The NaBaPO4:Eu2+,Yb3+ quantum-cutting (QC) phosphors were prepared by the solid-state reaction. We confirm the luminescence of Yb3+ is mainly derived from QC rather than common down-conversion. The QC efficiency 'q calculated from the luminescence decay curves reached a maximum as high as 197.4%. Furthermore, the QC emission was enhanced by decorating with quasi-spherical and uniform (similar to 100 nm) Ag nano-particles, due to localized surface plasmon resonance. The enhancement factor reached a maximum as 1.2337. (C) 2017 Elsevier Ltd. All rights reserved.