EFFECT OF Zn CONTENT ON OPTICAL PROPERTIES AND TUNING OF OPTICAL BAND GAP OF CHEMICALLY DEPOSITED Cd1-xZnxS THIN FILMS

In depositing nitrogen doped tungsten oxide thin films by using reactive dc pulsed magnetron sputtering process, nitrous oxide gas (N2O) was employed instead of nitrogen (N2) as the nitrogen dopant source. The nitrogen doping effect on the structural and optical properties of WO3 thin films was investigated by X-ray diffraction, transmission electron microscopy and UV-Vis spectroscopy. The thickness, refractive index and optical band gap energy of these films have been determined by analyzing the SE spectra using parameterized dispersion model. Morphological images reveal that the films are characterized by a hybrid structure comprising nanoparticles embeded in amorphous matrix and open channels between the agglomerated nanoparticles. Increasing nitrogen doping concentration is found to decrease the optical band gap energy and the refractive index. The reduced band gaps are associated with the N 2p orbital in the N-doped tungsten oxide films.

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Effect of gamma irradiation on structural, morphological and optical properties of p-quaterphenyl thin films

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v14i2.7549 ◽

2018 ◽

Vol 14 (2) ◽

pp. 5624-5637

Author(s):

A.A. Attia ◽

M.M. Saadeldin ◽

K. Sawaby

Keyword(s):

Thin Films ◽

Refractive Index ◽

Optical Properties ◽

Surface Morphology ◽

Absorption Coefficient ◽

Gamma Irradiation ◽

Band Gap ◽

Optical Band Gap ◽

Thermal Evaporation Method ◽

Single Oscillator Model

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.

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Conductivity and Density of States of New Polyphenylquinoline

Polymers ◽

10.3390/polym11060934 ◽

2019 ◽

Vol 11 (6) ◽

pp. 934 ◽

Cited By ~ 1

Author(s):

Shamil R. Saitov ◽

Dmitriy V. Amasev ◽

Alexey R. Tameev ◽

Vladimir V. Malov ◽

Marine G. Tedoradze ◽

...

Keyword(s):

Thin Films ◽

Optical Properties ◽

Absorption Coefficient ◽

Band Gap ◽

Density Of States ◽

Optical Band Gap ◽

Dark Conductivity ◽

Localized States ◽

Energy Distance ◽

Temperature Dependences

Electrical, photoelectrical, and optical properties of thin films of a new heat-resistant polyphenylquinoline synthesized using facile methods were investigated. An analysis of the obtained temperature dependences of the dark conductivity and photoconductivity indicates the hopping mechanism of conductivity over localized states arranging at the energy distance of 0.8 eV from the Fermi level located inside the band gap of the investigated material. The optical band gap of the studied material was estimated from an analysis of the spectral dependences of the photoconductivity and absorption coefficient before (1.8–1.9 eV) and after (2.0–2.2 eV) annealing at temperatures exceeding 100 °C. The Gaussian character of the distribution of the localized states of density inside the band gap near the edges of the bands was established. A mechanism of changes in the optical band gap of the investigating polymer under its annealing is proposed.

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Properties of TiO2 Thin Film Prepared by Sol-Gel Dip Coating

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.723.528 ◽

2015 ◽

Vol 723 ◽

pp. 528-531

Author(s):

Jun Wang ◽

Ling Yun Bai

Keyword(s):

Thin Film ◽

Thin Films ◽

Refractive Index ◽

Optical Properties ◽

Band Gap ◽

Optical Band Gap ◽

Sol Gel ◽

Dip Coating ◽

Gel Method ◽

Glass Substrates

TiO2 thin films were prepared on glass substrates by sol-gel method. The effect of withdraw speed on the thickness and optical properties of TiO2 thin films was investigated. The films were transparent in the visible wavelength. The thickness of the TiO2 films was increased from 90 nm for the withdraw speed of 1000 μm/s to 160 nm for the withdraw speed of 2000 μm/s. While, The refractive index of the TiO2 thin film decreased from 2.38 to 2.07. It may be due to the porosity of the film was increased. The optical band-gap of the films was around 3.45 eV.

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Single Phase CuO Thin Films Prepared by Thermal Oxidation in Air with Water Vapor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1109.544 ◽

2015 ◽

Vol 1109 ◽

pp. 544-548 ◽

Cited By ~ 2

Author(s):

Jian Bo Liang ◽

Xu Yang Li ◽

Naoki Kishi ◽

Tetsuo Soga

Keyword(s):

Thin Films ◽

Grain Size ◽

Optical Properties ◽

Water Vapor ◽

Band Gap ◽

Thermal Oxidation ◽

Single Phase ◽

Optical Band Gap ◽

Structural And Optical Properties ◽

Oxidation In Air

Single phase CuO films have been successfully synthesized by thermal oxidation of cupper foil in air with water vapor. The structural and optical properties of CuO films were investigated. It is observed that the grain size increases with increasing the oxidation temperature. The optical band gap of CuO film is determined by the transmittance and reflectance spectra.

