Multimodal responsive Dy3+, Li+ activated Gd2MgTiO6 phosphors for ideal wLED, potent anti-counterfeiting, fingerprint visualization, and encryption coding

The Gd2MgTiO6 is an infant luminescence host that portrays eclectic applications in displays, security devices, and forensic studies. The perovskites are synthesized by facile combustion method, decreasing the synthesis conditions from 1573 K, 5 h to 1173 K, 4 h, from conventional routes. The phosphors are then activated with Dy3+ ions, giving photoluminescence emission in the blue, yellow, and red regions of the visible spectrum owing to (4F9/2 -> 6H15/2), (4F9/2 -> 6H13/2), and (4F9/2 -> 6H11/2) transitions respectively. Further, monovalent Li+, divalent Sr2+, or trivalent Sm3+ ions are co-doped in the crystal matrix, which chiefly enhances the optical and crystalline properties for Li+ sensitization. Under 351 nm excitation, these samples show CIE coordinates (0.3290, 0.3313), color temperature 5759 K, color rendering index 86, and color purity of 2.5 %; signifying ideal white light emission for wLED with quantum efficiency 43 %. Under 980 nm excitation, these phosphors gave noble red emission, which can be effectually applied as a level 3 latent fingerprint visualization tool in criminology. The white and red emissions on UV and NIR excitation respectively are combined for potent anticounterfeiting security ink and encryption coding; which marked a new methodology for the multifunctional application of a single phosphor matrix.