Improvement of Optical Properties of Functionalized Polyvinyl Alcohol-Zinc Oxide Hybrid Nanocomposites for Wide UV Optoelectronic Applications
Alaa M. Abd‐Elnaiem, M. Rashad, Taha A. Hanafy, Nagih M. Shaalan
Abstract
Abstract The functionalized polyvinyl alcohol (PVA) based nanocomposites thick films of 80 μm containing 1–3 wt% zinc oxide (ZnO) nanoparticles (NPs) were studied. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy were utilized for studying the structural parameters and formed chemical bonds of the synthesized PVA-ZnO films. In addition, extensive characterization has been done on their linear and nonlinear optical properties. The structural analysis of the PVA-ZnO nanocomposites revealed the formation of a wurtzite hexagonal ZnO phase embedded inside the monoclinic PVA phase. The interaction between Zn–O, and functional groups of the PVA as well as the molecular vibration exhibited in the PVA-ZnO nanocomposites were confirmed by the Raman and FTIR spectroscopy and revealed that the PVA-ZnO is a hybrid nanocomposite. The incorporated ZnO NPs ratios slightly affect the PVA films' structure, meanwhile, exhibited a detectable change in the linear/nonlinear optical properties of PVA. For example, as ZnO concentration increased from 1 wt% to 3 wt%, the direct/indirect optical band gap of PVA slightly decreased from 5.1/4.93 eV to 4.45/4.89 eV, respectively. Other optical characteristics, such as optical conductivity, dielectric constants, absorption coefficient, refractive index, etc., were evaluated. All observed optical properties versus energy/wavelength display a distinct pulse at 1.4 eV/850 nm which corresponds to the difference between the direct and indirect optical band gaps. It is expected that PVA-ZnO hybrid nanocomposites have become appropriate for implementation in numerous electronic applications due to their improved optical characteristics.