Multifaceted luminescence in lanthanide-activated microrods for advanced multicolor anti-counterfeiting

Abstract

The increasing demand for robust anti-counterfeiting measures has prompted the development of advanced luminescent materials that offer multifaceted capabilities for secure information encryption and authentication. Here we present the rational design and synthesis of NaYF₄:Tb³⁺/NaYF₄:Eu³⁺ heterostructured microrods emitting multifaceted luminescence within a single microrod. Our experimental results demonstrate the effectiveness of the heterostructured design in preserving the afterglow intensity while facilitating controlled emission modulation. Notably, steady-state and transient spectroscopy confirms the capability of the designed heterostructured architecture to effectively prevent non-radiative transitions between activators. Moreover, the strategic integration of Eu³⁺ in the outer layer of the microrods allowed for the realization of diverse luminescent responses. Our results further show that the excitation-dependent multifaceted luminescence displayed by the synthesized microrods presents a compelling case to advance multicolor high-level anti-counterfeiting and information encryption. This study not only contributes to the advancement of multifunctional luminescent materials but also offers valuable insights into the design principles crucial for ensuring robust security measures in optical anti-counterfeiting technologies.