Room temperature single molecule absorption spectroscopy detected by STM

有了这个奖项，由化学系的化学测量和成像计划资助，Gruebele教授和他的学生将开发通过扫描隧道显微镜检测的单分子吸收光谱。 在该实验中，激光束激发沉积在半导体或金属表面上的单个分子，纳米尺寸的金属尖端检测激光激发引起的分子形状的变化。 然后扫描激光波长以测量分子的吸收光谱，同时可视化分子激发态的形状。 该技术还将用于研究具有缺陷的复杂表面，例如导电玻璃。 吸收光谱允许测量和可视化不发荧光的分子，并且不能通过单分子荧光技术检测。这项研究的更广泛的目标是了解分子电子学中使用的大分子的激发态是如何通过缺陷和复杂的表面环境进行调节的。 该项目中研究的碳纳米管、量子点和金属玻璃的应用范围从显示器到手机外壳;然而，利用这些材料的特性所需的许多基本物理化学仍有待发现。 本研究项目支持的本科生和研究生将获得推进美国化学技术和纳米器件领域教学所需的知识和实践技能。

With this award, funded by the Chemical Measurement and Imaging Program of the Division of Chemistry, Professor Gruebele and his students will develop single molecule absorption spectroscopy detected by a scanning tunneling microscope. In this experiment, a laser beam excites a single molecule deposited on a semiconductor or metal surface, and a nanometer-sized metal tip detects the change of the molecular shape caused by the laser excitation. The laser wavelength is then scanned to measure an absorption spectrum of the molecule, while simultaneously visualizing the shape of the molecule's excited state. The technique will also be used to study complex surfaces with defects, such as conductive glasses. Absorption spectroscopy allows for the measurement and visualization of molecules that do not fluoresce, and that cannot be detected by single molecule fluorescence techniques. The broader goal of this research is to understand how the excited states of large molecules used in molecular electronics are tuned by defects and by a complex surface environment. The carbon nanotubes, quantum dots and metallic glasses studied in this project have applications ranging from displays to cell phone shells; however, much of the fundamental physical chemistry needed to harness the properties of these materials remains to be discovered. The undergraduate and graduate students supported by this research project will acquire the knowledge and hands-on skills needed to advance U.S. chemical technology and teaching in the area of nanodevices.