Sm3+掺杂含银硼酸钙玻璃的制备及光谱性质

采用熔融淬火技术制备了掺杂Sm3+的组分为30CaO-60B2O3-10AgNO3-xSm2O3(x=0.05,0.25,0.5,1,3,5(摩尔分数))硼酸钙玻璃。采用吸收光谱及荧光激发和发射光谱对样品的光谱性质进行了研究。样品吸收光谱测量表明样品中存在Ag聚集体和金属Ag纳米颗粒,Sm3+掺杂浓度的改变对金属Ag纳米颗粒的浓度产生影响,而对Ag聚集体的吸收影响较弱。样品的荧光光谱测量发现该系列样品均表现为宽带吸收和宽带发射特性,同时观察到了在405 nm激发下Sm3+的掺杂对Ag聚集体的发光产生了猝灭作用,但可改善样品发射光谱的成分,提高红色发射比例。色度学研究表明样品的色坐标随Sm3+掺杂浓度及激发波长变化。这些研究结果表明该系列样品是一种潜在的白光LED用荧光体材料。     

On the fluorescence enhancement mechanism of Er3+ in germanate glass containing silver particles

The spectral properties of trivalent erbium ions(Er3+) are systematically studied in a melt-quenched germanate glass(60 GeO2-20PbO-10BaO-10K2O-0.1Ag2O) containing silver(Ag) particles.Thermal treatment of the material leads to the precipitation of Ag particles as observed by transmission electron microscopy and confirmed by absorption spectrum for the obvious surface plasmon resonance peak of Ag particles.The fluorescence from Er3+ in the 10-min-annealed sample with Ag particles is found to be 4.2 times enhanced compared with the unannealed sample excited by 488-nm Ar+ laser.A comparison is made between a spectral study performed on the unannealed Er3+-doped sample and the one annealed for 20 min.The data of absorption cross section and Judd-Ofelt intensity parameters show the agreement between the two samples no matter whether there are Ag particles,indicating that the introduction of Ag particles by post-heat treatment has no effect on the crystal field environment of Er3+ ions.The fluorescence enhancement is attributed to the surface plasmon oscillations of Ag particles in germanate glass.