Modification of Structural, Optical, and Electrical Properties of PVA/PVP Blend Filled by Nanostructured Titanium Dioxide for Optoelectronic Applications

Abstract

The PVA/PVP/TiO2 films were prepared using different TiO2 concentrations by solvent casting technique. An analysis was conducted to investigate the influence of TiO2 on the characteristics of PVA/PVP blends. The FTIR, UV/visible spectroscopy, and electrical bridge circuits were used to characterize the prepared nanocomposite films. The structural changes of the nanocomposite relative to pure PVA/PVP are indicated by FTIR spectra. The optical studies demonstrate that by increasing the TiO2 concentration inside PVA/PVP blends, the band gaps reduce from 5.40 eV for PVA/PVP to 4.20 eV for PVA/PVP/TiO2 (10 wt%), also the refractive indices the nanocomposites increase from 1.2020 for PVA/PVP blend into 2.5380 for PVA/PVP/TiO2 (10 wt%). Also, the transmittance decreased from 97.6% for PVA/PVP blend to approximately 55.4% at the largest concentration of TiO2. Additionally, studies were conducted on the parameters, as well, ac conductivity (σac). The outcomes of dielectric parameters of the prepared films are enhanced by the doping of TiO2 with different concentrations and dielectric relaxation is observed. The hopping mechanism of PVA/PVP/TiO2 films is supported by the ac conductivity. It is found that adding 10 wt% TiO2 inside PVA/PVP matrix at 5 MHz increases the conductivity of the pure PVA/PVP blend by 4.46 times. Highlights The impact of TiO2 nanoparticles on the PVA/PVP blend has been investigated. Optical and electrical properties have been significantly induced by TiO2 embedded on PVA/PVP. The optical parameters affirm that the TiO2 affect the optical response of PVA/PVP blend. The electrical parameters show amendments in AC electrical conductivity. The use of TiO2 in PVA/PVP is improving the optical and electrical properties of nanocomposites.