B2O3对Yb3+掺杂磷酸盐玻璃结构和光学性能的影响

Influence of B2O3 on Structure and Optical Properties of Yb3+ Doped Phosphate Glasses

采用传统熔融淬冷法制备了掺镱硼磷酸盐玻璃,研究了B2O3的引入对该玻璃系统光学性能的影响。利用洛仑兹拟合吸收光谱和荧光光谱得到Yb^3+在硼磷酸盐玻璃中的能级分裂,计算了晶体场强参数和Yb^3+周边配位体结构的非对称性,结合玻璃的结构信息解释Yb^3+局域环境和荧光性能的变化。实验结果表明,B2O3的引入改变了Yb^3+晶体场强参数和周边配位体结构的非对称性,能有效增大Yb^3+的dStark能级分裂值。B2O3的引入能交联起磷酸盐长链,使玻璃由链状结构转变为三维网络结构,增强了玻璃的化学稳定性,改善了Yb^3+的发光环境。因此,硼磷酸盐玻璃有望作为高功率掺镱基质材料。

The Yb^3+ doped borophosphate glasses were prepared by the melt-quenching method. The effect of B2O3 on optical properties was investigated, and stark splitting of Yb^3+ was obtained by fitting the absorption and emission spectra. Based on fitting results, the crystal field strength parameter NJ and asymmetry of the surrounding ligand structure were calculated which was used to explain the change of luminescence properties and Yb^3+ local environment with the help of structure information. The results show that B2O3 is good for enlarging the Stark splitting of Yb^3+ and changing the local environment. Compared with the previous single PO4 ligand, the difference in bond length of [BO4]-Yb and [PO4]-Yb will increase the asymmetry of Yb^3+. In addition, the electronegativity of P is stronger than that of B, and the reciprocity between P and O in [PO4] is stronger than that of [BO4], so the interaction between [BO4] and Yb^3+ is stronger than that between [PO4] and Yb^3+. Therefore, when xB2O3>10% was applied, the degree of asymmetry and NJ increased, which enhanced the fluorescence intensity around Yb^3+. Besides, with the increase of B2O3 mole fraction, the introduced B2O3 all exist in the form of [BO4], and BPO4 structure units are formed by alternating connection with PO4. Therefore, B2O3 could connect phosphate long chains and glass network transfers from chain structure to three-dimensional space which contributes to enhance the chemical stability and improve the environment of Yb^3+. Borophosphate glass is expected to be a high power ytterbium-doped matrix material.