76 Springer Series in Solid-State Sciences Edited by Hans-Joachim Queisser Electronic Properties of Conjugated Polymers Proceedings of an International Winter School, Kirchberg, Tirol, March 14-21, 1987 Editors: H. Kuzmany, M. Mehring, and S. Roth With 265 Figures Springer-Verlag Berlin Heidelberg New York London Paris Tokyo Professor Dr. Hans Kuzmany Institut fiir Festkorperphysik, Universitat Wien, Strudlhofgasse 4, A-1090 Wien, Austria and Ludwig Boltzmann Institut fiir Festkorperphysik, Wien, Kopemikusgasse 15, A·1090 Wien, Austria Professor Dr. Michael Mehring Physikalisches Institut II, Universitat Stuttgart, Pfaffenwaldring 57, D-7000 Stuttgart 80, Fed. Rep. of Germany Dr. Siegmar Roth Max-Planck-Institut fiir Festkorperforschung, Heisenbergstrasse 1, D-7000 Stuttgart 80, Fed. Rep. of Germany Series Editors: Professor Dr., Dres. h. c. Manuel Cardona Professor Dr., Dr. h. c. Peter Fulde Professor Dr. Klaus von Klitzing Professor Dr. Hans-Joachim Queisser Max-Planck-Institut fiir Festkorperforschung, Heisenbergstrasse 1 D-7000 Stuttgart 80, Fed. Rep. of Germany ISBN-13: 978-3-642-83286-4 e-ISBN-13: 978-3-642-83284-0 DOl: 10.1 007/978-3-642-83284-0 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in other ways, and storage in data banks. Duplication of this publication or parts thereof is only permitted under the provisions of the German Copyright Law of September 9, 1965, in its version of June 24, 1985, and a copyright fee must always be paid. Violations fall under the prosecution act of the German Copyright Law. © Springer-Verlag Berlin Heidelberg 1987 The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Printing: Druckhaus Beltz, 6944 Hemsbach/Bergstr. Binding: J. Schaffer GmbH & Co. KG., 6718 Griinstadt 2153/3150-543210 Preface The International Winter School on Electronic Properties of Conjugated Polymers held March 14-21,1987, in Kirchberg (Austria) was a sequel to a meeting held in Kirchberg two years before on a similar subject. The 1987 winter school was organized in cooperation with the "Bundesministerium fiir Wissenschaft und Forschung" in Austria and the "Bundesministerium fiir Forschung und Technologie" in the Federal Republic of Germany. The basic idea of the meeting was to provide an opportunity for experienced scientists from universities and industry to discuss their most recent re sults and for students and young scientists to inform themselves about the present state of the research in this field. As in 1985, the scientific interest was concentrated on the electronic structure of various conjugated polymers and related compounds. The focus of interest in the field now appears to have broadened and cov ers not only conductivity and relaxation phenomena of polyacetylene but also nonlinear optical properties, highly oriented and single-crystal poly mers, and electrochemical and opto-electrochemical properties of special materials such as polypyrrole and polyaniline. Exciting results on conduc tivity - the mass specific conductivity (i.e., the conductivity divided by the density) of polyacetylene is more than twice that of copper (!) - and a detailed interpretation of the meaning of conjugation length are reported. In spite of the high degree of orientation in several polymers, the mecha nism for the conductivity was confirmed to be similar to the mechanism in amorphous systems. Theoretical and experimental results have proved the importance of electron-electron correlation. Possible applications such as electrochemical cells, electrode materials, processable conducting poly mers, nonlinear optics devices, etc., are presented and now appear to be much more realistic than in previous reports. Discussion meetings were devoted to the conduction mechanism and possible limitations of the conductivity of conjugated polymers in general, and to the physical and chemical properties of polyaniline. In addition, a Tc spontaneous meeting on the new high oxidic superconductors and their relation to the conjugated polymers was held. v This book surrunarizes the tutorial and research papers presented at the winter school. We thank all the authors for their contributions and all the discussion speakers at the winter school for their stimulating remarks, which played an essential role in making the winter school an exciting and informative event. We acknowledge in particular the "Bundesministerium fur Wissenschaft und Forschung" (Austria) and the "Bundesministerium fur Forschung und Technologie" (FRG), as well as the sponsors from industry, for their fi nancial support. This support was not only a great help but was, in fact, indispensable for the goal of the meeting to be attained. Finally, we thank the manager of the Hotel Sonnalp, Herr J.R. Jurgeith, for his continuous support and for his patience with the many special arrangements required during the meeting. Wien, Stuttgart H. Kuzmany June, 1987 M. Mehring S. Roth VI Contents Part I Conductivity Electronic Transport in Low-Conductivity Metals and Comparison with Highly Conducting Polymers By A.B. Kaiser (With 8 Figures) ........................ 