Liu Lin, Peng Shanshan, Guo Yuxuan, Lin Ye, Sun Xia, Song Liang, Shi Junpeng, Zhang Yun
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen 361021, China.
ACS Appl Mater Interfaces. 2022 Sep 14;14(36):41215-41224. doi: 10.1021/acsami.2c12407. Epub 2022 Sep 5.
Persistent luminescent materials (PLMs) are promising candidates for the anti-counterfeiting and information encryption field. However, ultraviolet (UV) excitation and visible emission are partially responsible for enabling information that has been encrypted to combat counterfeiting to be accessed by trial and error, resulting in imitation and information leakage. Here, we propose the possibility of controlling the persistent luminescent (PersL) emission spectra and its excitation light source with the use of band gap engineering, while obtaining X-ray exciting, not UV exciting UV PLM for advanced anti-counterfeiting and encryption application. Cationic substitution was used to adjust the width of the band gap of Lu(X)O (X = V, Nb, Ta, and P) from ∼4 to 9 eV. In addition, Bi was introduced into the host as an emitter, which enabled the PersL emission spectra to be modulated from ∼550 to 230 nm. Among these PLMs, LuPO:Bi has unique optical properties. Under UV excitation, LuPO:Bi exhibits weak, inconspicuous visible down-conversion luminescence (DCL), without PersL ceasing once excitation is discontinued. Interestingly, LuPO:Bi displays UV PersL after X-ray excitation, and human eyes are insensitive to UV PersL, which requires specialized optical equipment to detect. A proof-of-concept assessment of LuPO:Bi for anti-counterfeiting and information encryption applications demonstrated its suitability in this regard.
持久性发光材料（PLMs）是防伪和信息加密领域很有前景的候选材料。然而，紫外线（UV）激发和可见光发射在一定程度上导致了通过反复试验就能获取已加密的防伪信息，从而造成仿冒和信息泄露。在此，我们提出利用带隙工程控制持久性发光（PersL）发射光谱及其激发光源的可能性，同时获得用于先进防伪和加密应用的X射线激发而非紫外线激发的紫外线PLM。采用阳离子取代法将Lu(X)O（X = V、Nb、Ta和P）的带隙宽度从约4 eV调整到9 eV。此外，将Bi作为发光体引入基质中，使PersL发射光谱能够从约550 nm调制到230 nm。在这些PLMs中，LuPO:Bi具有独特的光学性质。在紫外线激发下，LuPO:Bi表现出微弱、不明显的可见光下转换发光（DCL），且激发停止后PersL不会停止。有趣的是，LuPO:Bi在X射线激发后显示出紫外线PersL，而人眼对紫外线PersL不敏感，需要专门的光学设备来检测。对LuPO:Bi在防伪和信息加密应用方面的概念验证评估证明了其在这方面的适用性。
