Nano-spectroscopic imaging and control of coupled dynamics in local molecular environments

点击翻译按钮获取中文摘要

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Raschke of the University of Colorado, Boulder, plans to develop a series of close-up ("near field") spectroscopic and imaging techniques to study the behavior of molecules and how they interact with their environment. He and his group use a combination of creative approaches to measure fast events (i.e. at the femtosecond time scale) at high resolution (i.e. with nanometer spatial resolution). The experiment outcomes provide information about different quantum states of a molecule, which will help to understand a molecule's properties and function at the most elemental level. The knowledge will eventually help to understand and then make new materials as catalysts, electronics, and other photonic materials. This interdisciplinary project provides broad research training for graduate and undergraduate students in Professor Raschke's lab. They will also have the opportunity to participate in community outreach and experience technology transfer to industry. In order to gain the spectroscopic access into the nano- to molecular length scales and their dynamics, a combination of novel near-field optical scanning probe microscopy modalities is developed and applied. In nonlinear and ultrafast nano-imaging using femtosecond four-wave mixing and photo-current spectroscopy the coupled electronic and vibrational quantum dynamics is studied in quantum dots, quantum plasmonic, and strongly coupled plasmon-exciton systems, using femtosecond adiabatic nano-focusing. In variable temperature single molecule nano-Raman spectroscopy, with nano-mechanical tip-sample probing, and tunneling transport conditions, in polyaromatic hydrocarbons and self-assembled monolayer, spectra diffusion, intramolecular vibrational energy redistribution, orientational dynamics, and plasmon hot-electron processes are investigated. This research is advancing basic science while being technology enabling simultaneously providing for the understanding of molecular materials as chemical nano-imaging as the enabling technique is refined. With its interdisciplinary nature this project provides for broad research training for graduate and undergraduate students including their participation in community outreach and technology transfer to industry.