Mechanism of direct current electrical charge conduction in p-toluenesulfonate doped polypyrrole/carbon composites

Journal Article · Fri Mar 14 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4868088· OSTI ID:22277916

Kumar, Amit ^[1]; Singh, Rajiv K.; Singh, Hari K.; Singh, Ramadhar ^[1]; Srivastava, Pankaj ^[2]

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1. National Physical Laboratory, Council of Scientific and Industrial Research, Dr. K. S. Krishnan Marg, New Delhi 110012 (India)
2. Department of Chemistry, Banaras Hindu University, Varanasi 221005 (India)

Polypyrrole/carbon (PPy/C) composites have been synthesized using varying concentration of p-toluenesulfonate (pTS) dopant by surface initiated in-situ chemical oxidative polymerization. The synthesis and influence of pTS on the structure of the PPy/C composites are confirmed by Fourier transform infrared studies and the morphological features have been examined by scanning electron microscopy. X-ray photoelectron spectroscopy, employed to examine the surface composition and doping level of these composites, confirms the anionic doping into the polymer backbone. Electron spin resonance measurement has been carried out on these samples to identify the nature of the charge carriers and their concentration at different doping levels. The dc electrical conductivity of these composites has been measured in the temperature range ∼10–305 K. The observed results have been analyzed in the framework of existing theoretical models. Different Mott's parameters, such as characteristic temperature (T{sub 0}), density of states at the Fermi level (N(E{sub F})), average hopping distance (R), and average hopping energy (W), evaluated from dc conductivity data supports the applicability of Mott's three dimensional variable range hopping mechanism in this system.

• OSTI ID: 22277916
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
CARBON
CHARGE CARRIERS
COMPOSITE MATERIALS
CONCENTRATION RATIO
DIRECT CURRENT
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRON SPIN RESONANCE
FERMI LEVEL
FOURIER TRANSFORMATION
ORGANIC POLYMERS
OXIDATION
POLYMERIZATION
SCANNING ELECTRON MICROSCOPY
TEMPERATURE DEPENDENCE
X-RAY PHOTOELECTRON SPECTROSCOPY