Long-lived Photon Upconversion Phosphorescence in RbCaF3:Mn2+,Yb3+ and the Dynamic Color Separation Effect

The development of luminescence materials with long-lived upconversion (UC) phosphorescence and long luminescence rise edge (LRE) is a great challenge to advance the technology of photonics and materials sciences. The lanthanide ions-doped UC materials normally possess limited UC lifetime and short LRE, restricting direct afterglow viewing in visual images by the naked eye. Here, we show that the RbCaF3:Mn2+,Yb3+ UC luminescence material generates a long UC lifetime of similar to 62 ms peaking at 565 nm and an ultralong LRE of similar to 5.2ms. Density functional theory calculations provide a theoretical understanding of the Mn2+-Yb3+ aggregation in the high-symmetry RbCaF3 host lattice that enables the formation of the long-lived UC emission center, superexchange coupled Yb3+-Mn2+ pair. Through screen printing ink containing RbCaF3:Mn2+,Yb3+, the visualized multiple anti-counterfeiting application and information encryption prototype with high-throughput rate of authentication and decryption are demonstrated by the dynamic color separation effect.