Remarkable modulation effects of Ag+ ion on fluorescence of Eu3+ ion doped yttrium phosphate nanophosphors

Ag+ sensitized YPO4:Eu3+ nanomaterials were successfully synthesized by hydrothermal reaction. The fluorescent spectra indicate that Ag+ ion has remarkable modulation effects on the shape of the emission bands of YPO4:Eu3+, so that full width at half maximum (FWHM) of the 5D0 → 7F2 emission of YPO4:Eu3+ is extended to be 14 nm, broader than that (<9 nm) of ever reported Eu3+-doped materials. Meanwhile, it is observed that the doping of Ag+ ion leads to the lowering of the intensity ratio of 5D0 → 7F2 to 5D0 → 7F1 transition. The analysis demonstrates that doping of Ag+ ion will generate the local lattice aberration and the crystal field variation of Eu3+ ion and Y3+ ions due to a fact that the ionic radius (1.31 Å) of Ag+ is obviously larger than that (0.938 Å) of Eu3+ and that (0.90 Å) of Y3+. As a result, the excitation and emission bands of Eu3+ ion are correspondingly tuned.