Photo-Induced Assembly Rare-Earth-based nanoparticles into Multifunctional Supraparticles

This work presents a photo-induced assembly strategy for the fabrication of multifunctional supraparticles from independently synthesized rare-earth nanoparticles. The proposed modular approach overcomes limitations associated with conventional core–shell architectures by enabling the controlled assembly of luminescent building blocks into hierarchical structures with tunable size and composition. The influence of key processing parameters on supraparticle formation is investigated, demonstrating precise control over particle morphology. Spectroscopic studies reveal that the assembly process preserves the upconversion mechanism and thermometric performance of the rare-earth nanoparticles, while in situ photoluminescence measurements provide insights into the luminescence quenching occurring during assembly. The developed methodology offers a versatile platform for constructing multifunctional rare-earth superstructures while maintaining their intrinsic optical properties, opening new opportunities for advanced luminescent materials.