紫外激发Sr1-x-yMgP2O7:xCe3+,yTb3+荧光粉的发光特性及能量传递

采用高温固相法合成了Sr1-x-yMgP2O7:xCe3+,yTb3+荧光粉.研究了荧光粉的晶体结构、发光特性、荧光寿命、能量传递机理和荧光粉的热稳定性.研究结果表明:在SrMgP2O7基质中,Ce3+的发射峰值为398nm,Tb3+的主发射峰值为545nm,它们分别属于5d-4f跃迁和5D4→7F5跃迁.Ce3+和Tb3+共掺时,Ce3+和Tb3+通过电偶极子-电偶极子相互作用发生能量传递,能量传递的临界距离为0.614nm.通过计算得到单掺杂Ce3+、Tb3+时热猝灭过程的激活能分别为0.122和0.111eV,Tb3+离子的发光热稳定性比Ce3+离子的好.

Optical Properties and Energy Transfer of Sr1-x-yMgP2O7 :xCe3+,yTb3+ Phosphor under Ultraviolet Excitation

Sr 1-x-y MgP 2 O 7 :xCe 3+ ,yTb 3+ phosphors were successfully synthesized by a solid-state reaction method.The crystal structure,optical properties,luminescence decay,energy transfer,and thermal stability properties were investigated.The results showed that the emission peaks of the co-doped Ce 3+ and Tb 3+ ions in the SrMgP 2 O 7 host were located at 398 and 545 nm,respectively.The peaks were attributed to 5d-4f and 5 D 4 → 7 F 5 transitions,respectively.An efficient energy transfer from the Ce 3+ to Tb 3+ ions by means of dipole-dipole interactions was observed and the critical distance of the energy transfer was 0.614 nm. The thermal activation energies of 0.122 and 0.111 eV for SrMgP 2 O 7 :Ce 3+ and SrMgP 2 O 7 :Tb 3+ ,respectively, were obtained from the temperature dependent(313-453 K)luminescence intensities.The Tb 3+ ion was found to be superior to Ce 3+ ion in the thermal stability of light-emitting diodes.