Optical Properties of Cu2ZnSnSe4 Nanocrystalline Thin Films for Photovoltaic Devices

2015 ◽  
Vol 789-790 ◽  
pp. 90-94
Author(s):  
Anderson Dussan ◽  
Heiddy P. Quiroz ◽  
Jorge A. Calderón ◽  
Sandra M. López
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Refractive Index ◽  
Optical Properties ◽  
Extinction Coefficient ◽  
Optical Constants ◽  
High Surface ◽  
Photovoltaic Devices ◽  
Xrd Patterns ◽  
Nanocrystalline Thin Films

Presents a study of optical properties from transmittance measurements as a function of wavelength to CZTSe thin films (Cu2ZnSnSe4) using Bhattacharyya model and basic elements from the Swanepoel theory. The optical constants such as the absorption coefficient (α), the refractive index (n), the extinction coefficient (k) and physical properties such as gap (Eg), the real and imaginary part of the dielectric function (ε1 and ε2) and the film thickness (d), were determined. Gap values between 1.2 and 1.7 eV were obtained for compound when the mass (MX) of ZnSe was varied during the deposition stage. Inhomogeneity and high surface roughness were observed by SEM measurements for all samples. Size grain varying between 458.16 and 630.28 nm were obtained while the ZnSe binary mass varied from 0.171 to 0.153 g. Refractive index and extinction coefficient of Cu2ZnSnSe4 films were obtained for λ = 800 nm. A decrease of ε1 and ε2 was observed as the wavelength increases; it is associated with the presence of binary phases in the XRD patterns.

scholarly journals Growth of Atomic Layer Deposited Ruthenium and Its Optical Properties at Short Wavelengths Using Ru(EtCp)2 and Oxygen

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 413 ◽  
Author(s):  
Robert Müller ◽  
Lilit Ghazaryan ◽  
Paul Schenk ◽  
Sabrina Wolleb ◽  
Vivek Beladiya ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Optical Properties ◽  
Deposition Temperature ◽  
Film Growth ◽  
High Surface ◽  
Atomic Layer ◽  
Fused Silica ◽  
High Density ◽  
Adhesion Properties

High-density ruthenium (Ru) thin films were deposited using Ru(EtCp)2 (bis(ethylcyclopentadienyl)ruthenium) and oxygen by thermal atomic layer deposition (ALD) and compared to magnetron sputtered (MS) Ru coatings. The ALD Ru film growth and surface roughness show a significant temperature dependence. At temperatures below 200 °C, no deposition was observed on silicon and fused silica substrates. With increasing deposition temperature, the nucleation of Ru starts and leads eventually to fully closed, polycrystalline coatings. The formation of blisters starts at temperatures above 275 °C because of poor adhesion properties, which results in a high surface roughness. The optimum deposition temperature is 250 °C in our tool and leads to rather smooth film surfaces, with roughness values of approximately 3 nm. The ALD Ru thin films have similar morphology compared with MS coatings, e.g., hexagonal polycrystalline structure and high density. Discrepancies of the optical properties can be explained by the higher roughness of ALD films compared to MS coatings. To use ALD Ru for optical applications at short wavelengths (λ = 2–50 nm), further improvement of their film quality is required.

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.

The Influence of Substrate Temperature on the Morphological and Optical Properties of ZnTiO3 Thin Films Prepared by Magnetron Sputtering

2013 ◽  
Vol 804 ◽  
pp. 3-7
Author(s):  
Chao Zhan ◽  
Wen Jian Ke ◽  
Xin Ming Li ◽  
Wan Li Du ◽  
Li Juan Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Refractive Index ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Substrate Temperature ◽  
Dispersion Model ◽  
Film Surface ◽  
Cubic Phase ◽  
Different Temperatures

