Investigation of linear and nonlinear optical characterization of triple blended polymers incorporated with varying content of eriochrome black T dye for low-cost optical technologies and limiting absorption

• Published in: Materials science in semiconductor processing 2024-06, Vol.175, p.108179, Article 108179
• Main Authors: Nasrallah, Doaa A., AlAbdulaal, T.H., Zahran, H.Y., Yahia, I.S., Mohammed, M.I.
• Format: Article
• Language: English
• Subjects: EBT dye; Energy band gap; Nonlinear optical response; Optical limiting; Optical properties; XRD
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2024.108179

In this current research, polyvinyl alcohol (PVA)/polyethylene glycol (PEG)/methylcellulose (MC), (PVA-PEG-MC), (8:1:1) blend composite films reinforced with varying loadings of Eriochrome Black T dye were formed via a solution casting methodology. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Ultraviolet–visible (UV–vis) spectroscopy were applied to examine the influence of EBT dye packing on (PVA-PEG-MC) properties, especially optical ones. From XRD investigations, it became apparent that the incorporated EBT dye interrupted the crystallinity phase of the blend matrix. Furthermore, in the FTIR spectra, considerable band shifting and decreases in transmittance intensity for the doped samples were seen, which confirmed the development of the H-bond between the matrix and the dopant. The UV–Vis absorption and transmittance spectra are moved to longer wavelengths, suggesting the importance of these composites in light shielding devices. The indirect allowed transition was prominent in all studied samples, according to three effective approaches involving Tauc's equation, the ASF model, and the εi−hν plot, where increasing the addition of EBT dye resulted in a drop of two optical energy band gap (Eg(1)ind) and (Eg(2)ind) values. Tailing in the band gap was shown to follow the Urbach rule. Six distinct models were utilized to determine the approximate values of the linear refractive index (n) using the estimated gap energies values, where the mean (average) value of the refractive index for the pristine (PVA- PEG-MC) matrix was 2.082. In contrast, it was 2.28 for the EBT dye composite film. Additionally, several other optical parameters were identified, including the extinction coefficient (K), optical dielectric parameters, energy loss functions for surfaces and volumes, optical and electrical conductivity. Nonlinear optical parameters χ(3), χ(1) and n2 were calculated and analyzed for the EBT dye/(PVA-PEG-MC) composite films under examination. The optical limiting features revealed that the high amount of EBT dye incorporated in the ternary (PVA- PEG-MC) blend matrix reduces the output and normalized power utilizing different wavelength laser sources, which is suitable for optical limiting and laser attenuation in optoelectronic instruments. The unique results in the current work suggest applications for EBT dye/(PVA-PEG-MC) composite films in linear and nonlinear optical systems.