scholarly journals Reduced Graphene Oxide/Polyvinyl Alcohol Nanofibers Fabricated by Electrospinning Technique as An Ideal Candidate for Organic Solar Cell Devices

2021 ◽  
Vol 6 (1) ◽  
pp. 10-18
Author(s):  
Asriani Asriani ◽  
◽  
Iman Santoso ◽  
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Solar Cell ◽  
Ftir Spectroscopy ◽  
Organic Solar Cell ◽  
Chemical Reduction ◽  
Complex Refractive Index ◽  
Complex Dielectric Constant ◽  
Electrospinning Technique

Functionalization of rGO that previously obtained by chemical reduction using hydrazine hydrate, has been done by changing its morphology into nanofiber with electrospinning technique and using PVA as a polymer matrix. The rGO nanofibers that had been formed were then characterized using Fourier Transformation-Infra Red (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and UV-Vis Spectrophotometer. FTIR spectroscopy confirmed the presence of C – C group and C = O group in nanofibers. SEM showed the change of nanofibers morphology which is marked by the increasing of fibres diameter and the hollow fibres become brighter. Furthermore, the effect of rGO concentration to nanofiber optical properties was confirmed by UV-Vis spectrophotometer. According to this characterization, the absorbance of rGO/PVA nanofiber is decreased due to increased rGO concentration. The detail of optical properties of rGO is studied through complex refractive index and dielectric constant in which Kramers-Kronig transformation is then employed to calculate complex refractive index and complex dielectric constant. From the data, the optical properties of rGO/PVA nanofibers indicating that rGO/PVA nanofibers can be applied as transparent electrode an organic solar cell devices.

Optical properties of the different tapered silicon nanowires based on KK relation

2014 ◽  
Vol 23 (04) ◽  
pp. 1450049 ◽  
Author(s):  
Zhongyi Guo ◽  
Keya Zhou ◽  
Anjun Zhang ◽  
Jung-Ho Lee
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Silicon Nanowires ◽  
Complex Refractive Index ◽  
Complex Dielectric Constant ◽  
Reflection Spectra ◽  
Complex Dielectric Function ◽  
Concrete Material ◽  
Material Parameters

The optical properties of the various types of tapered silicon nanowires (SiNWs) have been investigated by the phase retrieving method of utilizing the experimental reflection spectra with the aid of the Kramers–Kronig (KK) relation. The effective refractive index (n) and the extinction coefficient (K) of each tapered SiNWs and combined silicon nanowires and microwires (CNMW) array samples can be obtained from concrete simulation by the KK relation. At the same time, we can also obtain the real part (ε′) and imaginary part (ε″) of the effective complex dielectric constant from the relation between the refractive index and the complex dielectric constant of samples. And the simulated results show that the relative material parameters (effective complex refractive index, effective complex dielectric function) can be modulated from a concrete material processing.

Study the Effect of Heat Treatment and Pressure on some the Optical Properties of the Pure PVA Nano Polymer

2021 ◽  
Vol 900 ◽  
pp. 16-25
Author(s):  
Tabarak Mohammed Awad ◽  
May A.S. Mohammed
Keyword(s):  
Heat Treatment ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Polyvinyl Alcohol ◽  
Complex Dielectric Constant ◽  
Different Temperatures ◽  
German Origin ◽  
Increasing Temperature

In this study, some optical properties were studied of the pure vinyl polyvinyl alcohol (PVA) nanopolymer (German origin). Under the influence of different temperatures and pressures of PVA. Where 25 samples were prepared for the purpose of conducting the research. Which studied the study of these samples was done by recording the absorbance and transmittance spectra of the wavelengths (200-900) nm. From them, absorbance, transmittance, reflectivity, absorption coefficient, refractive index, extinction coefficient, complex dielectric constant were calculated. At different temperatures (25,40, 80, 120, 160)°C. And with different pressures within the range (7.5,8,8.5,9,9.5) MPa. The results are that the permeability of the polymer (PVA) at different temperatures for each pressure decreases with increasing temperature, and that all other calculated optical properties increase with increasing temperature.

scholarly journals Complex Refractive Index of Strontium Titanate in the Terahertz Frequency Range

