Synthesis and Luminescence Properties of Eu-Doped SrMgSiO Blue Light-Emitting Phosphor for Application in Near-Ultraviolet Excitable White Light-Emitting Diodes.

In this study, [SrEu]MgSiO 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-SrSiO, SrMgSiO, and SrMgSiO phases coexisted in the [SrEu]MgSiO phosphors, which were synthesized at low temperatures. The particles of these phosphors had many fine hairs on their surface and resembled , which is a coral species. Transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the fine hairs contained the SrSiO and SrMgSiO phases. However, when the [SrEu]MgSiO phosphors were sintered at 1400 °C, the SrMgSiO phase was observed, and the Eu-doped SrMgSiO 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 4f5d-4f transition at the Sr(I) site, where Sr was substituted by Eu. The average decay time of the synthesized phosphors was calculated to be 1.197 ms. The aforementioned results indicate that [SrEu]MgSiO can be used as a blue-emitting phosphor in ultraviolet-excited white light-emitting diodes.