Additive Luminescence Lifetime Tuning of Upconversion Nanoparticles for High‐Capacity Optical Encoding

The tunable upconversion luminescence lifetime of lanthanide-doped upconversion nanomaterials offers great potential for stable and precise optical encoding in the temporal domain. However, typical methods for tuning upconversion luminescence lifetime, which depend on material synthesis, often suffer from inefficiency and unpredictability, hindering the application of upconversion luminescence lifetime. Here, using lanthanide-doped upconversion nanoparticles (UCNPs) as a representative, we demonstrate an additive strategy, akin to additive color mixing, to tune upconversion luminescence lifetime in a predictable and facile way. This strategy can easily generate a set of lifetimes using only two types of UCNPs, and the manipulated lifetimes can be quantitatively predicted according to the luminescence of the original UCNPs. Moreover, this strategy is applicable to lifetimes of lanthanide luminescence over a broad spectral range. Benefiting from this strategy, high-capacity encoding systems can be directly established by employing just a few types of UCNPs. These results should pave new ways for luminescence lifetime tuning and provide new opportunities for luminescence lifetime-based massive information storage and analysis.