Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : optical properties


Synthesis of Nano-TiO2 Thin Films by Sol-gel Dip-coating Method

Bushra R. Mahdi; Abass F. Al.mamori; Adnan meship Mahdi

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1303-1312

Synthesis of titanium dioxide (TiO2) Thin film on three microscope glasses using sol-gel method has been studied intensively. The starting materials were titanium(III)chloride, Ammonium Hydroxide. The components were mixed together to form the sol. Then, at 50℃ heating and ageing was applied to form stable sol-gel . Every glass substrate dipping in sol-gel beaker for period time (1,3,5)min respectively, for obtaining different thickness films. To evaluate the performance of films, After annealing at 500℃ , the crystallinity of the films was determined by using the x-ray diffractometer (XRD). The change on the surface morphology was observed using Atomic Force Microscope(AFM). Finally, Optical properties measurements Absorbance (A) and transmittance(T)) for (TiO2) films were studied by UV-Visible spectrometer.
analysis on the films. It has been successfully shown that the anatase crystalline phase was observed when the TiO2 thin film was annealing at 500°C. The roughness and the crystalline size of TiO2 thin film changed with the thickness. The minimum grain size( 6.92) nm for thickness 1.2µm UV-visible studying that absorption is maximum at UV spectrum (opaque) and the transmittance is maximum at the visible spectrum

Structural and Optical properties of CdO doped TiO2 thin films prepared by Pulsed Laser Deposition

Ghusson H. Mohammed; Ahmed M. Savore; Mohammed Hadi. Shinen; Kadhim A. Adem

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 918-931

TiO2 thin films have been deposited at room temperature with different concentration of CdO of x= (0.0, 0.05, 0.1, 0.15and 0.2) wt. % onto glass substrates by pulsed laser deposition (PLD) technique using Nd-YAG laser with λ=1064nm, energy=800mJ and number of shots=500. The structural, morphological and optical characterizations of as- deposited films were carried out using X-ray diffraction (XRD), atomic force microscopy (AFM), and UV–vis transmittance spectroscopy. The Effect of CdO content on these properties was investigated. Characterizations by X-ray diffraction show a polycrystalline film, with tetragonal structure and formation of Rutile phase and many peaks (110), (101), (111) and (211) were appear. In addition, AFM investigation shows no cracks in the formed layer. The optical properties concerning the absorption and transmission spectra were studied for the prepared thin films using an ultraviolet–visible near-infrared spectrophotometer. The results show that the transmittance of the TiO2 film in the visible domain reaches 75%.Optical band gaps were calculated and found to be (3.62, 3.54, 3.45, 3.3 and 3.21) eV for the concentration of CdO x= (0.0, 0.05, 0.1, 0.15 and 0.2) wt. % respectively. At 350 nm the refractive index,extinction coefficient and dielectric constant were determined.

Laser annealing effect on the optical properties of CuAlO2 thin film

Azhar A. Hassan; Nuha F. Abd Al-Rasheed

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 908-917

Transparent conducting oxides thin films of copper aluminium oxide (CuA1O2) were prepared from mixture of CuCl2 and Al2Cl3 salts by spray pyrolysis technique on a glass substrate at temperature (500oC). The as-deposited film show pure delaffosite phase of CuAlO2 by XRD spectra, also many peaks of CuAlO2 were appeared after annealing at different energy fluence. The optical transmission of thin films was measured by UV-VIS spectrometer and reach to 74% in visible region. The direct and indirect optical band gaps of the films are found in the range of (3.4-3.1) eV, and (2.1-1.5) eV, respectively depending on the annealing energy fluence at (300, 600, 900, 1200) mJ/cm2.

