Anti-counterfeiting and Optical storage applications based on reversible modulated Down-shift Luminescence in photocoloration of MoO3: Eu3+ phosphor

Abstract

Reversible and repeatable control of rare earth ions doped down-shift luminescence materials induced by the external field stimulation can be applied more widely. However, there is still a challenge on reversible luminescence regulation of photochromism-induced rare earth ions doped down-shift luminescence materials by light fields stimulation. The MoO3: Eu3+ phosphors changed color from light green to blue due to the formation of color centers caused by the trapping of electrons by oxygen vacancy defects under near infrared irradiation at 808 nm, and recovered from blue to initial light green after heating at 500 °C, showing a reversible change in color. The down-shift luminescence intensity of MoO3: Eu3+ phosphors reaches the maximum quenching degree, about 87%, after 20 s irradiation by 808 nm laser, which has the characteristics of fast response and great regulation rate. Moreover, the down-shift luminescence intensity can recover to the initial intensity after heating at 500 °C for 90 s, indicating reversible regulation of photochromism-induced down-shift luminescence. The application of MoO3: Eu3+ phosphors as the anti-counterfeiting labels and information storage of binary encoding was designed, these results suggest that it have certain potential applications in anti-counterfeiting and optical storage field.