Owing to the large coding capacity and high confidentiality, dual‐mode or multimode anticounterfeiting fluorescent materials are gradually substituting traditional single‐mode fluorescent materials. Herein, a facile hydrothermal method is designed and used to integrate lanthanide ion (Ln³⁺)‐doped NaLuF₄ nanoparticles with Y₂O₃‐based downconversion nanorods, achieving the construction of dual‐mode luminescent composite materials. The excellent optical properties of NaLuF₄/Y₂O₃ composites are confirmed by photoluminescence spectroscopy. The composites can be excited by a 980 nm laser to generate bright red, green, and blue colors (corresponding to Er³⁺/Tm³⁺‐, Yb³⁺/Ho³⁺‐, and Yb³⁺/Tm³⁺‐doped NaLuF₄, respectively), and turn into dim‐red and green colors under an excitation source of 254 nm. Furthermore, the polyvinyl alcohol (PVA)‐mediated stable fluorescent inks are successfully formulated and then printed onto the paper, aluminum foil, and fabric by low‐cost and simple screen printing techniques to fabricate various anticounterfeiting patterns. Interestingly, the printed patterns are hard to observe under ambient light, enabling the generation of multiple emission color under excitations of 980 and 254 nm. The prepared dual‐mode NaLuF₄/Y₂O₃ composite materials with outstanding stability and distinctive multicolor luminescent properties provide low‐cost, highly effective, multilevel protection for genuine products against counterfeit.

中文翻译：

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设计多色双模掺杂镧系元素的NaLuF4 / Y2O3复合材料以实现高级防伪

由于编码能力大和保密性高，双模或多模防伪荧光材料正逐步取代传统的单模荧光材料。在本文中，设计了一种简便的水热方法，并将掺镧离子（Ln ³⁺）的NaLuF ₄纳米颗粒与基于Y ₂ O ₃的下转换纳米棒集成在一起，从而实现了双模态发光复合材料的构建。通过光致发光光谱法证实了NaLuF ₄ / Y ₂ O ₃复合材料的优异光学性能。可以通过980 nm激光激发复合材料以产生明亮的红色，绿色和蓝色（对应于Er³⁺ / Tm ³⁺ -，Yb ³⁺ / Ho ³⁺ -和Yb ³⁺ / Tm ³⁺掺杂的NaLuF ₄），并在254 nm的激发源下变成暗红色和绿色。此外，成功地配制了聚乙烯醇（PVA）介导的稳定的荧光油墨，然后通过低成本和简单的丝网印刷技术将其印刷到纸张，铝箔和织物上，以制造各种防伪图案。有趣的是，印刷的图案很难在环境光下观察到，从而能够在980和254 nm的激发下产生多种发射颜色。准备好的双模NaLuF ₄ / Y ₂ O ₃ 具有出色稳定性和独特多色发光特性的复合材料可为正版产品提供低成本，高效，多层次的保护，以防伪造。