Ultraviolet light induced white light emission in Ag and Eu^3+ co-doped oxyfluoride glasses

Abstract

Transparent Ag and Eu(3+) co-doped oxyfluoride glasses with composition 50SiO(2)-20Al(2)O(3)-30CaF(2) were prepared by melt-quenching technique. The structural and luminescent properties of glasses, energy transfer mechanism between luminescent centers were systematically investigated. The missing nanoparticles signals in absorption spectra, XRD patterns and TEM images, the additional broad excitation band at 325-375 nm indicate that the broad emission band at 400-700 nm is originated from very small molecule-like, non-plasmonic Ag particles (ML-Ag-particles). A perfect white light emission was realized by combining intense red emission of Eu(3+) with broad band emission of ML-Ag-particles. These results suggest that Ag and Eu(3+) co-doped oxyfluoride glasses could be potentially applied as white light-emitting phosphors for ultra-violet LED chips.

White light emission from γ-irradiated Ag/Eu co-doped phosphate glass under NUV light excitation

“…White light emitting diodes (W-LEDs) received lots of interests because of their real application in substituting fluorescence or incandescent lamps for solid state lighting source over the last two decades [1][2][3][4][5][6]. Compared with the traditional lighting sources, W-LEDs have many advantages such as high efficiency, less energy consumption and longer lifetime [1].…”

“…However, the absorption coefficient of europium ions at UV range is very small leading to low efficiency of emission under UV excitation. As a consequence, many researchers investigated the effect of silver particles on the emission efficiency of Eu 3+ ions [5,6,23,24]. Malta et al and Hayakawa et al investigated the effect of silver nanoparticles on the luminescence properties of Eu 3+ ions in borofluoride glass and silicate glass, respectively.…”

Luminescent properties of lithium-phosphate-borate glasses doped with Tb3+/ Eu3+ions

“…the transmission coefficient is about 90%. In the sample with the europium concentration of 0.7, 1 wt%, absorption peaks with maxima at 350, 367, 378 and 485 nm are recorded in the transmission spectrum which is apparently associated with f-f transitions in the terbium ion [5].…”

Energy transfer based photoluminescence spectra of (Tb3++ Sm3+):PEO+PVP polymer nano-composites with Ag nano-particles

“…The excitation wavelength of the Ag had been reported in previous work [45] from 325 to 375 nm and emission bands from 400 to 600 nm. In some other literature [46] the excitation band of Ag NPs (which are synthesized by the green synthesis method) was reported as 350 nm.…”