The Enhancement of Photochromism and Luminescence Modulation Properties of Ferroelectric Ceramics via Chemical and Physical Strategies

Photochromic (PC) materials can be widely applied in light-driven devices such as optical antifake labels, optical switches, information storage. Herein, Er3+ and Pr3+ co-doped Na0.5+xBi2.5+xNb2O9 (x = -0.02, 0, 0.02) ferroelectric ceramics with excellent PC and luminescence modulation properties have been successfully prepared. Both chemical and physical strategies, namely excess Na+ and Bi3+ content during weighing of raw materials and an electric field poling, have been developed to enhance the PC and luminescence modulation. The largest reflectance difference Delta Ref between fresh and irradiated ceramics reaches a high value of 36% at x = 0.02, which is much higher than the usually obtained value in inorganic oxide ferroelectrics. Additionally, this value increases to 39% after an electric field poling. Accordingly, the up-conversion luminescence modulation Delta R-t reaches a high value of 91.6%. The mechanisms of enhanced PC reaction and luminescence modulation via an electrical poling are discussed. Furthermore, a fast response time of around 1 s for PC reaction is achieved in this material. Utilizing this advantage, a hand-rewritable display using the prepared ceramics has been achieved besides the applications in anti-counterfeiting.

Automated summary

In this study, Er3+ and Pr3+ co-doped ferroelectric ceramics with excellent photochromic and luminescence modulation properties were successfully prepared. Through chemical and physical strategies, the enhancement of these properties was achieved, making the material potentially useful in applications such as optical antifake labels, optical switches, and information storage, as well as a hand-rewritable display.