Effect of Ag-Nanoparticles Doped in Polyvinyl Alcohol on the Structural and Optical Properties of PVA Films

The effect of silver nanoparticles doped in PVA on the structural and optical properties of composite films is studied experimentally. Samples are PVA films of 0.14 mm thickness doped with different sizes and concentrations of silver nanoparticles. Structural properties are studied using X-ray diffraction and FTIR spectrum. Using the reflectance and transmittance of samples, the effect of doped nanoparticles and their concentration on optical parameters of PVA films include absorption coefficient, optical bandgap energy, complex refractive index, complex dielectric function, complex optical conductivity, and relaxation time is extracted and discussed. The dispersion of the refractive index of films in terms of the single oscillator Wemple-DiDomenico (WD) model is investigated and the dispersion parameters are calculated. Results show that by doping silver nanoparticles in PVA, number of Bragg’s planes in the structure of polymer and its crystallinity are increased noticeably. Ag–O bonds are formed in the films and the bandgap energy of samples is decreased. Calculations based on WD model confirm that by doping nanoparticles, the anion strength of PVA as a dielectric medium is decreased.

Download Full-text

Polymer Composites with 0.98 Transparencies and Small Optical Energy Band Gap Using a Promising Green Methodology: Structural and Optical Properties

Polymers ◽

10.3390/polym13101648 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1648

Author(s):

Muaffaq M. Nofal ◽

Shujahadeen B. Aziz ◽

Jihad M. Hadi ◽

Wrya O. Karim ◽

Elham M. A. Dannoun ◽

...

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Polymer Composites ◽

Amorphous Phase ◽

Absorption Edge ◽

Complex Form ◽

Bandgap Energy ◽

Optical Parameters ◽

Visible Spectroscopy ◽

Uv Visible

In this work, a green approach was implemented to prepare polymer composites using polyvinyl alcohol polymer and the extract of black tea leaves (polyphenols) in a complex form with Co2+ ions. A range of techniques was used to characterize the Co2+ complex and polymer composite, such as Ultraviolet–visible (UV-Visible) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The optical parameters of absorption edge, refractive index (n), dielectric properties including real and imaginary parts (εr, and εi) were also investigated. The FRIR and XRD spectra were used to examine the compatibility between the PVA polymer and Co2+-polyphenol complex. The extent of interaction was evidenced from the shifts and change in the intensity of the peaks. The relatively wide amorphous phase in PVA polymer increased upon insertion of the Co2+-polyphenol complex. The amorphous character of the Co2+ complex was emphasized with the appearance of a hump in the XRD pattern. From UV-Visible spectroscopy, the optical properties, such as absorption edge, refractive index (n), (εr), (εi), and bandgap energy (Eg) of parent PVA and composite films were specified. The Eg of PVA was lowered from 5.8 to 1.82 eV upon addition of 45 mL of Co2+-polyphenol complex. The N/m* was calculated from the optical dielectric function. Ultimately, various types of electronic transitions within the polymer composites were specified using Tauc’s method. The direct bandgap (DBG) treatment of polymer composites with a developed amorphous phase is fundamental for commercialization in optoelectronic devices.

Download Full-text

Flexible Methyl Cellulose/Polyaniline/Silver Composite Films with Enhanced Linear and Nonlinear Optical Properties

Polymers ◽

10.3390/polym13081225 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1225

Author(s):

