Wemple – Didomenico Research Articles

Thin film synthesis and photovoltaic performance of polypyrrole@cobalt hydroxide composites for solar cells and optoelectronic devices

Mono-nanocomposites (MNCs) comprising polypyrrole (PPy) and cobalt hydroxide nanoparticles (Co(OH)2 NPs) are emerging as highly favorable contenders for applications in solar cells and optoelectronic devices, owing to their distinctive attributes encompassing robust light absorption, elevated conductivity, and commendable chemical stability. This investigation delves into the production of a thin film [PPy@Co(OH)2]MNC utilizing the physical vapor deposition (PVD) method. The structural and morphological characteristics of the [PPy@Co(OH)2]MNC thin film were scrutinized through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties, namely reflectance (R), absorbance (Abs), and transmittance (T) within the UV–vis–NIR spectrum, were precisely gauged at room temperature. Time-dependent density functional theory (TD-DFT) calculations and optimizations were conducted to analyze the geometric parameters, while the refractive index dispersion was probed using the single oscillator Wemple-Didomenico (WD) model. Additionally, the energy of a single oscillator and the energy of dispersion were quantified. The [PPy@Co(OH)2]MNC thin film exhibited pronounced light absorption across the UV–vis–NIR spectrum, characterized by a bandgap of 1.6 eV. The Au/[PPy@Co(OH)2]MNC/p-Si/Al heterojunction device demonstrated a power conversion efficiency and fill factor (FF) of 2.6 % and 55.07 %, respectively, under an irradiance of 100 W/cm2. The findings of this investigation underscore the potential of [PPy@Co(OH)2]MNC-based thin films as auspicious candidates for deployment in solar cells and optoelectronic devices.

Spectroscopic ellipsometry investigation of a 6H–SiC single crystal plate for potential use in graphene optoelectronic devices

At room temperature, the spectroscopic ellipsometry SE parameters Epsi (ψ) and Delta (Δ) for 6H–SiC crystal substrate were measured in the wavelength range 350–1700 nm at four different angles of incidence, 60°, 65°, 70°, and 75°. An SE model was developed to extract optical consents of 6H–SiC crystal substrate from the experimentally measured SE parameters. In the wavelength range 350–1700 nm, the refractive index of the 6H–SiC crystal substrate was extracted and fitted to two terms of the Sellmeier dispersion function. In the wide spectral range (350–1700 nm), the Wemple-DiDomenico (WDD) dispersion model shows how the real refractive index changes with wavelength. The analysis of refractive index dispersion of the 6H–SiC crystal substrate using Sellmeier dispersion function and WDD optical model allows to extract oscillator strength Nfij, average oscillator energy Eo, dispersion energy of the single oscillator Ed, lattice oscillator strength El, Abbe dispersion number, energy gap Eg, density of valence electrons nv, refractive index at infinite wavelength n∞, lattice dielectric constant εL, the ratio of free carrier density to free carrier effective mass (N/m∗), and plasma frequency ωp. For the 6H–SiC crystal substrate, in the desired spectral range (240–1700 nm), it does not have any depolarization effect on the reflected polarized light.

Exploring the influence of sudan IV Azo dye on the structural, optical, and dispersion characteristics of PVA/Su-IV composites

Flexible polymeric film composites consisting of polyvinyl alcohol (PVA) and Sudan IV azo dye (Su-IV) were synthesized using a casting method. Despite the known optical properties of PVA and azo dyes individually, the combined effects of Su-IV doping in PVA on the material’s optical and nonlinear optical properties have not been thoroughly investigated. This study addresses this gap by exploring the interactions between PVA and Su-IV at various doping concentrations (0.1–0.8 wt%) and their subsequent impact on the material’s structural and optical characteristics. Fourier transform infrared (FTIR) spectroscopy was employed to identify distinct vibrational groups within the composites, revealing that the incorporation of Su-IV induced random deviations in most absorption intensities compared to pristine PVA. Notably, new peaks at 519 and 444 cm−1 emerged, intensifying with increasing Su-IV concentrations, indicating significant interactions between the composite constituents. The optical properties were analyzed through transmittance and reflectance measurements, which uncovered new absorption peaks at 518 and 357 nm in PVA/Su-IV composites. These peaks correspond to electronic energy transitions of 2.4 and 3.6 eV, respectively, and their intensities increased with higher Su-IV content. Additionally, the indirect and direct bandgaps were decreased as Su-IV concentrations increased. The refractive index (n) analysis showed typical dispersion behavior between 850 and 2500 nm, aligning with the Wemple-DiDomenico (WDD) model. Furthermore, the oscillator parameters were calculated. Also, the nonlinear optical susceptibility (χ(3)) was boosted from 4.19 × 10−6 for pure PVA to 3.60 × 10−4 for the sample with 0.8 wt% Su-IV. The nonlinear refractive index (n2) was also measured at 8.55 × 10−2 for the doped sample. These findings demonstrate the potential of PVA/Su-IV composites for applications in nonlinear optics and photonics.

