scholarly journals Determination of Optical Constants and Thickness of Nanostructured ZnO Film by Spin Coating Technique

2021 ◽  
Vol 7 (2) ◽  
pp. 119-125
Author(s):  
R. R. Ghimire ◽  
Y. P. Dahal ◽  
K. B. Rai ◽  
S. P. Gupta
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Spin Coating ◽  
Optical Constants ◽  
Complex Refractive Index ◽  
Visible Region ◽  
Spin Coating Technique ◽  
Transmittance Spectrum ◽  
Coating Technique ◽  
Envelope Method

In this report, we have investigated optical constants and thickness of nanostructured ZnO films grown on a glass substrate by sol-gel spin coating technique using zinc acetate as precursor. Optical constants such as complex refractive index ñ and dielectric constant ϵ determined from the transmittance spectrum in the ultraviolet, visible, near infrared (UV-VIS, NIR) region by envelope method. The value of refractive index decreases from 2.34 to 1.86 and extinction coefficient increases from 0.28 to 0.64 with increasing wavelength. The decreasing behavior of refractive index is attributed due to the increase in transmission and decrease in absorption coefficient with increasing wavelength. The film exhibits reasonably high transmittance (>80%) in the visible region. Absorbance coefficient α and film thickness (d) were calculated from the interference of fringes of transmittance spectrum. The band gap and thickness of the film were found 3.02 eV and 275nm, respectively. The thickness of the film measured by envelope method is validated with cross-section micrograph of SEM images which is about 285 nm. The real part of the dielectric function of nanostructured ZnO decreases with increasing wavelength where as the imaginary part of dielectric constant increases with increasing wavelength. The observed high value of refractive index n and real part of dielectric constant ϵ at lower wavelength is due to band edge absorption of carriers. The dispersion relation shows the increase of complex refractive index and dielectric constant at the high frequency regime is due to the discharging of defect levels using optical excitation of carriers in the visible region.

scholarly journals Structural, Optical Constants and Photoluminescence of ZnO Thin Films Grown by Sol-Gel Spin Coating

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Abdel-Sattar Gadallah ◽  
M. M. El-Nahass
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Spectral Range ◽  
Spin Coating ◽  
Optical Constants ◽  
Sol Gel ◽  
Free Carrier ◽  
Zno Thin Films ◽  
Free Carrier Absorption

We report manufacturing and characterization of low cost ZnO thin films grown on glass substrates by sol-gel spin coating method. For structural properties, X-ray diffraction measurements have been utilized for evaluating the dominant orientation of the thin films. For optical properties, reflectance and transmittance spectrophotometric measurements have been done in the spectral range from 350 nm to 2000 nm. The transmittance of the prepared thin films is 92.4% and 88.4%. Determination of the optical constants such as refractive index, absorption coefficient, and dielectric constant in this wavelength range has been evaluated. Further, normal dispersion of the refractive index has been analyzed in terms of single oscillator model of free carrier absorption to estimate the dispersion and oscillation energy. The lattice dielectric constant and the ratio of free carrier concentration to free carrier effective mass have been determined. Moreover, photoluminescence measurements of the thin films in the spectral range from 350 nm to 900 nm have been presented. Electrical measurements for resistivity evaluation of the films have been done. An analysis in terms of order-disorder of the material has been presented to provide more consistency in the results.

Structural, Optical and Electrical Characterization of Mo Doped In2O3 Thin Films Prepared via Sol-Gel Spin Coating Technique

2012 ◽  
Vol 576 ◽  
pp. 607-610 ◽  
Author(s):  
Saeed Mohammadi ◽  
Hossein Abdizadeh ◽  
Mohammad Reza Golobostanfard
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Sol Gel ◽  
Visible Region ◽  
Electrical Characterization ◽  
Optical Transmittance ◽  
Spin Coating Technique ◽  
Coating Technique ◽  
Glass Substrates ◽  
Average Optical Transmittance

The optically transparent conducting molybdenum doped indium oxide (IMO) thin films were deposited on glass substrates by sol-gel spin coating technique. The effect of various molybdenum contents in the range of 0.25–1 at.% on the structural, morphological, optical and electrical properties was studied. XRD results confirmed the formation of cubic bixbyite structure of In2O3 with preferred orientation along (222) plane. Microstructural studies show nearly spherical morphology for thin films with size in the range of 20-40 nm. The films doped with 0.25 at.% Mo found to exhibit a minimum electrical resistivity of 188×10-3 Ω.cm and an average optical transmittance of more than 80% in the visible region with a band gap of 3.85 eV.

