RGB-tricolor multimodal luminescence of Ce3+and Mn2+in Mg2Al4Si5O18 via site occupancy engineering for anticounterfeiting applications

Multimodal luminescent materials have shown important applications in anti-counterfeiting and information encryption, however, mostly difficult to adjust optical properties with the structure, which leads to relatively constant emission position and less selectable excitation wavelength. Herein, Ce3+ and Mn2+ co-doped Mg2Al4Si5O18 phosphors are designed for the applications in RGB-tricolor multimodal anti-counterfeiting. Due to site occupancies, energy transfer and different thermal behaviors of Ce3+ and Mn2+ emissions, the emitting color of Mg2Al4Si5O18: Ce3+, Mn2+ is rich and tunable with different excitation wavelengths, doping concentrations and temperatures. The site occupancies of Ce3+ and Mn2+ are clarified with crystal field analysis and indepth into transitions energies of Ce3+ and Mn2+. The energy transfer mechanism between Ce3+ and Mn2+ is analyzed via Inokuti-Hirayama model. The difference of thermal stabilities of Ce3+ and Mn2+ emissions is interpreted with construction of vacuum referred binding energy scheme. The as-designed molds of information encryption and decryption with Mg2Al4Si5O18: Ce3+, Mn2+ phosphors demonstrate the potential applications in anti-counterfeiting. The work provides an effective way for exploring Ce3+ and Mn2+ doped phosphors with RBGtricolor multimodal luminescence.