Pr³⁺-doped nanoscintillators with concentration-quenching-free properties

Luminescence concentration quenching exists widely in lanthanide-doped luminescent nanomaterials, and significantly hinders their emission intensity. In this work, we report the concentration-quenching-free properties of the 406 nm emission in Pr³⁺-doped nanoscintillators, which is attributed to the large energy gap between the ¹S₀ and ¹I₆ states (ΔE = ∼25 000 cm^-1) of Pr³⁺ ions, preventing the concentration quenching effects caused by both cross-relaxation and energy migration to surface quenchers. This work provides further understanding about the concentration quenching effect of lanthanide-doped luminescent nanomaterials and a new perspective for avoiding detrimental concentration quenching. In addition, we also demonstrate the potential use of Pr³⁺-doped nanoscintillators as anti-counterfeiting materials.