Fabrication and Characterization of Mesoscopic Plasmonic Structures

本项目的重点是规则和无序金属和介电纳米结构的定义制备和光学以及结构表征。制备将包括以下策略：(A)湿化学制备直径为2至50纳米的单分散纳米颗粒，并将其沉积在各种衬底上，以创建平面二维纳米结构以及基于纳米颗粒（NP）的空心球体结构。一方面，金属二维和三维粒子阵列可以建立极化电子结构，因此它们可以提供最高的光学滤光性能。另一方面，无序态和缺陷态会导致光约束。光学谐振器和输入/输出耦合器可以基于这些结构。在这些系统中，我们将研究Au和Ag纳米结构的等离子体脱相。一个重要的方面是直接研究具有强相互作用（二维阶）的金属粒子的消相时间及其与存储光能的局部能量场增强相关的耦合特性。特别注意将被吸引到单一缺陷以及非周期（无序）和准周期粒子排列的调查。(B)纳米球光刻技术（NSL）利用球形物体如聚苯乙烯或二氧化硅颗粒的周期性和准周期性自组装，直径在200至2000纳米之间，是另一个项目目标；二维和三维（2-D, 3-D）有序粒子将被用作随后沉积不同数量的不同金属的掩膜。与无序纳米结构相比，六边形和立方排列的光约束将被研究。(C)将采用标准抗蚀剂技术通过电子束光刻直接书写任意结构。(D)此外，将利用自组装有机单层方法。在周期性二维纳米点内，具有明确定义的几何形状、对称性和形状变化的缺陷结构，并具有明确的无序程度，将使用蒸发和电沉积进行。研究这种介观谐振结构中诱导的相关无序，以及是否可以像电子晶体一样实现极窄的带隙状态，是一个非常重要的问题。

The focus of this project is the defined preparation and optical as well as structural characterization of regular and disordered metallic and dielectric nanostructures. The preparation will include the following strategies: (A) Wet chemical preparation of monodisperse nanosized particles with a diameter of 2 to 50 nm and their deposition on various substrates for the creation of flat 2-D nanostructures as well as hollow sphere structures based an nanoparticles (NP). On the one hand the metallic 2-D and 3-D particle arrays can establish a polaritonic electronic structure, and they can therefore provide supreme optical filter properties. On the other hand, disorder and defect states can lead to optical confinement. Optical resonators and input/output couplers could be based an these structures. Within these systems we will study the plasmon dephasing of Au and Ag nanostructures. An important aspect is the direct study of the dephasing time for metal particles with strong interactions (2-D order) and their coupling properties with respect to local energetic field enhancements of the stored light energy. Special attention will be drawn to the investigation of single defects as well as non-periodic (disordered) and quasi-periodic particle arrangements. (B) Nanosphere lithography (NSL) using periodic and quasiperiodic self assembly of spherical objects like polystyrene or silica particles with a diameter in the range of 200 to 2000 nm is another project goal; the two and three-dimensional (2-D, 3-D) ordered particles will be used as a mask for the subsequent deposition of various amounts of different metals. Light confinement in hexagonal and cubic arrangements compared to disordered nanostructures will be studied. (C) Direct writing of arbitrary structures by electron beam lithography using standard resist techniques will be carried out. (D) Furthermore, self-assembled organic monolayer methods will be utilized. Defect structures with well defined geometry, symmetry, and shape variations within periodic 2-D nanodots and with defined degrees of disorder will be carried out using evaporation and galvanic deposition. It is of fundamental interest to study the induced correlated disorder in such mesoscopic resonant structures and whether, similar to electronic crystals, extremely narrow band gap states can be achieved.