Investigations of Morphology and Carrier Transport Characteristics in High-Performance PEDOT:PSS/Tellurium Binary Composite Fibers Produced via Continuous Wet-Spinning

Fiber-based flexible thermoelectric (TE) generators are highly desirable due to their capability to convert thermal energy into electricity and their potential applications in wearable electronics. High-performance poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/Tellurium (Te) composite TE fibers have been successfully developed via a continuous wet-spinning approach followed by sulphuric acid treatment. With a simple pre-modification to Te nanowires, the inorganic Te fillers form uniform distribution in PEDOT:PSS. At the optimal condition, the composite fibers exhibit a power factor of 233.5 mu W m(-1) K(-2 )and mechanical strength of 205 MPa, which are among the highest values reported so far for the PEDOT:PSS-based TE fibers. From the viewpoint of TE property enhancement mechanism, understanding the morphology and carrier transport behavior in the 1D organic/inorganic composite fibers remains still challenging. On basis of a series of PEDOT:PSS/Te composite fibers with varying Te fractions, orientations of both the inorganic and organic constituents are quantitatively evaluated. Their electrical conductivities and Seebeck coefficients are also analyzed with modified series-parallel models and energy filtering theory. This work may not only provide a universal approach to produce high-performance organic/inorganic composite TE fibers for various wearable applications, but also help to understand the morphology and charge transport between heterogeneous phases in a 1D composite.