Cubic ZnTiO3thin films have been prepared by radio frequency magnetron sputtering on n-type (100) Si substrate at different temperatures. The morphological and optical properties of ZnTiO3films in relation to substrate temperatures are investigated by spectroscopic ellipsometry (SE) and AFM as well as SEM in detail. X-ray diffraction (XRD) measurement shows that all the films have a cubic phase structure and the optimum substrate temperature to form crystalline ZnTiO3thin film is 250 °C. Through SEM and AFM, the particle size in thin films and film surface roughness increase with increasing the substrate temperature. Based on a parameterized TaucLorentz dispersion model, the optical constants and surface roughness of ZnTiO3films related to the substrate temperature are systematically extracted by SE measurement. The surface roughness of the film measured from AFM agrees well with result extracted from SE, which proved that the established SE model is reasonable. With increasing substrate temperature, the refractive index decreases and the main factor in determining the refractive index was deduced to be the surface roughness related to the film packing density. The extinction coefficient of the samples is close to zero, but increases slightly with the increase of the substrate temperature, which is due to the enhancement of scattering effect in the crystalline ZnTiO3film.

Determination of Optical Properties of Fluorocarbon Polymer Thin Films by a Variable Angle Spectroscopic Ellipsometry

1999 ◽  
Vol 588 ◽  
Author(s):  
Kang-Kuk Lee ◽  
Jin-Goo Park ◽  
Hyung-Jae Shin
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Optical Properties ◽  
Optical Constants ◽  
Visible Spectrum ◽  
Phase Model ◽  
Lorentz Model ◽  
Three Phase ◽  
Variable Angle Spectroscopic Ellipsometry ◽  
Best Fit

AbstractOptical properties of vapor phase (VP) deposited and spin-coated fluorocarbon (FC) thin films on silicon substrates, such as refractive index, extinction coefficient and film thickness were characterized by a variable angle spectroscopic ellipsometry (VASE) in the range of 300–800 nm. A Lorentz model allows us to simulate the optical constants of the FC films with a minimum number of parameters while maintaining Kramers-Kronig (KK) consistency between the real and imaginary parts of the optical constants. FC films are nearly transparent over the visible spectrum, so it is possible to assume k (extinction coefficient) = 0 over part of the visible spectrum in a Cauchy model. To accurately simulate the obtained ellipsometric spectra, we performed a regression analysis in two steps assuming a three-phase and a four-phase model. The regression analysis was performed using the three-phase model and a best-fit mean-squared error (MSE) value of 1.717 (VP deposited FC film, Lorentz model) was obtained. However, the four-phase model was used to improve the best-fit result of 0.531 (VP deposited FC film, Lorentz model). The surface roughness layer was assumed to be a mixture of FC films and voids under the Bruggeman effective medium approximation (EMA). We found that the best-fit MSE was reduced when surface roughness was included.

Substrate Temperature Effect on Optical Constants of Gd2O3 Thin Films

2010 ◽  
Vol 442 ◽  
pp. 96-101 ◽  
Author(s):  
M.F. Wasiq ◽  
M.Y. Nadeem ◽  
Franck Chollet ◽  
S. Atiq
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Substrate Temperature ◽  
Band Gap ◽  
Extinction Coefficient ◽  
Optical Constants ◽  
Urbach Energy ◽  
Band Gap Energy ◽  
Oxide Material ◽  
Atomic Force

Effect of substrate temperature on lanthanide oxide material Gd2O3 thin films deposited by e-beam evaporation has been reported in the present work. Optical properties and surface morphology of as deposited films have been measured using spectrophotometry and atomic force microscopy respectively. Optical constants such as refractive index, extinction coefficient, band gap and Urbach energy have been determined by analysis of experimentally recorded absorption, transmittance and reflection data in wavelength range 200-800nm. Optical band gap energy shows decreasing while Urbach energy shows increasing behavior with increasing temperature. Extinction coefficient and refractive index with varying wavelengths are also calculated. Surface topographies of all samples are studied by atomic force microscope (AFM) and root mean square (RMS) value of roughness is observed increasing with increasing substrate temperature.

scholarly journals Effect of Annealing Temperature in Improvement the Optical Properties of TiO2 Doped Fe2O3 to Use in Thin Film

2019 ◽  
pp. 1-12
Author(s):  
Abubakr Mahmoud Hamid ◽  
Hassan Wardi Hassan ◽  
Fatima Ahmed Osman
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Iron Oxide ◽  
Titanium Oxide ◽  
Extinction Coefficient ◽  
Tio2 Thin Film ◽  
Annealing Temperature ◽  
Spray Pyrolysis Deposition

