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

Abstract 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 µW 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.