Comparative study on structural, morphological, and optical properties of MS/Fe3O4 nanocomposites and M-doped Fe3O4 nanopowders (M = Mn, Zn)

In the present work, the un-doped, M-doped magnetite (Fe3O4); (M = Mn, Zn), and MS/Fe3O4 composite nanopowders with a cubic spinel-type structure and average crystallite size range from 8.30 to 12.33 nm were synthesized by co-precipitation method. The FESEM images revealed the shape of particles are spherical with a grain size in the range of 33.44–49.77 nm. Through the analysis of reflectance data using Tauc’s model, the direct band gap energies of 2.98 eV, 2.93 eV, 3.01 eV, 2.85 eV, and 2.95 eV were determined for Un-doped Fe3O4, Mn-doped Fe3O4, Zn-doped Fe3O4, MnS/Fe3O4 composite, and ZnS/Fe3O4 composite NPs respectively. The parameters such as extinction coefficient and refractive index of the nanoparticles were computed by the Kramers–Kronig (K–K) method. Non-linear optical (NLO) parameters were computed from DRS data using the Wemple–Di-Domenico (WDD) model. The calculated third-order NLO susceptibility χ(3)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }^{(3)}$$\\end{document} and also electrical susceptibility χe\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }_{\\left(e\\right)}$$\\end{document} represented the maximum value for MnS/Fe3O4 composite NPs compared to the other samples. Considering the advanced optical parameters of MS/Fe3O4 composite samples, these particles can be suitable candidates for non-linear optical applications.

Linear and nonlinear optical properties of hybrid Polyaniline/CoFe2O4 nanocomposites: Electrochemical synthesis, characterization, and analysis

This study presents a focused investigation and comprehensive analysis of the synthesis of hybrid Polyaniline/Cobalt ferrite (PANI/CoFe2O4) nanocomposites using an optimized electrochemical polymerization method. CoFe2O4 nanoparticles (NPs) were incorporated into the PANI matrix at varying concentrations (3, 6, and 12 wt%). The research examined the newly synthesized hybrid nanocomposites in terms of their structure, dielectric properties, and both linear and nonlinear optical properties. As a result of the Williamson-Hall method, the average crystallite size varied between 45 and 99 nm. Initially, adding a small quantity of NPs decreased the nanocomposite size, but further additions increased it due to aggregation. The Tauc plot showed a gradual increase in the energy band gap of the films as the concentration of CoFe2O4 NPs increased up to 12 wt%. This trend showed stronger absorption bands and higher coefficients, indicating improved light absorption compared to pure PANI films. Dielectric properties, including dielectric constants (ɛr, ɛi) and dielectric loss (tan δ), were examined as a function of frequency. The experimental results indicated that PANI/CoFe2O4 exhibited lower dielectric constants than bare PANI. Concentration-dependent optical properties, such as electronic transition excitation energies, dispersion energies, and optical conductivity, were also investigated. These properties were modeled using a single oscillator based on the Wemple-DiDomenico (WDD) approach. The study revealed a reduction in key optical parameters—linear susceptibility, nonlinear third-order susceptibility, and nonlinear refractive index—as nanoparticle content increased. Conversely, increasing concentrations of CoFe2O4 NPs led to a significant increase in the ratio of free carriers to effective mass (N/m٭), from 3.89 × 10³⁶ to 4.04 × 10³⁶ m⁻³ kg⁻1. Additionally, the electrical conductivity of both PANI and PANI/CoFe2O4 nanocomposites exhibited temperature-dependent improvement, reaching maximum values. The observed findings indicate that hybrid PANI-CoFe2O4 nanocomposites possess enhanced properties, highlighting their promising potential as active materials for a broad range of optoelectronic applications.