Solar energy is already has being widely successfully used in residential and industrial setting for thermal and electrical application such as space technology, communication, etc. I. Aims: The aim of this study the effect of the annealing temperature in improvement optical properties of titanium oxide nanostructure doped iron oxide for use in thin film. Study Design: The spray pyrolysis deposition method used for preparation the nanostructure material. Place and Duration of Study: This study was conducted in department of physics and department of materials sciences, Al-Neelain University, between January 2016 and January 2019.  Methodology: Thin films of Titanium Oxide (TiO2) doped Iron Oxide (Fe2O3) have been prepared by chemical spray pyrolysis deposition technique. A laboratory designed glass atomizer was used for spraying the aqueous solution. Which has an output nozzle about 1 mm. then film were deposited on preheated cleaned glass substrates at temperature of 400°C. we used different concentration to study optical parameters. A 1.5 g TiO2 powder of anatase structure doped with 1.5 g of Fe2O3 was mixed with 2 ml of ethanol and stirred using a magnetic stirrer for 30 minutes to form TiO2 paste to obtain the starting solution for deposition and spray time was 10 s and spray interval 2 min was kept constant. The carrier gas (filtered compressed air) was maintained at a pressure of 105 Nm-2, and distance between nozzle and substrate was about 30 cm ± 1 cm. Thickness of sample was measured using the weighting method and was found to be around 400nm. Optical transmittance and absorbance were record in wavelength range of (200-1100) nm using UV-Visible spectrophotometer (Shimadzu Company Japan). Results: The results obtained showed that the optical band gap decreased from 5.6eV before annealing to (3.9, 3.26, 3.24 and 3.27 eV) after annealing temperature at(450° – 500°) for TiO2:Fe2O3 thin films, this result refer to the broadening of  secondary levels that product by TiO2: doping to the Fe2O2thin films. Also the results showed the variation of refractive index with wavelength for different concentration after annealing temperature at (450° – 500°) of TiO2: Fe2O3 films from this figure, it is clear that n decrease with low concentration and increase with high concentration after annealing temperature that mean the density is decreased of this films. In addition the extinction coefficient of TiO2:Fe2O3 thin films recorded before annealing and with different concentration (1.1, 1.2, 1,5 and 1,6) and in the range of (300 – 1200) nm and at annealing temperature from (450° – 500°). It observed from that the extinction coefficient, decrease sharply with the increase of wavelength for all prepared films and all the sample after annealing is interference between them accept the sample before annealing is far from the other sample. Conclusion: The TiO2 thin film shows better result after annealing; By exposing temperature during annealing process degree at (450o- 500o) is found to be the best temperature for annealing TiO2 thin film. The study concluded that an annealing temperature Contributes to the improvement of optical properties related to increasing the efficiency of the solar cell, especially the refractive index, energy gap, extinction coefficient.

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.

scholarly journals Structural and optical properties of TiO2:NiO nanoparticles thin films prepare by chemical spray pyrolysis

2021 ◽  
Vol 19 (49) ◽  
pp. 22-31
Author(s):  
Wasan A. Al-Taa'y ◽  
Bushra A. Hasan
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Spray Pyrolysis ◽  
Extinction Coefficient ◽  
Energy Gap ◽  
Anatase Phase ◽  
Chemical Spray Pyrolysis ◽  
Chemical Spray ◽  
Structure Properties

The properties of structural and optical of pure and doped nano titanium dioxide (TiO2) films, prepared using chemical spray pyrolysis (CPS) technique, with different nanosize nickel oxide (NiO) concentrations in the range (3-9)wt% have been studied. X-Ray diffraction (XRD) technique where using to analysis the structure properties of the prepared thin films. The results revealed that the structure properties of TiO2 have polycrystalline structure with anatase phase. The parameters, energy gap, extinction coefficient, refractive index, real and imaginary parts were studied using absorbance and transmittance measurements from a computerized ultraviolet visible spectrophotometer (Shimadzu UV-1601 PC) in the wavelengths range (300-800)nm. Optical properties of TiO2 affected by the adding of NiO impurity where the transmittance increased as NiO concentration increased but with more adding the transmittance returned to decrease again. It was found the extinction coefficient, refractive index, real and imaginary parts values decreased with increasing doping percentage up to 7% and then increases occur one more again at 9%. Energy gap values increased after doping with NiO where the values lies in the range was 3.31 to 3.51 eV .

