Structural, optical and impedance spectroscopy study of thin film of polyaniline (PANI/ZnO) nanocomposite

Modern organic electronic and power electronic devices gained attention due their superior performance and efficiency with reduced cost. While nanocomposites of these organic semiconductors have high potential to further enhance these properties. In this work, thin films of zinc oxidepolyaniline (ZnO-PANI) nanocomposite with different compositions of ZnO (50, 60 and 70 wt%) are deposited by spin coater onto the surface of p-Si. The phase identification of the samples is identified through x-ray diffraction analysis. Pure ZnO showed wurtzite crystalline while PANI and nanocomposites of ZnO-PANI showed amorphous structure. The optical absorption band gap was evaluated from Ultraviolet-visible spectroscopy absorption studies and band gaps were calculated from Tauc's plots. The Ultraviolet-visible spectroscopy showed that by increasing ZnO content in the nanocomposite, the band gap increases from 3.25 eV to 3.3 eV and 3.4 eV for 50-50, 60-40 and 70-30 wt% respectively. The AC electrical properties of the nanocomposites were studied by using impedance spectroscopy. The parameters extracted from the impedance plots and conductivity values showed that 50-50 wt% is more conductive while that of 70%-30% wt is more resistive.