Single-Mode-Tuned Tricolor Emissions of Upconversion/Afterglow Hybrids for Anticounterfeiting Applications

Autor: Yanqing Hu, Songqi Li, Shijie Yu, Shuoran Chen, Yuyang Yan, Yan Liu, Yuanpeng Chen, Caosong Chen, Qiyue Shao, Yingshuai Liu
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Nanomaterials, Vol 12, Iss 18, p 3123 (2022)
Druh dokumentu: article
ISSN: 2079-4991
DOI: 10.3390/nano12183123
Popis: This work presents a highly secure anticounterfeiting strategy based on upconversion/afterglow hybrids with tricolor emissions tuned by a single 975 nm laser. The hybrids are composed of NaYF4:Yb/Tm and NaYF4:Yb/Er microrods and CaS:Eu2+ afterglow phosphors. Under 975 nm excitation, the hybrids exhibit multicolor emissions from green to white by adjusting laser power and then emit red afterglow light when the 975 nm laser is off. Under synergistic excitation of the blue-green light emitted by Tm/Er microrods, the red afterglow emission not only has a strong initial intensity but also lasts for 3 s. Obvious trichromatic changes from green to white to red can be observed by the naked eye. A pattern printed by the hybrid ink exhibits tricolor emissions by laser adjustment and switch. This proves that upconversion/afterglow hybrids are an excellent candidate for anticounterfeiting applications with high-level security but a simple recognition method.
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