银纳米颗粒的制备及其光散射特性

Preparation of Ag nanoparticles and its property of light scattering

采用热蒸发的方法在玻璃衬底上蒸镀厚度为32 nm的银薄膜,在氮气中退火形成银纳米颗粒。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)研究了不同退火温度对银纳米颗粒的结晶特性和形貌的影响,并用光散射仪研究了其光散射特性。结果表明,随着退火温度的升高,银薄膜从连续状逐渐变为分离状。在退火温度为400℃时形成完全分离的半球颗粒,颗粒大小集中在360 nm左右,平均高度约为250 nm,在散射角大于25°时,银纳米颗粒对光的散射较强。

The Ag films with 32 nm thickness were deposited on glass substrates by thermal evaporation, followed by annealing in nitrogen to form Ag nanoparticles. The Ag nanoparticles were studied by X-ray diffraction （XRD）, scanning electron microscope （SEM）, atomic force microscopy （AFM）, and the light scattering spectrometer. It is found that continuous Ag films gradually become isolated Ag nanoparticles with increase of annealing temperature. Completely isolated hemisphere nanoparticles formed at annealing temperature of 400 ℃, the size distribution of Ag nanoparticles is concentrated at about 360 nm, with an average height of about 250 nm, and light scattering of Ag nanoparticles is stronger when scattering angle greater than 25° .