34 is achieved at 342 K in tetrabutylammonium-intercalated SnSe2, approximately two orders of magnitude higher than that ofpristine SnSe2 single crystals. In addition, by openingvan der Waals gaps via organic cations, outstanding flexibility oforganic-intercalated SnSe2 is realized, with a superiorfigure of merit for flexibility of approximately 0.068. This workdemonstrates a general and facile strategy to fabricate organic-inorganicsuperlattice hybrids with a considerable improvement in the thermoelectricperformance via organic cation intercalation, which is promising forflexible thermoelectrics.