Abstract

PEDOT: PSS / Carbon nanotubes (CNT) nanocomposites have emerged as a versatile materials platform that synergistically combines the high electrical conductivity, mechanical robustness, and aspect ratio of CNT with the solution processibility, optical transparency, and mixed PEDOT: PSS. This review surveys the structure, property, processing relationships governing these hybrids, outlines interfacial engineering strategies that unlock ultra‐high conductivities and stretchability, and evaluates performance across key device classes: transparent electrodes, flexible/stretchable interconnects, chemical and biological sensors, thermoelectrics, energy storage and conversion electrodes, electromagnetic interference (EMI) shielding, and bioelectronics. Particular emphasis is placed on percolation physics, secondary dopants, acid/post‐treatment methods, morphology control, and printability. We summarize benchmarking figures of merit (conductivity, sheet resistance/optical transmittance, gauge factor, Seebeck coefficient, power factor, capacitance, and stability) and discuss reliability, environmental, and scalability considerations. Finally, we propose best‐practice processing workflows and identify open challenges—including long‐term hydration stability, junction resistance, alignment control, and sustainable manufacturing—that will shape next‐generation soft, conformal, and eco‐friendly electronics.