Optical characterization and dispersion discussions of the novel thermally evaporated thin a-S50-xGe10CdxTe40 films

Optical and electrical properties of polyethylene oxide‐poly(3,4‐ethylenedioxythiophene)/NiZnFeO4 NPs nanocomposite films

“…The optical constants of PEO À PEDOT=NiZnFeO 4 NPs nanocomposite films, such as extinction coefficient and refractive index, were determined using transmittance and reflectance UV-Vis spectra and established methods found in the literature. 3,5,29,30,32 The transmittance spectra of the PEO À PEDOT film displayed a significant increase from 0% to approximately 86% as the incident photon wavelength increased from 300 to 400 nm, with no discernible changes observed beyond 400 nm (Figure 5a). The introduction of NiZnFeO 4 NPs resulted in a decrease in the transmittance level due to the presence of free electrons in the NPs that can absorb incident photons with lower energy.…”

Time-dependent laser irradiation-induced kinetics of changes in linear–nonlinear optical properties of Bi15In20Se65 thin films for IR applications

“…Moreover, an increase in E d due to an increase in the lasing duration causes more disturbances or disorder in the bandgap region, thereby enhances the localized state density and, in turn, reduces "E g ." 56 Other than that, it also related with the other physical parameters of materials, which is expressed as E d = βN c N e Z a , where the constant "β" has two values such as β ionic = 0.26 ± 0.03 eV and β covalent = 0.37 ± 0.04 eV, "N c " is the effective coordination number of the cation nearest-neighbor to the anion, "N e " is the effective coordination number of valence electrons per anion, and "Z a " is the chemical valence of the anion. 57 Therefore, the "E d " enhancement with exposure time might be due to the enhancement in the values of "N c " and "N e .…”

Increasing the Accuracy of the Characterization of a Thin Semiconductor or Dielectric Film on a Substrate from Only One Quasi-Normal Incidence UV/Vis/NIR Reflectance Spectrum of the Sample

“…Equation ( 11) is derived by replacing the transmittance x = exp(−αd) in the film (for light passing once between its two surfaces) with its averaging transmittance x = exp(−αd) over the light spot, and ignoring k(λ) in the Fresnel coefficients denoted by "τ" and "ρ" in Equation ( 3). The novel Equation ( 11) makes it possible to expand the EMR framework to account for both the substrate absorption and the finite size of the thick planar substrate, unlike the respective expressions used in EMR from [67][68][69][70][71][72][73][74][75][76][77][78].…”

“…EMR for thin film characterization only from R(λ) was proposed in [67] for uniform film on a finite transparent thick planar substrate with n(λ) > n s (λ) > 1, whereas this EMR, also known as the method of Minkov, has been utilized by research groups in several countries [68][69][70][71][72]. Moreover, some modifications of EMR from [67] have been dedicated to the characterization of semiconductor or dielectric thin film from R(λ), assuming that the film has uniform thickness and the thick planar substrate is transparent [73][74][75][76][77].…”

“…Considering the above, the main goal of this study is to develop and use an optimizing envelope method for the characterization of a thin semiconductor or dielectric film on a finite and generally non-transparent thick planar substrate, only from quasi-normal incidence R(λ) of the sample. This method, abbreviated as OEMR, has to resolve the above-mentioned deficiencies of the approaches from [67][68][69][70][71][72][73][74][75][76][77][78][79][80]. An-other goal is to determine the most accurate method for the characterization of a-Si films with dissimilar thicknesses, only from UV/Vis/NIR spectrum R(λ), by comparing the accuracies of such characterizations employing different DM-based methods.…”