玻璃中银粒子对稀土离子发光影响的研究

Effect of Silver Particles on Spectroscopic Properties of Rare Earth in Glasses

在玻璃制备过程中加入硝酸银,然后通过高温退火得到包含银纳米粒子的Er3+掺杂锗酸盐玻璃和Eu3+掺杂硼酸盐玻璃样品。根据Mie-Drude理论拟合了这些玻璃样品中银纳米粒子等离子体振荡吸收谱,得到了退火时间与银粒子粒径的关系。用488 nm Ar+激光器激发不同退火时间的这些玻璃样品,分别监测Er3+的4S3/2-4I15/2和Eu3+的5D0-7F2的发射,发现包含银纳米粒子的玻璃样品较不包含银纳米粒子的玻璃样品,Er3+和Eu3+的发射分别增强3.6和1.25倍。通过分析玻璃样品的吸收谱和发射谱,排出了表面等离子振荡引起稀土离子发射增强的可能性。对Er3+掺杂的玻璃样品进行Judd-Ofelt理论分析,发现随着退火时间增加J-O强度参数减小,Er3+的4S3/2能级的辐射跃迁几率保持增加,表明引入银纳米粒子引起稀土离子周围晶体场发生变化是稀土离子发光增强的一个原因。

Er^3＋ doped germanium glasses and Eu^3＋ doped borate glasses containing silver nanoparticles were obtained by introducing AgNO3 at 450℃ annealing. The relation between silver nanoparticle sizes and the annealing times was determined by fitting the absorption spectra of silver nanoparticle using surface plasma resonance. The intensity of ^4S3/2 - ^4I15/2 transi tion of Er^3＋ ions and ^5D0 -^7F2 transition of Eu^3＋ ions under 488 nm Ar^＋ laser excitation as the function of annealing times was investigated. The result showedthat the emission intensity of rare earth ions were enhanced by doping silver nanoparticle into the glasses. The possibility that the surface plasma resonance of silver nanocrystals led to the enhanced emission intensity of rare earth ions by and absorption spectra of analyzing the fluorescence glasses were excluded. The Judd-Ofelt analysis was used to the absorption spectra of glasses samples and the changed host structure due to silver nanoparticle was affirmed as one reason that led to enhanced emission intensity of rare earth ions.