Chemically Exfoliated SnSe Nanosheets and Their SnSe/Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) Composite Films for Polymer Based Thermoelectric Applications

Tin selenide (SnSe) nanosheets (NSs) are prepared by hydrothermal lithium-intercalation and a subsequent exfoliation process from a SnSe ingot. Conducting polymer poly(3,4-ethylenedioxythiohene):poly(styrenesulfonate) (PEDOT:PSS)-based thermoelectric composites are fabricated with varying SnSe NSs content, and the thermoelectric properties of the composites are examined at 300 K. The exfoliated SnSe particles show thin two-dimensional sheet-like structures that are evenly distributed into the PEDOT:PSS matrix. The significantly enhanced power factor (S-2.sigma of the SnSe NS/PEDOT:PSS composites with increasing SnSe NSs content can be explained by the potential difference at the interface between the SnSe and PEDOT:PSS. The fabricated SnSe NS/PEDOT:PSS composites show a maximum figure of merit (ZT) of 0.32 at a SnSe NSs loading of 20 wt %. The mixing of inorganic nanoparticles with the conducting polymer matrix forms products with extremely low thermal conductivities, which is a promising strategy for the realization of polymer based efficient thermoelectric applications.