Optical and electrophysical properties of nanocomposites based on PEDOT: PSS and gold/silver nanoparticles

The absorption spectra in the visible region and current-voltage characteristics in a wide range of electric fields have been investigated at the macroscopic level (planar structures) and at the microscopic level (using a conductive atomic force microscope) in films based on the electroactive polymer PEDOT: PSS and gold/silver nanoparticles (PEDOT: PSS + Au/AgNP). It has been shown that the behavior of the current-voltage characteristics of the nanocomposite films depends significantly on the electric field strength. It has been found that the introduction of gold nanoparticles into PEDOT: PSS in weak electric fields leads to an increase in the bulk conductance by almost two orders of magnitude (due to donor-acceptor interactions), a 50% decrease in the conduction activation energy, and an increase in the sensitivity to adsorbed oxygen. It has been demonstrated that electrical conduction of PEDOT: PSS + AuNP films is provided by hopping charge transfer both in the system of intrinsic localized states and in the system of impurity states of adsorbed oxygen. In strong electric fields, the current-voltage characteristics exhibit a different behavior in the forward and reverse scanning modes.