2 Synthesis of New Conductive Electronic Polymers By H. Naarmann (With 4 Figures) . . . . . . . . . . . . . . . . . . . . . . . 12 Long Mean Free Path Coherent Transport in Doped Polyacetylene By N. Basescu, Z.-X. Liu, D. Moses, A.J. Heeger, H. Naarmann, and N. Theophilou (With 2 Figures) ..................... 18 Frequency- and Temperature-Dependent Dielectric Losses in Lightly Doped Conducting Polymers By J.P. Parneix and M. El Kadiri (With 4 Figures) .......... 23 Variable-Range Hopping in Polymers Prepared from Iodo-(2-nitrophenyl ) -acetylene By M. Rotti, H. Krikor, and P. Nagels (With 6 Figures) 27 Transport Studies on Polypyrrole Films Prepared from Aqueous TsONa Solutions of Different Concentrations By Shen Yueqiang, K. Carneiro, Wang Ping, and Qian Renyuan (With 2 Figures) ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Part II Defects and Conjugation Length Influence of the Conjugation Length of Polyacetylene Chains on the DC-Conductivity. By D. Scharer-Siebert, C. Budrowski, H. Kuzmany, and S. Roth (With 6 Figures) ................ 38 Conjugation Length and Localization in Conjugated Polymers By J. Kiirti and H. Kuzmany (With 4 Figures) . . . . . . . . . . . . . . 43 VII Theoretical Investigations of Segmented Polyacetylene By J.L. Bredas, J.M. Toussaint, G. Hennico, J. Delhalle, J.M. Andre, A.J. Epstein, and A.G. MacDiarmid (With 3 Figures) 48 Analysis of the Raman Spectra of Modified trans-(CH)x By S. Lefrant, G. Arbuckle, E. Faulques, E. Perrin, A. Pron, and E. Mulazzi (With 1 Figure) ......................... 54 Conformation of Conjugated Polymers and Their Relation to Electron Delocalisation By J.P. Aime, M. Rawiso, and M. Schott (With 3 Figures) ..... 58 Polyacetylene Segments in a Polyvinylidene-Chloride Matrix: Anisotropic Optical Properties. By G. Leising, B. Ankele, H. Kahlert, and P. Knoll (With 3 Figures) ................. 64 Part III Electron Energy Loss, Optical and Raman Spectroscopy Electronic Structure of Conducting Polymers by Electron Energy Loss Spectroscopy By J. Fink, N. Niicker, B. Scheerer, W. Czerwinski, A. Litzelmann, and A. vom Felde (With 11 Figures) ..................... 70 Electronic Structure of Undoped and Doped Polyphenylenevinylene. By J. Fink, N. Niicker, B. Scheerer, A. vom Felde, H. Lindenberger, and S. Roth (With 8 Figures) 79 Electronic Structure of Doped Highly Oriented Polyacetylene By J. Fink, N. Niicker, B. Scheerer, A. vom Felde, and G. Leising (With 3 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Polarization Dependence of Recombination Kinetics in Stretch- Oriented trans-Polyacetylene By H. Bleier, S. Roth, and G. Leising (With 3 Figures) . . . . . . . . 88 Photogeneration Mechanism and Mobility in Polydiacetylene By D. Moses, M. Sinclair, and A.J. Heeger (With 2 Figures) 95 Polarised Photoexcitation in Oriented Polyacetylene By P.D. Townsend and R.H. Friend (With 4 Figures) ......... 101 Radiative and Non-radiative Recombination Processes in Photoexcited Poly(p-phenylene vinylene) By D.D.C. Bradley, R.H. Friend, K.S. Wong, W. Hayes, H. Lindenberger, and S. Roth (With 3 Figures) ............. 107 Photoinduced Absorption in Poly(p-phenylene vinylene) By D.D.C. Bradley, R.H. Friend, F.L. Pratt, K.S. Wong, W. Hayes, H. Lindenberger, and S. Roth (With 2 Figures) ............. 113 VIII Spectroscopy of Photo-Induced Solitons in cis-rich and trans-Polyacetylene By N. Colaneri, R.H. Friend, H.E. Schaffer, and A.J. Heeger (With 3 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 118 Photoinduced Infrared Absorption in Polydiacetylene By F.L. Pratt, K.S. Wong, W. Hayes, and D. Bloor (With 3 Figures) ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 124 Towards Solid State Investigations on Polyacetylene By G. Leising and M. Filzmoser (With 4 Figures) ... . . . . . . . .. 128 Raman Scattering of Highly Oriented Polyacetylene By P. Knoll, H. Kuzmany, and G. Leising (With 6 Figures) .. . .. 134 Experimental Raman Investigation of Oriented Undoped and Iodine Doped Polyacetylene By S. Lefrant and E. Mulazzi (With 3 Figures) . . . . . . . . . . . . .. 141 Polarization Properties of the Raman Spectra in trans- and cis-Polyacetylene By S. Fuso, C. Cuniberti, G. Dellepiane, S. Luzzati, and R. Tubino (With 5 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 146 Interpretation of the Raman Spectra of n-doped trans-(CH)x Films. By E. Mulazzi and S. Lefrant (With 3 Figures) ........ 