Dual optical properties of NiO-doped PVA nanocomposite films

In this work, we prepared composites of functionalized polyvinyl alcohol by NiO nanoparticles with of 1.0-5.0 wt %. Crystal structure analysis were well studied by XRD, Raman and FTIR. The optical properties of the functionalized PVA have been deeply characterized. XRD analysis reveals the polycrystalline feature of pure and functionalized PVA, containing both amorphous and crystalline phases. The structure of the PVA films is influenced by adding the nanoparticles. The dual optical properties exhibit the features of both PVA and dopant materials. Clear change in the optical properties of PVA was observed with various NPs content that has been increased up to 5%. The optical band gap of PVA was changed from 5.4 eV for 0.1% NiO up to higher value at 0.4% NiO. Interesting is the appearance of another indirect band at lower energy. This band gap energy was recorded at 3.8 and 3.36 eV at 0.1% NiO, and 2.85 and 2.3 eV at 0.5% NiO for various phonon energies. The other important optical parameters such as refractive index, dielectric, absorption coefficient, and optical conductivity were evaluated. The observations propose the applicability of the prepared thick film for optoelectronic applications.

Automated summary

In this study, composites of functionalized polyvinyl alcohol were prepared with NiO nanoparticles, and the crystal structure analysis and optical properties of the functionalized PVA were well studied. The addition of nanoparticles influenced the structure of PVA films, leading to changes in optical properties with increasing NiO content. The dual optical properties of the composites showed features of both PVA and dopant materials, with the appearance of a lower energy indirect band gap at higher NiO concentrations.