Ali Atta ◽

Mostufa M. Abdelhamied ◽

Ahmed M. Abdelreheem ◽

Mohamed R. Berber

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Band Gap ◽

Nonlinear Optical ◽

Composite Films ◽

Methyl Cellulose ◽

Carbon Cluster ◽

Nonlinear Susceptibility ◽

Optical Parameters ◽

Flexible Polymer

In order to potentiate implementations in optical energy applications, flexible polymer composite films comprising methyl cellulose (MC), polyaniline (PANI) and silver nanoparticles (AgNPs) were successfully fabricated through a cast preparation method. The composite structure of the fabricated film was confirmed by X-ray diffraction and infrared spectroscopy, indicating a successful incorporation of AgNPs into the MC/PANI blend. The scanning electron microscope (SEM) images have indicated a homogenous loading and dispersion of AgNPs into the MC/PANI blend. The optical parameters such as band gap (Eg), absorption edge (Ed), number of carbon cluster (N) and Urbach energy (Eu) of pure MC polymer, MC/PANI blend and MC/PANI/Ag films were determined using the UV optical absorbance. The effects of AgNPs and PANI on MC polymer linear optical (LO) and nonlinear optical (NLO) parameters including reflection extinction coefficient, refractive index, dielectric constant, nonlinear refractive index, and nonlinear susceptibility are studied. The results showed a decrease in the band gap of MC/PANI/AgNPs compared to the pure MC film. Meanwhile, the estimated carbon cluster number enhanced with the incorporation of the AgNPs. The inclusion of AgNPs and PANI has enhanced the optical properties of the MC polymer, providing a new composite suitable for energy conversion systems, solar cells, biosensors, and nonlinear optical applications.

Download Full-text

Broadband spectroscopy of astrophysical ice analogues

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935619 ◽

2019 ◽

Vol 629 ◽

pp. A112 ◽

Cited By ~ 8

Author(s):

B. M. Giuliano ◽

A. A. Gavdush ◽

B. Müller ◽

K. I. Zaytsev ◽

T. Grassi ◽

...

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Time Domain ◽

Complex Refractive Index ◽

Far Infrared ◽

Infrared Region ◽

Thz Radiation ◽

The Real ◽

Thz Range ◽

The Time Domain

Context. Reliable, directly measured optical properties of astrophysical ice analogues in the infrared and terahertz (THz) range are missing from the literature. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-infrared region. Aims. Coherent THz radiation allows for direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. Methods. We recorded the time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5 K and annealed to 33 K at different thicknesses. We developed a new algorithm to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. Results. The complex refractive index in the wavelength range 1 mm–150 μm (0.3–2.0 THz) was determined for the studied ice samples, and this index was compared with available data found in the literature. Conclusions. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables us, for the first time, to determine the optical properties of astrophysical ice analogues without using the Kramers–Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground-based facilities as well as future space telescope missions, and we used these data to estimate the opacities of the dust grains in presence of CO ice mantles.

Download Full-text

Synthesis of PVA/CeO2 Based Nanocomposites with Tuned Refractive Index and Reduced Absorption Edge: Structural and Optical Studies

Materials ◽

10.3390/ma14061570 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1570

Author(s):

Shujahadeen B. Aziz ◽

Elham M. A. Dannoun ◽

Dana A. Tahir ◽

Sarkawt A. Hussen ◽

Rebar T. Abdulwahid ◽

...

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Absorption Edge ◽

Ceo2 Nanoparticles ◽

Poly Vinyl Alcohol ◽

Optical Parameters ◽

Single Oscillator Model ◽

Vis Spectroscopy ◽

The Impact ◽

Host Polymer

In the current study, polymer nanocomposites (NCPs) based on poly (vinyl alcohol) (PVA) with altered refractive index and absorption edge were synthesized by means of a solution cast technique. The characterization techniques of UV–Vis spectroscopy and XRD were used to inspect the structural and optical properties of the prepared films. The XRD patterns of the doped samples have shown clear amendments in the structural properties of the PVA host polymer. Various optical parameters were studied to get more insights about the influence of CeO2 on optical properties of PVA. On the insertion of CeO2 nanoparticles (NPs) into the PVA matrix, the absorption edge was found to move to reduced photon energy sides. It was concluded that the CeO2 nanoparticles can be used to tune the refractive index (n) of the host polymer, and it reached up to 1.93 for 7 wt.% of CeO2 content. A detailed study of the bandgap (BG) was conducted using two approaches. The outcomes have confirmed the impact of the nanofiller on the BG reduction of the host polymer. The results of the optical BG study highlighted that it is crucial to address the ɛ” parameter during the BG analysis, and it is considered as a useful tool to specify the type of electronic transitions. Finally, the dispersion region of n is conferred in terms of the Wemple–DiDomenico single oscillator model.

