纳米Y_2O_3:Eu^(3+)荧光强度降低的J-O理论分析

Analysis of the Fluorescence Intensity Decrease of Nanocrysalline Y_2O_3:Eu^(3+) Based on the J-O Theory

用均相沉淀法制备了纳米Y2O3:Eu3+样品。归纳了纳米Y2O3:Eu3+荧光强度降低的原因及提高途径。应用Judd-Ofelt理论从Y2O3:Eu3+的发射光谱编程计算了纳米与微米Y2O3:Eu3+的跃迁强度参数之比Ω′2/Ω2,比值均小于1,这表明纳米Y2O3:Eu3+颗粒的5D0→7F2电偶跃迁几率比微米材料小,5D0→7F2跃迁几率小则612nm的荧光强度低。因此纳米YO:Eu3+颗粒的荧光强度较微米材料低。

Different sizes of nanocrysalline Y2O3：Eu3＋ were prepared by the homogeneous precipitation method.The influence of the nano particle size on the its fluorescence intensity were studied.According to Judd-Ofelt（J-O） therory,the ratio of the transition intensity parameters Ω′ 2Ω 2 between the nanocrystalline Y2O3：Eu3＋ and the bulk material were calculated from the emitting spectra of Eu3＋ ions by computer programs.All the ratio less than one indicates that the 5D0→7F2 transition probability of the nanocrystalline Y2O3：Eu3＋is smaller than that of the bulk material.Low 5D0→7F2 transition probability causes light fluorescence intensity of 612nm.Thus the fluorescence intensity of nanocrysalline Y2O3：Eu3＋ is lower than that of bulk material.