Primary Photoexcitations in Conjugated Polymers: Molecular Exciton Versus Semiconductor Band Model

Conducting polymers comprises a new class of materials achieving electrical conductivities which rival those of the best metals. The parent compounds (conjugated polymers) are quasi-one-dimensional semiconductors. These polymers can be doped by electron acceptors or electron donors. The prototype of these materials is polyacetylene (PA). There are various other conjugated polymers such as polyparaphenylene, polyphenylenevinylene, polypoyrrole or polythiophene. The doped systems, i.e. the conducting polymers, have intersting potential technological applications such as replacement of conventional metals in electronic shielding and antistatic equipment, rechargable batteries, and flexible light emitting diodes.Although these systems have been investigated almost 20 years, the electronic structure of the doped metallic systems is not clear and even the reason for the gap in undoped semiconducting systems is under discussion.

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SHEAR BAND OBSERVATIONS AND DERIVATIONS OF REQUIREMENTS FOR A SHEAR BAND MODEL

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1985535 ◽

1985 ◽

Vol 46 (C5) ◽

pp. C5-273-C5-282

Author(s):

L. Seaman ◽

D. R. Curran ◽

D. C. Erlich ◽

T. Cooper ◽

O. Dullum

Keyword(s):

Shear Band ◽

Band Model

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On the Influence of Low Magnetic Fields on the Photocurrent of Conjugated Polymers*

Zeitschrift für Physikalische Chemie ◽

10.1524/zpch.1992.1.part_2.189 ◽

1992 ◽

Vol 1 (Part_2) ◽

pp. 189-199

Author(s):

K. Lüders ◽

S. Blumstengel

Keyword(s):

Magnetic Fields ◽

Conjugated Polymers

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Oriented Luminescent Nanostructures From Single Molecules Of Conjugated Polymers

MRS Proceedings ◽

10.1557/proc-771-l9.8 ◽

2003 ◽

Vol 771 ◽

Author(s):

Adosh Mehta ◽

Pradeep Kumar ◽

Jie Zheng ◽

Robert M. Dickson ◽

Bobby Sumpter ◽

...

Keyword(s):

Conjugated Polymers ◽

Polarization Anisotropy ◽

Emission Pattern ◽

Spectral Signatures ◽

Dipole Emission ◽

Ink Jet ◽

Molecular Scale ◽

Jet Printing ◽

Photochemical Stability ◽

Printing Techniques

AbstractDipole emission pattern imaging experiments on single chains of common conjugated polymers (solubilized poly phenylene vinylenes) isolated by ink-jet printing techniques have revealed surprising uniformity in transition moment orientation perpendicular to the support substrate. In addition to uniform orientation, these species show a number of striking differences in photochemical stability, polarization anisotropy,[1] and spectral signatures[2] with respect to similar (well-studied) molecules dispersed in dilute thin-films. Combined with molecular mechanics simulation, these results point to a structural picture of a folded macromolecule as a highly ordered cylindrical nanostructure whose long-axis (approximately collinear with the conjugation axis) is oriented, by an electrostatic interaction, perpendicular to the coverglass substrate. These results suggest a number of important applications in nanoscale photonics and molecular-scale optoelectronics.

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