Synthesis and Luminescence Properties of Eu(2+)-Doped Sr(3)MgSi(2)O(8) Blue Light-Emitting Phosphor for Application in Near-Ultraviolet Excitable White Light-Emitting Diodes

In this study, [Sr(0.99)Eu(0.01)](3)MgSi(2)O(8) phosphors were sintered at 1200–1400 °C for 1–5 h by using the solid-state reaction method. The crystallinity and morphology of these phosphors were characterized through X-ray diffraction analysis and field-emission scanning electron microscopy, respectively, to determine their luminescence. The photoluminescence properties, including the excitation and emission properties, of the prepared phosphors were investigated through fluorescence spectrophotometry. The α-Sr(2)SiO(4), Sr(2)MgSi(2)O(7), and Sr(3)MgSi(2)O(8) phases coexisted in the [Sr(0.99)Eu(0.01)](3)MgSi(2)O(8) phosphors, which were synthesized at low temperatures. The particles of these phosphors had many fine hairs on their surface and resembled Clavularia viridis, which is a coral species. Transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the fine hairs contained the Sr(2)SiO(4) and Sr(2)MgSi(2)O(7) phases. However, when the [Sr(0.99)Eu(0.01)](3)MgSi(2)O(8) phosphors were sintered at 1400 °C, the Sr(3)MgSi(2)O(8) phase was observed, and the Eu(2+)-doped Sr(3)MgSi(2)O(8) phase dominated the only broad emission band, which had a central wavelength of 457 nm (blue light). The emission peaks at this wavelength were attributed to the 4f(6)5d(1)–4f(7) transition at the Sr(2+)(I) site, where Sr(2+) was substituted by Eu(2+). The average decay time of the synthesized phosphors was calculated to be 1.197 ms. The aforementioned results indicate that [Sr(0.99)Eu(0.01)](3)MgSi(2)O(8) can be used as a blue-emitting phosphor in ultraviolet-excited white light-emitting diodes.