Deepa, Melepurath and Kharkwal, Aneeta and Joshi, Amish G. and Srivastava, Avanish Kumar (2011) Charge Transport and Electrochemical Response of Poly(3,4- ethylenedioxypyrrole) Films Improved by Noble-Metal Nanoparticles. Journal of Physical Chemistry B , 115 (22). pp. 7321-7331. ISSN 1520-5207

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Abstract

Charge-transport phenomena and redox switching of poly(3,4-ethylenedioxypyrrole) (PEDOP) films embedded with Au and Ag nanoparticles have been investigated. In the bulk, charge transport can be described by an ohmic regime at low voltages and a space-charge-limited current regime at high voltages in PEDOP–Au, which is in contrast to trap-filled domains deduced for neat PEDOP and PEDOP–Ag nanocomposites, all indicating transitions driven by an external bias. This also allowed a direct estimation of a fairly high charge-carrier mobility at room temperature in PEDOP–Au, in addition to a higher donor density, which are advantageous for device applications. X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy affirmed the prevalence of Au/Ag nanoparticles as nonleachable entities in PEDOP, thus allowing the movement of electrons through the conducting nanoaparticles during electrochemical switching, an effect that is absent in the neat PEDOP film. Valence-band spectra and optical studies revealed that nanoparticles narrowed the band gap and increased the absorption coefficient of PEDOP, which enhanced the electrochromic switching ability of PEDOP. A coloration efficiency enhancement by an order of magnitude, higher electrochemical charge intercalation capacity, and higher diffusion rates reflect the role of noble-metal nanoparticles in improving the conduction and electrochemical activity of PEDOP.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s American Chemical Society.
Subjects:	Chemistry Chemistry > Physical Chemistry
Divisions:	UNSPECIFIED
Depositing User:	Mr. Abhishek Yadav
Date Deposited:	08 Nov 2012 09:03
Last Modified:	08 Nov 2012 09:03
URI:	http://npl.csircentral.net/id/eprint/810

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