Three birds with one stone: Interfacial engineering of flexible MoS2/Cu nanocomposites for high thermoelectric performance

There is a big challenge in simultaneously optimizing the Seebeck coefficient and electrical conductivity to improve thermoelectric performance. Herein, an interfacial engineering strategy is employed to decouple thermoelectric properties in solution-processable MoS 2 /Cu nanocomposites. Specifically, a facile electrochemical method enables the exfoliation of natural molybdenite into high-quality nanosheets and the concurrent in-situ decoration of Cu nanoparticles. Within the MoS 2 /Cu heterostructure, the Cu nanoparticles act as electron donors to regulate the carrier concentration. Crucially, Cu nanoparticles also establish robust conductive bridges between adjacent MoS 2 nanosheets, leading to a highly continuous conductive network with high carrier mobility. Furthermore, the constructed MoS 2 /Cu heterointerfaces introduce strong energy filtering to preferentially scatter low-energy carriers and transport high-energy carriers, effectively improving the Seebeck coefficient. Consequently, the all-inorganic flexible film achieves an outstanding room-temperature power factor of 293.8 μW m −1 K −2 . Furthermore, a MoS 2 /Cu-based flexible thermoelectric generator exhibits highly efficient photo-thermo-electric energy conversion. Under simulated AM 1.5 G (1 sun) illumination, the device establishes a stable temperature difference of approximately 12.3 ℃ and an open-circuit voltage of 9.5 mV. This work highlights the profound efficacy of rational interfacial design in developing high-performance, scalable flexible thermoelectric materials for advanced energy harvesting applications.