Linearization and characterization of the Wemple – DiDomenico model of ZnO/Ni/ZnO tri-layer thin films prepared by ALD and DC magnetron sputtering

Our present work is devoted to analyzing the influence of Ni on the optical properties of ZnO thin films deposited on glass and Si (100) substrates, with the use of ALD for ZnO deposition and DC magnetron sputtering for Ni interlayer deposition. The compositions as well as the crystalline structure of various multilayer thicknesses of Ni (10, 30, 50, and 70 nm), that sandwiched between ZnO Films (70 nm), before being optically characterized, were carried out by the X-ray diffraction (XRD). Based on the XRD results, the crystallite size was increased with the increase of the Ni interlayer concentration. Additionally, the material densities for both ZnO and Ni show the expected close-to-bulk values in all formations, where the large cavities between atoms, on the films make the dislocation density become smaller and the surface roughness values decrease as well, with the increase of Ni interlayer concentration. Different optical properties were observed for different Ni content. The optical absorption coefficient (α), refractive index (n), and extinction coefficient (k) have been deduced from the transmission T(λ) and absorption measurements A(λ). The optical energy gap Egoptare estimated from Tauc΄s extrapolation procedure and the Kubelka-Munk approach. The static refractive index (no), the oscillator energy (Eo), and the dispersion energy (Ed) are calculated using the Wemple-DiDomenico (WDD) theoretical model. Analysis of third-order nonlinear optical properties in crystalline ZnO/Ni/ZnO are being detailed. These promising results imply that the high-quality films produced by ALD, show how the insertion of Ni could enhance the quality of the optical properties of ZnO films.

Insight on the optoelectronic properties of novel quaternary Ge–Se–Tl–Sb non-crystalline glassy alloy films for optical fiber sensing devices

Chalcogenide glass (Ge0.1Se0.7Tl0.2)85Sb15 is synthesized in bulk form by the melt quenching method and thermally evaporated as thin films. The amorphous character of the studied films is examined by XRD analysis. The values of refractive index (n\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n$$\\end{document}) and extinction index (k\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$k$$\\end{document}) are estimated from transmittance T(λ)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T(\\lambda )$$\\end{document} data using Swanepoel’s method and are found to be thickness independent. The values of the indirect optical band gap (Egopt\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${E}_{g}^{{\ ext{opt}}}$$\\end{document}) and Urbach tail (EU\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${E}_{{\ ext{U}}}$$\\end{document}) energies are 1.164 eV and 0.176 eV, respectively. The optical σopt\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\sigma }_{{\ ext{opt}}}$$\\end{document} and electrical σelec\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\sigma }_{{\ ext{elec}}}$$\\end{document} conductivities of (Ge0.1Se0.7Tl0.2)85Sb15 films increase while the penetration depth Pd\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${P}_{{\ ext{d}}}$$\\end{document} decreases with photon energy (hν\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$h\ u$$\\end{document}). The Wemple-DiDomenico (WDD) oscillator model calculates optical parameters such as single-oscillator Eo\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${E}_{{\ ext{o}}}$$\\end{document} and strength Ed\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${E}_{{\ ext{d}}}$$\\end{document} energies, lattice dielectric constant εL\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\varepsilon }_{{\ ext{L}}}$$\\end{document} and ratio N/m∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{N}}/{{\ ext{m}}}^{*}$$\\end{document}. The calculated values of third-order susceptibility χ(3)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\chi }^{(3)}$$\\end{document} and nonlinear index of refraction n2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${n}_{2}$$\\end{document} are 6.34 × 10–12 and 3.76 × 10–11 esu\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{esu}}$$\\end{document}. Dielectric constant ε′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\varepsilon }^{\\prime}$$\\end{document} and loss ε′′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\varepsilon }^{{\\prime}{\\prime}}$$\\end{document} decrement with frequency and increment with temperature. The ac conductivity σac\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\sigma }_{{\ ext{ac}}}$$\\end{document} increases with frequency and temperature, which is proportional to ωs\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\omega }^{s}$$\\end{document} and the exponent s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$s$$\\end{document} decreases with temperature. The obtained results of σac\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\sigma }_{{\ ext{ac}}}$$\\end{document} and s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$s$$\\end{document} are interpreted via the correlated barrier hopping (CBH) model. Values of the density of localized states NEF\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$N\\left({E}_{{\ ext{F}}}\\right)$$\\end{document} are enhanced with frequency and temperature. The results obtained suggest that ε′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\varepsilon }^{\\prime}$$\\end{document}, ε′′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\varepsilon }^{{\\prime}{\\prime}}$$\\end{document}, σac\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\sigma }_{{\ ext{ac}}}$$\\end{document} and NEF\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$N\\left({E}_{{\ ext{F}}}\\right)$$\\end{document} are improved by decreasing the film thickness. These research results emphasize the composition’s applicability for several optical potential applications, like optical fiber sensing devices, photo-detectors, and narrow band optical filters.

