Drastic Control of Texture in a High Performance n-Type Polymeric Semiconductor and Implications for Charge Transport

Abstract
Control of crystallographic texture from mostly face-on to edge-on is observed for the film morphology of the n-type semicrystalline polymer {[N,N-9-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl] -alt-5,59-(2,29-bithiophene)}, P(NDI2OD-T2), when annealing the film to the polymer melting point followed by slow cooling to ambient temperature. A variety of X-ray diffraction analyses, including pole figure construction and Fourier transform peak shape deconvolution, are employed to quantify the texture change, relative degree of crystallinity and lattice order. We find that annealing the polymer film to the melt leads to a shift from 77.5% face-on to 94.6% edge-on lamellar texture as well as to a 2-fold increase in crystallinity and a 40% decrease in intracrystallite cumulative disorder. The texture change results in a significant drop in the electron-only diode current density through the film thickness upon melt annealing, while little change is observed in the in-plane transport of bottom gated thin film transistors. This suggests that the texture change is prevalent in the film interior and that either the (bottom) surface structure is different from the interior structure or the intracrystalline order and texture play a secondary role in transistor transport for this material. © 2011 American Chemical Society.

Citation
Rivnay J, Steyrleuthner R, Jimison LH, Casadei A, Chen Z, et al. (2011) Drastic Control of Texture in a High Performance n-Type Polymeric Semiconductor and Implications for Charge Transport. Macromolecules 44: 5246–5255. Available: http://dx.doi.org/10.1021/ma200864s.

Acknowledgements
Portions of this research were carried out at the Stanford Synchrotron Radiation Lightsource, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences. A.S. and J.R. gratefully acknowledge financial support from the National Science Foundation in the form of respectively a Career Award and a Graduate Student Fellowship. A.C. gratefully acknowledges funding from Amber Capital Investment Management received through the Italian Scientists and Scholars of North America Foundation. This publication was partially based on work supported by the Center for Advanced Molecular Photovoltaics (Award No. KUS-C1-015-21), made by King Abdullah University of Science and Technology (KAUST). The work in Potsdam was financially supported by the German Federal Ministry of Science and Education (BMBF FKZ 03X3525D). We thank Dr. Eric Verploegen for use of the in-situ heating chamber at SSRL beamline 11-3 and Dr. Stefan Mannsfeld for providing the 2D GIXS analysis software WxDiff. Polyera Corp. thanks the FexTech Alliance for supporting the synthesis of P(NDI2OD-T2).

Publisher
American Chemical Society (ACS)

Journal
Macromolecules

DOI
10.1021/ma200864s

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