Regulating Isolated‐Molecular and Aggregated‐State Phosphorescence for Multicolor Afterglow by Photoactivation

Abstract Ultralong organic phosphorescence (UOP) materials have attracted considerable attention in recent years. Herein, a new type of flexible films is fabricated by doping amphipathic pyrene tetrasulfonic acid sodium salts into amorphous poly(vinyl alcohol) matrix, which enables the realization of color‐tunable UOP spanning from orange‐red to green after excitation light is switched off. Interestingly, precise control of the proportion of isolated‐molecular and aggregated‐state phosphorescence is demonstrated for colorful afterglow using photo‐activation. An increase in the dynamic phosphorescence lifetime of isolated molecules is observed from 894.75 to 1735.71 ms following an 8 min irradiation under ambient conditions. The photo‐activation, however, showed little influence on aggreated‐state phosphorescence. This flexible and processable film exhibits versatile applications in multicolor afterglow displays, ultraviolet detection, multilevel information encryption, etc. This study not only provides a strategy for the rational regulation of UOP colors but also expands the application potential of color‐tunable UOP materials.