Confined Assembly of Polymer Nanowires for High‐Performance Organic Thermoelectrics

ABSTRACT Polymeric thermoelectrics provide a lightweight and intrinsically flexible platform for converting ubiquitous low‐grade waste heat into sustainable electricity. However, their practical deployment has been hindered by a low dimensionless figure of merit (ZT) and the reliance on high performance on complex processing routes. Here, we introduce a simple and controllable solvent‐assisted soft lithography approach for fabricating polymeric nanowires with exceptional thermoelectric performance. 1D confinement drives ordered chain assembly, boosting charge mobility ( µ ), while enhanced phonon‐boundary scattering suppresses lattice thermal conductivity ( κ L ). Compared with spin‐coated films, the nanowires achieve a 274% increase in µ and a 63% reduction in κ L , culminating in a peak ZT of 1.02 at 353 K. This nanowire‐based strategy is broadly applicable to diverse polymers, providing a robust route to nanostructure‐engineered plastic thermoelectrics with both high performance and scalable manufacturability, and opening new opportunities for practical organic thermoelectric devices.