A series of CaFCl：Tb3＋ and CaFCI：Tb3＋,A＋ （A=Li, Na and K） nanophosphors were synthesized by the one-step sol-gel method, which were reported for the first time. The sample consisted of monodisperse particles, the average size of which was 37 nm. The emissions of Tb3＋ ions and oxygen defects OF＇ were demonstrated in the CaFCl：Tb3＋ samples. The former was made up of several peaks at 488, 545, 587 and 623 nm, ascribed to 5D4→7FJ （j=6-3） transitions of Tb3＋ ions. The latter was shown as a broad band peaked at about 450 nm. Alkali metal ions A＋ （A=Li, Na and K） were introduced as the charge compensators to improve the luminescence of samples. The influence of charge compensators on the emissions of Tb3＋ ions and oxygen defects OF＇ was investigated by the measurement of fluorescence spectra and luminescence decay curves. The results indicated that all the charge compensators weakened the defects emission. Furthermore, Li＋ ion was the best charge compensator, because it not only reduced the defects emission but also increased the emission intensity of Tb3＋ significantly. Our results suggested that this nanophosphor sensitized by the charge compensator might broaden potential applications of rare-earth doped CaFCl.
NaBaPO4:Eu^2+,Er^3+phosphors and Ag nano-particles(NPs)were prepared by the solid-state reaction and chemical reduction method,respectively.The fluorescence spectra and decay curves demonstrate the effective energy transfer from Eu^2+to Er^3+and the existence of three-photon quantum-cutting through two-step cross-relaxation of Er^3+.The quantum-cutting emission is peaked at 1534 nm with a broad excitation band centered at 352 nm,Plasmon-enhanced quantum-cutting of NaBaPO4:Eu^2+,Er^3+phosphors was realized by decorating Ag NPs.The largest enhancement factor is 1.395.It is hopeful to improve the photovoltaic conversion efficiency of Ge solar cells by using this phosphor.
