7/21/2019 Abstract NaSAEAST 2014

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Optical characteristics and effective Schottky barrier of polyaniline

(PANI) film doped with dodecylbenzene sulphonic acid (DBSA)

Sanjib Kumar Baglari and D. Sarkar*Department of Physics, Gauhati University, Guwahati, Assam 781014

Email: sanjibbaglari@gmail.com

*Email: sarkardeepali@gmail.com

Abstract: Conducting polymers show large range of modulation of electrical

conductivity on doping(oxidation) and dedoping(reduction) cycle due to contribution

of protonic conduction. This has been used in various fields for this astonishing

property. In this communication, we report studies on optical characteristics ofpolyaniline film and metal-polyaniline (PANI) Schottky barrier junction and the effect

of junction property on DBSA doping. PANI has been synthesized by the most

conventional chemical polymerization methods using ammonium persulphate (APS)

as oxidizing agent. Three different concentrations of DBSA, viz, 0.1, 0.3, 0.5 M/M,are used during polymerization process. DBSA is known as a dopant as well as

surfactant. The optical band gap of PANI film as estimated from UV-visible spectra

absorption data has been found within the range 2.1-2.4eV. A Schottky junction with

configuration Ag/PANI-DBSA/ITO has been fabricated by coating of PANI-DBSA

on ITO and then taking Ag contact on to it. Current density-voltage (J-V)

characteristics of this junction show rectifying behavior. Junction parameter such asbarrier height, ideality factor has been calculated from J-V curves shows decrease of

barrier height and increase of ideality factor with increasing concentration of DBSA.

Keywords: Polyaniline, optical properties, schottky barrier, ideal factor