Pr 3+ -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 Pr-doped nanoscintillators, which is attributed to the large energy gap between the S and I states (Δ = ∼25 000 cm) of Pr 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 Pr-doped nanoscintillators as anti-counterfeiting materials.