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1

Annealing Effects on the Interband Transition and Optical Constants of Cobalt Doped Cadmium Oxide Thin Films

Habubi N. F.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 43

81--90

EN

The CdO: Co films have been deposited on substrate temperature at 400 °C by spray pyrolysis method using cadmium chloride and cobalt chloride as a precursors for Cd and Co ions, respectively. The effect of annealing temperature on optical constants of Co: CdO thin films are investigated using UV-Visible spectrophotometer in the range of (300-900) nm at room temperature. The absorbance and optical parameters such as α, n, ε1, ε2, and χ are increased when the annealing temperature increases, while the energy gap decreased from 2.5 eV before annealing to 2.48 eV after 500 °C annealing temperature. Urbach energy is increased with the increasing of annealing temperature from 353 meV for sample before annealing to 715 meV for the same samples annealed at 500 °C.

2

Optical and Dispersion parameters of ZnS Thin Films Prepared by Flash Evaporation Method

Bakr N. A., Jandow N. N., Habubi N. F.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 20, iss. 1

52--63

EN

Zns thin films are obtained by flash evaporation method onto preheated glass substrates. The transmittance analysis allowed the determination of refractive index and thickness using envelope method. It was found that the refractive dispersion data obeyed the single oscillator model. The calculated value of the refractive index (n0 ) was found to be equal to 2.27, which is in a good agreement with the value obtained from Cauchy’s fitting. Also the value of the optical energy gap, extinction coefficient, real and imaginary parts of the dielectric constant and optical conductivity have been measured.

3

Effect of annealing temperature on the optical properties of ZnO nanoparticles

Ismail R. A., Habubi N. F., Abid H. R.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 4

37--47

EN

In this work, ZnO films were prepared by drop casting technique. The films were deposited on quartz substrates under different annealing time (15,30,45 and 60 min.) at a constant temperature (800 °C). The optical properties were achieved by measuring the absorbance and transmittance spectra in the wavelength range (200-900) nm. It was found that the absorbance decreases while transmission increases as the annealing time increases, while the reflectance decreases as the annealing time increases. The optical measurements indicate the kind of transition which was a direct allowed with an average band gap energies lie between 3.3 eV and 3.54 eV with the change of annealing time.

4

Optical dispersion characterization of sprayed Zn1-xMnxO thin films

Habubi N.F., Chiad S.S., Oboudi S.F., Toma Z.A.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 4

1-8

EN

Uniform and adherent Zn1-xMnxO films have been deposited by using spray pyrolysis technique on glass substrates. The optical properties and dispersion parameters of zinc oxide have been studied as a function of doping concentration with Mn. Changes in direct optical energy band gap of cobalt oxide films were confirmed after doping, The optical energy gap Eg increased from 3.13 eV for the undoped ZnO to 3.39 eV with increasing the doping concentration of Mn to 4%. The changes in dispersion parameters and Urbach tails were investigated. An increase in the doping concentration causes a decrease in the average oscillator strength. The single-oscillator parameter has been reported.

5

Fabrication and characterization of porous silicon layer prepared by photo-electrochemical etching in CH3OH:HF solution

Hadi H.A., Ismail R.A., Habubi N.F.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 3

29-36

EN

Porous silicon (PS) has been fabricated by Photo-electrochemical etching. Porous silicon was anodized on n-type Si in light using a current density of 20mA/cm2 for 10 min. The porous structure formation was confirmed using XRD and AFM studies. The root mean square (RMS) roughness of the Porous silicon layer is found to be around 47.5 nm and the ten point height was 317 nm. The average of pores diameter was 419.98nm, and the grain growth is columnar with a (211) preferred orientation. The grain size of the PS was estimated from the Scherer's formula and found to be 73 nm. All the properties of the porous silicon layer, such as porosity and the thickness depend on the anodization parameters. The porosity (P) was approximately 77 %. The thickness of the layer formed during an anodization in constant current was 3.54nm in gravimetric method, while its value was 1.77nm by using the theoretical relation.

6

Effect of Gamma Irradiation on the Optical Properties of Mg doped CdO Thin films deposited by Spray Pyrolysis

Hassouni M.H., Mishjil K.A., Chiad S.S., Habubi N.F.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 11

26--37

EN

Thin films of CdO and 9 % Mg doped CdO doped have been prepared using spray pyrolysis technique. Transmission and absorption spectra were recorded in order to estimate these films. The deposited thin films were exposed to γ - rays. We have studied the transmission, absorptions and absorption coefficient as a function of photon energy before and after irradiation. The optical constants such as: reflectance, extinction coefficient, refractive index, real and imaginary parts of the dielectric constant and the electrical conductivity were calculated also.

7

Composition and Optical Dispersion Characterization of Nanoparticles ZnO-NiO Thin Films: Effect of Annealing Temperature

Oboudi S.F., Habubi N.F., Mohamed G.H., Chiad S.S.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 8, iss. 1

78--86

EN

Thin films of ZnO0.7NiO0.3 have deposited on glass substrates at room temperature by using thermal evaporation technique under vacuum 10-5 mbar. The optical properties and dispersion parameters of the films have been studied. Changes in direct optical energy band gap of films were confirmed before and after annealing. The optical energy gap Eg decreased from 3.11 to 2.86 eV with increasing of annealing temperature to 200 ºC. Some of the optical absorption parameters, such as optical dispersion energies Eo and Ed, Urbach tails EU , dielectric constant ε, the average values of oscillator strength So, and wavelength of single oscillator λo have been reported. An increase in the annealing temperature causes an increase in the average oscillator strength from 62.02 to 87.71 eV.