Enhanced blue-violet and ultraviolet fluorescence from Eu3+ doped silver colloids

Fluorescence spectra of Eu3+ ions and silver colloid containing Eu3+ have been recorded and analysed at room temperature. For solution containing Eu3+, three blue-ultraviolet emission peaks are observed at 362, 380 and 420 nm, respectively, when the corresponding excitation wavelength is at 250-300 nm. When silver colloids were added to the solution containing Eu3+, all these fluorescence peaks were enhanced about 10 times. We believe that these increased emission are due to the intense 7F0 → 5H6 transitions in Eu3+ owing to the fluorescence at 315 nm from silver nanoparticles.