Abstract

Chain aggregation in electroluminescent polymers such as MEH-PPV has a profound effect on their emission and charge transport characteristics. Here we present studies of aggregates of shorter-chain oligomers of MEH-PPV and other conjugated polymers that exhibit highly structured emission both at the bulk and single aggregate level. Trends are seen in the emission intensity, fluorescence lifetimes, and Franck-Condon structure as a function of chain length and are modeled to obtain an understanding of the inter-molecular interactions in the aggregate species. Fluorescence lifetime imaging of single aggregates is used to develop a “core-shell” model for their structure that successfully explains their spectroscopy and dynamics.

© 2010 Optical Society of America