Low-temperature in situ preparation of Eu3+/Tb3+-doped CaMoO4/SrMoO4 nanoparticle thin films and their application in anti-counterfeiting

Abstract

Rare earth-doped metal oxide thin films exhibit remarkable potential for application in anti-counterfeiting, owing to their exceptional fluorescent properties. However, the existing fabrication techniques for these rare earth-doped luminescent thin films are predominantly complex and necessitate high-temperature conditions. In light of this issue, we present a low-temperature method for in situ fabrication of luminescent Ca_1−xMoO₄:Eu_x³⁺ and Sr_1−xMoO₄:Tb_x³⁺ nanocrystal thin films by a solution deposition process. The developed method has the advantages of simple operation, rapid and low-temperature synthesis. The optimal chemical compositions of molybdate-based luminescent films are Ca_0.90MoO₄:Eu_0.10³⁺ and Sr_0.90MoO₄:Tb_0.10³⁺. Moreover, we evaluate the practical feasibility of luminescent nanoparticle films in the field of anti-counterfeiting by combining the unique fluorescent properties of rare earth ions and designing customized fluorescent patterns.