白光LED用铕掺杂硼铋钙玻璃的结构与光学性能

采用熔融冷却法制备了铕掺杂的硼铋钙玻璃。研究了不同硼铋比（n_B/n_Bi）和钙离子浓度条件下的密度、摩尔体积、折射率等物理性质，分析了玻璃的结构、光学性质和热稳定性。实验结果表明，Eu³⁺较好的熔融于玻璃中，形成发光中心，在465 nm蓝光激发下，613 nm处有较为强烈的发射，光谱强度值随n_B/n_Bi变化不明显，但随CaO浓度升高而逐渐递减。玻璃结构总体呈现非晶态，对称性相对较低，结构致密程度和对称性均随n_B/n_Bi的降低而降低，随CaO浓度的升高而升高。玻璃结构主要组成为BO₃]三角体、BiO3]三角体，BO₄]四面体和BiO₆]八面体，不存在BO₃]组成的硼六元环。研究结果表明，此系列硼铋钙玻璃能有效匹配蓝光芯片发射红光，且具有熔点低、热稳定较好、折射率相对适宜的特点。

Structure Analysis and Optical Properties of Europium Doped Calcium Bismuth Borate Glasses for WLED

The Eu³⁺ doped calcium bismuth borate glasses were prepared by a rapid melt quenching technique. The general physical properties including density, molar volume,refractive index and so on were studied. Furthermore, the structure, optical properties and thermal stability of glasses with different n_B/n_Bi and CaO concentration were also investigated. The experimental results demonstrate that Eu³⁺ is melted homogeneously in glass samples and acts as a well activator. An intense emission peak at 613 nm appears in the emission spectra under 465 nm excitation. The excited and emitted spectra intensities have no obvious variation as n_B/n_Bi gradually decreasing, but which decrease with CaO concentration increasing. All glass samples present amorphous states and relative low symmetric structure. The tightness and symmetries of glass structure decrease totally as n_B/n_Bi decreasing, but increase as CaO concentration increasing. The BO₃], BO₄], BiO3] and BiO₆] units are identified in glass samples, however, six member rings consisting of BO₃] are not observed. The glass samples possess red light under matching blue light chip, and exhibit many virtues such as well thermal stability, low melting temperature and appropriate refractive index.