Exciton Transport in Individual Nanotubular J-Aggregates

University Of Texas At Austin, Austin TX

Investigators

Abstract

This project targets the study of exciton energy transport in supramolecular organic systems by means of spectroscopic investigation of individual nanotubular J-aggregates used as a model light-harvesting system. Cyanine dyes such as C8S3 self-assemble in aqueous solution to form nanotubular supramolecular assemblies that are 13 nm in diameter and several microns in length. These nanotubes are similar to the highly efficient antenna systems of the natural light-harvesting complexes in Green Sulfur Bacteria and are thus attractive as a model for studying light harvesting in quasi-one-dimensional excitonic systems. These J-aggregates are studied using a combination of laser spectroscopy, near-field scanning optical microscopy (NSOM), and confocal microscopy that allows probing of individual nanotubes. Additionally, fluorescence imaging is used to directly measure the spatial extent of energy transfer in individual nanotubular aggregates to understand exciton transport in supramolecular organic systems. The project has a number broader societal impacts: an increase in the number and diversity of students pursuing chemical research, the development and dissemination of tools for nanoscale characterization of heterogeneous materials, molecular electronics, and an expanded understanding of light harvesting as it pertains to harnessing solar energy. Educational efforts leverage the Freshman Research Initiative (FRI) at UT-Austin, a program designed to bring capable underrepresented student populations that might otherwise not chose research as a career goal into the research laboratories. This award is made by the Macromolecular, Supramolecular and Nanochemistry program of the Division of Chemistry and the recipient is David Vanden Bout of the University of Texas at Austin.