Green emitting Eu^2＋ doped（CaxSr（1–x））6Si（25.6）Al（6.4）N（41.6）O（4.4） phosphors with x value ranging from 0 to 0.1 were synthesized by the solid state reaction method under nitrogen atmosphere.The X-ray di...Green emitting Eu^2＋ doped（CaxSr（1–x））6Si（25.6）Al（6.4）N（41.6）O（4.4） phosphors with x value ranging from 0 to 0.1 were synthesized by the solid state reaction method under nitrogen atmosphere.The X-ray diffraction（XRD）patterns of the phosphors with different Ca^2＋ concentrations indicated that pure sialon phases were obtained.Crystal structure of these sialon phases was estimated to be a commensurate composite network stacking by two different types of layers.Intense and tunable green emissions with a slight red shift from 515 to 520 nm were observed with varying Ca/Sr ratios.The emission intensity decreased gradually because of the increase of the crystal splitting effect.Thermal quenching properties of the phosphors with different Ca^2＋ saturation were also discussed.The thermal stability became worse as more Ca^2＋ ions substituted for Sr^2＋ ions according to a larger Stokes shift.The solid solution phosphors could be a promising candidate for white LEDs for their interesting photoluminescence properties when the thermal stability would be improved.展开更多
基金Project supported by the National Key Basic Research Program of China(2014CB643801)the National Natural Science Foundation of China(51102021,51302016)
文摘Green emitting Eu^2＋ doped（CaxSr（1–x））6Si（25.6）Al（6.4）N（41.6）O（4.4） phosphors with x value ranging from 0 to 0.1 were synthesized by the solid state reaction method under nitrogen atmosphere.The X-ray diffraction（XRD）patterns of the phosphors with different Ca^2＋ concentrations indicated that pure sialon phases were obtained.Crystal structure of these sialon phases was estimated to be a commensurate composite network stacking by two different types of layers.Intense and tunable green emissions with a slight red shift from 515 to 520 nm were observed with varying Ca/Sr ratios.The emission intensity decreased gradually because of the increase of the crystal splitting effect.Thermal quenching properties of the phosphors with different Ca^2＋ saturation were also discussed.The thermal stability became worse as more Ca^2＋ ions substituted for Sr^2＋ ions according to a larger Stokes shift.The solid solution phosphors could be a promising candidate for white LEDs for their interesting photoluminescence properties when the thermal stability would be improved.
