scholarly journals Study of Absorption Spectra, Fluorescence and Energy Levels of Fluorescein Dye

2018 ◽  
Vol 26 (8) ◽  
pp. 164-175
Author(s):  
Afrah M. AL Hussainey ◽  
Salar Hussein Ibrahem ◽  
Talib M. Abbas ALShafie

The absorption and fluorine spectra of dissolved fluorescein solution in ethanol and different concentrations were studied. The optical properties(absorbance, permeability, linear absorption, and refractive index, as well as time and fluoridation)were calculated. The results showed that a decrease in concentration leads to a decrease in absorption values and an increase in permeability values. This results in a decrease in the values of the absorption coefficient and refractive index. This is in accordance with Lambert's law. Also, the values of the fluorine are lower. The top of the emission spectrum is transferred to the longer wavelengths. The temporal age of fluoride decreases and the quantitative output increases, thus using this dye as an effective laser medium in liquid state lasers. The infrared spectroscopy of the dye was also studied using the (Gaussian 9) program.                                         

2021 ◽  
Vol 900 ◽  
pp. 16-25
Author(s):  
Tabarak Mohammed Awad ◽  
May A.S. Mohammed

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.


2010 ◽  
Vol 19 (03) ◽  
pp. 427-436
Author(s):  
A. MENDOZA-GARCÍA ◽  
A. ROMERO-DEPABLOS ◽  
M. A. ORTEGA ◽  
J. L. PAZ ◽  
L. ECHEVARRÍA

We have developed an analytical method to describe the optical properties of nanoparticles, whose results are in agreement with the observed experimental behavior according to the size of the nanoparticle under analysis. Our considerations to describe plasmonic absorption and dispersion are based on the combination of the two-level molecular system and the two-dimensional quantum box models. Employing the optical stochastic Bloch equations, we have determined the system's coherence, from which we have calculated expressions for the absorption coefficient and refractive index. The innovation of this methodology is that it allows us to take into account the solvent environment, which induce quantum effects not considered by classical treatments.


2018 ◽  
Vol 26 (10) ◽  
pp. 249-256
Author(s):  
Waleed Khalid Kadhim

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.


Author(s):  
J. Damisa ◽  
J. O. Emegha ◽  
I. L. Ikhioya

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.


2011 ◽  
Vol 8 (2) ◽  
pp. 561-565
Author(s):  
Baghdad Science Journal

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.


2013 ◽  
Vol 677 ◽  
pp. 36-41 ◽  
Author(s):  
Yurii N. Kulchin ◽  
Vladimir P. Dzyuba ◽  
Valentin A. Milichko

The study of optical properties of Al2O3, SiO2, TiO2, and ZnO nanoparticles in weak optical fields is presented. We found that some nanoparticles have unique optical nonlinearity: The values of portions to nanoparticle refractive index and absorption coefficient increase to maxima, and then decrease to zero when the radiation intensity changes from 1 to 500 W/cm2. We estimated electron energy structures of nanoparticles and experimentally determined that such nonlinearity is directly related to peculiarities of the energy structure. We obtained a good fitting of theoretical results to the experimental ones (e.g. absorbance spectra of nanoparticles; the dependence of nanoparticle refractive index and absorption coefficient on radiation intensity).


2013 ◽  
Vol 27 (17) ◽  
pp. 1350127
Author(s):  
S. HADJI ◽  
S. BERRAH ◽  
H. ABID

In this paper, we present numerical calculations based on the full potential augmented plane wave (FP-LAPW) method within the local density approximation (LDA) to study the optical properties of the ternary alloy Al x Ga 1-x N . The shape of the dielectric function, the refractive index, and the absorption coefficient versus photon energy were presented. From the results, we deduce the possibility of this alloy to be used in the optoelectronic and photovololtaic area.


2018 ◽  
Vol 14 (2) ◽  
pp. 5624-5637
Author(s):  
A.A. Attia ◽  
M.M. Saadeldin ◽  
K. Sawaby

Para-quaterphenyl thin films were deposited onto glass and quartz substrates by thermal evaporation method. p-quaterphenyl thin films wereexposed to gamma radiation of Cobat-60 radioactive source at room temperature with a dose of 50 kGy to study the effect of ?-irradiation onthe structure and the surface morphology as well as the optical properties of the prepared films. The crystalline structure and the surface morphology of the as-deposited and ?-irradiated films were examined using the X-ray diffraction and the field emission scanning electron microscope. The optical constants (n & k) of the as-deposited and ?-irradiated films were obtained using the transmittance and reflectance measurements, in the wavelength range starting from 250 up to 2500 nm. The analysis of the absorption coefficient data revealed an allowed direct transition with optical band gap of 2.2 eV for the as-deposited films, which decreased to 2.06 eV after exposing film to gamma irradiation. It was observed that the Urbach energy values change inversely with the values of the optical band gap. The dispersion of the refractive index was interpreted using the single oscillator model. The nonlinear absorption coefficient spectra for the as-deposited and ?-irradiated p-quaterphenyl thin films were obtained using the linear refractive index.


Author(s):  
Maan A. Saleh ◽  
Abdulazeez O.Mousa ◽  
Mohammed Hadi Shinen

The study includes the recording the absorption and permeability spectra of a combination of polyaniline compound solution with poly(3,4-ethylenedioxythiophene) PEDOT and calculating the absorption factor and other optical constants. These samples were attended to different concentrations (0.01%,0.02%,0.03%) of PEDOT added to polyaniline. The values of absorbance, the refractive index values of pure polymer and its additives are increasing with the increase of the concentrations of these polymer,noting that the increment of absorption coefficient values under the influence of addition caused by increasing density of the solutions as a result of the increased concentrations, that led to the increase of light absorbed because the interaction of the electromagnetic wave and the large molecules of the polymer increases with concentration,the results show that decreasing in the values of transmittance with all concentrations, the values of reflectance are increases with increasing concentration before and after the doping, the results showed decrease energy gap with increasing ratio of doping.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Shahin ◽  
Wesam Bachir ◽  
Moustafa Sayem El-Daher

The optical properties of 1 μm polystyrene in the wavelength range of 500–750 nm were estimated by using a white light spectrophotometric transmittance spectroscopy and a single integrating sphere system. To retrieve the optical characteristics, two analytical methods, namely, diffusion approximation and Kubelka–Munk were used, and then their results were compared with Mie theory calculations. The correspondence of the Kubelka–Munk scattering coefficient with Mie was obvious, and relative errors varied between 6.73% and 2.66% whereas errors varied between 6.87% and 3.62% for diffusion theory. Both analytical methods demonstrated the absorption property of polystyrene over the abovementioned wavelength range. Although absorption coefficient turned out to be much lower than scattering, constructing a realistic optical phantom requires taking into account absorption property of polystyrene. Complex refractive index of polystyrene based on these two methods was determined. Inverse Mie algorithm with scattering coefficient was also used to retrieve the real part of refractive index and absorption coefficient for calculating the imaginary part of refractive index. The relative errors of the real part did not exceed 2.6%, and the imaginary part was in consistence with the prior works. Finally, the presented results confirm the validity of diffusion theory with a single integrating sphere system.


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