稀土离子(Eu3+,Tb3+,Ce3+)掺杂ZnAl2O4/SiO2微晶玻璃的制备与发光性能(英文)

Preparation and Luminescence Properties of ZnAl_2O_4/SiO_2∶RE^(3+)( RE = Eu,Tb,Ce)Glass Ceramics by Sol-gel Method

采用凝胶法分别制备出4.5ZnO-5.5Al2O3-90SiO2(ZAS)以及ZAS∶RE3+(RE=Eu,Tb,Ce)透明微晶玻璃。利用X射线衍射仪(XRD)、透射电子显微镜(TEM)和荧光光谱仪(PL)等测试手段,研究了稀土离子掺杂浓度对ZAS微晶玻璃的结构和发光性能的影响。XRD结果表明,ZAS∶RE3+(RE=Eu,Tb,Ce)微晶玻璃包含ZnAl2O4晶相和SiO2非晶相,ZnAl2O4平均晶粒尺寸约为30 nm,稀土离子的掺杂没有显著改变原来的ZnAl2O4晶体结构。TEM结果表明,900℃时ZnAl2O4从ZAS体系中析出。PL光谱显示,Eu3+存在5D0→7F2跃迁,ZAS∶Eu3+在611 nm处发出强烈的红色光;由于Tb3+的5D4→7F5跃迁,ZAS∶Tb3+在541 nm处发出明亮的绿色光;ZAS∶Ce3+在381 nm处显示了蓝光发射,对应于Ce3+的5d→4f轨道跃迁。ZAS∶RE3+(RE=Eu,Tb,Ce)的PL发射光谱存在着浓度猝灭现象,Eu3+、Tb3+和Ce3+的最佳单掺杂摩尔分数分别为20%、20%和3%。CIE色度图表明,ZAS∶RE3+(RE=Eu,Tb,Ce)的色坐标分别位于红光、绿光和蓝光区域。实验结果表明,ZAS∶RE3+(RE=Eu,Tb,Ce)微晶玻璃是一种良好的可用于全色显示的白光LED材料。

Transparent bulk glass ceramics of 4. 5ZnO-5. 5Al2O3-90 SiO 2( ZAS) and single doped ZAS ∶ RE3 +( RE = Eu,Tb,Ce) were synthesized by sol-gel method. X-ray diffraction( XRD),transmission electron microscopy( TEM) and photoluminescence( PL) spectra were employed to study the influence of doping rare-earth ions concentration on the structure and luminescence properties of ZAS glass-ceramics. XRD results show that ZAS∶ RE3 +( RE =Eu,Tb,Ce) glass ceramics heat-treated at 900 ℃ consist of ZnA l2O4 phase with average grain size of 30 nm and amorphous SiO 2. TEM results show that ZnA l2O4 were precipitated from ZAS system when heat-treated at 900 ℃,and doping ions have not changed the original structure. PL spectra indicate that ZAS ∶ Eu3 +emits intense 611 nm red light originating from5D0→7F2transition of Eu3 +ions,ZAS ∶ Tb3 +shows 541 nm green emission attributed to5D4→7F5transition of Tb3 +ions,and ZAS∶ Ce3 +gives 381 nm blue light corresponding to the 5d to 4f transition of Ce3 +ions. Furthermore,the concentration quenching phenomena are observed while the single doping mole fraction of Eu3 +,Tb3 +and Ce3 +was 20%,20% and 3%,respectively. The excellent Commission International de I'Eclairage( CIE) chromaticity coordinates of ZAS∶ RE3 +( RE = Eu,Tb,Ce) glass-ceramics indicate that they are good candidates for the application of white LEDs.