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

Abstract Photochromic (PC) materials can be widely applied in light‐driven devices such as optical antifake labels, optical switches, information storage. Herein, Er 3+ and Pr 3+ co‐doped Na 0.5+ x Bi 2.5+ x Nb 2 O 9 ( 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 Bi 3+ 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 ΔRef 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 Δ 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.