采用高温固相法制备了荧光粉Sr1.96-xEu0.04SiO4∶xLa3+(x=0、0.01、0.02、0.03、0.04、0.05)和Sr1.94+yEu0.04La0.02SiO4∶ySr2+(y=0、0.05、0.10、0.20、0.30).使用 X 射线粉末衍射仪、荧光分光光度计表征了荧光粉的物质结构和发光性质.结果表明:荧光粉的XRD均与Sr2SiO4标准卡片PDF 39-1256对应,没有杂质相产生.荧光粉Sr1.96Eu0.04SiO4中掺入La3+能增强其发光强度,且发射峰的位置不变.当La3+掺杂量为2%(摩尔分数)时,荧光粉Sr1.94Eu0.04La0.02SiO4的发光强度最强.在Sr1.94Eu0.04La0.02SiO4中掺入一系列过量浓度Sr2+,能增强其发光强度,且不改变发射峰的位置和形状.当Sr2+过量10%时,荧光粉的发光强度最强.荧光粉的宽带发射光谱可以拟合为2个独立的发射峰,对应Eu2+的4f65d1→4f7跃迁,2个发射峰的强度随着通气量的增大有规律变化,使得荧光粉的发光颜色从绿光区过渡到黄光区.
Effect of co-doped La3+and excessive concentration Sr2+on the luminescence properties of Sr1.96Eu0.04SiO4
Sr1.96-xEu0.04SiO4∶xLa3+(x=0,0.01,0.02,0.03,0.04,0.05)and Sr1.94+yEu0.04La0.02SiO4∶ySr2+(y=0,0.05,0.10,0.20,0.30)were synthesized by high-temperature solid-state method.The struc-ture and luminescence properties of the phosphors were characterized by X-ray powder diffractometer and fluorescence spectrophotometer.The results showed that the XRD of the phosphors are consistent with the Sr2SiO4 standard card PDF 39-1256,and no impurity phase is produced.The luminescence intensity of phosphors Sr1.96Eu0.04SiO4 is enhanced by doped La3+,and the position of emission peak remain un-changed.The phosphors show the strongest luminescence intensity when the doped concentration of La3+is 2%(molar fraction).The luminescence intensity of Sr1.94Eu0.04La0.02SiO4 can be further enhanced by doped series of excessive concentrations of Sr2+without changed the position and shape of the emission peak.When Sr2+is excessive 10%,the luminescence intensity of the phosphors is the strongest.The broadband emission spectrum of the phosphors can be fitted as two independent emission peaks,which correspond to Eu2+4f65d1→4f7 transition.The intensity of two emission peaks changes regularly with increas-ing ventilation volume,which give rise to the luminescence color of phosphors changes from green to yellow.