Abstract
Although polymerized aniline (polyaniline, PANI) with and without iodine (I&sub2;) doping has already been extensively studied, little work has been done on the synthesis of PANI films using atmospheric pressure plasma (APP) deposition. Therefore, this study characterized pure and I&sub2;-doped PANI films synthesized using an advanced APP polymerization system. The I&sub2; doping was conducted ex-situ and using an I&sub2; chamber method following the APP deposition. The pure and I&sub2;-doped PANI films were structurally analyzed using field emission scanning electron microscope (FE-SEM), atomic force microscope (AFM), X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and time of flight secondary ion mass spectrometry (ToF-SIMS) studies. When increasing the I&sub2; doping time, the plane and cross-sectional SEM images showed a decrease in the width and thickness of the PANI nanofibers, while the AFM results showed an increase in the roughness and grain size of the PANI films. Moreover, the FT-IR, XPS, and ToF-SIMS results showed an increase in the content of oxygen-containing functional groups and C=C double bonds, yet decrease in the C-N and C-H bonds when increasing the I&sub2; doping time due to the reduction of hydrogen in the PANI films via the I&sub2;. To check the suitability of the conductive layer for polymer display applications, the resistance variations of the PANI films grown on the interdigitated electrode substrates were also examined according to the I&sub2; doping time.