A brief review on optical properties of polymer Composites: Insights into Light-Matter interaction from classical to quantum transport point of view

In recent years, the optical capabilities of polymer composites have dominated the marketplace for applications in optoelectronic and energy devices. Supercapacitors, light-emitting displays, optical waveguide sensors, and organic photovoltaic cells are a few examples of the applications of the optical behavior of composites. Polymer composites are composed of nano/micro-sized inorganic particles (such as semiconductors, metal complexes, and synthetic nanoparticles) that are distributed within a polymer matrix. These materials have a significant role because they combine the optical properties of inorganic materials with the ease of processing of polymers, which utilizes the potential and performance of polymer-based optical systems.Optical features of polymer composites, such as indices of refraction, transparency, dispersion, and coefficients of absorption, influence their potential uses in optical systems and devices. The purpose of this research is to establish more insight into the optical characteristics of polymer composites and to understand the correlations between the structure and optoelectronic behavior of polymer composites. This review involves general concepts, scientific guidelines, and feasible mathematical sections. The unique optical characteristics of some common polymers (PEO, PMMA, PVA, and CS) and polymer composites are briefly reviewed. This review article establishes the fact that metal complexes are excellent over ceramic filler or nano-particles to improve optical absorption and decrease the optical band gap. An inspection of the fundamentals of light-matter interaction, ranging from classical (Drude-Lorentz model) to quantum methods for studying electron transition was exhibited. Furthermore, the applications of Tauc’s model and optical dielectric loss parameters to estimate the optical energy band gap of polymer composites are explained. Other fundamental optical parameters, such as absorption coefficient, optical dielectric constant, and refractive index are also explored. Finally, the Wemple-DiDomenico (WD) model is applied to investigate; the refractive index, optical dielectric constant, and optical spectra moments. The correlations between the optical dielectric function and several parameters such as ε∞, τ, N/m*, µopt, ρopt, ωp, and Eg are derived. Various models based on refractive index and absorption coefficient are discussed in detail to estimate crucial optical parameters.

Electrochemical synthesis of a novel hybrid nanocomposite based on Co3O4 nanoparticles embedded in PANI- camphor sulfonic Acid matrix for optoelectronic applications

In this study, we report on the preparation and characterization of Co3O4 nanoparticles (NPs) embedded in polyaniline-Camphor Sulfonic Acid (PANI-CSA) polymer matrix via electrochemical polymerization method. Developing conductive organic films with tunable optical properties are crucial for many novel optoelectronic applications. Thus, incorporation of metallic oxide nanoparticles (Co3O4 NPs) into polymer matrix (PANI-CSA) represents an alternative approach to address these desired features. As a result of careful optimization of several growth conditions, PANI-CSA/Co3O4 hybrid nanocomposites with high crystalline and homogeneous structures were successfully synthesized on ITO substrates. The impact of Co3O4 NPs concentrations on the structural and optical properties has been extensively investigated. A variety of structural and optical techniques, including FTIR, UV-VIS spectroscopy, and XRD, were employed to characterize the prepared hybrid nanocomposites. The initial findings and analysis reveal that the integration of Co3O4 NPs into PANI-CSA matrix have a trifunctional role in reducing π-polaron and Urbach energies (EU) whereas increasing π-π* band gaps. A further increase in NPs concentration up to 12 wt % results in continuous increase in the absorbance bands and absorption coefficients, indicating improved optical properties as compared to the control sample (PANI-CSA without NPs). The observed redshifts in absorbance band positions are attributed to narrowing of the optical band gap caused by interactions between PANI-CSA chains and Co3O4 NPs. FTIR spectra confirmed the exact chemical composition of PANI-CSA/Co3O4 nanocomposites, exhibiting broadened and less intense peaks compared to the control sample, indicating their interaction at the molecular levels. Additionally, XRD measurements indicate that no peaks of other phases were detected in all nanocomposites, demonstrating their purity and crystallinity. Finally, A single oscillator model by Wemple-DiDomenico (WDD) coupled with a Sellmeier dispersion relation based on one term has been utilized to model the typical electronic transition excitation energies, dispersion energies, optical conductivities, and many other optical desperation parameters for PANI-CSA and PANI-CSA/Co3O4 at various concentrations. For instance, in response to increased NPs content, linear optical susceptibility, third-order nonlinear optical susceptibility, and nonlinear refractive index decrease. In contrast, the ratio of free carriers to effective mass (N/m) increased from 4.73 × 1039 to 4.91 × 1039 m−3 kg−1 with increasing NPs concentration. Based on the observed results, these hybrid nanocomposites possess improved properties, indicating their potential use as active materials in a variety of novel optoelectronic applications.

