Optical properties and anti-counterfeiting applications of Mn2+-doped Na-β″-Al2O3 phosphors

• This ink allows for effective waterproof and anti-counterfeiting applications under commercial UV light at 360 nm • Exhibit a prominent green light emission influenced by the characteristic emission peak of Mn 2+ at 508 nm under 358 nm • The epoxy resin , doped Mn 2+ , and Na-β″-Al 2 O 3 matrix involved in this material are all low-cost and chemically stable Using Na-β″-Al 2 O 3 as a matrix, a series of Mn 2+ -doped Na-β″-Al 2 O 3 phosphors were synthesized via the solid-state method. The phase structure, microstructure, and optical properties of the synthesized samples were characterized using XRD, SEM, EDS, and fluorescence spectrometry. The results show that the intrinsic luminescence characteristics of Na-β″-Al 2 O 3 crystals, due to inherent defects, exhibit emission peaks between 360 and 650 nm. Upon the introduction of Mn 2+ , the prepared Na-β″-Al 2 O 3 :Mn 2+ phosphors, under 358 nm light excitation, exhibit a prominent green light emission influenced by the characteristic emission peak of Mn 2+ at 508 nm and the emission peaks of the Na-β″-Al 2 O 3 matrix. Furthermore, with increasing Mn 2+ doping, the luminescence intensity of the phosphor initially increases and then decreases, reaching a maximum when the Mn 2+ doping concentration is 0.05. Additionally, the excitation peaks of the prepared phosphors not only meet the emission wavelength of commercial near-UV LED chips but also integrate well with a two-component epoxy resin . This compatibility allows for effective waterproof and anti-counterfeiting applications under commercial UV light at 360 nm wavelength, providing strong support for long-distance maritime goods transportation.