SPECTROSCOPIC ELLIPSOMETRY INVESTIGATION ON OPTICAL PROPERTIES OF Fe:SNO2 THIN FILMS: EFFECTS OF IRON CONCENTRATION

2020 ◽  
pp. 2050044
Author(s):  
SAHAR MORADI ◽  
HASSAN SEDGHI

Nanostructured Fe:SnO2 thin films were deposited on glass substrates through sol–gel spin coating method. Films were synthesized with different iron quantities including 0%, 4%, 8% and 12% (wt.%). The effects of Fe concentration on optical properties of films were investigated by spectroscopic ellipsometry (SE) technique. SE measured ([Formula: see text]) parameters for films in the wavelength range between 300[Formula: see text]nm to 800[Formula: see text]nm. Optical properties including the refractive index, extinction coefficient, transmittance, dielectric constants and optical conductivity were determined by fitting the SE measured ([Formula: see text]) parameters and data obtained from the optical model-based analysis. Results showed that the transmittance values increase by increment of Fe concentration from 0% to 12%. The bandgap energy ([Formula: see text] of prepared thin films was also calculated. [Formula: see text] values were between 3.44 and 3.58[Formula: see text]eV. Dispersion parameters including the high frequency dielectric constant ([Formula: see text] and the ratio of free carrier concentration to effective mass (N/m[Formula: see text] were then obtained for the prepared films.

2015 ◽  
Vol 1109 ◽  
pp. 593-597
Author(s):  
M.F. Nasir ◽  
Mohd Hannas ◽  
Mohamad Hafiz Mamat ◽  
Mohamad Rusop

This project has been focused on the electrical and optical properties on the effect of Indium doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different In dopant concentrations at 1 at%, 1.5 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 oC. In doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-Vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% In doping concentration which is 8.27× 103Ωcm-1The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.


2013 ◽  
Vol 16 (1) ◽  
pp. 92-100
Author(s):  
Chien Mau Dang ◽  
Dam Duy Le ◽  
Tam Thi Thanh Nguyen ◽  
Dung Thi My Dang

In this study, we have successfully synthesized Fe3+ doped SiO2/TiO2 thin films on glass substrates using the sol-gel dip-coating method. After synthesizing, the samples were annealed at 5000C in the air for 1 hour. The characteristics and optical properties of Fe3+ doped SiO2/TiO2 films were then investigated by X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FT-IR). An antifogging ability of the glass substrates coated with the fabricated film is investigated and explained by a water contact angle under visible-light. The analyzed results also show that the crystalline phase of TiO2 thin films comprised only the anatase TiO2, but the crystalline size decreased from 8.8 to 5.9 nm. We also observed that the absorption edge of Fe3+- doped SiO2/TiO2 thin films shifted towards longer wavelengths (i.e. red shifted) from 371.7nm to 409.2 nm when the Fe3+-doped concentration increased from 0 to 1 % mol.


2019 ◽  
Vol 27 (01) ◽  
pp. 1950092
Author(s):  
BATOOL AHMADI KHANEGAHI ◽  
HASSAN SEDGHI

In the present work, zinc sulfide thin films were deposited on glass substrates by sol–gel process with different coating speeds 3600, 4800, 6000 and 7200[Formula: see text]rpm. Zinc acetate (Zn(CH3COO)[Formula: see text]H2O) and thiourea (CH4N2S) were used as precursors. Two-methoxyethanol and monoethanolamine were used as solvent and stabilizer, respectively. The optical properties of ZnS thin films such as refractive index, extinction coefficient, dielectric function and optical band gap energy of the films were obtained by spectroscopic ellipsometry (SE) analysis method in the wavelength range of 300–800[Formula: see text]nm. The incidence angle of the layers was kept at 70∘. The measured SE parameters [Formula: see text] and [Formula: see text] are fitted against the designed model by minimizing the mean square error (MSE). Considering the data obtained, it can be deduced that the optical properties of ZnS films are highly influenced by rotation rates. The extinction coefficients of the films were increased with increasing rotation rates of the films. From these results, it is found that the energy gap of the ZnS films increases with increasing rotation rates of the films in the range of 3.13–3.20[Formula: see text]eV.


2015 ◽  
Vol 1109 ◽  
pp. 577-581 ◽  
Author(s):  
M.F. Nasir ◽  
Mohd Hannas ◽  
Mohamad Hafiz Mamat ◽  
Mohamad Rusop

This project has been focused on the electrical and optical properties respectively on the effect of Tin doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different Sn dopant concentrations at 1 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 oC. Sn doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (Perkin Elmer Lambda 750) for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% Sn doping concentration with the value 3.08 × 103Ωcm-1. The absorption coefficient spectrum obtained shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.


2012 ◽  
Vol 430-432 ◽  
pp. 310-314 ◽  
Author(s):  
Wei Wang ◽  
Wei Meng ◽  
Ming Hui Liu ◽  
Xin Bo Wang

Na-doped ZnO thin films were deposited on microscope glass substrates by sol-gel spin coating method, the Na/Zn ratio were 0at.%, 5at.%, 7.5at.%, 10at.%, 15at.%. The crystal structures, surface morphology, and optical properties were analyzed by X-ray diffraction, scanning electron microscopy, ultraviolet–visible spectrophotometer, respectively. The results show that all the films are preferentially oriented along the c-axis perpendicular to the substrate surface. With the increase of the doping concentration, the roughness of the surfaces decrease and grain size grows from 17.1nm to 21.7nm, the sample with 10at.% Na exhibits best crystallinity and has lowest strain along the c-axis. The average optical transparency of the samples is higher than 70%, optical band gaps are between 3.213eV and 3.289eV.


2015 ◽  
Vol 1109 ◽  
pp. 572-576
Author(s):  
M.F. Nasir ◽  
Mohd Hannas ◽  
Mohamad Hafiz Mamat ◽  
Mohamad Rusop

This project has been focused on the electrical and optical properties respectively on the effect of Undoped zinc oxide (ZnO) thin films at different annealing temperature which is varied 400 oC, 450 oC, 500 oC, and 550 oC.Undoped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 500 oC which its resistivity is 5.36 × 104Ωcm-1. The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.


2013 ◽  
Vol 547 ◽  
pp. 145-151 ◽  
Author(s):  
Sirirat T. Rattanachan ◽  
P. Krongarrom ◽  
Thipwan Fangsuwannarak

In this study, undoped and B-doped ZnO thin films were successfully deposited on the glass substrates by a sol-gel spin coating method. The influence of doping concentrations and the annealing temperature effects on the structural and optical properties of ZnO thin films were investigated. All of films exhibited polycrystalline structure, with a preferential growth along the c-axis plane and the optical transparency with visible transmittance was higher than 90%. The crystallite size was calculated using a well-known Scherrer’s formula and found to be in the range of 11-18 nm. The optical band gap of these films were determined and compared with those obtained for undoped ZnO thin film.


Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.


2013 ◽  
Vol 665 ◽  
pp. 159-167
Author(s):  
M.S. Jani ◽  
H.S. Patel ◽  
J.R. Rathod ◽  
K.D. Patel ◽  
V.M. Pathak ◽  
...  

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.


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