真空退火对AAO模板上Ag纳米颗粒膜的结构和光学性质的影响

Effect of Vacuum Annealing on Structure and Optical Properties of Ag Nanoparticle Films Deposited on AAO Templates

采用蒸发镀膜方法,在孔径约为200 nm的多孔阳极氧化铝(AAO)模板上室温沉积名义厚度为300 nm的银薄膜样品,研究真空退火对AAO模板上Ag纳米颗粒膜的结构和光学性质的影响。微观结构利用X射线衍射仪和扫描电镜观测,光学性质采用分光光度计检测。结果表明,(111)取向的银衍射峰强度随退火温度的升高逐渐增强,当退火温度为250℃时达到最大值;银纳米颗粒平均直经随退火温度的升高呈现先缓慢增大,后迅速增大,再减小的态势,当退火温度为250℃时达到最大值140 nm,比制备态大47 nm;薄膜经真空退火后,漫反射率普遍得到提高,在可见光区域,当退火温度为200℃时,漫反射率达到最大,其值为80%,大约为制备态的3倍左右。

Ag nanoparticles films with normal thickness of 300 nm were deposited on anodic aluminum oxide （AAO） templates （200 nm pore diameter） by thermal evaporation technique. The effects of vacuum annealing on structure and optical and properties were investigated. The microstructure was studied by X-ray diffraction and scanning electron microscopy. Optical properties were measured by spectrophotometer . The results showed that the intensity of diffraction peak （111） Ag enhances with the increases of annealed temperature. The intensity reached the maximum at 250℃. The average diameter of Ag nanoparticle first increased slowly, then increased sharply and last decreased. As the annealed temperature reach 250℃, the maximum of average diameter was about 140 nm, and 57 nm bigger than that of the as-deposited sample. The diffuse reflectance of the film generally increased after vacuum annealing. In the visible spectral region, the diffuse reflectance reach the maximum （80%） when the annealed temperature was 200℃, which was about there times of that of the as-deposited sample.