September 29, 2009 - Dr. John R. Reynolds
“Spanning the Spectrum with Spray-Processable Donor-Acceptor Polymers for Electrochromics and Photovoltaics”
The development of organic electronic and redox active devices that provide a response or interaction over large-areas and on flexible substrates is enabled by access to solution processble conjugated materials. We will present results on a family of fully conjugated polyheterocycles and crosslinkable telechelic oligomers with controlled light absorption for photovoltaic and electrochromic applications. Two band absorption induced by the incorporation of a donor-acceptor-donor (DAD) triad induces long wavelength light collection well into the near infrared for photovoltaic (PV) devices, along with providing processable vibrantly-colored to transmissive electrochromic (EC) polymers. Careful control of this two band absorption can lead to band coalescence and a fully black colored conjugated polymer that can be converted to a transmissive form. Black to clear electrochromism can also be obtained in multi-component devices and materials by planned spectral overlap. Telechelic functionalization of conjugated oligomers allows linear polymerization to chromophore containing polymers, while incorporation of acrylate moities provides UV crosslinkable coatings which have been photopatterned while retaining charge transport and redox activity.
We will discuss fundamental optical and electrochemical data in order to establish the electronic structure of the newly synthesized oligomers and polymers, along with presenting results from various device studies (photovoltaic and electrochromic) as platforms for materials property optimization.
Dr. John R. Reynolds is a V.T. and Louise Jackson Professor of Chemistry at the University of Florida with expertise in polymer chemistry and serves as an Associate Director for the Center for Macromolecular Science and Engineering. His research interests have involved electrically conducting and electroactive conjugated polymers for over 30 years with work focussed to the development of new polymers by manipulating their fundamental organic structure in order to control their optoelectronic and redox properties. His group has been heavily involved in the areas developing new polyheterocycles, visible and infrared light electrochromism, along with light emission from polymer and composite LEDs (both visible and near-infrared) and light emitting electrochemical cells (LECs). Further work is directed to using organic polymers and oligomers in photovoltaic cells. Reynolds obtained his M.S. (1982) and Ph.D. (1984) degrees from the University of Massachusetts in Polymer Science and Engineering, he has published over 235 peer-reviewed scientific papers, has 8 patents issued and 20 patents pending, and served as co-editor of the “Handbook of Conducting Polymers” which was published in 2007. He serves on the editorial board for the journals ACS Applied Materials & Interfaces, Macromolecular Rapid Communications, Polymers for Advanced Technologies, and the Journal of Macromolecular Science, Chemistry.