Color-Tunable Organic Room-Temperature Phosphorescence From Single-Luminophore Aggregation in Polymer

Abstract

Organic room-temperature phosphorescence (ORTP) materials with tunable afterglow colors are highly desirable for advanced optoelectronic applications. Herein, color-tunable ORTP materials were achieved by simply doping different concentrations of a single luminophore into a melamine-formaldehyde (MF) polymer matrix. The doped luminophores (Me2-BCF and Spiro-BCF), which feature a planar π-conjugated core and sterically hindered side groups, were designed to exhibit a distinctly low critical aggregation concentration. The states of Me2-BCF and Spiro-BCF in the MF polymer matrix can be precisely tuned from dispersed monomers to different stacked dimers by varying their doping concentrations. ORTP materials with a tunable afterglow color transition from green to orange–red and a phosphorescence lifetime exceeding one second were realized, and they displayed good performance in information encryption. This work provides fundamental insights into aggregation-controlled luminescence and offers a versatile pathway toward color-tunable ORTP materials.