Morphological control for multicomponent organic electronics using rod-coil block copolymers

PMSE 5

Bradley D. Olsen, bdolsen@berkeley.edu1, Yuefei Tao, yftao@uclink.berkeley.edu2, Xuefa Li3, Michael F. Toney, mftoney@slac.stanford.edu4, Jin Wang3, and Rachel A. Segalman, segalman@berkeley.edu1. (1) Department of Chemical Engineering, University of California Berkeley, 402 Hildebrand Hall, Berkeley, CA 94720, (2) Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1462, (3) Experimental Facilities Division, Argonne National Laboratory, Argonne, IL 60439, (4) Stanford Synchrotron Radiation Lab, Menlo Park, CA 94025
Control over morphology in organic electronics on the 10 nm length scale of exciton diffusion is critical to optimizing their performance. Semiconducting block copolymers are an attractive route to self-assemble these structures. The rigid conjugated polymers give many of these materials a rod-coil structure, and the liquid crystalline interactions between the rod blocks have a large effect on the microphase structures. Studies of model poly(phenylenevinylene-b-isoprene) block copolymers show that the crystal structure of the rod block is directly translated into lamellar phases in thin films, and the orientation of the lamellar microphase determines the orientation of the rod. The high bending modulus of the liquid crystalline nanodomains causes defect structures characterized by the dilation of lamellae, and the magnitude of this effect decays with increasing film thickness. Similar self-assembly is observed in a functional block copolymer with a p-type poly(phenylenevinylene) rod and an n-type oxidiazole coil.
 

New Concepts in Polymeric Materials
8:00 AM-11:20 AM, Sunday, August 19, 2007 Westin Boston Waterfront -- Grand Ballroom D, Oral

Division of Polymeric Materials: Science & Engineering

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007