Transparent and Hybrid Multilayer Films with Improved Thermoelectric Performance by Chalcogenide-Interlayer-Induced Transport Enhancement

Abstract

Transparent thermoelectric thin films for efficient heat energy conversion can be extensively applied in healthcare and small electronics. We report a strategy for the fabrication of organic/inorganic hybrid multilayer films with improved thermoelectric performances. As an organic layer, a highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is deposited after a solvent treatment. An inorganic interlayer consisting of PEDOT-coated SnSeTe nanosheets (PEDOT-SnSeTe nanosheets) is introduced between the PEDOT:PSS layers to fabricate an alternately deposited PEDOT:PSS/PEDOT-SnSeTe nanosheets/PEDOT:PSS (PSP) multilayer film. To demonstrate the interlayer-induced thermoelectric behaviors, the thermoelectric properties and corresponding carrier transport properties of single-layer, bilayer, and multilayer films are investigated. The inorganic layer influences the intrinsic conduction toward a favorable value for an improved thermoelectric transport. A considerably increased thermoelectric power factor of 110 μW·m^-1·K^-2 is achieved for a PSP multilayer film fabricated at 4000 rpm, greatly higher than that of the PEDOT:PSS and solution-mixed SnSeTe/PEDOT:PSS composite film. The multilayer strategy proposed in this study is promising for the fabrication of transparent and hybrid thin-film thermoelectrics with high thermoelectric performances.

Keywords: chalcogenide; conductive polymer; multilayer; thermoelectric; thin films.