Rare-earth materials are widely used in the optical field due to their rich energy-level structures, and if endowed with photoelectric response characteristics, they are expected to be applied to photoelectric multifunctional devices. In this paper, Ho³⁺- and Yb³⁺-codoped K_0.5Na_0.5NbO₃ (KNN) ferroelectric ceramics are synthesized, and the up-conversion and down-conversion luminescence intensity as well as the decay degree after photochromism can be controlled by the content of Yb³⁺. Strong green luminescence visible to the naked eye is realized, and the maximum luminescence decay is more than 50%. 2 s of color change fully indicates that the ceramic has the characteristics of fast response photochromic, under the most efficient wavelength of 405 nm by changing the irradiation wavelength. By incorporating data from thermal and electrical stimulation experiments, a comprehensive photochromic mechanism diagram is constructed, where the photochromic properties are predominantly governed by defects. It is believed that this work will provide a theoretical basis for the design of high-performance photochromic ceramics.

中文翻译：

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K0.5Na0.5NbO3陶瓷的光电相互作用和光致变色机理


稀土材料因其丰富的能级结构而在光学领域得到广泛应用，如果被赋予光电响应特性，有望应用于光电多功能器件。本文合成了Ho³⁺-和Yb³⁺-共掺杂的K_0.5Na_0.5NbO₃ （KNN）铁电陶瓷，光致变色后的上转换和下转换发光强度以及衰减程度都可以由Yb³⁺的含量来控制。实现了肉眼可见的强绿色发光，最大发光衰减超过 50%。2 s 的颜色变化充分表明陶瓷具有快速响应光致变色的特性，在最有效的波长 405 nm 下通过改变照射波长。通过结合来自热刺激和电刺激实验的数据，构建了一个全面的光致变色机制图，其中光致变色特性主要由缺陷控制。相信这项工作将为高性能光致变色陶瓷的设计提供理论依据。