IR reflection spectra of monolayer films sandwiched between two high refractive index materials.
IR reflection spectra of monolayer films sandwiched between two high refractive index materials.
复制标题
夹在两种高折射率材料之间的单层薄膜的红外反射光谱。
作者：
T. Lummerstorfer;H. Hoffmann
吸附在高折射率基底上的单层膜，如金属或半导体，当它们与透明的高折射率环境介质接触时，产生强烈增强的红外反射光谱，并以高入射角用p偏振光探测。灵敏度的增加源于夹在两个高折射率材料之间的薄的低折射率层内的垂直电场的增强，并且结合仅垂直表面振动的基本上排他性的检测，引起信号强度增益高达2个数量级。实验光谱的有序单层膜的octaganetherglycol在金和十八烷基硅氧烷在硅上，在这个三明治配置产量之间的增强因子15（硅）和30（金）相比，传统的掠入射外反射光谱，并由一个共同的，简单的表面选择规则，它允许立即定量评估和比较不同基板上的膜结构。
Monolayer films adsorbed on substrates with high refractive indices such as metals or semiconductors yield strongly enhanced infrared reflection spectra when they are contacted with a transparent, high refractive index ambient medium and are probed with p-polarized light at high incidence angles. The sensitivity increase arises from the enhancement of the perpendicular electric field within a thin, low refractive index layer sandwiched between two high refractive index materials and gives rise to signal intensity gains up to 2 orders of magnitude in combination with an essentially exclusive detection of only perpendicular surface vibrations. Experimental spectra of ordered monolayer films of octadecanethiol on gold and of octadecylsiloxane on silicon in this sandwich configuration yield enhancement factors between 15 (on Si) and 30 (on gold) compared to conventional grazing incidence external reflection spectra and are governed by a common, simple surface selection rule, which allows immediate quantitative evaluation and comparison of the film structures on different substrates.