Nonlinear optical characteristics of chemical bath-deposited pure and Cu-doped SnO2 thin films: A comparative evaluation

A chemical bath deposition method is used to grow SnO2 thin films doped with copper (0, 1, 2, and 3 wt) on glass substrates that exhibit linear and nonlinear optical properties. XRD analysis of the films verified their polycrystalline phases oriented strongly of the c-axis along the preferred (110) direction depending on the doping concentration and substrate temperature. SEM images of pure SnO2 film showed the formation of granular cubic structures. Conversely, the Cu-doped films displayed the existence of spherical granules with porosity. The transmittance spectra of the films for UV–visible light indicated large values for pure films, and that the transmittance decreased with greater doping levels. As a result of copper ions in the nanostructures, it was found that the transmittance decreased as doping levels increased. Pure SnO2 has an optical band gap of 3.63 eV; it decreases with increasing Cu doping concentrations. Wemple-Di Domenico (WDD) model for single oscillator energy was used to estimate each oscillator's optical refractive index, while the static refractive index and dispersion energy were also determined. In addition, the film's WDD parameters and nonlinear refractive index were in the range of 320–1200 nm, and the wavelength was determined. During the doping concentration increase, the nonlinear refractive index of the films increased primarily because the linear refractive index of the films at 520 nm increased. This nonlinearity of the film may arise because of the thermal effect, saturated atomic absorption, and electrostriction. For pure SnO2, third-order nonlinear susceptibility (2.77 × 10-12m2/V2) is caused by thermal effects, and for doped samples, it is caused by photorefractive effects.

Modification of the Structure and Linear/Nonlinear Optical Characteristics of PVA/Chitosan Blend through CuO Doping for Eco-Friendly Applications.

The solution casting technique is utilized to fabricate blank and CuO-doped polyvinyl alcohol/chitosan (PVA/CS) blends for eco-friendly applications. The structure and surface morphologies of prepared samples were explored by Fourier transform infrared (FT-IR) spectrophotometry and scanning electron microscopy (SEM), respectively. FT-IR analysis reveals the incorporation of CuO particles within the PVA/CS structure. SEM analysis exposes the well-dispersion of CuO particles in the host medium. The linear/nonlinear optical characteristics were found on the basis of UV-visible-NIR measurements. The transmittance of the PVA/CS decreases upon CuO increasing to 20.0 wt%. The optical bandgap (Eg dir./Eg ind.) decreases from 5.38/4.67 eV (blank PVA/CS) to 3.72/3.12 eV (20.0 wt% CuO-PVA/CS). An obvious improvement in the optical constants of the PVA/CS blend is achieved by CuO doping. The Wemple-DiDomenico (WDD) and Sellmeier oscillator models were utilized to examine the CuO role dispersion behavior of the PVA/CS blend. The optical analysis shows clear enrichment of the optical parameters of the PVA/CS host. The novel findings in the current study nominate CuO-doped PVA/CS films for applications in linear/nonlinear optical devices.

