Dual-mode luminescence anti-counterfeiting and white light emission of NaGdF:Ce,Eu,Tb/carbon dot hydrophilic nanocomposite ink.

NaGdF:Ce,Eu,Tb nanocrystals were successfully prepared by a one-step hydrothermal method with Ce ions as sensitizers, Eu and Tb ions as activators, and polyethylenimine (PEI) as surfactants. Color-adjustable fluorescence emission was achieved by the energy transfer effect between rare earth ions. Blue fluorescent carbon quantum dots (CDs) with a double UV response under 254 nm and 365 nm excitation were synthesized by a one-step hydrothermal method.