Ameliorating and tuning the optical, dielectric, and electrical properties of hybrid conducting polymers/metal oxide nanocomposite for optoelectronic applications

Abstract

Quaternary nanocomposite films with favorable electrical and optical properties have been produced by adding nickel oxide nanoparticles (NiO NPs) to polyvinyl alcohol (PVA), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), and polypyrrole (PPy) with a solution casting technique. In this study, different concentrations of NiO NPs were added to pure PVA/PEDOT:PSS/PPy blends and investigated through various characterization methods. From transmission electron microscopy (TEM) and X-ray diffraction (XRD) observations, the synthesized NiO NPs have a cubic phase and a diameter that varies between 6 and 40 nm. XRD analysis also indicates that the filling of PVA/PEDOT:PSS/PPy with NiO NPs results in a decrease in the crystallinity of the nanocomposites prepared. Raman analysis demonstrated the existence of prominent distinctive peaks associated with vibrational groups that characterize the synthesized samples, which change randomly with increasing concentrations of NiO NPs. In the UV/VIS spectrum for the PVA/PEDOT:PSS/PPy blend, there were two absorbance peaks at 202 and 224 nm that may result from π→π* and n→π* transitions. The results show that, by increasing NiO NP concentrations, UV/Vis absorbance increased by about 44 % at wavelength ranges from 190 to 240 nm, while optical band gap energies for indirect transitions decreased from 4.96 to 4.85 eV. The AC electrical conductivity of the films has been investigated via impedance spectroscopy at frequencies from 10−1 to 107 Hz. As the NiO NPs concentration in the blend rises, the AC electrical conductivity increases and is shown to follow Jonscher's rule. Additionally, it has been demonstrated that nanoparticle concentration causes a rise in composite dielectric loss and dielectric constant. The reduction in the optical bandgap energies and the enhancement of electrical properties due to the filling with NiO NPs suggest the possibility of using the prepared nanocomposites in optoelectronic devices.