Controllable photoactivated organic persistent room-temperature phosphorescence for information encryption and visual temperature detection

Organic luminophores exhibiting reversible changes in persistent room-temperature phosphorescence (RTP) upon exposure to external stimuli have shown great potential in diverse advanced photonic areas. Here, we present a molecular design strategy for the rational control of photoactivated persistent RTP behaviors of a series of triphenylphosphine oxide derivatives. By introducing various substituent groups, the responsive behaviors, such as photoactivation speeds and emission decay times upon UV excitation, are finely controlled. Crystal analyses and simulated calculations reveal that variations in molecular stacking upon photoirradiation are responsible for different persistent RTP behaviors. Also, one of the luminophores exhibits tunable persistent RTP from blue to green upon changing temperatures. Eventually, information encryption and visual temperature detection of these molecules are successfully demonstrated. Our study will pave the way for further development of novel stimuli-responsive persistent RTP materials with controllable responsive behavior for advanced photonic applications.