(K,Na)NbO3 ferroelectrics: a new class of solid-state photochromic materials with reversible luminescence switching behavior

In this paper, we reported a new photosensitive material, Sm doped K0.5Na0.5NbO3 (KNN) ceramics, fabricated using a solid-sate reaction method, which exhibits both photochromism and luminescence switching properties. By alternating visible light irradiation (lambda > 407 nm) and thermal stimulus, the samples show a reversible color change from the initial green to pale gray. Interestingly, luminescence emission intensity can be effectively tuned using photochromic reactions. Furthermore, the luminescence switching degree strongly depends on the firing temperature. These results suggest that KNN-based perovskite oxides with photochromism, luminescence switching and ferroelectric energy storage properties are particularly attractive for optical data storage applications as multi-functional materials.