2019 ◽  
Vol 7 (4) ◽  
pp. 71-80 ◽  
Author(s):  
V. R. Bilyk ◽  
K. A. Grishunin
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Strontium Titanate ◽  
Time Domain ◽  
Complex Refractive Index ◽  
Complex Dielectric Constant ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Time Domain Spectroscopy ◽  
Terahertz Frequency Range

The recent progress in terahertz time-domain spectroscopy enables the accurate and reliable measurements of dielectric properties in comparison with the traditional far-infrared spectroscopy using an incoherent light source. The broadband THz-TDS is a powerful tool to determine the real and imaginary parts of a complex dielectric constant by the transmission which allows to detect the parameters of the soft modes in ferroelectrics. In this work, the terahertz time-domain spectroscopy was used to investigate the dependence of the complex refractive index of a single-crystal quantum paraelectric strontium titanate in the terahertz frequency range from 0.3 to 2 THz. It was shown that the low-frequency terahertz response of the material is determined by the soft phonon mode TO1. The measured experimental dependences showed a good agreement with the theoretical curves obtained from the analysis of the Lorentz oscillator model for the complex dielectric constant of strontium titanate. The obtained results are necessary for understanding the principle of possibility to manipulate the order parameter in ferroelectric materials and can be used to create energy-efficient memory devices with a speed of recording information close to the theoretical limit.

scholarly journals Broadband spectroscopy of astrophysical ice analogues

2019 ◽  
Vol 629 ◽  
pp. A112 ◽  
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.

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

Photonics ◽  
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.

scholarly journals Characteristics of Poly(vinyl Alcohol) (PVA) Based Composites Integrated with Green Synthesized Al3+-Metal Complex: Structural, Optical, and Localized Density of State Analysis

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1316
Author(s):  
Shujahadeen B. Aziz ◽  
Muaffaq M. Nofal ◽  
Hewa O. Ghareeb ◽  
Elham M. A. Dannoun ◽  
Sarkawt A. Hussen ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Metal Complex ◽  
Band Gap ◽  
Optical Band Gap ◽  
Complex Dielectric Constant ◽  
Poly Vinyl Alcohol ◽  
Optical Parameters ◽  
Dispersion Energy ◽  
Casting Technique

The influence of dispersing Al-metal complex on the optical properties of PVA was investigated using UV–visible spectroscopy. Polymer composite films with various Al3+-complex amounts in the PVA matrix were arranged by solution casting technique by means of distilled water as a widespread solvent. The formation of Al3+-metal complex was verified through Ultraviolet–visible (UV-Vis) and Fourier-transform infrared spectroscopy (FTIR) examinations. The addition of Al-complex into the polymer matrix led to the recovery of the optical parameters such as dielectric constant (εr and εi) and refractive index (n). The variations of real and imaginary parts of complex dielectric constant as a function of photon wavelength were studied to calculate localized charge density values (N/m*), high-frequency dielectric constant, relaxation time, optical mobility, optical resistivity, and plasma angular frequency (ωp) of electrons. In proportion with Al3+-complex content, the N/m* values were amplified from 3.68 × 1055 kg−1 m−3 to 109 × 1055 kg−1 m−3. The study of optical parameters may find applications within optical instrument manufacturing. The optical band gap was determined from Tauc’s equation, and the type of electronic transition was specified. A remarkable drop in the optical band gap was observed. The dispersion of static refractive index (no) of the prepared composites was analyzed using the theoretical Wemple–DiDomenico single oscillator model. The average oscillator energy (Eo) and oscillator dispersion energy (Ed) parameters were estimated.

