稀土掺杂的(K,Sr)Cl·SiO_2复合凝胶的荧光性能

Luminescence Properties of (K,Sr)Cl·SiO_2 Composite Gels Doped with RE Ions

采用sol gel法制备了单掺铕及共掺铕、铈的(K,Sr)Cl·SiO2复合凝胶,研究了复合凝胶的荧光性能。根据荧光测试结果,复合凝胶中,Eu3+在没有还原剂的作用下,可以与基质作用形成还原态的Eu2+,复合凝胶表现出相应的Eu2+荧光性能;研究认为,Ce3+,Eu3+共掺杂时,复合凝胶激发光谱与发射光谱峰位基本不变,但强度有所不同。330nm处的激发光谱明显增强,且发射光谱随Ce3+的掺杂量增加而增强。当Ce3+掺杂浓度为3.0%(原子分数)时,复合凝胶具有最大的荧光发射强度,表明Ce3+具有很好的敏化作用。在Ce3+,Eu3+共掺杂复合凝胶体系中,复合凝胶荧光强度增大的原因既可能是电子转移过程,也可能是Ce3+→Eu2+的能量传递过程所致。

Eu^(3+)/Ce^(3+)-doped and Eu^(3+), Ce^(3+)-codoped composite silica gels were prepared by sol-gel method. The luminescence spectra of composite gels were examined. The conversion of Eu^(3+)Eu^(2+) ions was found in composite gels and energy transfer between Ce^(3+) and Eu^(2+) ions without reduction agent when annealing gels at 600 ℃. The energy transfer is proposed based on the electric multipole-multipole interaction in this system, at the same time the electron transfer of Ce^(3+)→Eu^(3+) is found in the Eu^(3+), Ce^(3+)-codoped gels.