Π-Conjugated Polymers: Pushing the Limits Using Chemistry

Special Seminar

Conjugated polymers provide a unique encompassing set of structurally tunable optical, electronic transport, and redox properties that allows their present and potential use in a host of applications which span nearly metallic materials, field effect transistors, light emitting diodes, solar cells and photodetectors, chem/bio-sensors, electrochromism, along with batteries and supercapacitors. Each of these properties can be controlled by repeat unit, macromolecular, and solid-state structure which are all dependent on the chemical identity of each system. In this presentation, we will explore how chemistry enables the creation of new polymers where a specific property is pushed towards its limit. Dioxypyrrole-based polymers provide the most electron rich, and most easily oxidized, conjugated polymer family as desired for stable conductivity and long lived redox switching.¹ The flexible synthetic chemistry of dioxythiophene-based polymers has allowed us to complete the color palette of vibrantly colored to transmissive switching electrochromes of any color, including black.^2,3 Two band absorption induced by the incorporation of a donor-acceptor-donor triad in the polymer chain induces long wavelength light collection well into the near infrared for photovoltaic devices,⁴ and even into the mid infrared as desired for photodetectors.⁵ Accessing highly solution processble conjugated polymers allows us to spray- and print-process for a response or interaction over large-areas and on flexible substrates. These examples serve to demonstrate the approach the chemist uses in conjugated polymer research, and provides insight for making great strides in the future.

¹Walczak, R. M.; Reynolds, J. R. Adv. Mater. 2006, 18, 1121-1131. “Poly(3,4-alkylenedioxypyrroles): The PXDOPs as Versatile yet Underutilized Electro-active and Conducting Polymers”
²Beaujuge, P.M.; Reynolds, J.R. Chem. Reviews, Special Edition â€" Organic Electronics 2010, 110, 268-320. “Color Control in Π-Conjugated Organic Polymers for Use in Electrochromic Devices”
³Beaujuge, P.; Ellinger, S.; Reynolds, J.R. Nature Materials, 2008, 7, 795-799. “The Donor-Acceptor Approach Allows a Black to Transmissive Switching Polymer Electrochrome”
⁴Beaujuge, P.M.; Amb, C.M.; Reynolds, J.R. Acc. Chem. Res., ASAP August 20, 2010 DOI: 10.1021/ar100043u “Spectral Engineering in Π-Conjugated Polymers with Intramolecular Donor-Acceptor Interactions”
⁵Steckler, T.T., Zhang, X., Hwang, J., Honeyager, R., Ohira, S., Zhang, X-H., Grant, A., Ellinger, S., Odom, S.A., Seat, D., Tanner, D.B., Rinzler, A.G., Barlow, S., Bredas, J-L., Kippelen, B., Marder, S.R., Reynolds, J.R. J. Am. Chem. Soc. 2009,131, 2824-2826. “A Spray Processable, Low Bandgap, and Ambipolar Donor-Acceptor Conjugated Polymer”

For more information contact Prof. Seth Marder (404-385-5-6048).