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QUANTUM SIZE EFFECT ON THE OPTICAL PROPERTIES OF RF MAGNETRON SPUTTERED NANOCRYSTALLINE CADMIUM OXIDE THIN FILMS

International Journal of Nanoscience ◽

10.1142/s0219581x11009003 ◽

2011 ◽

Vol 10 (04n05) ◽

pp. 713-716 ◽

Cited By ~ 2

Author(s):

B. SAHA ◽

R. THAPA ◽

N. S. DAS ◽

K. K. CHATTOPADHYAY

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Optical Band Gap ◽

Quantum Confinement Effect ◽

Cadmium Oxide ◽

Quantum Size ◽

Device Applications ◽

Cdo Films ◽

Different Thickness

CdO thin film with different thickness and different particle size are prepared through radio frequency magnetron sputtering technique. Quantum confinement effect causes the significant changes in their optical properties showing significant changes in the optical band gap. The CdO films are very highly conducting and transparent. Transparent and conducting thin films of CdO with effectively increased optical band gap are very useful for different device applications like solar cell, optoelectronic devices.

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Investigation of optical band-gap and related optical properties in thin-films of Ge containing Se-Te-Sn alloys

Journal of Non-Crystalline Solids ◽

10.1016/j.jnoncrysol.2020.120399 ◽

2021 ◽

Vol 551 ◽

pp. 120399

Author(s):

Shiv Kumar Pal ◽

Neeraj Mehta ◽

H.E. Atyia ◽

S.S. Fouad

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Optical Band Gap

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Structural and Optical Properties of ZnO Thin Films Prepared by Molecular Precursor and Sol–Gel Methods

Crystals ◽

10.3390/cryst10020132 ◽

2020 ◽

Vol 10 (2) ◽

pp. 132 ◽

Cited By ~ 4

Author(s):

Theopolina Amakali ◽

Likius. S. Daniel ◽

Veikko Uahengo ◽

Nelson Y. Dzade ◽

Nora H. de Leeuw

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Optical Band Gap ◽

Sol Gel ◽

Zno Thin Films ◽

Structural And Optical Properties ◽

Gel Method ◽

Sol Gel Method ◽

Molecular Precursor

Zinc oxide (ZnO) is a versatile and inexpensive semiconductor with a wide direct band gap that has applicability in several scientific and technological fields. In this work, we report the synthesis of ZnO thin films via two simple and low-cost synthesis routes, i.e., the molecular precursor method (MPM) and the sol–gel method, which were deposited successfully on microscope glass substrates. The films were characterized for their structural and optical properties. X-ray diffraction (XRD) characterization showed that the ZnO films were highly c-axis (0 0 2) oriented, which is of interest for piezoelectric applications. The surface roughness derived from atomic force microscopy (AFM) analysis indicates that films prepared via MPM were relatively rough with an average roughness (Ra) of 2.73 nm compared to those prepared via the sol–gel method (Ra = 1.55 nm). Thin films prepared via MPM were more transparent than those prepared via the sol–gel method. The optical band gap of ZnO thin films obtained via the sol–gel method was 3.25 eV, which falls within the range found by other authors. However, there was a broadening of the optical band gap (3.75 eV) in thin films derived from MPM.

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Morphological and Optical Properties of Different Mg Percentage of ZnO/Mg Thin Films Prepared by Sol-Gel Spin-Coating and Immersion Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1107.637 ◽

2015 ◽

Vol 1107 ◽

pp. 637-642 ◽

Cited By ~ 1

Author(s):

Aadila Aziz ◽

R. Mohamed ◽

A.N. Afaah ◽

N.A.M. Asib ◽

M. Rusop ◽

...

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Spin Coating ◽

Optical Band Gap ◽

Sol Gel ◽

Immersion Method ◽

Weight Percentage ◽

Tauc Plot ◽

Vis Spectroscopy

We have successfully demonstrated ZnO/Mg thin films on Mg seeded-template by using sol-gel spin-coating and immersion technique. By increasing weight percentage of Mg, zinc particles become agglomerate and displayed flower formed as displayed in FESEM characterization. It was observed that the morphology of the zinc particles on Mg seeded-template change from inconsistently distribution for 1 and 3 % into cluster flower-like of zinc particles for 5 and 7 % weight percentage of Mg. The optical properties of the ZnO/Mg thin films were examined by UV-Vis spectroscopy and the Tauc plot methods was used to estimate the optical band gap. The study reveals that, 7 % weight percentage of Mg was recorded as the highest transmittance which is more than 60 % in visible wavelength compared to others. With the rise weight percentage of Mg, the transmittance of the thin films was increased except for 5 %. This gradually downgraded to below 60 % of transmission most probably due to the grain size that becomes bigger. The optical band gap can be tuned by using different Mg percentage to the ZnO/Mg thin films.

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OPTICAL PROPERTIES OF AsSeTl THIN FILMS DEPOSITED BY e-BEAM EVAPORATION TECHNIQUE

Surface Review and Letters ◽

10.1142/s0218625x11014394 ◽

2011 ◽

Vol 18 (01n02) ◽

pp. 71-75 ◽

Cited By ~ 2

Author(s):

M. M. ABD EL-RAHEEM

Keyword(s):

Thin Films ◽

Optical Properties ◽

Electron Beam ◽

Band Gap ◽

Optical Band Gap ◽

Plasma Frequency ◽

Electron Beam Evaporation ◽

Dispersion Energy ◽

Electron Beam Evaporation Technique ◽

Evaporation Technique

Five compositions of the system As 25 Se 75-x Tl x (x = 12, 16, 20, 24 and 28%) have been prepared using melt quench technique. Thin films of the same thickness (200 nm) were deposited by electron beam evaporation technique. Optical and other parameters of the films have been studied. The optical band gap E op found to decrease by increasing the coordination number r and average number of bonds per atom N av and by decreasing the heat of atomization H s . Other parameters as an oscillator energy E o , dispersion energy E d and plasma frequency ω p found to be affected by changing thallium content.

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