Structure and optoelectronic properties of ferroelectric PVA-PZT nanocomposites

PbZr0.8Ti0.2O3 lead zirconate-titanate was prepared using the tartrate precursor method, and (Polyvinyl alcohol (PVA)/PbZr0.8Ti0.2O3 (PZT)) thin films systems were designed by the traditional casting technique. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) methods were used to investigate the effect of the annealing temperature of PZT on the structural characteristics of the prepared composite films. PZT was annealed at various temperatures (600 degrees C, 700 degrees C, 800 degrees C, 900 degrees C, 1000 degrees C, and 1100 degrees C), and X-ray examination indicated that it included rhombohedral and tetragonal perovskite structures. Moreover, the effect of the annealing temperature on the optical band gaps, refractive index, extinction coefficient, and optical conductivity of the samples was studied using the UV-VIS spectrophotometer technique. The photoluminescence (PL) tech-nique showed that the studied PVA/PZT films illustrated three spectra for all the samples. The Raman spectra evaluated five major Raman modes (A1(1TO), E(2TO), E (3TO+2LO)+B1, E(3TO), and A1(3LO), and T2g, which are expected in the perovskite structure. This study showed that adding PZT to the PVA matrix leads to changes in the morphological and structural properties, and the direct and indirect energy band gap (Eg) was decreased. We consider that the clustering effect in our samples increases as the crystallite size increases and prevents the vibration of the C-H bond, resulting in the disappearance of this bond in the Raman spectra. The formation of defects in synthesized compounds was analyzed using PL spectra. This system's compositional (the studied samples) dependency on optical properties makes it appropriate for optoelectronic applications.