Tunable Tri‐Channel Orthogonal Full‐Color Luminescence in Nanostructure toward Anticounterfeiting and Information Security

Abstract

Tunable orthogonal full‐color luminescence has emerged as a new class of smart luminescence phenomenon with wide applications ranging from photonics to biomedicine. However, the current research is focused on complex multilayer core‐shell nanostructures (e.g., 5–8 shell layers) with a single upconversion mode, greatly limiting their synthesis and practical application. Herein, this work proposes a simple core‐shell structure to integrate upconversion and downshifting dual‐mode luminescence based on Gd3+‐mediated interfacial energy transfer and Ce3+‐assisted cross relaxation. This design is able to suppress cross‐talk of multiple emissions and simplify the sample structure by removing the conventionally required intermediate isolation layer. Importantly, it further enables the arbitrarily controllable multicolor output at a single nanoparticle level by adopting the tri‐channel selective excitation wavelengths (980/808/254 nm), greatly expanding the conventional red‐green‐blue (RGB) color gamut. Moreover, the use of these nanoparticles promotes the information security level and the complexity of anti‐counterfeiting modes by adopting a pre‐set logic Morse information encryption and decryption strategy. These results provide effective guidance for the rational nanostructure design of novel orthogonal trichromatic emissive materials for a variety of frontier applications such as advanced anticounterfeiting and information security.