Carrier transport behavior in as-deposited and iodine-doped plasma polymerized 2, 6-diethylaniline thin films

Abstract

The temperature dependent electrical carrier transport properties of as-deposited and iodine-doped plasma polymerized 2, 6-diethylaniline (PPDEA) thin films of different thicknesses prepared using a capacitively coupled glow discharge reactor at room temperature were investigated. The FTIR analyses show that iodine doping process occurred at the quinoid units in the polyaniline backbone of PPDEA. The activation energy (ΔE) of both types of PPDEA thin films suggests hopping type conduction of carriers between the localized states at temperatures ranging from 298 K to 423 K. The ΔE in the higher temperature region suggests a thermally activated charge carrier transition mechanism in the energy band gap. The ΔE of as-deposited PPDEA thin films is higher for the applied voltages of 5 and 15 V as compared to those for the iodine-doped ones. The lower value of ∆E of iodine-doped PPDEA thin films indicates formation of charge-transfer-complex.