Synthesis and Tuning the Morphological, Structural, Optical and Dielectric Features of SiO2/CuO Futuristic Nanocomposites Doped PVA–PEG for Optoelectronic and Energy Storage Applications

Abstract

This work is essential for the advancement of nanocomposite technology, with substantial societal ramifications. The evolution of economically viable and high-performing nanocrystals (NCs) may result in the creation of more efficient and adaptable optoelectronic devices, hence contributing to technical progress and economic advantages. The (PVA–PEG–SiO₂/CuO) nanocomposites have been produced using a casting method. Optical microscopy has allowed us to observe that the (SiO₂/CuO) NMs create a connected network within the NCs, in contrast to the pure (PVA–PEG). The FTIR ray displays changes in the position of peaks and variations in shape and size. The findings of the optical characteristics indicate a significant increase in absorption by approximately 2275% at a wavelength of 550 nm. Additionally, the energy gap experienced a decrease of roughly 57% (from 4.37 to 2.80 eV) for allowed indirect transitions and 120% (from 1.68 to 3.69 eV) for forbidden indirect transitions. An experimental and theoretical investigation explored the optical characteristics of (PVA–PEG–SiO₂/CuO) NCs. As the concentration of (SiO₂/CuO) nanoparticles rose, several optical characteristics of the pure (PVA–PEG) material demonstrated an upward trend. Based on the electrical properties of alternating current, it can be observed that as the frequency (f) increases, the dielectric [constant (ε′) and loss (ε″)] of NCs diminish. However, these values increase as nanomaterials (NMs) concentration increases. The ε′ and σ_a.c (electrical conductivity) of the (PVA–PEG) increased by approximately 101% (from 0.60 to 1.20) and 173% (from 1.25 × 10^–11 to 3.41 × 10^–11), respectively, when the amount of (SiO₂/CuO) reached 6% by weight at a frequency of 100 Hz. The obtained results indicated that the doping (PVA–PEG) with (SiO₂/CuO) NMs improved the structural and electrical characteristics, which made the (PVA–PEG–SiO₂/CuO) nanostructures promising materials for a wide range of optoelectronic devices, including but not limited to solar cells, transistors, electronic gates, photovoltaic cells, lasers, diodes, and other related fields. The results of the pressure sensor application showed that the (PVA–PEG–SiO₂/CuO) nanostructures have high sensitivity for pressure with excellent flexibility and high environmental resistance compared to other sensors.