White-light-excited multicolour room-temperature phosphorescence: Mg²⁺-coordinated metal-organic amorphous composites...

The development of white-light-excited room-temperature phosphorescent (RTP) materials with tunable emission remains a significant challenge for practical applications. Herein, we report a novel strategy to achieve this goal using amorphous metal-organic amorphous composites (MOACs) based on Mg²⁺ coordination. Mechanistic studies reveal that the MgO coordination bonds not only broaden the visible-light absorption but also suppress non-radiative decay by restricting molecular motion and blocking O₂ permeation within the rigid MOACs matrix. By rationally redesigning the luminescent centers, we successfully tuned the phosphorescence emission from green to orange. Notably, the optimized yellow-emitting material exhibits a naked-eye-visible afterglow lasting up to 8 s under white-light (300 W Xe lamp) excitation and achieves a prolonged lifetime of 768 ms upon 400 nm excitation. This approach not only obviates the need for high-melting-point processing but also demonstrating considerable potential for applications in dynamic 3D artworks and information encryption.