Synthesis of PEDOT: PSS thin film doped with silver nanoparticles via green approach and study their refractive indices and dispersive parameters using Wemple–DiDomenico (WDD) single oscillator model

Silver nanoparticles (AgNPs) synthesised via green synthesis using clove extract were incorporated into PEDOT:PSS polymers using the chemical solution deposition technique (CSD), and the effect of surface plasmon resonance in the nanocomposites was investigated. To assess the effect of Silver nanoparticles (AgNPs) (and surface plasmon resonance) on the polymer, TEM, UV–Visible spectroscopy, FTIR, Ellipsometry, and Photoluminescence are used. The surface plasmon peak of the curves in UV–Vis spectroscopy study of these films has shifted towards the infrared region, which may be useful in increasing the efficiency of optical devices. The optical band gap calculated using UV–Vis results reduced from 1.77eV for pure PEDOT: PSS to 1.53eV for the nanocomposite. Ellipsometry data is used to calculate Ψ, Δ values and thickness of films. The Wemple-DiDomenico (WDD) single oscillator model was used to analyse and estimate the dispersion parameters of these films. Refractive indices the films were calculated in the range 1.256–1.643 using the Ellipsometry data.

Polymeric Solar Cell with 19.69% Efficiency Based on Poly(o-phenylene diamine)/TiO2 Composites.

Conducting poly orthophenylene diamine polymer (PoPDA) was synthesized via the oxidative polymerization route. A poly(o-phenylene diamine) (PoPDA)/titanium dioxide nanoparticle mono nanocomposite [PoPDA/TiO2]MNC was synthesized using the sol-gel method. The physical vapor deposition (PVD) technique was successfully used to deposit the mono nanocomposite thin film with good adhesion and film thickness ≅ 100 ± 3 nm. The structural and morphological properties of the [PoPDA/TiO2]MNC thin films were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). The measured optical properties of the [PoPDA/TiO2]MNC thin films such as reflectance (R) in the UV-Vis-NIR spectrum, absorbance (Abs), and transmittance (T) were employed to probe the optical characteristics at room temperatures. As well as the calculations of TD-DFT (time-dependent density functional theory), optimization through the TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-DFT/CASTEP) was employed to study the geometrical characteristics. The dispersion of the refractive index was examined by the single oscillator Wemple-DiDomenico (WD) model. Moreover, the single oscillator energy (Eo), and the dispersion energy (Ed) were estimated. The obtained results show that thin films based on [PoPDA/TiO2]MNC can be utilized as a decent candidate material for solar cells and optoelectronic devices. The efficiency of the considered composites reached 19.69%.

Optical, electrical and morphological studies of complex composite films of rubidium bis(2-methyllactato) borate monohydrate doped with iodine

The chemical, morphological, optical, and electrical properties of the deposited rubidium bis(2-methyllactato) borate monohydrate (RMB) nanocomposite films deposited on glass doped with iodine (I2) are studied. The RMB nanocomposite films exhibit a monoclinic structure, while the doped films with iodine exhibit amorphous microstructural nature. The extinction coefficient, band structure, refractive index, and optoelectronic parameters are calculated and interpreted. Wemple–DiDomenico (WDD) and Sellmeier models are utilized to deduce the dispersion energy (Ed), effective single oscillator energy (E0), oscillation strength (f), average oscillator wavelength (λ0). and the oscillator length strength (S0). The bandgap of pure RMB film is 3.96 eV and decreases gradually to 3.65 eV as the iodine content increases to 10 wt%. also, the sheet resistance decreases from 2.2×109Ω/sq to 4.4 ×108Ω/sqas RMB doped with 10 wt% iodine. Polyiodide ions enhance the free carrier’s diffusivity, quantity, and mobility in the host matrix of the RMB.

Remark on the correlation between the refractive index and the optical band gap in some crystalline solids

The correlation between static refractive index (ns) and optical band gap (Eg) based on the Wemple-DiDomenico (WD) model and the empirical correlation between the energy of an effective dispersive oscillator and optical band gap is examined for 52 crystalline solids. A comparison with two recently published empirical relationships between ns and Eg indicates that the use of the WD model provides better results and, more importantly, connects the ns versus Eg dependence with some chemical characteristics of solids such as the coordination number of cation, the valence of anion, the effective number of valence electrons and ionicity.

