基于合作能量传递的Sm^(2+)离子上转换发光

Upconversion Luminescence of Sm^(2 +)Ions Based on Cooperative Energy Transfer

报道了Sm^(2+)离子的上转换发光。在实验上证明了变价镧系离子同样可以作为上转换材料的发光中心。在近红外光的激发下,复合Ba FCl_(0.5)Br_(0.5)∶1%Sm^(2+)-Ca F_2∶1%Yb^(3+)化合物发出红色上转换发光。上转换发射光谱中位于631,644,665,689,704,729 nm的特征发射分别来自于样品中Sm^(2+)的~5D_i(i=0,1)→~7F_j(j=0,1,2)特征跃迁。根据动力学分析及光子数拟合的结果,我们将二价Sm离子的上转换过程归因于合作能量传递,即:两个同时被激发的Yb^(3+)离子合作将能量传递给一个Sm^(2+)离子。

We report the observation of upconversion luminescence from Sm^2＋ ions,which demonstrate that changeable valence lanthanides can served as the ions for optical frequency transformation. Upon the excitation of 980 nm diode laser,the doped Sm^2＋ ions in the hybrid material of Ba FCl0. 5 Br0. 5∶ 1% Sm^2＋-Ca F2∶ 1% Yb^3＋emit red upconversion fluorescence peaked at 631,644,665,689,704,729 nm from the-5 D0,1→7 F0,1,2 transitions,respectively. By transient dynamic analysis,we attribute the excitation of Sm^2＋ions to the cooperation energy transfer process： two excited Yb^3＋ions simultaneously transfer their energy to one Sm^2＋ion.