scholarly journals Nanostructured device based on coated ZnO layer as a window in solar cell applications

2018 ◽  
Vol 36 (4) ◽  
pp. 570-583
Author(s):  
H. Mokhtari ◽  
M. Benhaliliba ◽  
A. Boukhachem ◽  
M.S. Aida ◽  
Y.S. Ocak
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Electrical Properties ◽  
Spray Pyrolysis Technique ◽  
Optical Measurements ◽  
Visible Range ◽  
Optical Parameters ◽  
Dispersion Energy ◽  
Doping Element ◽  
Single Oscillator

AbstractThis work highlights some physical properties related to the influence of aluminum, tin and copper incorporation on nanostructured zinc oxide (ZnO:M; M:Al, Sn and Cu) thin films prepared by ultrasonic spray pyrolysis technique (USP) on glass substrate at 350±5 °C. For the as-grown layers, M- to Zn-ratio was fixed at 1.5 %. The effects of metal doping on structural, morphological, optical and electrical properties were investigated. X-ray diffraction pattern revealed that the as-prepared thin films crystallized in hexagonal structure with (0 0 2) preferred orientation. The surface topography of the films was performed by atomic force microscopy. AFM images revealed inhibition of grain growth due to the doping elements incorporation into ZnO matrix, which induced the formation of ZnO nanoparticles. Optical measurements showed a high transparency around 90 % in visible range. Some optical parameters, such as optical band gap, Urbach energy, refractive index, extinction coeffi-cient and dielectric constant were studied in terms of doping element. Particularly, dispersion of refractive index was discussed in terms of both Cauchy and single oscillator model proposed by Wemple and DiDomenico. Cauchy parameters and single oscillator energy E0 as well as dispersion energy Ed were calculated. Finally, electrical properties were investigated by means of electrical conductivity and Hall effect measurements. The measurements confirmed n type conductivity of the prepared thin films and a good agreement between the resistivity values and the oxidation number of doping element. The main aim of this work was the selection of the best candidate for doping ZnO for optoelectronics applications. The comparative study of M doped ZnO (M:Al, Sn and Cu) was performed. High rectifying efficiency of the Al/n-ZnO/p-Si/Al device was achieved and non-ideal behavior was revealed with n > 4.

ANNEALED In2S3 THIN FILMS PREPARED BY SPRAY TECHNIQUE: REPORT ON THE STRUCTURAL, OPTICAL AND DISPERSION ENERGY PARAMETERS

2019 ◽  
Vol 26 (07) ◽  
pp. 1850223
Author(s):  
Y. BCHIRI ◽  
N. BOUGUILA ◽  
M. KRAINI ◽  
S. ALAYA
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Near Infrared ◽  
Spray Pyrolysis Technique ◽  
Dielectric Constants ◽  
Index Formula ◽  
Optical Parameters ◽  
Dispersion Parameters ◽  
Dispersion Energy ◽  
Molar Ratios

In2S3 thin films with different S/In molar ratios (from 1.5 to 3.5) were deposited via a spray pyrolysis technique on glass substrates at 340∘C. Then, the obtained films were annealed at the same temperature 400∘C for 2[Formula: see text]h. X-ray diffraction study reveals the formation of cubic [Formula: see text]-In2S3 phase with (400) as preferred orientation. The crystallite size varies in the range 64–97[Formula: see text]nm. Optical analysis exhibits that transmittance in visible and near infrared regions is higher than 65% for all films. The optical band gap varied from 2.58[Formula: see text]eV to 2.67[Formula: see text]eV. The optical parameters (refractive index, extinction coefficient, dielectric constants) were calculated through the transmittance ([Formula: see text]) and reflectance ([Formula: see text]). Dispersion parameters ([Formula: see text], [Formula: see text]), high frequency dielectric constant ([Formula: see text]), refractive index ([Formula: see text]), oscillator length strength ([Formula: see text]), average oscillator wavelength ([Formula: see text]) and optical moments ([Formula: see text]) were determined by Wemple–DiDomenico model. The surface and volume energy losses with photon energy were also calculated. The optical and electrical conductivities were estimated. These properties of In2S3 films are important for photovoltaic applications.

scholarly journals Estimation of optical parameters of silicon single crystals with different orientations

