Evaluation of structure and functions of organic ultrathin films on metal films utilizing surface plasmon polariton excitation

利用金属表面激发的表面等离子体激元（SPP）研究了金属薄膜上有机电致变色膜的结构和功能。金属膜和LB膜的金属上的表面粗糙度进行了评估，使用由SPP激发引起的薄膜的散射光。蒸镀银膜上LB膜的散射光强于溅射膜上LB膜的散射光。结果表明，溅射薄膜比蒸镀薄膜具有更光滑的表面。在衰减全反射（ATR）结构中，通过反向入射光观察到新的光发射。据认为，SPP被激发的薄膜的表面粗糙度和/或膜的不均匀结构和一些SPP被转换为从棱镜侧的光发射。由于SPP激发，可以使用ATR测量来评估单元中液晶分子的排列。通过将理论ATR曲线与实验曲线拟合，确定了薄盒和厚盒中的倾斜角分布。建立了一个瞬逝场检测系统。用CdS作覆盖层的针尖发出的光被测量为倏逝场。由于SPP激发的倏逝场被观察到作为ATR配置中的激光束的入射角的函数。还测量了光致异构体膜的ATR性质。由于螺吡喃和偶氮染料LB膜的光致异构化，ATR特性发生了变化。本文研究了用表面等离子体激发增强水银LB膜光电器件的短路光电流。在ATR配置中，在入射光的SPP激发角周围观察到大的光电流。

Structure and functions of organic ultrathin films on metal films have been investigated utilizing surface plasmon polaritons (SPP) excited on the metal surface. Surface roughnesses of metal films and LB films on the metals were evaluated using scattered light from thin films caused by SPP excitation. Scattered light from LB films on evaporated silver films was stronger than that on the sputtered films. The results showed that sputtered films had smoother surface than evaporated films. New light emission was observed by the reverse incident light in the attenuated total reflection (ATR) configuration. It Was thought that SPPs were excited by surface roughness of thin films and/or non-uniform structure of the films and some SPPs were converted to the light emission from the prism side. Alignments of liquid crystal molecules in cells could be evaluated using ATR measurements due to SPP excitations. Profiles of the tilt angles were decided in the thin and thick cells by fitting theoretical ATR curves to the experimental ones. A system was constructed to detect evanescent fields. Luminescent light from a needle tip covered with CdS was measured to be evanescent fields. Evanescent fields due to SPP excitations were observed as a function of the incident angle of the laser beam in the ATR configuration. ATR properties were also measured for photoisomeric ultrathin films. The ATR properties changed due to the photoisomerization in spiropyrane and azo dye LB films. Enhancement of short-circuit photocurrents utilizing SPP excitations was investigated for merocyanine LB film photoelectric device. Large photocurrents were observed around the SPP excitation angles of the incident light in the ATR configuration.