中文摘要：

采用磁控溅射法在Si衬底上制备了SiO2介质膜，系统地研究了SiO2膜引入对Ag纳米颗粒的表面覆盖率、形貌、形成机理和光学性质的影响．研究发现引入SiO2介质膜后，Ag纳米颗粒的表面覆盖率显著增加，平均粒径明显降低．基于现有的Ag纳米颗粒形成机理，提出了粗糙表面Ag膜断裂模型以解释其形貌发生变化的原因．紫外一可见光分光光度计测试表明，引入Si02膜并优化其厚度，可使Ag纳米颗粒的偶极消光峰最大红移86nm，但消光峰强度明显下降．数值模拟计算表明，引入SiO2膜的Ag纳米颗粒所能散射的光子数量最小减少2×10^18个．因此，在Si衬底上沉积Si02膜，不利于Ag纳米颗粒陷光性能的提高．

英文摘要：

Introducing silica dielectric film deposited by magnetron sputtering on silicon suhstrates, thedependence of the surface coverage ratio, morphology, formation mechanism and optical properties forsilver nanoparticles on silica dielectric film was exploited. The results indicate that the surface coverageratios of silver nanoparticles increase but the mean diameters for silver nanoparticles decrease obviouslyafter introducing silica dielectric film. The reason of morphological evolution for silver nanoparticles wasexplained by an improved model for silver film rupture based on the formation mechanism of silvernanoparticles. A red shift of up to 86 nm of the dipole extinction peak of silver nanoparticles is realized byadjusting the thickness of the silica film but the peak intensity decrease greatly, as analyzed by anultraviolet-visible spectrophotometer. Numerical simulations of the optimized structures demonstrate thatthe number of scattered photons by the silver nanoparticles is decreased by as much as 2 × 10^18 afterinserting a silica layer. Therefore, it is undesirable to deposit silica layer on silicon substrate before silvernanoparticle formation for the light trapping performance of silver nanoparticles.