Fabrication of Polyaniline-Coated SnSeS Nanosheet/Polyvinylidene Difluoride Composites by a Solution-Based Process and Optimization for Flexible Thermoelectrics

The fabrication of dodecylbenzenesulfonic acid-doped polyaniline (PANI)-coated SnSe0.8S0.2 (PANI-SnSeS) nanosheets and their application to flexible thermoelectric composite films are demonstrated. The thermoelectric power factor of PANI-SnSeS nanosheets was optimized by manipulating the number of PANI coating cycles, and changes in their electrical conductivity and Seebeck coefficients were investigated and analyzed by considering carrier transport properties. An optimized, solution-based procedure for introducing inorganic nanoparticles comprising PANI-SnSeS nanosheets into a polyvinylidene fluoride (PVDF) matrix maximized the power factor. A composite film with a PANI-SnSeS nanosheet-to-PVDF weight ratio of 2:1 showed outstanding durability and thermoelectric performance, exhibiting a maximum power factor of ∼134 μW/m·K2 at 400 K. These results demonstrate that the incorporation of conductive PANI into SnSeS nanosheets can facilitate high-performance flexible thermoelectric applications.