Facile Preparations Of Layer-Like And Honeycomb-Like Films Of Poly (3,4-Ethylenedioxythiophene)/Carbon Nanotube Composites For Thermoelectric Application

The morphologies of conjugated polymers and their composites have significant effects on their thermoelectric (TE) performance. In this study, flexible films of poly (3,4-ethyienedioxythiophene):poly(styrene sulfonate)/ single-walled carbon nanotube (PEDOT:PSS/SWCNT) composites were fabricated by convenient solution mixing of commercialized PEDOT:PSS and SWCNT. Their morphologies displayed remarkable dependency on filmformation procedure. An unusual submicron-size honeycomb-like porous structure was observed for the vacuumfiltration composite film, whereas the solution-casting film showed a parallel layer-like morphology. Importantly, the film with honeycomb-like structure revealed a much higher power factor (similar to 20.68 mu W m(-1) K-2) than the layer-like structure film (similar to 8.67 mu W m(-1) K-2). Furthermore, the composite film with submicron-size honeycomb-like porous structure also reveals higher TE performance than most micron-sized porous materials and dense solid film with nano- or micro-structure of the neat PEDOT and PEDOT/SWCNT composites. After H2SO4 post-treatment, the power factor can be enhanced further to 45.72 +/- 1.76 mu W m(-1) K-2. Therefore, the PEDOT: PSS/SWCNT composites with submicron honeycomb-like porous morphology are promising for flexible TE application.