Au/SiO_2纳米多层薄膜的制备及其性质表征

Preparation and characterization of Au/SiO_2 nano-composite multilayer films

利用多靶磁控溅射技术制备了Au/SiO2纳米颗粒分散氧化物多层复合薄膜.研究了在保持Au单层颗粒膜沉积时间一定时薄膜厚度一定、变化SiO2的沉积时间及SiO2的沉积时间一定而改变薄膜厚度时,多层薄膜在薄膜厚度方向的微观结构对吸收光谱的影响.研究结果表明具有纳米层状结构的Au/SiO2多层薄膜在560nm波长附近有明显的表面等离子共振吸收峰,吸收峰的强度随Au颗粒的浓度增加而增强,在Au颗粒浓度相同的情况下,复合薄膜光学吸收强度随薄膜厚度的增加而增强.但当金属颗粒的浓度增加到一定程度时,金属颗粒相互接触,没有观察到纳米层状结构,薄膜不显示共振吸收峰特征.用修正后的M-G(Maxwell-Garnett)理论对吸收光谱进行了模拟,得到了与实验一致的结果.

Au/SiO2 nano-composite muhilayer thin films were prepared by magnetron plasma sputtering. The effect of microstructure on the absorption spectra of films of the same thickness but under different deposition conditions, and films deposited under the same conditions but having different thicknesses was investigated. The results show that the optical absorption peaks appeared at 560 nm for the Au/SiO2 nano-composite multilayer films, the intensity of the absorption peak increased with increasing Au content and thickness of films. No nano-multilayer structure and absorption peak was observed when Au particle connected together due to high Au content. The optical absorption spectra of Au/SiO2 multilayer thin films well agree with the theoretical optical absorption spectra calculated from modified Maxwell-Garnett effective medium theory.