Luminescent nanomaterials containing rare earth ions can be used for security printing. The materials are based on yttrium, cerium, terbium, europium ions which luminescence with distinct primary red and green colors.
Tran Kim Anh et al., Vietnam Academy of Science and Technology, fabricated various high-efficiency luminescent nanoparticle structures just 10-30 nm across.
The luminescence makes them particularly useful for security printing of bank notes and other documents, for instance. High resolution printing in combination with colored inks was possible either using conventional screen printing or a commercially available Epson inkjet printer.
- Luminescent nanomaterials containing rare earth ions for security printing
Tran Kim Anh, Dinh Xuan Loc, Tran Thu Huong, Nguyen Vu, Le Quoc Minh,
Int. J. Nanotechnol. 2011, 8, No.3/4/5, 335-346.