Optical characterization of Sb2S3 vacuum annealed films by UV–VIS–NIR spectroscopy and spectroscopic ellipsometry: Determining the refractive index and the optical constants

Using UV–VIS–NIR spectroscopy and spectroscopic ellipsometry (SE) techniques, we studied the optical characteristics of Sb2S3 thin films produced by a one-step thermal evaporation process and annealed for 2 h at various temperatures under vacuum atmosphere. The X-ray diffraction study shows that a structural transition from amorphous to polycrystalline nature occurred at vacuum annealing temperature of 200 °C. According to UV–VIS–NIR spectroscopic measurements, the Sb2S3 films showed a high absorption coefficient in the visible region (α > 104 cm−1) and a direct band gap energy that decreases from 2.00 eV to 1.63 eV as the annealing temperatures increase. Furthermore, we calculate the optical constants of the elaborated Sb2S3 films, such as refractive index n and extinction coefficient k, by fitting the ellipsometric measurements of the pseudo-refractive index < n > and the pseudo-extinction coefficient < k > . It was observed that the obtained values for n at 800 nm are 2.7, 2.9, 3.5, and 4.0 for as-deposited and annealed films, respectively, at 150, 200, and 250 °C. The dielectric properties were also determined using the Wemple DiDomenico (WDD) and Spitzer-Fan models.

Uncovering the replacement of Zn2+ ions on nano-structural, opto/magneto/electrical, antibacterial and antifungal attributes of nickel oxide nanoparticles via sol-gel strategy

Transition metal oxides have gathered momentum among the scientific community on account of their peculiar procession in physico-chemical, opto-electronic, magnetic, electro-chemical, and biological attributes resulting from anisotropic charge distribution of partly filled d-orbitals, non-stoichiometric behaviour, and diverse oxidation states of the cations. The current work emphasize on the systematic synthesis and characterization of pristine and zinc (Zn) incorporated nickel oxide (NiO) nanoparticles in varying concentrations ZnxNi1-xO (x=0, 0.1, 0.2, and 0.3) via a scalable sol-gel approach assisting citric acid (C6H8O7) as a congealing factor. A series of extensive analyses were executed to investigate the structural, opto-electrical, and magnetic characteristics of prepared nanoparticles. X-Ray Diffraction (XRD) studies confirmed the face-centered cubic structure of as-synthesized samples and the corresponding crystallite size is found to decrease with an increasing dopant concentration as estimated from the Scherrer method. Scanning Electron Microscopy (SEM) studies portrayed the spherical structure and porous nature of NiO nanoparticles. Particle size calculated from SEM shows the decreasing trend with dopant discrepancy which is in accordance with crystallite size measured from XRD results. Energy Dispersive X-ray (EDX) spectra revealed the presence of estimated molecular assembly in synthesized samples. The cubic configuration and the presence of functional groups existing in synthesized nanoparticles were endorsed from Fourier Transform Infra-Red (FTIR) spectroscopy operated in the vibrational IR frequency region. The optical absorption spectrum examined from Ultra Violet-visible (UV–vis) spectroscopy evaluates the energy bandgap and it is noticed to increase from 2.48 to 2.87 ​eV affirming the Burstein Moss shift. The energy dispersion of optical parameters plays a crucial contribution in optical materials pursuant to its prominence in optical communications and in fabricating novel devices for spectral dispersion. Optical and energy dispersion parameters evaluated from Wemple-DiDomenico (WDD) model and non-linear optical parameters were deliberated from optical studies. The performance of integrated optical systems such as monochromatic filters, optical and electrical switches, laser diodes, detectors, and amplifiers can be controlled by the dispersion parameters. Urbach energy and another pivotal optical criterion highly correlated with the bandgap energy anchored in the fabrication of optoelectronic devices were assessed. The electrical characteristics such as dielectric constant, loss, and conductivity exhibited by pure and Zn doped nickel oxide nanoparticles were reported. Molecular electronic polarizability assessed through elementary solid-state parameters is in better concurrence with diverse relations like Clausius-Mossotti, Lorentz-Lorent, bulk modulus, optical electronegativity, and energy band gap. The pore size distribution of substance matrix and the associated surface area were elucidated from Brunauer-Emmett-Teller (BET) analysis. Dispersive magnetic properties and two pivotal parameters were derived from the Law of Approach to Saturation (LAS) operandi. Further, microbial cell mechanism was illustrated through nano-architecture design, and the antibacterial and antifungal activity encountered by undoped and zinc doped NiO nanoparticles against different microbial strains were deeply discussed for pilot production of antimicrobial agents.

