Inspired by their excellent thermal stability and strong fatigue resistance, inorganic photochromic materials have been highlighted as promising candidates in various photonic applications ranging from photoswitches, anti‐counterfeiting, and encryption to information storage. However, the lack of suitable inorganic materials with both fast photoresponse and strong coloration contrast heavily restricts their applications. Herein, a new strategy is proposed to achieve high photochromic performance via constructing deep‐lying traps in ferroelectric ceramics. The obtained K_0.5Na_0.5NbO₃‐Eu (KNN‐Eu) ceramic exhibits a reversible yellow–gray color change with high fatigue resistance upon alternating illumination (420 nm) and thermal stimulus (450 °C). A fast response time of around 1 s and a large reflectivity difference of 39.2% between the colored and bleached states are simultaneously achieved in KNN‐Eu ceramic, which is by far the best performance ever reported in inorganic photochromic materials. Benefiting from these excellent properties, KNN‐Eu is the first ferroelectric photochromic ceramic to support an instant and hand‐(re)writable information display. The enhanced photochromic performance is expected to facilitate the application of photochromic materials in numerous optical devices and provides a significant guidance to design other inorganic photochromic materials.

中文翻译：

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用于高对比度可重写信息显示器的高响应性光致变色陶瓷

无机光致变色材料具有出色的热稳定性和强的抗疲劳性，因此受到人们的青睐，成为光开关，防伪，加密和信息存储等各种光子应用中的有前途的候选材料。然而，缺乏同时具有快速光响应和强着色对比的合适无机材料严重限制了它们的应用。本文提出了一种通过在铁电陶瓷中构建深陷阱来实现高光致变色性能的新策略。所获得的K _0.5 Na _0.5 NbO ₃‐Eu（KNN-Eu）陶瓷在交替照射（420 nm）和热刺激（450°C）时表现出可逆的黄灰色颜色变化，并具有较高的抗疲劳性。在KNN-Eu陶瓷中，可同时实现约1 s的快速响应时间以及有色和漂白状态之间的39.2％的较大反射率差异，这是迄今为止在无机光致变色材料中所报告的最佳性能。得益于这些出色的性能，KNN-Eu是第一个支持即时和手动（可重写）信息显示的铁电光致变色陶瓷。预期增强的光致变色性能将促进光致变色材料在众多光学器件中的应用，并为设计其他无机光致变色材料提供重要指导。