Photoaggregator-mediated phase engineering for high-performance polymer semiconductors and OLEDs

Despite their ease of processing in optoelectronics, polymer semiconductors continue to face limitations in charge transport efficiency, largely due to the lack of a dynamic strategy to control local conductive domains with nanoscale spatial resolution. Here, we report a light-triggered strategy with photoresponsive molecules, termed photoaggregators. Photoexcitation drives their controlled aggregation, induces cooperative self-assembly of poly (3,4-ethylenedioxythiophene), planarizes backbones, boosts π–π stacking, and connects isolated conductive domains into continuous networks. As a proof of concept, photolithography enables the selective enhancement of polymer semiconductor properties. This process enables mild UV-driven real-time in situ spatiotemporal domain engineering and forms efficient charge transport pathways with a Hall mobility up to 12.95 cm² V⁻¹ s⁻¹. The resulting material functions as a universal hole-injection layer, enhancing full-color RGB OLED performance. This work provides a versatile approach for the self-assembly of polymer semiconductors, paving an avenue for the fabrication of high-performance polymer-based optoelectronic devices.