A facile method to prepare g-carbon nitride/poly(vinyl alcohol) nanocomposite films with remarkable optoelectrical properties: Laser attenuation approach

Abstract

Nanocomposites consisting of polyvinyl alcohol (PVA) and graphitic carbon nitride nanoparticles (g-C3N4) were fabricated by solution casting technique. XRD has shown that the semicrystalline PVA structure is greatly affected by the incorporation of g-C3N4, which is confirmed by SEM images. Optical characteristics are investigated at room temperature within the wavelength range (200–1500 nm). The effect of g-C3N4 content on the optical band gap was studied. The optical bandgaps, direct and indirect, of g-C3N4 doped films, is lower than pristine PVA. Urbach’s energy increased from 0.42 eV for PVA to 0.96 eV for 14.8 wt% g-C3N4 doped film. The dielectric constant ε′, dielectric loss ε″, and AC electrical conductivity σac at RT as a function of frequency from 100 Hz to 1 MHz, and g-C3N4 doping level were studied. The variation of σacwith frequency was analyzed in view of Jonscher's universal power law. Adding g-C3N4 appears to enhance the σacof the films to higher values that candidates them in semiconductors applications. The results optical limiting indicates that the samples doped with g-C3N4 are highly attenuated for the laser beam of 638.2 nm. g-C3N4-doped PVA is a promising candidate for electronic and optoelectronic applications, especially the attenuation of laser power.