Laser optical limiting, optical and dielectric performance of PVA/PVP/PEG/MC polymeric blend loaded with eriochrome black T for optoelectronic devices

Today, the most recent advancements in polymeric composites and their applications in optical limiting have gained specific attention. Polyvinyl alcohol/Polyvinylpyrrolidone/Polyethylene glycol/Methylcellulose (PVA/PVP/PEG/MC) polymeric blend loaded with Eriochrome Black T (EBT) is made with varying amounts of (EBT) dye (0 wt%, 0.072 wt%, 0.1 wt%, 0.14 wt%, 0.28 wt%, 0.5 wt%, and 0.72 wt%). The present study examined nanocomposites' structural, optical, and electrical characteristics comprising (PVA/PVP/PEG/MC) doped with (EBT) dye. The samples were examined using X-ray diffraction (XRD) and Fourier infrared spectroscopy (FTIR). The XRD profile shows the polymer composite's semi-crystalline structure, and FTIR indicates the possible interactions between the (EBT) dye and the base blend. The obtained results reveal that the incorporation of (EBT) dye enhances the crystallite size with reduced dislocation density in the polymeric composites. The optical properties of the samples showed magnificent results as the direct band gap decreased from 5.56 to 4.69 eV, and the indirect band gap also decreased from 5.05 to 3.54 eV mean while, the Urbach's tail energy showed significant increase with increasing the amounts of (EBT) dye. The refractive index rises from 1.8 to 2.9 (at λ = 500 nm) when EBT dye is added to the polymeric blend matrix. Moreover, the dielectric constant ε^′ is high at lower frequencies and decreases with frequency increment, While the A.C. electrical conductivity rises with the rising frequency and weight content of EBT dye. The Jonscher Power Law analysis revealed that the power index (s) ranged from 1.092 to 0.63. Furthermore, this composite's outstanding optical limitation performance shields three laser diode sources with distinct wavelengths. The laser diode (450 nm) generated a shielding percentage up to 88.3 %. The laser diode (532 nm) produced 94 % of the shielding, whereas the laser diode (650 nm) produced 99.3 %. We also tried to test the optical limiting performance of the composite films from the UV–Vis light source. We have a range of shielding that reaches 30 %. According to very good optical studies conducted in this work in visible light range, we can consider that this polymeric composite can be used in optoelectronic applications, such as optoelectronic devices, visible photodiodes, solar cell concentrators, etc.