Ce~(3+)和Tb~(3+)掺杂的BaO-La_2O_3-B_2O_3-SiO_2玻璃的发光性质

采用传统熔体冷却技术制备Ce~(3+)和Tb~(3+)掺杂的BaO-La_2O~3-B_2O_3-SiO_2玻璃,并测试样品的吸收光谱和荧光光谱.实验结果表明:由于Ce~(3+)在5d-4f轨道之间的电子跃迁,基础玻璃掺Ce~(3+)后吸收截止边明显红移;掺Ce~(3+)的BaO-La_2O_3-B_2O_3-SiO_2玻璃的荧光发射光谱为峰值位于410 nm附近的宽带,对应于Ce~(3+)的5d-4f跃迁;由于SiO~2比B_2O_3的光碱度大,玻璃的荧光发射波长,体现出随硼硅比的降低而略有红移;还原性气氛有利十提高玻璃中Ce~(3+)的含量,从而增强发光强度;对Ce~(3+)和Tb~(3+)共掺玻璃,Ce~(3+)和Tb~(3+)在波长200-311 nm间有激发带重叠,因存在竞争吸收,导致以此区间波长激发时Tb~(3+)的发光有所减弱;Ce~(3+)和Tb~(3+)在311-444 nm间也有激发带(或激发带与发射带)部分重叠,因Ce~(3+)和Tb~(3+)之间存在的辐射和无辐射能量传递导致Ce~(3+)强烈敏化Tb~(3+)的发光.

Luminescent properties of Ce~(3+) and Tb~(3+) doped BaO-La_2O_3-B_2O_3-SiO_2 glasses

Ce~(3+) and Tb~(3+) doped BaO-La_2O_3-B_2O_3-SiO_2 glasses were prepared by conventional melt quenching technology. Absorption spectrum and fluorescence spectrum of samples were investigated. Due to 5d-4f electronic transition, absorbent border of Ce~(3+) doped BaO-La_2O_3-B_2O_3-SiO_2glasses shifts toward longer wavelength. Photoluminescence spectra of Ce~(3+) doped BaO-La_2O_3-B_2O_3-SiO_2 glasses show an obvious broad band with peak value of about 410 nm, which ascribes to 5d-4f electronic transition of Ce~(3+) ion. Emission wavelength increases with the reduce of the ratio of boron and silicon reduced in glasses, which can be explained with optical basicity of SiO_2 and B_2O_3. Luminescent intensity of glasses can be enhanced as Ce~(3+) concentration increases in deoxidization atmosphere. For Ce~(3+) and Tb~(3+) co-doped glass, luminescent intensity of Tb~(3+) decreases, which can be related to the competitive absorption between Ce~(3+) and Tb~(3+) when excitation wavelength locates at 200-311 nm. However, the luminescent sensitization of Tb~(3+) by Ce~(3+) was observed on the wavelength of 311-444 nm, which is explained with the radiation energy transfer and non-radiation energy transfer from Ce~(3+) to Tb~(3+).