Multi‐Color Circularly Polarized Room‐Temperature Phosphorescence from Processable Chiral Photonic Films

Abstract Circularly polarized luminescence (CPL) plays a crucial role in chiral science and photonic technologies. However, developing multi‐color and tunable circularly polarized room temperature phosphorescence (CP‐RTP) materials with high luminescent dissymmetric factor ( g _lum ) and superior processibility remains challenging. Here, an effective strategy is demonstrated to construct remarkably processable chiral photonic films that exhibit multi‐color tunable CP‐RTP characteristics by incorporating RTP polymers into cholesteric cellulose nanocrystals (CNCs) with the assistance of D‐(+)‐glucose (Glu). The Glu is especially selected to prepare flexible and iridescent colors of responsive photonic CNC‐RTP films and modulate the photonic band gaps (PBGs) of the CNCs via hydrogen‐bonding interactions. The tunable PBGs allow for flexible control of the wavelength and handedness of CP‐RTP while achieving a high | g _lum | value of up to 0.59 and a long phosphorescence lifetime of 371 ms. Importantly, 3D arbitrarily patterned CP‐RTP films with excellent processability and multiple polarized characteristics are demonstrated. Furthermore, by leveraging structural colors, fluorescence, long phosphorescence lifetimes, circular polarization characteristics, and time‐dependent afterglow properties of these CP‐RTP films, multilevel data encryption applications are also presented. These sustainable and scalable CP‐RTP materials with remarkable processibility, present novel opportunities and pave the way for diverse technological applications in information processing and multilevel information encryption.