2019 ◽  
Vol 37 (1) ◽  
pp. 65-70
Author(s):  
M.M. El-Nahass ◽  
H.A.M. Ali
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Single Crystals ◽  
Energy Gap ◽  
Optical Parameters ◽  
Dispersion Energy ◽  
High Frequency Dielectric Constant ◽  
Single Oscillator Model ◽  
Indirect Allowed Transition ◽  
Single Oscillator

AbstractOptical properties of Si single crystals with different orientations (1 0 0) and (1 1 1) were investigated using spectrophotometric measurements in a spectral range of 200 nm to 2500 nm. The data of optical absorption revealed an indirect allowed transition with energy gap of 1.1 ± 0.025 eV. An anomalous dispersion in refractive index. The normal dispersion of the refractive index was discussed according to Wemple-DiDomenico single oscillator model. The oscillator energy Eo, dispersion energy Ed, high frequency dielectric constant ∈∞, lattice dielectric constant ∈L and electronic polarizability αe were estimated. The real ∈1 and imaginary ∈2 parts of dielectric constant were also determined.

Effect of Annealing Temperature on the Optical Parameters of CdS Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 747 ◽  
pp. 329-332
Author(s):  
Thitinai Gaewdang ◽  
Ngamnit Wongcharoen ◽  
Tiparatana Wongcharoen
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Optical Parameters ◽  
Spectral Transmission ◽  
Dispersion Energy ◽  
Thermal Evaporation Method ◽  
Transmission Data ◽  
Cds Thin Films

CdS thin films were prepared by thermal evaporation onto glass substrate in vacuum better than 5.5x10-5 mbar. The obtained films were subsequently annealed in a pure nitrogen atmosphere at temperature between 100 to 500°C for 30 min. The crystal structure and surface morphology of the as-deposited and annealed films were investigated by XRD and SEM, respectively. Optical band gap and Urbach tail values of the films, determined from spectral transmission data, were found to be slightly varied in the range 2.36-2.40 eV and 110-160 meV, respectively, due to annealing temperature. The refractive index of the films was also evaluated from the spectral transmission data. The dependence of the refractive index on the wavelength obeys the single oscillator model, from which the important parameters such as refractive index, extinction coefficient, oscillator energy (E0) and dispersion energy (Ed) of the films with different annealing temperatures were determined. From the experimental results, the optical parameters of the films are obviously influenced by annealing temperature.

Optical properties of Al-doped ZnO thin films obtained by the method of high-frequency magnetron sputtering

2021 ◽  
pp. 2150189
Author(s):  
A. Kashuba ◽  
H. Ilchuk ◽  
R. Petrus ◽  
I. Semkiv ◽  
O. Bovgyra ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
High Frequency ◽  
Optical Constants ◽  
Zno Thin Films ◽  
Optical Parameters ◽  
Single Oscillator ◽  
Doped Zno

The optical constants and thickness of Al-doped ZnO (ZnO:Al(2.5 wt.%)) thin films prepared by high-frequency magnetron sputtering method are determined. ZnO:Al thin films are crystallized in the hexagonal structure from XRD studies. The optical constants and the bandgap of the films under study have been determined. Optical properties (refractive index [Formula: see text], absorption coefficient [Formula: see text], extinction coefficient [Formula: see text], dielectric functions [Formula: see text] and optical conductivity [Formula: see text]) of thin films and thickness [Formula: see text] can be determined from the transmission spectrum. The dispersion of the refractive index was explained using a single oscillator model. Single oscillator energy and dispersion energy are obtained from fitting. Optical parameters of the films were determined using the Cauchy, Sellmeier and Wemple models. The increasing value of dispersion parameter for polycrystalline thin films than for single crystals is observed. The fundamental absorption edge position (3.26 eV) in the transmittance spectrum of studied thin films corresponds to the values that are typical for ZnO:Al compound. No significant increase of the bandgap width was revealed by comparing ZnO:Al thin films with the known results of the optical studies of ZnO thin films. Possible reasons of such behavior were analyzed and the influence of bandgap increase on spectral behavior of optical functions are investigated. The material optical parameters such as normalized integrated transmission, zero and high-frequency dielectric constant, density of state effective mass ratio were also calculated.

scholarly journals Optical Properties of Materials for Solar Energy Based on Cadmium Chalcogenides Thin Films