Download Full-text

Optical Characterization of Ultra-Thin Films of Azo-Dye-Doped Polymers Using Ellipsometry and Surface Plasmon Resonance Spectroscopy

Photonics ◽

10.3390/photonics8020041 ◽

2021 ◽

Vol 8 (2) ◽

pp. 41

Author(s):

Najat Andam ◽

Siham Refki ◽

Hidekazu Ishitobi ◽

Yasushi Inouye ◽

Zouheir Sekkat

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Spectroscopic Ellipsometry ◽

Plasmon Resonance ◽

Complex Refractive Index ◽

Resonance Spectroscopy ◽

Doped Polymers

The determination of optical constants (i.e., real and imaginary parts of the complex refractive index (nc) and thickness (d)) of ultrathin films is often required in photonics. It may be done by using, for example, surface plasmon resonance (SPR) spectroscopy combined with either profilometry or atomic force microscopy (AFM). SPR yields the optical thickness (i.e., the product of nc and d) of the film, while profilometry and AFM yield its thickness, thereby allowing for the separate determination of nc and d. In this paper, we use SPR and profilometry to determine the complex refractive index of very thin (i.e., 58 nm) films of dye-doped polymers at different dye/polymer concentrations (a feature which constitutes the originality of this work), and we compare the SPR results with those obtained by using spectroscopic ellipsometry measurements performed on the same samples. To determine the optical properties of our film samples by ellipsometry, we used, for the theoretical fits to experimental data, Bruggeman’s effective medium model for the dye/polymer, assumed as a composite material, and the Lorentz model for dye absorption. We found an excellent agreement between the results obtained by SPR and ellipsometry, confirming that SPR is appropriate for measuring the optical properties of very thin coatings at a single light frequency, given that it is simpler in operation and data analysis than spectroscopic ellipsometry.

Download Full-text

Self-assembled silver nanoparticles for plasmon-enhanced solar cell back reflectors: correlation between structural and optical properties

Nanotechnology ◽

10.1088/0957-4484/24/26/265601 ◽

2013 ◽

Vol 24 (26) ◽

pp. 265601 ◽

Cited By ~ 63

Author(s):

Seweryn Morawiec ◽

Manuel J Mendes ◽

Salvatore Mirabella ◽

Francesca Simone ◽

Francesco Priolo ◽

...

Keyword(s):

Silver Nanoparticles ◽

Optical Properties ◽

Solar Cell ◽

Structural And Optical Properties ◽

Back Reflectors ◽

Self Assembled

Download Full-text

Thickness Dependent Structural and Optical Properties of Cadmium Selenide Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.665.159 ◽

2013 ◽

Vol 665 ◽

pp. 159-167

Author(s):

M.S. Jani ◽

H.S. Patel ◽

J.R. Rathod ◽

K.D. Patel ◽

V.M. Pathak ◽

...

Keyword(s):

Thin Films ◽

Optical Properties ◽

Hexagonal Wurtzite Structure ◽

Optical Bandgap ◽

Bandgap Energy ◽

Structural And Optical Properties ◽

Structural Investigations ◽

Glass Substrates ◽

Optical Bandgap Energy ◽

Different Thickness

In this paper structural and optical properties of CdSe thin films with different thickness deposited by thermal evaporation under vacuum onto glass substrates are presented. The structural investigations performed by means of XRD technique showed that the films have a polycrystalline and hexagonal (würtzite) structure. The values of some important parameters of the studied films (absorption coefficient and optical bandgap energy) are determined from transmission spectra. The values of the optical bandgap energy (Eg) calculated from the absorption spectra, ranged between 1.67 - 1.74 eV.

Download Full-text

Effect of non-annealed and annealed ZnO on the optical properties of PVC/ZnO nanocomposite films

Journal of Thermoplastic Composite Materials ◽

10.1177/08927057211038631 ◽

2021 ◽

pp. 089270572110386

Author(s):

Ali F Al-Shawabkeh ◽

Ziad M Elimat ◽

Khaleel N Abushgair

Keyword(s):

