Elemental migration in core/shell structured lanthanide doped nanoparticles

Lanthanide doped core/shell structured nanoparticles have being widely studied because of their unique optical properties and promising applications in many fields. However, the elemental migration of the lanthanide ions in the core/shell nanoparticles still lacks sufficient understanding, which may influence the optical properties of the nanoparticles. By monitoring of the variation of optical properties during the postannealing progress in the solution at high temperature, the elemental migration of Er³⁺ in the core/shell structured NaErF₄@NaYF₄ luminescent nanoparticles is investigated, which are influenced by the annealing temperature, relative ion radius of lanthanide elements, and doping concentration differential between two adjacent layers. Based on the dopants migration in the core/shell structured nanoparticles, the emission profile of the luminescent nanoparticles can be well tuned by the postannealing process. The findings described here suggest a general insight into constructing lanthanide doped core/shell luminescent nanomaterials with controllable dopant ions spatial distributions and energy migration in the core/shell nanostructure.