稀土(Tb,Gd)掺杂多孔硅的光致发光性能研究

The photoluminescence characterization of rare earths (Tb, Gd) embedded into porous silicon

用电化学方法对多孔硅薄膜进行了稀土 (Tb ,Gd)离子的化学掺杂 .利用荧光分光光度计测试了样品的光致发光特性 .用扫描电子显微镜研究了薄膜的表面形貌 .用卢瑟福背散射谱分析了稀土离子在多孔硅薄膜中的分布情况 .结果表明 ,Tb的掺入显著增强了多孔硅的发光强度 ,并且发光峰位出现蓝移 .这是由于Tb3+ 的 4f能级5D4 —7F3,5D4 —7F2 和5D4 —7F0 的跃迁发光引起的 .而在掺入Gd情况下 ,则观察到蓝光发射 .初步分析了稀土掺杂多孔硅的发光机理 .

Rare earth (Tb, Gd) ions were embedded into porous silicon films by electrochemical method. Fluorescence photospectrometer and scanning electron microscope were employed to characterize the photoluminescence and surface morphology of samples. The distribution of rare earth ions embedded into porous silicon films was observed by Rutherford backscattering spectrometry. The luminescence intensity of porous silicon after doping is greatly increased. Blue shift of luminescence peak was observed also. It is attributed to the transition luminescence of transitions between 4f energy levels of Tb3+ such as D-5(4)-F-7(3), D-5(4)-F-7(2) and D-5(4)-7F(0). Intense blue luminescence was observed after doping with Gd. The luminescence mechanism of porous silicon doped with rare earths was discussed also.