2019 ◽  
Vol 20 (4) ◽  
pp. 367-371 ◽  
Author(s):  
R.Yu. Petrus ◽  
H.A. Ilchuk ◽  
A.I. Kashuba ◽  
I.V. Semkiv ◽  
E.O. Zmiiovska ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
High Frequency ◽  
Optical Constants ◽  
Optical Parameter ◽  
Constant Density ◽  
Dispersion Energy ◽  
Cadmium Chalcogenides ◽  
Single Oscillator

The optical constants and thickness of cadmium chalcogenides (CdX, X= S, Se and Te) thin films prepared by quasi close-space sublimation and high-frequency magnetron sputtering method are determined. The optical constants and the band gap of the films under study have been determined. Optical properties (refractive index n(λ), extinction coefficient k(λ) and dielectric functions ε(λ)) of thin films and thickness d can be determined from the transmission spectrum. The dispersion of the refractive index was explained using a single oscillator model. Single oscillator energy and dispersion energy are obtained from fitting. The material optical parameter such as normalized integrated transmission, zero and high-frequency dielectric constant, density of state effective mass ratio was also calculated.

Effect of Mn Doping on Optical Properties of Nanostructured ZnO Thin Film

2012 ◽  
Vol 462 ◽  
pp. 201-205 ◽  
Author(s):  
M. Ebrahimizadeh Abrishami ◽  
A. Kompany
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Spray Pyrolysis Technique ◽  
Unconstrained Minimization ◽  
Optical Transmittance ◽  
Wurtzite Structure ◽  
Dispersion Parameters ◽  
Dispersion Energy ◽  
Mn Content

Undoped and ZnO: Mn thin films with different Mn content ( 5, 10 and 15 mol%) were grown on glass substrates by spray pyrolysis technique. X-ray diffraction analysis showed that single phase wurtzite structure is formed in all samples. XRD results also indicated that the undoped ZnO were crystallized in c-axis oriented wurtzite structure, while the ZnO: Mn thin films were polycrystalline. The SEM results revealed that Mn presence were modified the surface morphology of the samples. The optical transmittance measurements were performed in the wavelength range from 190 to 1100 nm. The refractive index, extinction coefficient and film thickness were determined by using pointwise unconstrained minimization model. It was observed that the refractive index increased with the increase in Mn concentration. Also, the thin films exhibited the direct band gap increased from 3.20 to 3.28 eV with the increase in Mn content. The optical dispersion parameters have been calculated and analyzed by using Wemple-Di Domenico relation. The obtained values showed that dispersion energy Ed of doped samples was found to be decreasing comparing to undoped thin film.

scholarly journals Influence of Bath Temperature and Deposition Time on Topographical and Optical Properties of Nanoparticles ZnS Thin Films Synthesized by a Chemical Bath Deposition Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Raghad Zein ◽  
Ibrahim Alghoraibi
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Chemical Bath Deposition ◽  
Deposition Time ◽  
Bath Temperature ◽  
Oscillator Model ◽  
Homogeneous Distribution ◽  
Dispersion Energy ◽  
Single Oscillator Model ◽  
Single Oscillator

In this paper, zinc sulfide nanoparticle (ZnS-NP) thin films were deposited onto glass substrates by chemical bath deposition using zinc sulfate as the cation precursor and thiourea as the anionic precursor. Different bath temperatures (65, 70, 75, and 80°C) and different deposition times (20, 30, 40, and 50 min) were selected to study the performance of ZnS thin films. Topographical and optical characterizations of the films were studied using the atomic force microscope (AFM) and UV-Vis spectroscope. The best ZnS thin films were deposited at a bath temperature (70°C) and a deposition time (30 min) with homogeneous distribution, high density, and small average diameter (106 nm). The energy gap (Eg) was found to be in the range of 4.05-3.97 eV for the ZnS films. Optical constants (refractive index, n, extinction coefficient, k, and dielectric constant, ε) of the films were obtained in the wavelength range 300-500 nm by using spectrophotometric measurement. The dispersion of the refractive index is analyzed by using a single oscillator model. The oscillator energy E0 and dispersion energy Ed were determined using the Wemple-DiDomenico single oscillator model. Urbach’s energy increases from 0.907 eV to 2.422 eV with increasing of deposition time. The calculated radius of nanoparticles using Brus equation was 1.9, 2.3, 2.45, and 2.51 nm at deposition times 20, 30, 40, and 50 min, respectively.

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.

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