Semiconductor Carrier Dynamics in Metal-Semiconductor Nanostructures

技术描述：该项目旨在利用独特的材料生长技术来研究金属-半导体混合纳米结构的光学性质和基本科学。利用量子点和量子阱的光致发光光谱和光致发光激发光谱研究了表面等离子体激子与激子相互作用的本质。主要研究人员和学生使用这些光学技术来观察和控制金属和半导体材料之间的界面上的能量作为生长参数的函数的相干转移。此外，频率分辨光学门控光谱与光谱干涉测量相结合产生了一种灵敏的时间表征方法。正在研究的材料系统是银、镓、铝和铟金属纳米粒子以及砷化铟和砷化铟镓量子阱和量子点。该研究项目设计、制造、表征和研究了混合金属-半导体纳米结构的线性和非线性光学行为的起源。非技术描述：在其最简单的形式中，表面等离子激元是一种电磁波，它沿着金属-介质界面被引导和限制，其方式与光可以被光纤引导的方式非常相似。这种限制导致界面处产生强烈的电磁场，从而极大地提高了材料的性能。当金属和介电材料之间的分离达到纳米级时，这一点尤其正确。在这个项目中，利用新的材料制备技术，增加了金属-半导体混合纳米结构的功能，以展示在纳米长度尺度上对光波的控制和超短的光开关时间。因此，传播表面等离子激元偏振子波的受限性质使全光集成电路成为可能。人们可以想象微小的有源光子元件，它基于非线性表面等离子激元偏振光学，允许纳米级光束的传播和开关，受限于金属-半导体界面。除了潜在的技术影响外，该项目还为学生提供了设计和制造纳米结构、表征其形貌并利用他们的数据来质疑和提高对激子-表面等离子体极化子耦合的理解的技能。通过这种方式，学生在学习连续波和超快光学光谱学的激动人心技术的同时，发现了新的和有用的光学行为。

Technical Description: This project is designed to utilize unique materials growth techniques to investigate the optical properties and the underlying science of metal-semiconductor hybrid nanostructures. Photoluminescence spectroscopy and photoluminescence excitation spectroscopy of quantum dots and quantum wells are used to probe the nature of the interaction between surface plasmon polaritons and excitons. The principal investigator and students use these optical techniques to observe and control the coherent transfer of energy across the interface between metal and semiconductor materials, as a function of growth parameters. In addition, frequency-resolved optical gating spectroscopy combined with spectral interferometry yield a sensitive method for temporal characterization. The material systems being studied are silver, gallium, aluminum, and indium metal nanoparticles and indium arsenide and indium gallium arsenide quantum wells and dots. The research project designs, fabricates, characterizes and investigates the origin of the linear and non-linear optical behavior of hybrid metal-semiconductor nanostructures.Non-technical Description: In its simplest form, a surface plasmon polariton is an electromagnetic wave that is guided and confined along a metal-dielectric interface much in the same way that light can be guided by an optical fiber. This confinement leads to an intense electromagnetic field at the interface, resulting in an extraordinary enhancement of materials properties. This is particularly true when the separation between metal and dielectric materials is at the nanoscale. In this project, using novel materials fabrication techniques, the functionality of metal-semiconductor hybrid nanostructures is increased to demonstrate control of light waves on a nanometer length scale and ultra-short optical switching times. As a result, the confined nature of propagating surface plasmon polariton waves enables all-optical integrated circuits. One can imagine tiny active photonic elements based on nonlinear surface plasmon polariton optics that allows propagation and switching of nanoscale light beams confined by the metal-semiconductor interface. In addition to the potential for technology impact, the project gives students the skills to design and fabricate nanostructures, characterize their morphology and utilize their data to question and advance the understanding of the exciton-surface plasmon polariton coupling. In this way, students uncover novel and useful optical behavior while learning exciting techniques in both continuous wave and ultra-fast optical spectroscopy.