World Premier International Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan.
Phys Chem Chem Phys. 2011 Mar 21;13(11):4935-41. doi: 10.1039/c0cp01450h. Epub 2011 Feb 3.
Flat nano-island films prepared by wet-chemical deposition were investigated with attenuated total reflection infrared (ATR-IR) spectroscopy and scanning electron microscopy (SEM) in order to analyze the correlation between film morphology and optical properties. Here we choose Au as representative coinage metal (Au, Ag, Cu) that shows strong structure-dependent surface-enhanced infrared absorption (SEIRA). Infrared spectra of octadecanethiol monolayers on films of different stages of morphologic development show effects that are characteristic for SEIRA, such as enhanced vibrational signals, Fano-type line shape, and adsorbate induced baseline shifts. Their extent was found to be strongly dependent on the structural details and the strongest enhancement occurs at the percolation threshold of the two-dimensional island system. Also films beyond percolation show significant enhancement due to residual nanoholes that are acting as hotspots.
采用湿化学沉积法制备的平面纳米岛薄膜，通过衰减全反射红外（ATR-IR）光谱和扫描电子显微镜（SEM）进行了研究，以分析薄膜形貌和光学性质之间的相关性。在这里，我们选择 Au 作为代表性的硬币金属（Au、Ag、Cu），它表现出强烈的结构依赖性表面增强红外吸收（SEIRA）。不同形态发展阶段薄膜上十八硫醇单层的红外光谱显示出 SEIRA 的特征效应，例如增强的振动信号、Fano 型线形状和吸附物诱导的基线移动。发现它们的程度强烈依赖于结构细节，最强的增强发生在二维岛系统的渗流阈值处。此外，由于作为热点的残留纳米孔，超过渗流的薄膜也表现出显著的增强。
