Dual-mode multicolor luminescence based on lanthanide-doped Na2CaGe2O6 phosphor for anticounterfeiting application

The lanthanide doped luminescent materials have been of great importance to the anticounterfeiting applications. At present, these materials combing with the up/down-conversion luminescence could provide a promising assumption to design an advanced anticounterfeiting. Herein, a series of distinct combinations of rare earth (RE3+) doped Na2CaGe2O6 phosphors are synthesized for dual-mode anticounterfeiting. An up-conversion luminescent phosphor Na2CaGe2O6: Ln(3+), Yb3+ (Ln(3+) = Er3+, Ho3+, Tm3+) is reported, which could emit green, red and blue light under 980 nm excitation, respectively. Based on the up-conversion luminescence of Na2CaGe2O6: Ln(3+), Yb3+ phosphor, these samples could simultaneously possess three luminescent modes of up -conversion, down-conversion and persistent luminescence with rich emission colors due to the co-doping Tb3+ ions. Furthermore, the Na2CaGe2O6: Eu3+ phosphor could be efficiently excited by ultraviolet lamp around 393 nm and exhibits intense red down-conversion luminescence. These outstanding luminescent properties make as -prepared phosphors particularly attractive for multilevel anticounterfeiting.

Automated summary

The rare earth doped Na2CaGe2O6 phosphors exhibit rich emission colors and multiple luminescence modes, making them highly attractive for multilevel anticounterfeiting applications.