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

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.