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Description
Polyaniline (PANI) is a material known for its high conductivity and also huge range of
obtainable conductivities. In general, three types of charge carriers are considered in PANI
salt, namely holes, polarons and protons. Many authors attribute the high conductivity of acid
doped PANI to polarons [1-3]. We show that conductivity of polarons might not be
necessarily the prevailing mechanism of charge transport. In our research in order to separate
contributions from different charge carriers PANI/Si heterojunction was studied. Impedance
spectra were measured to distinguish between polaron and hole mobilities. From V-A
characteristics on PANI/Si structure contribution of polaron and hole conductivity was
calculated. Dielectric spectra of heterojunction were measured to estimate conductivity of
ions. Both measurements resulted in values in order of magnitude ~ 10 -7 S.cm -1 . On the
contrary conductivity of several S.cm -1 on films of PANI on glass substrates were obtained
using ohmic gold electrodes. To explain discrepancy between obtained values of conductivity
a model utilising redox reaction of hydrogen and chlorine was proposed and diffusion of
hydrogen and chlorine molecules in PANI films were studied.
The work was supported by the project SVV 260 444/2018 and grant GAUK No. 190119 provided by Charles
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345, 239-244 (2001).
[2] M. Chipara, G. Aldica, D. Hui, M. Dimonie, K. T. Lau, L. Georgescu, I. Munteanu,
H.Maroscoiu, J. Optoel. Adv. Mater. 6, 297–305 (2004).
[3] J. Kim, S. Park, and N. F. Scherer, J. Phys. Chem. B112, 15576-15587 (2008).
