Polaron localization in polyaniline through methylene blue dye interaction for tuned charge transport and optical properties

Abstract

An excellent control over the charged transport process and optical properties in polyaniline has been attained through successful localization of polarons formed in the polyaniline chain. The localization of polaron in polyaniline has been achieved through its interaction with methylene blue (MB) dye. Polyaniline has been synthesized on paper substrate from aniline using FeCl3 as polymerizing agent. On optical measurement of prepared sample, a remarkable red shift in the optical band gap has been observed varying from 2.63 to 2.47 eV. The charge transport behavior as reflected from its I-V measurement shows a nice tuning in the logarithmic scale. The chemical interaction between the MB dye and the polaronic charged defect states brings this brilliant tuning in the optical and electrical properties of polyaniline. Predominantly, the intra-chain charge transport of the polyaniline backbone is affected by the MB dye interaction.