Confined Assembly of Polymer Nanowires for High-Performance Organic Thermoelectrics.

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 (κL). Compared with spin-coated films, the nanowires achieve a 274% increase in µ and a 63% reduction in κL, 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.