Integrating Photochromism, Mechanoluminescence, and Excitation-Dependent Multicolor Persistent Luminescence in Ce3+/Tb3+-Doped Garnet toward Multimodal Optical Anticounterfeiting and Orthogonal Information Encryption

Abstract Excitation-wavelength‑dependent multicolor persistent luminescence (PersL) in a single material holds great promise for orthogonal information writing, low‑crosstalk decoding, and optical anticounterfeiting. However, such materials remain scarce. Moreover, the lack of coupling with photochromism and mechanoluminescence effects has restricted their expanded applications in advanced optical anticounterfeiting and high‑capacity information storage. In this work, a phosphor of Lu3Al2Ga3O12:Ce3+, Tb3+ with excitation‑wavelength‑dependent PersL is developed. After 254, 310, and 420 nm excitation, it exhibits violet, cyan-violet, and cyan PersL, respectively, together with 254 nm UV-induced photochromism and pre-irradiation free mechanoluminescence. Multispectroscopic analyses reveal that the wavelength‑dependent PersL relies on precise energy level structures, distinct excitation characteristics of the luminescent centers, and Ce3+ → Tb3+ energy transfer; the photochromism is related to color centers formed by oxygen‑vacancy‑trapped electrons; and the mechanoluminescence involves charge transfer from the PDMS matrix to the PersL material. Leveraging the above properties, this material enables multichannel information encoding, multimodal coupled anticounterfeiting verification, and synchronous hierarchical readout. These results provide promising materials and design strategies for developing advanced photofunctional PersL materials.