TITLE:
Meyer-Neldel Rule in Plasma Polythiophene Thin Films
AUTHORS:
J. Cuauhtemoc Palacios, M. Guadalupe Olayo, Guillermo J. Cruz, J. A. Chávez-Carvayar
KEYWORDS:
Polythiophene, Plasma, Conductivity, Meyer-Neldel Rule, Multi-Excitation Entropy Model
JOURNAL NAME:
Open Journal of Polymer Chemistry,
Vol.4 No.3,
August
6,
2014
ABSTRACT: In polymers, the electronic activation energy depends on the
fragmentation, crosslinking, dopants, moisture and in general on the
structure-environment interaction. This has a special importance in plasma
polymers because fragmentation and crosslinking are usually higher than in
other polymers. In this work, DC electrical conductivity of polythiophene thin
films prepared by plasma (pPTh) was studied using the Meyer-Neldel (MN) rule to
calculate the characteristic MN energy and temperature as a function of
moisture and metallic dopants. The experimental data for pPTh synthesized in
different conditions indicated that EM = 32 meV and TM =
373 K, suggesting a thermally activated conduction mechanism; however, in
polymer-metal matrices with metal concentration higher than the percolation
threshold, the conduction mechanism is different causing that the MN rule was
only partially fulfilled. The congruence of the experimental data with the
multiexcitation entropy model is discussed.