Study of Structural , Optical and Electrical Properties for Cr -Doped Tio2 Sensor for NH3 Gas

SelmaM.H.Al-Jawad; Zahraa Yassar Abbas

Engineering and Technology Journal, 2014, Volume 32, Issue 6, Pages 1137-1145

Titanium doxide (TiO2) thin films were deposited on quartz substrates by spray pyrolysis method using titanium tetrachloride as precursor solution. Thin films were deposited at temperature substrate 350 ◦C and annealed at 550 ◦C in air for 120 min. Polycrystalline thin films with anatas crystal structure, as evidenced from X-ray diffraction pattern. Optical study shows the optical band gap has been increased with increasing of dopant. Electrical properties have been studied by means of electrical resistivity and Hall measurement. The sensitivity of TiO2: 5% Cr to NH3 gas with concentration 5ppm at room temperature has been modified to (93) % as compared with a pure TiO2.

γ-Irradiation Effect on the Optical Constants, and the Electric Loss of PM-355

Nahida J.H Al-Mashhada

Engineering and Technology Journal, 2014, Volume 32, Issue 6, Pages 1158-1168

The optical reflection, transmission, and UV/VIS- absorption spectra had been recorded in the wavelength(200-500nm) for PM-355 before and after irradiation with γ-ray irradiation by using 60Co-dose within range of(30-160Mrad) at normal conditions. The absorption spectra of irradiated samples showed radiation induced absorption changes by photodegradation. There was an increment in absorption proportional with irradiation dose. The optical constants (α,Kex,n,εi,εr,Eg,) were calculated for all samples. The effect of irradiation on the optical constants of the PM-355 before and after irradiation had been investigated.

Oxygen Effect on Structural and Optical Properties of WO3 Films by Pulsed Laser Deposition

Ruaa W.Gabbar; Adawiya J. Haider

Engineering and Technology Journal, 2014, Volume 32, Issue 6, Pages 1068-1073

This work includes the deposition of WO3 as a thin film on glass substrates by pulsed laser deposition method. The influence of Oxygen pressure on the structural and optical properties of tungsten trioxide films was investigated. The X-ray diffraction results show that the structure of the films changes from amorphous to crystalline at an Oxygen pressure higher than 10-2 mbar. The color of WO3 films formed at Oxygen pressure of 10-2 mbar is translucent white and it changes to pale blue with increasing the Oxygen pressure. From UV-visible spectroscopy the distinct variations in the transmission spectra and optical energy gap of the thin films were also observed. The optical band gap of the prepared films determined at different Oxygen pressures and it is found to be 3-3.1-3.12 eV at Oxygen pressures of 10-2 -2×10-1 -5×10-1 mbar respectively.

Annealing Effect on the Growth of Nanostructured TiO2 Thin Films by Pulsed Laser Deposition (PLD)

Sarmad S.Kaduory; Ali A.Yousif; Adawiya J. Haider; Khaled Z.Yahya

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 460-470

In this work, Nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates at 300 °C. TiO2 thin films were then annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structure, morphology and optical properties were studied. The X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) measurements confirmed that the films grown by this technique have good crystalline tetragonal mixed anatase and rutile phase structure and homogeneous surface. The study also reveals that the RMS value of thin films roughness increased with increasing annealing temperature .The optical properties of the films were studied by UV-VIS spectrophotometer. The optical transmission results shows that the transmission over than ~65% which decrease with the increasing of annealing temperatures. The allowed indirect optical band gap of the films was estimated to be in the range from 3.49 to 3.1 eV. The allowed direct band gap was found to decrease from 3.74 to 3.55 eV with the increase of annealing temperature. The refractive index of the films was found from 2.27 -2.98 at 550nm. The extinction coefficient increase with annealing temperature.

Optical Properties of Tin Oxide Nanostructure Thin Films Prepared by Simple and Classical Method

Rana Osamah Mahdi

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 3565-3572

In the present work, preparation of transparent conductive SnO2 thin films by
classical-oxidation technique of thermal evaporated tin metal films, on glass substrates
was carried out. The optical properties showed high transmission at visible and NIR
regions. The energy band gap was found to be (3.82eV). The structure properties
showed that the tin oxide peak appears at (2q =30.24) and (2ϴ=63.39°) . The atomic
force microscopy (AFM) results showed a nano-structured for the thin film with
particle size ranging (15-140)nm and its root mean square (RMS) value was found to
be (5.72 nm ).

