LiCaBO_3:Sm~(3+)材料的发光特性

以CaCO3(99.9%)、Li2CO3(99.9%)、Na2CO3(99.9%)K2CO3(99.9%)、H3BO3(99.9%)、Sm2O3(99.9%)为原料,按所设计的化学计量比称取以上原料,在玛瑙研钵中混合均匀并充分研磨,装入刚玉坩埚,采用固相法制备LiCaBO3:Sm3+材料;通过美国XRD6000型X射线衍射仪和日本岛津RF-540荧光分光光度计对材料的性能进行表征,所有测量均在室温条件下进行。LiCaBO3:Sm3+材料的发射光谱由三个橙红色发射峰组成,主峰位于561,602,651nm,分别对应Sm3+的4G5/2→6H5/2、4G5/2→6H7/2和4G5/2→6H9/2跃迁;监测602nm发射峰,得到其激发光谱由320～420nm的宽激发带组成。由激发和发射光谱看出,LiCaBO3:Sm3+能够有效地被紫外LED芯片激发,发射红色光。研究了Sm3+浓度(x)对LiCa1-xBO3:xSm3+材料发射强度的影响,结果表明:随Sm3+浓度的增大,发射强度先增强后减弱,Sm3+掺杂摩尔分数为3%时,发射强度最大,依据Dexter理论,计算得出其浓度猝灭机理为电偶极-偶极相互作用。掺入电荷补偿剂Li+、Na+和K+均提高了LiCaBO3:Sm3+材料的发射强度。

Luminescence Characteristics of LiCaBO3 : Sm3+ Phosphor

LiCaBO_3:Sm~(3+) phosphor was synthesized by solid state reaction and its luminescent properties were studied. The emission spectrum consists of three major orange-red emission bands at 561, 602 and 651 nm, which correspond to the ~4G_(5/2)→~6H_(5/2), ~4G_(5/2)→~6H_(7/2) and ~4G_(5/2)→~6H_(9/2) typical transitions of Sm~(3+) , respectively. The excitation spectrum for the strongest emission (602 nm) extends in 320~420 nm, which indicated that this phosphor can be effectively excited by near-ultraviolet light-emitting diodes. The influences of Sm~(3+) concentration (x) on the emission intensity of LiCa_(1-x)BO_3:xSm~(3+) phosphors were also investigated. The results showed that the intensity increases with increasing Sm~(3+) concentration, then decreases, and reaches the maximal value at 3% Sm~(3+). And the concentration self-quenching mechanism is the d-d interaction according to Dexter theory. The emission intensity of LiCaBO_3:Sm~(3+) can be enhanced by doping charge compensator Li~+ , Na~+ , K~+.