Synthesis, characterization, and tailoring variations in the linear optical of erbium‐ions doped (PVA/PVP) polymeric composites for optical devices: Improvement of the dielectric characteristics

Abstract

The simple solution casting method was utilized for preparing composite films (PVA-30 wt% PVP) incorporated with various content of erbium ions (Er 3+ ) (0.11, 0.37, 1.85, 3.7, 9.25, and 18.5) wt%. The composite films' properties were investigated using XRD, UV-Vis, and dielectric spectrometers. The XRD patterns showed a noticeable decline in structural elements, including crystallinity level. The transmittances of the investigated samples decrease as Er 3+ increases. Studies on UV-Vis absorption have revealed that the UV-Vis absorption spectra are shifting to the higher wavelengths, causing a decrease in the optical energy bandgap values from 4.66 to 3.48 eV for an indirect transition and from 5 to 4.84 eV for a direct transition, which suggests that the filler interacts with the blend matrix. As the number of localized states in the forbidden energy bandgap rises, it has been shown that with increasing Er 3+ -the estimated Urbach's energy increases from 1.95 to 32 meV. The addition of erbium ions raises the refractive index of the blend film. The optical limits of the samples are investigated using a He-Ne laser beam with a wavelength of 632.8 nm and a solid-state green diode laser beam with a wavelength of 532 nm. The prospect of greater charge carrier concentration and mobility was confirmed by increased AC conductivity with increasing frequency. Dielectric permittivity and dielectric loss tangent were utilized to analyze dielectric behavior. The analysis of the electric modulus (M 0 and M 00 ) of as-prepared samples has been completed. These findings are anticipated to notably impact a broad spectrum of applications, including organic semiconductors, optoelectronic devices, polymer solar cells, and polymer waveguides. K E Y W O R D Sdielectric characteristics, erbium ions (Er 3+ )-doped PVA/PVP, optical limiting/CUT-OFF laser filters, refractive index-bandgap analysis, XRD/FTIR