Optical Properties of Polyaniline Synthesized by Oxidative Polymerization and Electrical Characterization of Ag/PANI/PEDOT:PSS/Ag Structures

Abstract

Polyaniline was synthesized in the presence of aniline hydrochloride and ammonium peroxydisulfate in water solution. The type of majority charge carriers in polyaniline was determined by hot probe measurement setup and it was found that polyaniline behaves as p-type semiconductor. This compound has been characterized by FT-IR, together with SEM and UV-Vis spectral data. The electronic properties of the PANI have been studied by fabricating metal polyaniline metal (MIM) capacitors. It was observed that the insertion of Poly(3,4 ethylenedioxythiophene):poly(styrenesulfonate) conducting layer between Ag electrode and PANI modifies the current voltage characteristics of the Ag/PANI/Ag structure. The non-linear behavior of In(IIV) versus V-1/2 and In(IIV2) versus In(1/V) plots indicated that the thermoionic emission theory can be applied to evaluate junction parameters for the Ag/PANI/PEDOT:PSS/Ag structure. The Cheung's and Norde method, combined with conventional forward I-V, was used to extract the electronic parameters such as, barrier height, ideality factor and series resistance values.