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

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.

scholarly journals Preparation and Studying the Optical Properties of (Sb2o3) Thin Films

2018 ◽  
Vol 26 (10) ◽  
pp. 249-256
Author(s):  
Waleed Khalid Kadhim
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Thermal Evaporation ◽  
Glass Slide ◽  
Antimony Trioxide ◽  
Hot Plate ◽  
Different Thickness

In this paper I present the preparation of (Sb2o3) thin films using thermal evaporation in vacuum, procedure with different thickness  (100 ,150 ,200 ,and 250) nm, by using ( hot plate) from Molybdenum matter at temperature in ( 9000c) and the period of time (15mint) ,the prepared in a manner thermal evaporation in a vacuum and precipitated on glass bases, pure Antimony Trioxide (sb2o3 ) thin films with various condition have been successfully deposited by (T.E.V) on glass slide substrates. The substrates temperature of about 100oC and the vacuum of about 10-6 torr, to investigated oxidation of evaporated, measure spectra for prepared films in arrange of wavelength (250 – 1100 nm). The following optical properties have been calculated: the absorption coefficient, the forbidden (Eg) for direct and indirect transitions "absorbance, refractive index,  extinction coefficient, real and imaginary parts" of the dielectric constant.

scholarly journals Annealing Effect on Some Optical Properties of Cr2O3 Thin Films Prepared by Spray Pyrolysis Technique

2011 ◽  
Vol 8 (2) ◽  
pp. 561-565
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Spray Pyrolysis ◽  
Annealing Temperature ◽  
Spray Pyrolysis Technique ◽  
Annealing Effect ◽  
Before And After

Cr2O3 thin films have been prepared by spray pyrolysis on a glass substrate. Absorbance and transmittance spectra were recorded in the wavelength range (300-900) nm before and after annealing. The effects of annealing temperature on absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant and optical conductivity were expected. It was found that all these parameters increase as the annealing temperature increased to 550°C.

scholarly journals Optical properties of atmospheric fine particles near Beijing during the HOPE-J<sup>3</sup>A Campaign

2015 ◽  
Vol 15 (22) ◽  
pp. 33675-33730
Author(s):  
X. Xu ◽  
W. Zhao ◽  
Q. Zhang ◽  
S. Wang ◽  
B. Fang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Fine Particles ◽  
Complex Refractive Index ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Organic Mass ◽  
Absorption Coefficients ◽  
Aerosol Composition ◽  
Inorganic Species

Abstract. The optical properties and chemical composition of PM1.0 (particulate with an aerodynamic diameter of less than 1.0 μm) particles in a suburban environment (Huairou) near the mega-city Beijing were measured during the HOPE-J3A (Haze Observation Project Especially for Jing-Jin-Ji Area) field campaign. The campaign covered the period November 2014 to January 2015 during the winter coal heating season. The average and standard deviations for the extinction, scattering, absorption coefficients, and the aerosol single scattering albedo (SSA) at λ = 470 nm during the measurement period were 201 ± 240, 164 ± 202, 37 ± 43 Mm-1, and 0.80 ± 0.08, respectively. The mean mass scattering (MSE) and absorption (MAE) efficiencies were 4.77 ± 0.01 and 0.87 ± 0.03 m2g-1, respectively. Highly time-resolved air pollution episodes clearly show the dramatic evolution of the PM1.0 size distribution, extensive optical properties (extinction, scattering, and absorption coefficients) and intensive optical properties (single scattering albedo and complex refractive index) during haze formation, development and decline. Time periods were classified into three different pollution levels (clear, slightly polluted, and polluted) for further analysis. It was found that: (1) The diurnal patterns of the aerosol extinction, scattering, absorption coefficients, and SSA differed for the three pollution classes. (2) The real and imaginary part of complex refractive index (CRI) increased, while the SSA decreased from clear to polluted days. (3) The relative contributions of organic and inorganic species to observed aerosol composition changed significantly from clear to polluted days: the organic mass fraction decreased (50 to 43 %) while the proportion of sulfates, nitrates, and ammonium increased strongly (34 to 44 %). (4) The fractional contribution of chemical components to extinction coefficients was calculated by using the modified IMPROVE algorithm. Organic mass was the largest contributor (58 %) to the total extinction of PM1.0. When the air quality deteriorated, the change of the relative contribution of sulfate aerosol to the total extinction was small, but the contribution of nitrate aerosol increased significantly (from 17 % on clear days to 23 % on polluted days). (5) The observed mass scattering efficiencies increased consistently with the pollution extent, however, the observed mass absorption efficiencies increased consistently with increasing mass concentration in slightly pollution conditions, but decreased under polluted conditions.

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