Poly(vinyl pyrrolidone) matrix and SiO2, Al2O3, SnO2, ZnO, and TiO2 nanofillers comprise biodegradable nanocomposites of controllable optical properties for optoelectronic applications

Abstract

This paper reports the detailed ultraviolet-visible (UV-Vis) range absorbance, transmittance, and reflectance spectra, and the various optical parameters (viz. energy band gaps, Urbach energy, refractive index, extinction coefficient, complex dielectric permittivity, and optical conductivity) of the polymer nanocomposite (PNC) films comprising biodegradable poly(vinyl pyrrolidone) (PVP) matrix and different oxide nanofillers (i.e., silica (SiO2), alumina (Al2O3), tin oxide (SnO2), zinc oxide (ZnO), and titanium dioxide (TiO2)). The effects of these oxide nanofillers and their concentrations (1–5 wt%) on the optical properties of the nanocomposites were systematically explored and comparatively demonstrated, especially with the consideration of optical behaviour of the wide band gap semiconductor nanomaterials (SnO2, ZnO, and TiO2). The results confirmed that the optical parameters of the SiO2 and Al2O3 nanoparticles containing PNCs were found controllable in a narrow range by the variation of filler concentration, whereas the band gap can be tuned in a wide range for the SnO2, ZnO, and TiO2 nanoparticles loaded PVP matrix-based PNC films. The multifunctionalities of these biodegradable PNCs revealed their appropriateness in the development of band gap regulator, UV-shielder, light diffuser, photo-sensor, and various detector-type optoelectronic devices.