Advancing Fully Solution‐Processed Blue OLEDs with Low‐Temperature Cross‐Linkable Single‐Component Polymeric Emitters

Abstract The development of fully solution‐processed organic light‐emitting diodes (fs‐OLEDs) remains a significant challenge, primarily due to the lack of low‐temperature cross‐linkable materials for the emissive layer (EML). In this study, a novel material design strategy is reported for blue fs‐OLEDs, where a single framework can be adapted as a cross‐linked hole transport layer ( X‐HTL ), polymer hosts, or single‐component EML ( P27 , X‐P33 ), with minor structural modifications. Particularly, the single‐component EML ( X‐P33 ) demonstrates a remarkably low cross‐linking temperature ( T CL ) of 135 °C, showing no reduction in the photoluminescence quantum yield of the EML. A blue fs‐OLED comprising the single‐component EML ( X‐P33 ) achieves a comparable efficiency with the partial solution‐processed device, demonstrating its promised application. A rationally designed novel pyrene‐based blue emitting small molecule, 3,8‐DI‐DAP‐C7 , is additionally introduced. Employing this material as a blue dopant, a current efficiency of ≈4.7 cd A −1 and external quantum efficiency of 3.2% is achieved.