Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : optical properties


Study the effect of irradiation by laser-ray on the optical properties of the nanostructure In2O3 thin films

Ali A. Yousi; Zainab S. Mahdi

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 938-950

In this research the effect oflaser irradiation N2 at 337 nm on the optical properties of the nanocrystalline In2O3 films subjected to laser irradiations with different power average (0.85, 1.70, 2.125 and 2.55mW ) for irradiation time (5min). By, by using UV-VIS spectrophotometer technique, can many of the optical properties account of study change spectral transmittance and absorbance of these membranes, such as the expense of absorption coefficient, and energy gap for direct transitions It was found that the band gap decreases when the thickness increases and the band gap values ranges between 3.5eV to 3.0eV.and calculate the reflectivity and extinction coefficient and refractive index and dielectric constant real and imaginary and optical connectivity. the exposure of the as deposited films to a selected dose of laser irradiation, the optical properties films varies with increase in the power average

Study of Methyl Orange Effect on the Optical and Electrical Properties of Polystyrene (PS)

Karrar M. Ali; Nahida J.H

Engineering and Technology Journal, 2014, Volume 32, Issue 6, Pages 39-53

The present work was concerned with study of the methyl orange(MO) dye concentration effect on the optical properties ,and electrical properties of polystyrene(PS).
The samples were casted as films from the homopolymer(PS) stated above and the Dye/PS(MO/PS)composites at (3.44,6.7,and 12.5%) concentration. These prepared polymer systems were evaluated spectrophotometically. It was found increasing in absorption spectra with increasing of the dye concentration in Dye/PS composites above, which was attributed to the increasing in localized states. The results proved that the best absorption was of (12.5%MO/PS), and of the lowest energy gap was (3.15eV),The optical constant (α,k,n, εr, and εi)for the homopolymer (PS) , (Dye/PS) composites, and hybrid composites at different concentration were investigated at(λc,300nm). It was seen that there was nonlinear relationship between the optical constants and the concentration ratio, which was attributed to their incompatibility. These results were confirmed with optical micrographs. The (FTIR) spectra showed shifting, appearance ,and disappearance of new band, which was attributed to change in tacticity, geometry in the structure ,and overlapping of polymer composites band involved. The results proved that there was nonlinear relationship between the carrier concentration, mobility, fast increase in the (12.5%MO/PS, and became of order(10-6). The increase in the conductivity with dye concentration was attributed to increase of the localized states in the energy gap.

Effect of Experimental Parameters on the Fabrication of Silver Nanoparticles by Laser Ablation

Mohammed J. Haider; Mohammed S. Mehdi

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 704-709

In this work, silver nanoparticles has been prepared via ablation of pure Ag metal target in distilled water was accomplished using Q-switched Nd:YAG laser at (1.06 µm) laser wavelength , with different laser energy and number of laser pulses. The effect of these parameters on the optical and surface morphology have been studied , UV-Visible show a red shift in the absorption spectra related to the shift in the energy gap due to increment of the grain of prepared particles size is increased as laser energy. Grain size of the obtained NPs are found to increase with laser energy with rang (20-112) nm as shown by the SEM result.

Preparation and Characterization of (Tio2-Sno2) Thin Films by Pulsed Laser Deposition

Saja H.Rashed; Adawiya J. Haider; Samar Younis

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 658-665

In this work, mixed oxide (TiO2-SnO2) thin films were grown on Si (111) and glass substrates by pulsed laser deposition (PLD) method. The influences of increasing amounts of SnO2 were investigated. The X-ray diffraction results show the peaks position of the plane was shifted towards higher angle values with increasing amounts of SnO2. The surface morphology of the deposits materials was also studied by using a scanning electron microscope(SEM) The results show that, the grain sizes decreases with increasing SnO2 content from the largest value (53.6)nm to smallest value (25.5) nm. From UV-visible spectroscopy, the distinct variations in the transmission spectra, and optical energy gap, of the thin films were also observed.

