纳米锗颗粒镶嵌薄膜的吸收光谱研究

用离子束溅射技术和热处理方法，制备出颗粒尺寸和镶嵌密度均可控制的高质量Ｇｅ－ＳｉＯ２纳米颗粒镶嵌薄膜，在室温下测量了不同粒度纳米锗颗粒镶嵌薄膜样品的吸收光谱，观测到在可见光区有较强的光吸收和吸收带边蓝移。研究表明：镶嵌在经缘介质薄膜中的纳米锗颗粒的能量带是量子化的，随着纳米锗粒子平均尺寸的减小，其吸收带隙增加，吸收带边蓝移的程序相应增大。

Optical Absorption Characteristics of Nanocrystalline Ge SiO 2 Thin Films

Nanocrystalline Ge SiO 2 thin films were successfully prepared by the ion beam sputtering technique followed by annealing. Optical absorption spectra of the Ge crystallites of size 3 to 9 nm in diameter, on the average, have been studied. In comparison with that of the bulk Ge crystals, the nanocrystalline Ge show a blue shift of energy and the optical band gap increases with decreasing of the particle size of the nanocrystallites. The effective mass approximation model based on the quantum size effect is suggested to discuss the observed optical experimental details with satisfaction but only qualitatively. An effect of the dielectric confinement of the Ge nanocrystallites on the optical absorption spectra was observed.