Sr_3Y(PO_4)_3∶Sm^(3+)荧光粉的制备及发光特性

Preparation and Luminescence Properties of Sr_3Y(PO_4)_3∶Sm^(3+) Phosphor

采用高温固相法合成Sr3Y1--x(PO4)3∶xSm3+发光材料。X射线衍射表明,1 400℃高温烧制的Sr3Y(PO4)3荧光粉为纯相晶体结构。荧光粉的主激发峰为343、360、373、400、436和468nm;主发射峰为550~575nm(4 G5/2→6 H5/2)、580~620nm(4 G5/2→6 H7/2)和630~660nm(4 G5/2→6 H9/2)。荧光粉在599nm附近有很强的发射,呈现良好的红橙光,符合广泛应用的UV-LED芯片。研究了不同Sm3+掺杂量对样品发射谱的影响,发光强度随着Sm3+掺杂量的增大而增强。当掺杂量x=0.04时,发光强度最强。继续增大Sm3+掺杂量,样品的发光强度反而减弱,即出现浓度猝灭现象。根据Dexter理论,猝灭机理为离子之间的能量转移作用。

St3 Yl-x （PO4 ）3＋ xSm3＋ phosphors were synthesized via high temperature solid state reaction. The analysis by X-ray diffraction indicates that the phosphors synthesized at 1400℃ are a pure phase of Sr3Y（PO4 ）3. The main excitation peaks are located at 343, 360, 373, 400, 436 and 468 nm, respectively. The main emission peaks are located at 550-575 nm （4G5/2→6 Hs/2 ）, 580-620 nm （4 G5/2→6 H7/2 ）, and 630-660 nm （4 G5/2→6 Ho/2 ）, respectively. The phosphors exhibit a red perform- ance at 599 nm, which are appropriate to the widely-applied UV-LED. The effect of the doping amount of Sins＋ activator ion on the luminescence properties of the sample was investigated. The luminescent intensity increases with increasing the doping a- mount of Sm3＋. The luminescent intensity has the optima[ value when x=0.04. When the doping amount of Sm3＋ further in- creases, however, the luminescence intensity decreases, and the concentration quenching phenomenon appears. According to the Dexter theory, the quenching mechanism is based on the energy transfer among the nearest-neighbor ions.