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Poly- and Oligoaniline Thin Films: Charge Transport, Optical Properties and Effect of Doping

Published online by Cambridge University Press:  10 February 2011

J. Paloheimo
Affiliation:
Åbo Akademi University, Department of Physics, FIN-20500 Åbo (Finland), henrik.stubb@abo.fi
A. J. Pal
Affiliation:
Indian Association for the Cultivation of Science, Department of Solid State Physics, Jadavpur, Calcutta 700032 (India)
H. Stubb
Affiliation:
Åbo Akademi University, Department of Physics, FIN-20500 Åbo (Finland), henrik.stubb@abo.fi
P. Granholm
Affiliation:
Åbo Akademi University, Department of Physics, FIN-20500 Åbo (Finland), henrik.stubb@abo.fi
H. Isotalo
Affiliation:
VTT Electronics, Electronic Materials and Components, FIN-02150 Espoo (Finland)
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Abstract

We report a study of the electrical and optical properties of thin films of tetraanilinobenzene (TAB) and polyaniline (PANI) deposited using the Langmuir-Blodgett (LB), layer-by-layer selfassembly and vacuum-evaporation techniques. The paper will mainly concentrate on TAB LB films, but also results for other films are presented for comparison. The optical studies of undoped TAB LB films indicate H-aggregates. Upon doping new polaronic absorption bands appear and the photoluminescence of TAB becomes quenched. Doped LB and self-assembled films can reach conductivities up to about 10−4/cm for TAB and a few S/cm for PANT. The conductivity has a temperature dependence logσ α T−1/2, suggesting variable-range hopping in a quasi-gap, possibly due to the Coulomb interactions between localized carriers.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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References

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