Preparation and characterization of PLD deposited Indium Selenide thin film

Khaled Z. Yahea; Amar H. Jareeze; Heba Salam Tariq

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 264-270

Indium Selenide films were deposited by pulsed laser deposition (PLD) with a Nd-YAG laser under vacuum condition. During the deposition, the substrates were kept at room temperature. The typical thicknesses of films were 200nm, 800 nm. The films were analyzed by X-ray diffraction for the crystallographic, the surface morphology of the film were investigated by AFM. It has been observed that grain growth depend on film thickness. The optical properties were characterized in the ultraviolet–visible region employing optical transmission, absorption, band gap. The direct optical band gap value for the films was found to be of the order of (2.2, 2.1) eV for thickness (200,800) nm respectively at room temperature.

Optical Properties of Cuo Thin Films with Different Concentration by Spray Pyrolysis Method

Khawla S. Khashan; Jehan A. Saimon; Azhar I. Hassan

Engineering and Technology Journal, 2014, Volume 32, Issue 1, Pages 86-93

In this work, CuO thin films were prepared by spray pyrolysis method using different concentration of CuCl2 .2H2O. X- ray diffraction (XRD) and UV-VIS transmission spectroscopy were employed to characterize the structure and optical properties of prepared films.XRD patterns show that the films are polycrystalline and monoclinic with (-111) and (111) crystalline orientations. The optical band gaps (2.05 to2.42eV) ,with high absorption coefficient change from (3*105 - 1*105) cm-1 at 0.3M concentration , and excitation coefficient change from (0.85 – 0.7). These constants are found to be oscillatory in nature, which are attributed to the particular structure of films and their concentration.

Optical and Structural Properties of Cdo Thin Film

Azhar I. Hassan; Khawla S. khashan; Aseel A. Hadi

Engineering and Technology Journal, 2013, Volume 31, Issue 5, Pages 613-620

Cadmium oxide thin film has been synthesized using spray pyrolysis method. The structural and optical properties of the film were study by usingX-ray diffraction (XRD), scanning electron microscopy (SEM), Atomic Force microscope (AFM), and UV- VIS spectroscopy. Result show that the film has spherical shape grain with size (460nm) and band gap (2.49eV). Moreover, the RMS equal to 58.7 nm.

Structural and Optical Characterization of NanocrystallinePbs Thin Films Synthesized by CBDMethod

Ali M. Mousa; Selma M. Al-Jawad; Suad M.Kadhim Al-shammari

Engineering and Technology Journal, 2013, Volume 31, Issue 5, Pages 603-612

Nanocrystalline PbS thin films have been deposited on glass substrates by Chemical Bath Deposition (CBD) technique using lead acetate ,KoH, thiourea and T.E.A. The films were btained in a reaction bath at times of (15 ,30 ,45 ,60 and 90)min. Structure and surface morphology of thin films were characterized by X-ray diffraction and scanning electron microscopy (SEM). XRD indicates that the films have cubic structure. The crystallite size of the films were found to vary from (4.9 to 11.3 nm).The band gaps of the nanocrystalline PbS were determined from UV-Vis spectrophotometer and were found to be in the range( 1.72 -2.4 eV).

Study of Degradation Effect on Physical Properties of Methyl Orange Doped PMMA

Mohamad S; Nahida J.Hameed Al-Mashhadan

Engineering and Technology Journal, 2011, Volume 29, Issue 1, Pages 20-32

The samples were cast as thin film from homopolymer (PMMA) before
and after doping with methyl orange at different concentration. The samples were
exposed to UV-radiation for exposure time within (10-50hr) range. These polymer
systems were evaluated spectrophotometrically for using the UV-detector. The
absorption spectra of UV-irradiated samples showed radiation induced absorption
changes in the wavelength range, which depends on the polymer type and polymer
composites. The increment depends dopant concentration, especially in ultra violet
region in exposed PMMA doped with methyl orange at 6.7×10-2wt/wt
concentration. Decreasing in absorption was found for the cases in which, photo
degradation caused surface damage, i.e. crazes or cracks formation, especially at
ultraviolet region. Calibration curves were drawn at peaks, selected wavelength in
the absorption spectra. The linear regions from the calibration curves were selected,
and dosimeter range was determined from the UV-irradiation sample response. It
was found that PMMA doped with methyl orange at 6.7×10 -2wt/wt concentration
can be use the UV-detector within range (10-40hr) at the wavelength of (300nm)
for its linear response at this range of irradiation.
Morphological investigations for the surface damages caused by thermal and photo
degradation are detected by optical microscope. It is found that the photo
degradation could easily lead to some mechanical surface degradation i. e (crazes
and cracks) formation.