Realizing Multicolor, 3D‐Printable Ultralong Room Temperature Phosphorescence PLA Materials via Regulating the π‐System of Aryl‐Annulated Carbazoles

Abstract Bio‐based degradable organic ultralong room temperature phosphorescence (URTP) polymers should become a mainstream research topic in the future. Meanwhile, shaping URTP polymers into 3D‐printable materials is of great significance for applications in optical and optoelectronic fields. Nevertheless, the fabrication of full‐color, ultralong, bright, and 3D printable bio‐based RTP polymer materials using a single‐dopant component still faces significant challenges. Here, by regulating the π‐system of aryl‐annulated carbazoles, the triplet energy levels are successfully regulated which enabled wavelength‐tunable RTP emissions spanning from blue to red afterglow (440 – 628 nm) in PLA matrix. Non‐radiative decay of dopant triplet excitons are effectively suppressed by the rigid environment of polymer matrix and dopant‐polymer interactions. This enables the prepared PLA‐based RTP materials exhibited ultralong lifetimes of 3.84 s and the naked‐eye‐visible afterglow duration up to 48 s. Recyclable and reprocessable RTP objects are fabricated via 3D printing and are successfully applied in the fields of artworks, monitoring and anti‐counterfeiting. This successfully expands the application of polymer‐based RTP materials in 3D fields, and will promote the commercialization of RTP materials and the development of environmentally friendly ultralong RTP materials.