Achieving time-dependent and color-tunable ultralong room temperature phosphorescence through sodiation reconfiguration for dynamic 5D information encryption

Abstract

Achieving dynamic optical tunability of ultralong room temperature phosphorescence (RTP) materials is critical for the design of advanced multi-level information encryption. In this work, we develop a facile metal–organic thermal polymerization strategy for the preparation of aluminium/phenylalanine phosphorescent materials (Al/Phe-PMs) with a production capacity on a kilogram scale. The Al/Phe-PMs show an ultralong lifetime of up to 1015.3 ms, with a phosphorescent quantum yield of 7.98%. Most importantly, the Al/Phe-PMs have a unique time-dependent phosphorescence color (TDPC) phenomenon because of the presence of multiple emission peaks with diverse decay times, causing the dynamic transition of RTP color from yellow to chartreuse and then to green with the extension of the decay time. Furthermore, NaOH can be used for effectively regulating the optical properties of Al/Phe-PMs, causing a great blue shift in RTP emission and a decrease in RTP efficiency. NaOH-stimulated color tunability is proven to be ascribed to the sodiation reconfiguration effect that results in the depolymerization of Al/Phe-PMs and the destruction of the rigid conformation. Benefitted by the advantages of both TDPC and color-tunability, the proposed Al/Phe-PMs can be designed for constructing dynamic colored 5D information encryption systems.