掺Tb-硅基发光材料制备过程中结构及发光性能

采用溶胶 凝胶技术,制备了不同退火温度下掺Tb3＋的SiO2玻璃,掺Tb3＋的凝胶玻璃在448,544,585,620 nm显示Tb3＋的5D4 7FJ(J=3,4,5,6)的特征发光光谱.通过不同退火温度下样品的激发光谱、发射光谱、红外光谱、远红外光谱及差热 热重谱研究了掺Tb3＋的硅基材料由凝胶向玻璃转变过程中的结构变化及对Tb3＋发光性能的影响.结果显示,在50～100 ℃退火温度下,凝胶大部分吸附水分子被除去,在150～500 ℃退火温度区,是凝胶向玻璃转变的主要结构变化区,并且其发光强度也明显增加,到800 ℃时趋于稳定.这些现象得出一个结论,Tb3＋的发光跃迁被O－H基强烈猝灭而随退火温度的升高而加强.

Structure and Luminescence Properties of Tb-doped Si-based Light-emitting Materials in Preparation Process

Tb3＋ ions were incorporated in SiO2 glasses using a sol gel process with appropriate heat treatment.Glasses incorporated with Tb3＋ showed emission peaks at 488,544,585,and 620 nm,respectively,exhibiting,respectively,5D4—7FJ(J=3,4,5,6) transition of the Tb3＋ ions.The structural evolution during the transition from gel to glass of Tb3＋ doped SiO2 glasses and the effect on luminescence properties were studied by excitation spectra,emission spectra,IR,far IR and DTA TG at differential heat treatment conditions.The results show that most of absorbed water molecules in gel were removed during heat treatment at 50～100 ℃,conversion from gel to glasses was the main structural changes when gel was heat treated in the range 150～500 ℃,and the luminescence intensity increased remarkably also,becoming stable structure at 800 ℃.This observation leads to a conclusion that the radiation electronic transitions of Tb3＋ were quenched strongly by O－H group and were enhanced by temperature elevation.