Controlling the architectures and optical properties of conjugated polymer aggregates and films

The semiconducting properties of conjugated polymers are finding use in various optoelectronic applications, including chemical sensors and light-emitting diodes. In this thesis, we investigate aggregation in conjugated polymers and how it affects the optical properties of these organic materials. We discuss how aggregation enhances exciton transport properties in fluorescent polymers, thereby increasing the probability of excitons reaching low-energy sites in the polymer. A consequence of this aggregation-enhanced exciton migration is that low-energy defect sites in a conjugated polymer can dramatically alter the polymer's fluorescence properties when it is in an aggregated state. In a poly(pphenylene ethynylene) (PPE) that was previously proposed to form green-emitting excimers, we found that a small concentration of anthryl defects in the polymer emitted green fluorescence that was only noticeable when the polymer was in an aggregated state (otherwise the polymer was fluorescent blue). After elucidating the origin of the green fluorescence, we purposely added more emissive anthryl units into the polymer to enhance the blue-to-green fluorescence color change that accompanied polymer aggregation.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Satrijo, Andrew

Advisor dc:contributor.advisor

• Timothy M. Swager.

• Chemistry.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/39673

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/39673