Dielectric Constant ◽

Refractive Index ◽

Optical Properties ◽

Zno Nanoparticles ◽

Oscillator Strengths ◽

Nanocomposite Films ◽

Optical Parameters ◽

Zno Nanoparticle ◽

Dispersion Energy ◽

Optical Susceptibility

The goal of this study was to investigate the optical properties of the prepared polyvinyl chloride (PVC)/zinc oxide (ZnO) nanocomposite films. The PVC/ZnO nanocomposite films consist of the addition of different concentrations with both non-annealed ZnO nanoparticles and ZnO nanoparticles annealed at temperature of 700°C. The PVC/ZnO nanocomposite films by weight concentrations of (0 wt.%, 2.5 wt.%, 5 wt.% and 10 wt.%) have been prepared by the casting method. The optical absorbance and transmittance values of the composites films were measured in the wavelength range between (250 to 1100 nm) at room temperature by using the UV-1800 Shimadzu spectrophotometer. The optical properties (absorption coefficient, dielectric constant, refractive index, and optical conductivity) have been investigated by the ultraviolet (UV) spectrophotometer. The optical parameters (direct optical energy gap, excitation energy for electronic transitions, the dispersion energy, static refractive index, static dielectric constant, optical oscillator strengths, the moments of optical spectrum, linear optical susceptibility, third-order nonlinear optical susceptibility, nonlinear refractive index, high-frequency dielectric constant, the carrier concentration to the effective mass ratio, the long wavelength refractive index and the plasma frequency) were calculated. The results showed that the optical properties behavior of the PVC/ZnO nanocomposite films was found to be dependent on the ZnO concentration, and photon wavelength. In addition, the results of the study show that the optical parameters can be influenced by alter the concentration of the nonannealed and annealed a ZnO nanoparticle in the PVC polymer matrix.

Download Full-text

Deposition Time induced Structural and Optical Properties of Lead Tin Sulphide Thin Films

Journal of the Nigerian Society of Physical Sciences ◽

10.46481/jnsps.2021.157 ◽

2021 ◽

pp. 455-458

Author(s):

J. Damisa ◽

J. O. Emegha ◽

I. L. Ikhioya

Keyword(s):

Thin Films ◽

Refractive Index ◽

Optical Properties ◽

Absorption Coefficient ◽

Tin Oxide ◽

Deposition Time ◽

Deposition Process ◽

Structural And Optical Properties ◽

X Ray ◽

Prepared Material

Lead tin sulphide (Pb-Sn-S) thin films (TFs) were deposited on fluorine-doped tin oxide (FTO) substrates via the electrochemical deposition process using lead (II) nitrate [Pb(NO3)2], tin (II) chloride dehydrate [SnCl2.2H2O] and thiacetamide [C2H5NS] precursors as sources of lead (Pb), tin (Sn) and sulphur (S). The solution of all the compounds was harmonized with a stirrer (magnetic) at 300k. In this study, we reported on the improvements in the properties (structural and optical) of Pb-Sn-S TFs by varying the deposition time. We observed from X-ray diffractometer (XRD) that the prepared material is polycrystalline in nature. UV-Vis measurements were done for the optical characterizations and the band gap values were seen to be increasing from 1.52 to 1.54 eV with deposition time. In addition to this, the absorption coefficient and refractive index were also estimated and discussed.

Download Full-text

UV-Visible Characterization of Zinc and Potassium Zinc Pyrophosphate

10.21203/rs.3.rs-932638/v1 ◽

2021 ◽

Author(s):

Rahma Ben Said ◽

N. Moutia ◽

B. Louati ◽

K. Guidara ◽

K. Khirouni

Keyword(s):

Refractive Index ◽

Band Gaps ◽

Visible Range ◽

Optical Parameters ◽

Solid Reaction ◽

Dispersion Parameters ◽

Optical Band Gaps ◽

Uv Visible ◽

Fitting In

Abstract New Zn2P2O7, K2ZnP2O7 and KZn1.5P2O7 compounds were synthesized with conventional solid solid reaction method. The optical properties have been studied by using UV-Visible spectrophotometer. The optical band gaps (Eg) were found to be 3.76 eV, 3.39 eV and 3.59eV respectively. Optical parameters such as refractive index, Cauchy’s parameters and conductivity were deduced. The refractive index fitting in the visible range and the dispersion parameters (E0 and Ed) of these compounds were estimated using the Wemple–DiDomenico model.

Download Full-text