Article ID Journal Published Year Pages File Type
10633587 Optical Materials 2005 7 Pages PDF
Abstract
We present a potential rare earth activated white-emitting nanocrystalline phosphor powders produced by combustion synthesis and report their luminescent properties and thin films deposited by pulsed laser ablation. Effects of varying the atomic concentration of rare earth dopants in Y2SiO5:Cex,Tby (0.0065 < x < 0.0085, 0.010 < y < 0.040), along with morphological, microstructural and photoluminescence (PL) properties were investigated in order to produce white-light emission close to D65 with optimized luminescent efficiency. Characteristic electronic transitions measured from photoluminescence spectra at λem = 544 nm (5D4 → 7F5) in Tb3+ and λem = 418 nm (5d → 2F7/2) in Ce3+ show that an inductive energy transfer occurs when Tb3+ ions absorbs the energy from Ce3+ upon excitation with long-UV photons (λexc = 358-380 nm). The optimal concentration for the best luminescence intensity has been obtained in Y2SiO5:Ce0.0075,Tb0.025, and the closest to daylight white emission was found with a composition of Y2SiO5:Ce0.0075,Tb0.040. These activated phosphors with two rare earth ions in the yttrium silicate host (Y2SiO5) represent an efficient way to produce white-light emission close to D65 with chromaticity coordinates of x = 0.225 and y = 0.320.
Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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