Improved charge transport in PANI:PSS by the uniform dispersion of silver nanoparticles

Abstract

In the present work, polyaniline:poly (4-styrenesulfonic acid) (PANI:PSS) and silver (Ag) nanoparticle-incorporated PANI:PSS (4-styrenesulfonic acid) are synthesized through a chemical route. The synthesized materials are characterized via X-ray diffractogram (XRD), ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM). The thermal stability of the samples is realized via thermogravimetric analysis (TGA) study. To gain detailed information about the electrical charge transport properties of the synthesized samples, the temperature-dependent current density (J) and voltage (V) data of the samples within a vast temperature range (143 K-303 K) are recorded. The deep analysis of those data reveals that the electrical charge transport mechanism within PANI:PSS and its composites with Ag nanoparticles is governed by a trap-dependent space-charge-limited current (SCLC) mechanism. The evaluated field-dependent mobility data at different temperatures show that silver nanoparticle incorporation within the PANI:PSS matrices below the percolation threshold enhances charge carrier mobility by reducing the trap density. From the analysis of the electrical data, various parameters associated with the charge transport mechanism are estimated, including disorder parameters, the density of states, the optimal hopping distance, and localization lengths. All the parameters estimated from the detailed analysis indicate that a small amount of silver nanoparticle dispersion within a PANI:PSS matrix enhances the overall semiconducting nature of PANI:PSS.