KLa(MoO4)2:Sm3+, Eu3+荧光粉中能量传递研究

Energy Transfer in KLa(MoO4)2:Sm3+,Eu3+ Phosphors

摘要:

采用高温固相法合成了KLa0.7-x(MoO4)2:0.3Eu3+, xSm3+系列红色发射荧光粉, 利用XRD对样品的晶体结构进行了分析，发现所得到的样品均为纯相。采用荧光光谱手段对样品的发光性质及能量传递进行了研究。在低Sm3+掺杂浓度时采用277及394 nm激发样品，其发光强度几乎不随掺杂浓度变化，若利用404 nm激发样品发光随Sm3+浓度有明显增强；当Sm3+掺杂浓度较高时，利用277, 394及404 nm激发观察到了Sm3+对Eu3+发光产生了猝灭作用。采用电多极相互作用模型及交换相互作用模型对Sm3+到Eu3+的能量传递过程的物理本质进行了探讨，确定了在低掺杂浓度下Sm3+到Eu3+的能量传递是基于交换相互作用的结果。通过对Eu3+的5D0能级荧光动力学过程的分析进一步证实了在低Sm3+掺杂浓度时Sm3+充当能量传递供体，而高掺杂浓度时Sm3+对Eu3+发光产生了猝灭作用

Abstract:

Red emitting phosphors KLa0.7-x(MoO4)2:0.3Eu3+, xSm3+ were synthesized by a solid-state reaction. Analysis on XRD patterns confirms that all the obtained phosphors exhibit pure phase. The luminescence properties and energy transfer behavior were studied via fluorescence spectral measurements. When the Sm3+ concentration is lower, the emission intensities under 277 and 394 nm excitations almost do not change with Sm3+ concentration, but effective luminescent enhancement is discovered in the samples with lower Sm3+ concentrations by 404 nm. However, Sm3+ doping quenches the emission of Eu3+ when the Sm3+ doping concentration is higher. The electric multipole interaction and exchange interaction models were adopted to explore physical nature for the energy transfer mechanism, and the exchange interaction between Sm3+ and Eu3+ is confirmed to be the right mechanism. It is found from the fluorescence decays that Sm3+ is the donor when the Sm3+ concentration is lower, but the Sm3+ doping quenches the luminescence of Eu3+ when the Sm3+ concentration is higher