Abstract
The solvothermal synthesis and structural characterization of silicate based oxyapatite Tb3+ activated Ca2 Gd8 Si 6 O26 (CGS) nanophosphors have been reported. The structure of these phosphors was elucidated by the powder x-ray diffraction (XRD) and further characterized by scanning electron microscopy. The XRD results revealed that the obtained Tb3+:CGS shows the characteristic peaks of oxyapatite in a hexagonal lattice structure. The photoluminescence (PL) properties were studied with variations of Tb3+ concentration and sintering temperature. Under 275 nm excitation, both Tb3+ ( 5D3,4 → 7FJ=6,5,4,3) and Gd3+ (6P7/2 → 8S7/2) characteristic emissions associated with 4f-4f transitions have been observed, and when the concentration of Tb3+ increases above 1 mol % the 5D3 emission intensity decreases due to cross relaxation. The Gd3+ emission intensity decreases with increasing Tb3+ concentration and the PL intensity of Tb3+ at 378 nm excitation was much weaker than the obtained intensity with excitation at 275 nm, suggesting that the efficient energy transfer occurred from Gd3+ to Tb 3+ ions in CGS host lattice. The decay curves of the 5D4 level show that the lifetime decreases with increasing crystallite size and concentration of Tb3+ ions. These luminescent powders are expected to find potential applications such as white light emitting diodes and optical display systems.
Original language | English |
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Pages (from-to) | J20-J26 |
Journal | Journal of the Electrochemical Society |
Volume | 158 |
Issue number | 2 |
DOIs | |
State | Published - 2011 |