Self-adjusted hybrid structures consisting of a semiconductor quantum dot and a plasmonic nanostructure in droplet etched nanoholes

在该项目中，新型混合系统由单个外延半导体量子点和非常接近的金属纳米结构组成，即，将制造和研究几纳米的接近度。作为中心方面，该制造方法允许在纳米孔中自调节量子点和金属纳米结构。这使得定义良好且受控的几何形状和距离。该混合结构将通过分子束外延和局部液滴蚀刻纳米孔到半导体表面来制造。主要方面是除了液滴蚀刻和随后的过度生长过程，这是我们在最近几年建立的，在半导体量子点中的量子化激子态和金属纳米结构中的局域等离子体激元激发之间的近场耦合效应。我们期望激子和等离子体激元模式的影响。电磁场将在靠近混合纳米结构处被强烈地修改，因为金属纳米结构充当光学纳米天线。除了紧凑的金属纳米粒子，我们还将研究孔或环型纳米结构。计划在单杂化结构上进行光学光谱学研究，在实验过程中将利用DC-Stark效应进行进一步的调谐。最后，将进行数值模拟，以了解实验结果。

In this project novel hybrid systems consisting of a single epitaxial semiconductor quantum dot and a metallic nanostructure in very close, i.e., a few nanometer proximity will be fabricated and studied. As a central aspect the fabrication method allows for self-adjusting the quantum dot and the metallic nanostructure in a nanohole. This makes well-defined and controlled geometries and distances. The hybrid structures will be fabricated with molecular beam expitaxy and local droplet etching of nanoholes into a semiconductor surface. The main aspects are aside from the droplet-etching and the subsequent overgrowth process, which we have established in the recent years, the near-field coupling effects between the quantized excitonic states in the semiconductor quantum dot and the localized plasmonic excitation in the metallic nanostructure. We expect both an influence on the exciton and the plasmon modes. The electromagnetic field will be strongly modified in close proximity to the hybrid nanostructure, because the metal nanostructure acts as an optical nanoantenna. Aside from compact metallic nanoparticles we will also study hole- or ring-type nanostructures. Optical spectroscopy on single hybrid structures is planned, in which the DC-Stark effect will be employed for further tuning during the experiments. Finally, numerical simulations will be performed in order to understand the experimental results.