Excitation-Controlled Host-Guest Multicolor Luminescence in Lanthanide-Doped Calcium Zirconate for Information Encryption.

Efficient control over lanthanide luminescence by regulating excitations offers a real-time and reversible luminescence-managing strategy, which is of great importance and highly desirable for various applications, including multicolor display and information encryption. Herein, we studied the crystal structure, luminescence properties, and mechanisms of undoped and Tb/Eu-doped CaZrO in detail. The intrinsic purple-blue luminescence from host CaZrO and the introduced green/red luminescence from guest dopants Tb/Eu were found to have different excitation mechanisms and, therefore, different excitation wavelength ranges. This enables the regulation of luminescent color through controlling the excitation wavelengths of Tb/Eu-doped CaZrO. Furthermore, preliminary applications for information encryption with these materials were demonstrated using portable UV lamps of 254 and 302 nm. This study not only promotes the development of multicolor luminescence regulation in fixed-composition materials, but also advances the practical applications of lanthanide luminescent materials in visually readable, high-level anti-counterfeiting and information encryption.