150 Part IV Magnetic Resonance a Pulsed ENDOR and TRIPLE Resonance on trans-Polyacetylene la Durham Route By A. Grupp, P. Hofer, H. Kass, M. Mehring, R. WeizenhOfer, and G. Wegner (With 2 Figures) ........................ 156 ESR Study of Metallic Complexes of Alkali-Doped Polyacetylene By F. Rachdi and P. Bernier (With 2 Figures) .............. 160 In situ ESR Study During the Electrochemical Intercalation of Potassium in Polyacetylene By C. Fite and P. Bernier (With 1 Figure) ................. 165 7Li NMR Study of the Electrochemical Doping of Poly( acetylene) By A.K. Whittaker, C. Fite, K. Zniber, and P. Bernier (With 3 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 170 PrRadical Electron Structure in Polydiacetylene (PDA) Molecules By H. Sixl and C. Kollmar (With 6 Figures) ............... 175 Triplet State ODMR of Polydiacetylene Crystals By W. Riihle and H. Sixl (With 6 Figures) ...... . . . . . . . . . .. 180 IX Part V Theory Electronic and Nonlinear Optical Properties of Conjugated Polymers: A Quantum Chemistry Approach By J.L. Bredas (With 2 Figures) ........................ 186 On the Role of the Coulomb Interaction in Conjugated Polymer By D. Baeriswyl .................................... 198 Lattice Relaxation Approach to Soliton and Polaron Dynamics in Conducting Polymers. By Su Zhao-bin and Yu Lu (With 1 Figure) .................................... 204 Part VI Polyaniline Photo electrochemistry of Polyaniline By Mei Xiang Wan, A.G. MacDiarmid, and A.J. Epstein (With 4 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 216 Redox Mechanisms in Polyaniline Films By E.M. Genies and M. Lapkowski (With 4 Figures) 223 In situ FTIR Spectroscopy of Polyaniline By N.S. Sariciftci, H. Neugebauer, H. Kuzmany, and A. Neckel (With 2 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 228 Spectroscopic Investigation of Polyaniline By A.P. Monkman and D. Bloor (With 2 Figures) 232 In situ Ellipsometry of Early Steps of Polyaniline Electrosynthesis By B. Grodzicka, K. Brudzewski, R. Minkowski, J. Plocharski, and J. Przyluski (With 2 Figures) ....................... 235 Electronic Properties of Polyaniline By S. Stafstrom (With 3 Figures) 238 On the Acidic Functions of Polyaniline By C. Menardo, F. Genoud, M. Nechtschein, J.P. Travers, and P. Hani (With 2 Figures) .......................... 244 Thermochromism and Acidochromism in Substituted Polyanilines By Ph. Snauwaert, R. Lazzaroni, J. Riga, and J.J. Verbist (With 3 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 249 Spectroscopic Studies of some Model Molecules for Polyaniline By W.R. Salaneck, C.R. Wu, S. Stafstrom, M. Lindgren, T. Hjertberg, O. Wennerstrom, M. Sandberg, C.B. Duke, E. Conwell, and A. Paton (With 3 Figures) ................ 253 x ESCA Studies of Polyaniline and Polypyrrole By H.S. Munro, D. Parker, and J.G. Eaves (With 2 Figures) 257 Mass Spectroscopy of Chemical Processes in Conducting Polymers: Polyaniline. By K Uvdal, M.A. Hasan, J.O. Nilsson, W.R. Salaneck, 1. Lundstrom, A.G. MacDiarmid, A. Ray, and M. Angelopoulos (With 3 Figures) ....................... 262 Synthesis and Properties of a Conducting Polymer Derived from Diphenylamine. By E. Pater, M. Samoc, R. Zuzok, and P. Drozdzewski (With 3 Figures) ........................ 266 Part VII Polypyrrole, Polythiophene and Polyparaphenylene On Polaron and Bipolaron Formation in Conducting Polymers By F. Devreux, F. Genoud, M. Nechtschein, and B. Villeret (With 3 Figures) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 270 ESR of BFi -Doped Poly(3-methylthiophene) By M. Scharli, H. Kiess, G. Harbeke, W. Berlinger, KW. Blazey, and KA. Miiller (With 3 Figures) ....................... 277 Influence of the Monomer Size on the Electronic Structure of Thiophene-Like Polymers By R. Lazzaroni, R. Sporken, J. Riga, J.J. Verbist, J.L. Bredas, R. Zamboni, and C. Taliani (With 3 Figures) ............... 281 Ion Implantation of Polythiophene By H. Isotalo, H. Stubb, and J. Saarilahti (With 4 Figures) . . . .. 285 Characterization of Polypyrrole-Polyvinyl Alcohol Composite Prepared by Chemical Oxidation of Pyrrole By A. Pron and K Wojnar ............................ 291 Electrochemistry of Polypyrrole-Ferrocyanide Films By M. Zag6rska (With 3 Figures) ....................... 294 Synthesis and Physical Properties of 3,4-Disubstituted Polypyrroles. By J. Riihe, Ch. Krohnke, T. Ezquerra, and G. Wegner (With 4 Figures) ........................... 298 A New Polyparaphenylene Thin Film Obtained by Electroreduction: Characterization and Electrochemical Studies By G. Froyer, Y. Pelous, and G. Ollivier (With 5 Figures) 302 XI