Tunable Optical and Electrical Properties of Poly(meta-aminophenol) via Doping with FeCl₃ and I₂ for Advanced Applications

Abstract— Conjugated conductive organic polymers, such as polyacetylene, polythiophene, polypyrrole, and polyaniline, are among the most widely studied materials due to their unique properties and diverse applications. To explore their potential for advanced technologies, poly(meta-aminophenol) was synthesized and characterized using FTIR, XRD, UV–Vis spectroscopy, TGA, and electrical measurements. The optical properties of the doped polymer were investigated through oxidation-reduction reactions using FeCl₃ and I₂ to analyze its redox behavior. Upon doping, the energy gap of the polymers decreased, influenced by the oxidation potential of the dopants. The undoped polymer exhibited an energy gap of 3.4 eV, which reduced to 1.8 eV for the I₂-doped polymer and 2.05 eV for the FeCl₃-doped polymer. This reduction in energy gap correlated with an increase in electrical conductivity, from 8.85 × 10⁻⁴ S/m for the undoped polymer to 7.28 × 10^–3 S/m for the I₂-doped polymer and 4.22 × 10⁻³ S/m for the FeCl₃-doped polymer.