Chemical Control of Quantum Defects in Low-Dimensional Carbon Materials

University Of Maryland, College Park, College Park MD

Investigators

Abstract

With this award, the Macromolecular, Supramolecular and Nanochemistry (MSN) program of the Division of Chemistry is funding Professor YuHuang Wang of the University of Maryland to investigate the effect of chemical defects on the physical properties of linear and two dimensional carbon materials. As with islands in the sea, these defects serve as focusing points of activity on an otherwise plain surface. These points are where interesting new chemistry and physics can occur. Successful completion of the proposed study may open an entirely new approach to engineering materials that could translate into new entries into optical probes and selective chemical sensors. The proposed work is also projected to engage undergraduate students, including students from underrepresented groups, directly in the research program through graduate-undergraduate mentorship. The proposed defects are being synthetically created in Prof. Wang's laboratory by covalently attaching a controlled number of functional groups to semiconducting carbon nanotube model systems. The beauty of this type of defect is its better-defined structure, excellent chemical tunability, and more importantly, previously unexpected fluorescent properties. An exciton, or electron-hole pair, can light up at the quantum defect site, making it possible to experimentally probe defects using conventional spectroscopic techniques. These chemically tailored, fluorescent quantum defects will be explored as a new tool to engineer nanomaterials, potentially to break the dark exciton limit of nanotube photoluminescence, and to probe chemical events that could be otherwise difficult to capture.