Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : thin films

Preparation and Study the Characteristics of Tungsten Trioxide Thin Films for Gas Sensing Application


Engineering and Technology Journal, 2016, Volume 34, Issue 4, Pages 462-469

In this study, Tungsten Trioxide thin films were successfully synthesized at different substrate temperatures by pulse laser deposition. Structural, morphological and electrical properties of WO3 thin films, were investigated by X-ray diffraction (XRD), Atomic Force Microscope AFM), Scanning Electron Microscope (SEM), Hall Effect and sensing measurements.
The results was indicated that WO3 thin films prepared at 450ᵒC was optimum condition where sensitivity toward H2S gas has been measured, sensitivity was higher than other films preparation at (250ᵒC,350ᵒC) temperature.

Structure and Optical Properties of Nano PbS Thin Film Deposited by Pulse Laser Deposition

Yasmeen Z. Dawood; Suad M. Kadhim; Ayad Z. Mohammed

Engineering and Technology Journal, 2015, Volume 33, Issue 9, Pages 1723-1730

The present work the structure properties of nano Lead sulfide PbS thin films were studied. Thin samples were prepared by pulse laser deposition and deposited on glass substrate at 1064nm wavelength with 800mj laser energy. The structure properties of films were determined by X-ray diffraction studied the effect of variation of substrate temperature on these properties. The films are adherent to the substrate and well crystallized according to the centered cubic structure with the preferential orientation (111) and (200). The minimum value of grain size was 16.5 nm when the film deposited of at 70 oC substrate temperature. The optical investigation showed that, depending on the substrate temperature have direct allowed transitions in the range 1.55–2.45 eV.

Structural and Optical Characterization of Nickel Oxide Thin Films Prepared by Spray Pyrolysis Technique

Fadheela H. Oleiwe

Engineering and Technology Journal, 2015, Volume 33, Issue 8, Pages 1503-1512

In this research, Nickel oxide (NiO) thin film were prepared by using nickel chloride ( NiCl2.6H2O) on glass substrate by using Spray Pyrolysis technique. The Structural and optical properties were studied for the growth thin films under influence different molarities (0.5,1,2 M) by XRD , SEM . The optical properties studied in the wavelength range from 200-1100nm measured by UV-VIS Spectrometer device.
The X-ray diffraction studies indicated that intensity was increased with molarities increase and had cubic structure , these films has grain size values (4.13-11.95 nm) with different molarities (0.5, 1 , 2M) , SEM found the films has smooth surface with grains scattered throughout the surface and the surface the films filled with the clusters of the larger grains the at increase molarities and AFM it is found the (RMS) of NiO films increased from 7.77 to 20.7 nm and the roughness average increased from 5.73-15.6 nm with the increase of molarities from 0.5-2 M .
From the optical studies it is found the film thickness increased with molarities increase, while the transmittance decreased from approximately 75% to approximately 54% and the energy gap for the NiO films varies from ( 3.65 to 3.1eV) as the molarities increase.

A Study on the Structural, Optical and Electrical Properties of Tungsten TrioxideWO3Thin Film for Gas Sensing Applications

Adawiya J. Haider; Huda A. Mutasher

Engineering and Technology Journal, 2015, Volume 33, Issue 8, Pages 1473-1482

The pulsed laser deposition method, PLD, has been used in this project to deposit the pure Wo3 The aim was to study the influence of temperature on surface morphology of the deposits materials using Atomic Force Microscope measurements at different temperatures of (RT,300 ,400)°C. The structural characteristics of the films prepared on glass substrates have been studied by using X-ray diffraction and AFM. These tests show that there is a direct relationship between the grain sizes of the nanoparticles observed at the surface and influence of temperature which means as temperature increases there will be a similar enhancement in the grain size as well. Additionally, we were able to find that the best of temperature was 400ᵒC. Furthermore, the characterizations of the gas sensing of these thin films were strongly influenced by the surface morphology. It has been also found that nanocrystalline Wo3 gas sensing material was presented a better sensitivity as temperature increases

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.