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(B1) 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 that 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 and 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.