Modulation of the optoelectronic properties of polyimide (Kapton-H) films by gamma irradiation for laser attenuation and flexible space structures

polyimide (PI or Kapton-H) has proven its potential in the field of optoelectronic, nuclear technology and space industry due to its excellent electric insulation, transparency and flexibility. The present study focuses the effect of γ-irradiation (0, 25, 50 and 100 Mrd) on the structural, optical, AC electrical conductivity and dielectric properties of PI film samples. In the results, the crystallite size was shown to be increased from 37.77 to 73.42 Å in the X-ray diffraction XRD study. Certain variations in assignment bands like (O–H) stretching and carbonyl (CO) symmetric stretching were observed in FTIR spectrum. A shift in the absorption edge is observed in the UV–vis spectroscopy to higher wavelengths and consequently a decrease in both direct and indirect band gap energy Egopt. The calculated values of the refractive index n is also increased upon γ-irradiation. The parameters of Wemple - DiDomenico (WDD) are calculated for pristine and γ-irradiated film samples. The dependence of the dissipation factor tanδ and optical conductivity σopt are studied as a function of the photon energy (hν) at different γ-doses. Moreover, the 3rd order non-linear susceptibility χ(3) and non-linear index of refraction n2 were also studied. Optical limiting measurements indicate that irradiation of PI samples with high γ-dose (100 Mrd) highly attenuated the laser beams (532 and 632.8 nm) which may be useful for use in optoelectronic laser limiters and filters. The AC electrical conductivity σac, dielectric constant ε′ and dielectric loss ε″ are also investigated in the range of frequency (100 Hz - 1 MHz). The values of σAC are enhanced by irradiation with γ-rays and the behaviors of the frequency exponent s indicates that the AC conduction in PI samples is governed by the correlated barrier hopping (CBH) mechanism.

Studying the Optical and Electrical Properties of CuGa0.5In0.5Se2 Chalcopyrite Due to Substrate Temperature and Gamma Irradiation

Thin films of chalcopyrite CuGa0.5In0.5Se2 (CGIS) with thickness ≈2000 Å are prepared by thermal evaporation method at different values of substrate temperature (Ts) 373, 473, and 573 K. Crystal structure and elemental chemical composition are examined by X‐ray diffraction and energy dispersive X‐ray analysis, respectively. The optical constants of the films in the spectral range 200 nm ≤ λ ≤ 2500 nm are calculated. It is found that the transmittance and band gap (Eg) decrease with increasing the substrate temperature (Ts) while Urbach energy increases with the increase of Ts. The Wemple–DiDomenico (WDD) model is used to calculate the oscillator parameters. Furthermore, the prepared films are irradiated with γ‐ray at different doses 2, 4, and 8 kGy. The results reveal that the optical band gap increases and Urbach energy decreases as γ‐doses increase. Finally, the substrate temperature and γ irradiation upon the electrical resistivity are studied. Consequently, it is found that the electrical resistivity decreases with the increase of both the substrate temperature and γ‐irradiation. In conclusion, the γ‐irradiation stimulates a change in optical parameters and electrical resistivity which can be utilized for industrial dosimetric purposes.

High refractive index (Dy) doped (GeTe)80(InTe)20 thin films for sub-THz and millimeter-wave applications

Chalcogenide materials are ideal for IR applications because of their wide transmission window, variable bandgap, and high nonlinearity. In this regard, optical characteristics of ( Dy ) doped ( GeTe 2 ) 80 ( In 2 Te 3 ) 20 thin films have been measured and investigated. The influence of annealing on the optical characteristics of thin films has been reported. The reflectance and transmittance spectra were used to calculate the refractive index ( n ) and extinction coefficient ( k ) of thin films. With the annealing of as-prepared film, the penetration depth (Δ) measured at a wavelength of 1.1 μm and bandgap ( E g ) decrease. The relaxation process has been realized using electric modulus ( M ) determination, and the dielectric loss has been estimated in terms of loss tangent (tan δ). Wemple Di-Domenico (WDD) model has been employed to calculate dispersion energy ( E d ) and average energy gap ( E 0 ). Using the values of E 0 and E d , the static refractive index ( n 0 ) and the moments ( M -1 , M -3 ) of the optical spectra have been determined. Sellmeier oscillator parameter ( λ 0 ) increases while S o decreases with a rise in the annealing temperature.