Synthesis and characterization of PVA embedded with peanut-shaped AgcAus nanoparticles: optical and electrical properties

Peanut-shaped Ag core Au shell (AgcAus) nanoparticles (NPs) synthesized by facile chemical reduction approach have been used to alter the optical and electrical parameters of polyvinyl alcohol (PVA). Synthesized AgcAus NPs and AgcAus PVA nanocomposites (NC) have been examined using high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and UV-Visible absorption spectroscopy. HRTEM and FE-SEM confirmed the presence of peanut-shaped NPs with Au shell over Ag core. Williamson-Hall method has been used to compute crystallite size and induced lattice strain. Linear as well as nonlinear optical parameters have been computed using absorption data. Decline in the optical band gap (E-g) from 4.7 to 2.57 eV and increase in the Urbach's energy (E-u) from 0.91 to 2.12 eV of PVA on addition of 0.36 wt% of AgcAus NPs are significant outcomes of this study. In addition, significant increase in refractive index, optical conductivity and nonlinear optical parameters of PVA with increasing concentration of AgcAus NPs has been observed. The current-voltage characteristics have been examined to verify the conduction mechanisms responsible for increased conductivity of AgcAus PVA NC. [GRAPHICS] .