Sr2ScAlO5：Eu^2＋, a red oxide phosphor with a perovskite-type structure, has been synthesized through a solid-state reaction and its luminescence properties have been investigated. An absorption band centering at 450 nm is observed from the diffuse reflection spectra and the excitation spectra, indicating that the phosphor can match perfectly with the blue light of InGaN light-emitting diodes. A broad red emission band at 620 nm is found from the emission spectra, originating from the 4f^65d-4f^7 transition of the Eu^2＋ ions. The best doping content of Eu in this material is about 5%. S Sr2ScAlO5：Eu^2＋ is a highly promising red phosphor for use in white light-emitting diodes.
Oxonitridosilicate phosphors with compositions of Y 1-xCexSiO2N （x=0-0. 1） were synthesized by a new synthetic route based on a solid state reaction among YSi, CeSi, SiO2 and Y203 compounds at high temperature and high pressure. The photohtminescence properties dependent on Ce concentration and temperature were investigated. Concentration quenching occurred when the doped Ce3＋ concentration was more than 3 tool.%. The emission spectra showed red shifts from 430 to 447 nm with the increased Ce concentration from 0.5 mol.% to 10 mol.%. The quenching temperature was estimated as ~380 K. The chromaticity coordinates of the excitation and emission spectra were stable against the temperature. This study showed these YSiO2N：Ce3＋ phosphors the potential applications in the three-RGB phosphor-converted white LEDs.
Divalent europium activated tristrontium dialuminum hexaoxide phosphor, （Sr1-xEux）3Al2O6, was obtained by solid state reaction. Crystal structure and luminescence properties of synthesized （Sr1-xEux）3Al2O6 were investigated. The major excitation band of （Sr1-xEnx）3Al2O6 located in blue light region, the photoluminescence spectrum showed red light emission peaked at 618 nm which could be attributed to the d-f transition of the Eu^2＋. The influence of Ca^2＋ substitution for Sr^2＋ on structural and luminescence properties of Eu^2＋ doped Sr3Al2O6 was also studied. The photoluminescence peak position of （Sr1-yCay）2.94Euo.06Al2O6 varied from 618 to 655 um with increasing y value. The reason for redshift in the emission band of （Sr1-yCay）2.94Euo.06Al2O6 phosphor was also discussed.
Nitrogen-rich Ca-α-sialon： Eu2＋ phosphors with saturated calcium solubility are synthesized through a solid- state reaction （SSR） at 2173 K with stable alloy and nitride as the starting materials. The Ca1.83-1.sxSi8.34 A13.66 Ox N16-x： xEu phosphors have intensive orange emissions, whose peaks are located at approximately 585 600 nm, and the emission wavelengths tend to shift toward the red region when the Eu concentrations increase from 0.5% to 18% （mole percentage）. When the Eu concentration is equal to 9%, the phosphors suffer from concentration quenching. The low-temperature photoluminescence properties indicate that Cal.aa-l.5xSi8.34Ala.66OzN16-x： xEu phosphors show ex- cellent thermal quenching. The crystal structures of Cal.83-1.5xSis.34A13.660xN16-x： xEu are also investigated, and are found to have nitrogen-rich compositions with saturated calcium cations at the interstitial sites of the α-sialons. In addition, tile influencing factors of α-sialons with different compositions on the crystal lattice are discussed in detail.
