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.