Study of the Optical Constants of the PMMA/PC Blends

Marwa. R. F; Nahida. J. H

Engineering and Technology Journal, 2011, Volume 29, Issue 4, Pages 698-708

The aim of the present work is concerned with the study of the optical
constants of the PMMA/PC blend at different concentrations.
The samples are casted as films from the PMMA and PC homopolymers and
blend. These polymer systems are evaluated spectrophotometically. The
absorption spectra of homopolymers and PMMA/PC blends at different
concertation showed absorption changes in the wavelength range, which depends
on the polymer type, and the concentration of the polymer blends. It was found
that 50% ratio from these polymers showed higher absorption values in
comparison with the homopolymers, besides, the absorption spectroscopy of the
polymer blends did not always effect the similar information obtained from the
spectroscopy of the homopolymers .A phenomenon was attributed to immiscibility
or phase separation as associated with the blends formation. The results of the
optical constant proved that 50%ratio was the best, which was attributed to the
lowest energy gap (2.5 eV). Morphological investigations for the
casted polymer systems were introduced.

Effect of Substrate Temperature on the Structural and Morphological Properties of Nano-structure ZnO films by Pulsed Laser Deposition

Adawiya J. Haider; Afnan k. yousif

Engineering and Technology Journal, 2011, Volume 29, Issue 1, Pages 58-64

In this work, ZnO thin films were grown on sapphire (0001) substrate by
Pulsed Laser Deposition using SHG with Q-switched Nd:YAG pulsed laser operation
at 532nm in O2 gas ambient 5×10-2 mbar at different substrate temperatures varying
from room temperature to 500°C. The influence of the substrate temperature on the
structural and morphological properties of the films were investigated using XRD and
SEM. As result, at substrate 400°C, a good quality and crystalline films were deposited
that exhibits an average grain size (XRD) of 22.42nm with an average grain size
(SEM) of 21.31nm.

Data Acquisition of TiO2 for Optical Material by using Spectroscopic Ellipsometry Technique

Asad Sabih Mohammad Raouf

Engineering and Technology Journal, 2010, Volume 28, Issue 20, Pages 6128-6139

An Ellipsometric experimental set up of SOPRA ES4G type with a powerful
WVASE software for the theoretical calculus of the Ellipsometry parameters. The
Ellipsometry Technique can determine amplitude and phase information Ψ( and Δ)
dependent on wavelength range 250 nm to 900 nm (1.5 - 5 eV), including original
practical solutions, were developed. Encouraging results of TiO2 were obtained in
applying the simple Ellipsometric method of azimuths to determine the optical
constants for TiO2 with this optoelectronic device.

Influence of Post- Annealing on The Properties of Cuxs: Al, Fe Films Deposited By C B D

Ali M . Mousa; Abbas F. Sabbar

Engineering and Technology Journal, 2009, Volume 27, Issue 14, Pages 2632-2641

Thin films of copper sulfide (CuxS) were deposited at room temperature on glass substrates from solution containing copper (II) chloride, triethanolamine, and thiourea at appropriate pH (10-11). Two types of doping salts were used (AlCl3 & FeCl3) in four different weights (1, 1.5, 2, and 2.5) mg. The effect of introducing impurities and post-annealing was studied .The as-deposited films were found to
be amorphous, while the post annealed were polycrystalline. The changes in optical and electrical properties of doped films were also studied. The electrical conductivity was found to be highly dependent on annealing conditions, the resistivity of doped films was between (0.022-8.75) Ω cm. Optical band gaps of doped films determined from absorption spectra were found to have values within the range of (2.17-2.33) eV.