Ultrahigh Power Factor of Ternary Composites with Abundant Se Nanowires for Thermoelectric Application

In this work, ultrahigh-performance single-walled carbon nanotube (SWCNT)/Se nanowire (NW)/poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) ternary thermoelectric (TE) nanocomposite films are successfully designed by rational design of CNT/Se/PEDOT:PSS ternary nanocomposites. The addition of CNTs apparently improves the electrical conductivity of composite films, resulting in a relatively huge growth of the power factor. The PEDOT:PSS interface layers uniformly attach on both sides of the Se NWs and CNTs effectively, forming a tightly interleaving and interconnected three-dimensional network. As a consequence, a maximum power factor of 863.83 mu W/(m.K-2) has been achieved for the sample containing 26 wt % CNTs at 434 K. Ultimately, a flexible TE generator prototype consisting of 5-unit freestanding composite film strips is fabricated using the optimized composite films, which can generate a maximum output power of 206.8 nW at a temperature gradient of 44.7 K. Therefore, the present work has a further potential to be used for the flexible polymer/carbon TE nanocomposite films and devices.

Automated summary

In this study, ultrahigh-performance ternary nanocomposite films consisting of single-walled carbon nanotubes (SWCNTs), selenium nanowires (Se NWs), and poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) were successfully designed. The addition of SWCNTs significantly enhanced the electrical conductivity of the films, leading to a remarkable increase in the power factor. The optimized composite films were used to fabricate a flexible thermoelectric (TE) generator prototype, which demonstrated a high output power.