EFFECT OF REPETITION RATES OF LASER PULSES ON MICROSTRUCTURE AND OPTICAL PROPERTIES OF DIAMOND-LIKE CARBON FILMS

2009 ◽  
Vol 23 (30) ◽  
pp. 5671-5681 ◽  
Author(s):  
X. L. DING ◽  
Q. S. LI ◽  
X. H. KONG
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Optical Absorption ◽  
Extinction Coefficient ◽  
Repetition Rate ◽  
Laser Pulses ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Graphite Target

Hydrogen-free diamond-like carbon (DLC) thin films were prepared at different repetition rates of laser pulses by pulsed laser ablation of graphite target at room temperature. The microstructure of the thin films was characterized by Raman spectroscopy. Raman measurements showed that sp3 bonded carbon fraction is reduced with increase of repetition rates of laser pulses from 5 to 20 Hz. Optical properties, namely photoluminescence (PL), optical absorption, extinction coefficient (k), and refractive index (n), were measured by fluorescence spectrophotometer, scanning spectrophotometer, and spectroscopic ellipsometer. By changing the repetition rates of laser pulses from 5 to 20 Hz, the PL and optical absorption were gradually increased, while the deposition rate and optical band gap of the films decreased strictly with the increase of repetition rate. The extinction coefficient (k) and refractive index (n) were found to be in the range of 0.468–0.938 and 1.92–2.27, respectively. These results indicate that repetition rate of laser pulses has a strong influence on the microstructure and optical properties of the films. Based on the experimental results, a possible causation about the effect of repetition rate on PL was proposed.

INFLUENCE OF THE SUBSTRATE TEMPERATURE ON TiO2 THIN LAYERS DEPOSITED BY THE DIRECT CURRENT MAGNETRON SPUTTERING TECHNOLOGY

2020 ◽  
pp. 2050054
Author(s):  
RADOUANE GRAINE ◽  
KHOULOUD BEDOUD ◽  
NADJETTE SEHAB ◽  
DJAMEL ZELMATI
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Direct Current ◽  
Extinction Coefficient ◽  
Future Application ◽  
X Ray ◽  
Uv Visible ◽  
Substrate Temperatures

In this study, Anatase thin films of titanium dioxide (TiO[Formula: see text] are deposited by the Direct Current (DC) magnetron sputtering technique on glass substrate for future application in gas sensors. In our work, we focused and discussed the effect of various substrate temperatures [Formula: see text]C, [Formula: see text]C and [Formula: see text]C, and film thicknesses 142, 220 and 410[Formula: see text]nm, respectively, in order to study the structural and optical properties of the TiO2 thin films. The crystalline structure and optical properties of TiO2 nanoparticles were investigated using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Atomic Force Microscopy (AFM), Raman spectroscopy and UV–visible spectroscopy. The formation of the Anatase TiO2 with Tetragonal crystal structure has been confirmed with XRD. UV–visible spectrophotometry characterization of the developed thin films showed that all the films had an optical transmission greater than 92% in the visible region. In addition, the obtained direct and indirect optical band gaps using the Tauc plot are 3.66, 3.34[Formula: see text]eV at [Formula: see text]C 3.74, 3.37[Formula: see text]eV at [Formula: see text]C and 3.71, 3.37[Formula: see text]eV at [Formula: see text]C, respectively. Forouhi–Bloomer (FB) physical model has been used to obtain the refractive index and extinction coefficient by fitting theoretical transmittance curves to experimental ones. The optical refractive index is found to vary from 2.350 for [Formula: see text]C, 2.1499 for [Formula: see text]C and 2.1420 for [Formula: see text]C. Moreover, we have obtained an extinction coefficient [Formula: see text] ([Formula: see text] of around [Formula: see text] for both substrate temperatures [Formula: see text]C and [Formula: see text]C, and around [Formula: see text] for the [Formula: see text]C.

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