白光LED用荧光粉Na3Ce(PO4)2∶Dy^3+ 的制备与发光性能

Preparation and luminescent properties of Na 3Ce(PO 4)2∶Dy^3+phosphor for white LED

采用高温固相法合成了Na3Ce1-x(PO4)2∶xDy^3+系列白色荧光粉。利用X射线粉末衍射、荧光光谱和荧光寿命技术对样品进行了表征。实验结果表明,在313nm紫外光激发下,Na3Ce(PO4)2:∶Dy^3+显示了3个发射带:363nm的宽带发射可归属为Ce3+离子的4f05d1→4f1跃迁;483nm和575nm的2个窄带分别来自于Dy^3+的4F9/2→6H15/2和4F9/2→6H13/2跃迁。Na3Ce1-x(PO4)2∶xDy^3+(x=0.005~0.12)系列样品的发射峰形状并未随掺杂剂浓度的变化而改变。其强度在Dy^3+摩尔浓度等于0.01时达到最大值,进一步增加Dy^3+浓度将导致浓度猝灭现象发生。样品的荧光寿命随着Dy^3+掺杂浓度的增大而逐渐减小,表明Dy^3+离子之间存在能量传递现象。Na3Ce(PO4)2∶Dy^3+荧光粉的色坐标为(0.3429,0.3183),位于白光区域,是潜在的白光LED用荧光粉材料。

A series of Na3Ce1-x(PO4)2∶xDy^3+ white phosphor was synthesized by high temperature solid state method in this work.X-ray powder diffraction,photoluminescence spectroscopy and luminescent lifetime was adopted to characterize these samples.Experimental results show that Na3Ce(PO4)2∶Dy^3+can exhibit three emission bands under the excitation of 313 nm including broad band at 363 nm corresponding to 4f 05d 1→4f 1 transitions of Ce 3+and narrow bands at 483 nm and 575 nm corresponding to 4F9/2→6H 15/2 and 4F 9/2→6H 13/2 transitions of Dy^3+,respectively.It is worthy noted that the emission peak shapes are independent to the dopant concentration.When the concentration of Dy^3+ reaches 0.01,the emission intensity of the phosphor gets to its maximum.If the concentration of Dy^3+ increases continually,concentration quenching will appear.The luminescent lifetime of samples decreases with the increase of Dy^3+ ion concentration,indicating energy transfer among Dy^3+ ions.The Commission Internationale de L Eclairage coordinates(CIE)of Na 3Ce(PO 4)2∶0.01Dy^3+ phosphor is(0.3429,0.3183),which is in the white light range,indicating the potential applications in white light LED display.