Evidence of refractive index anisotropy in hybrid sol-gel slab waveguides deposited by spin-coating technique

2006 ◽  
Author(s):  
Paolo Prosposito ◽  
Mauro Casalboni ◽  
Christian Palazzesi ◽  
Stefano Schutzmann
Keyword(s):  
Refractive Index ◽  
Spin Coating ◽  
Sol Gel ◽  
Spin Coating Technique ◽  
Slab Waveguides ◽  
Coating Technique

scholarly journals Effect of iron doping on structural and optical properties of TiO2 thin film by sol–gel routed spin coating technique

2017 ◽  
Vol 07 (04) ◽  
pp. 1750024 ◽  
Author(s):  
Stephen Lourduraj ◽  
Rayar Victor Williams
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Sol Gel ◽  
Visible Region ◽  
Spin Coating Technique ◽  
Optical Measurements ◽  
Structural And Optical Properties ◽  
Coating Technique

Thin films of iron (Fe)-doped titanium dioxide (Fe:TiO[Formula: see text] were prepared by sol–gel spin coating technique and further calcined at 450[Formula: see text]C. The structural and optical properties of Fe-doped TiO2 thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy (UV–vis) and atomic force microscopic (AFM) techniques. The XRD results confirm the nanostructured TiO2 thin films having crystalline nature with anatase phase. The characterization results show that the calcined thin films having high crystallinity and the effect of iron substitution lead to decreased crystallinity. The SEM investigations of Fe-doped TiO2 films also gave evidence that the films were continuous spherical shaped particles with a nanometric range of grain size and film was porous in nature. AFM analysis establishes that the uniformity of the TiO2 thin film with average roughness values. The optical measurements show that the films having high transparency in the visible region and the optical band gap energy of Fe-doped TiO2 film with iron (Fe) decrease with increase in iron content. These important requirements for the Fe:TiO2 films are to be used as window layers in solar cells.

Influence of Film Thickness and Annealing Temperature on Optical Properties of Nanostructured-TiO2 Thin Films Prepared by Sol–Gel Spin Coating Technique

2016 ◽  
Vol 16 (02) ◽  
pp. 1650028 ◽  
Author(s):  
A. A. A. Darwish ◽  
F. S. Abu-Samaha ◽  
Z. Mohamed ◽  
M. M. El-Nahass
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Spin Coating ◽  
Optical Constants ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Spin Coating Technique ◽  
Tio2 Thin Films ◽  
Coating Technique ◽  
Quartz Substrates

TiO2 powder was found to be polycrystalline with rutile system. TiO2 films were deposited on quartz substrates by a sol–gel spin coating technique. X-ray diffraction and transmission electron microscope results have confirmed that the TiO2 films have nanostructure nature. It is found the crystallite size increased with annealing temperature. The optical constants of nanostructured TiO2 films were found to be independent of film thickness in the range from 100[Formula: see text]nm to 500[Formula: see text]nm. It is found that the optical constants and the dielectric constant of the thin films were all affected by annealing temperature. The existing allowed optical transitions in the as-deposited and annealed films were found to be direct and indirect transitions. Finally, the bandgaps of the as-deposited film were found to decrease with the annealing temperature.

Silica-Templated Continuous Mesoporous Carbon Films by a Spin-Coating Technique

2004 ◽  
Vol 16 (11) ◽  
pp. 884-886 ◽  
Author(s):  
J. Pang ◽  
X. Li ◽  
D. Wang ◽  
Z. Wu ◽  
V. T. John ◽  
...  
Keyword(s):  
Spin Coating ◽  
Mesoporous Carbon ◽  
Carbon Films ◽  
Spin Coating Technique ◽  
Coating Technique

Photoconductivity of Nanocomposite MEH-PPV: TiO2 Thin Films

2011 ◽  
Vol 13 ◽  
pp. 87-92 ◽  
Author(s):  
M.S.P Sarah ◽  
F.S. Zahid ◽  
M.Z. Musa ◽  
U.M. Noor ◽  
Z. Shaameri ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Morphology ◽  
Spin Coating ◽  
Glass Substrate ◽  
Spin Coating Technique ◽  
Coating Technique ◽  
Current Voltage ◽  
Current Voltage Characteristics

The photoconductivity of a nanocomposite MEH-PPV:TiO2 thin film is investigated. The nanocomposite MEH-PPV:TiO2 thin film was deposited on a glass substrate by spin coating technique. The composition of the TiO2 powder was varied from 5 wt% to 20 wt% (with 5 wt% interval). The concentration of the MEH-PPV is given by 1 mg/1 ml. The current voltage characteristics were measured in dark and under illumination. The photoconductivity showed increment in value as the composition of the TiO2 is raised in the polymer based solution. The absorption showed augmentation as the amount of TiO2 is increased. The escalation of the current voltage is then supported by the results of surface morphology.

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