Organic Materials With Dual-Morphology (Crystalline/Glassy) and High-Temperature Phosphorescence Emission

Organic room-temperature phosphorescence (RTP) materials have attracted considerable attention due to their ultralong afterglow lifetimes and significant Stokes shift. However, most reported systems exhibit single-mode emission, operating either in crystalline forms (typically small-molecule matrices) or in amorphous states (often polymer-based). Herein, we employ 1,2,3,4-butanetetracarboxylic acid (BTA) as the host matrix and construct a series of doped materials by incorporating nine benzofuran[2,3-c]pyridine derivatives as guest dopants through supramolecular self-assembly. By tuning the solvent evaporation rate, the materials can be prepared as either ordered, tightly packed crystals or disordered amorphous (glassy) materials. Enabled by the combined effects of the flexible alkyl chains and abundant hydrogen-bonding sites in the BTA host, these doped materials overcome the conventional morphology constraints and exhibit excellent dual-morphology (crystalline/glassy) RTP. The phosphorescence quantum yield reaches > 60%, and the afterglow remains stable even up to 460 K. To the best of our knowledge, this is the first doped RTP system that exhibits dual-morphology emission.