1550 nm pumped upconversion chromaticity modulation in Er3+ doped double perovskite LiYMgWO6 for anti-counterfeiting

1550 nm near-infrared (NIR) light excited lanthanide ion (Ln(3+)) doped up-conversion (UC) materials with tunable emission color have great application potential in optical anti-counterfeiting and it is essential to explore new stable phosphors and expand the emission color gamut for multicolor security printing. Herein, a new type of double perovskite tungstate UC phosphors LiYMgWO6: Er3+ with green and red double color emissions under 1550 nm excitation were synthesized by high temperature solid-state method. The emission color output of LiYMgWO6: Er3+ was adjusted from yellow-green to red by introducing Ho3+ ion to enhance the red emission and suppress the green emission. Fluorescent lifetime measurements were carried out to illustrate the color modulation mechanism. As a proof of concept, the fluorescent printing inks based on as-prepared phosphors were synthesized and fluorescent labels with special patterns were designed to demonstrate the anti-counterfeiting application. (C) 2019 Elsevier B.V. All rights reserved.