An active-core/active-shell structure with enhanced quantum-cutting luminescence in Pr-Yb co-doped monodisperse nanoparticles.

Monodisperse Pr(3+)/Yb(3+):NaGdF₄@NaYF₄ active-core/inert-shell nanoparticles, which exhibit efficient near-infrared quantum-cutting luminescence, are successfully prepared. In order to relieve the adverse effect caused by concentration quenching in the core, the extra Yb(3+) ions are introduced into the shell, forming an active-core/active-shell structure which leads to a much intensified near-infrared emission.