Materials Science
Farhan A. Mohammed; Evan T. Salim; Azhar I. Hassan; Mohammed H. A. Wahid
Abstract
Using a chemical spray technique, an n-type WO3 polycrystalline thin film was prepared with optimizing parameters (molarity concentration of 80 mM and a substrate temperature of 350 °C). Study the physical properties of WO3 thin film via UV-Visible spectroscopy, XRD, Field Emission-Scanning Electron ...
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Using a chemical spray technique, an n-type WO3 polycrystalline thin film was prepared with optimizing parameters (molarity concentration of 80 mM and a substrate temperature of 350 °C). Study the physical properties of WO3 thin film via UV-Visible spectroscopy, XRD, Field Emission-Scanning Electron Microscope, Energy Dispersive X-ray Spectroscopy, Atomic Force Microscopy, and current-voltage. Tungsten oxide was deposited on glass surfaces at different molarities ranging from 50–90mM. In the UV-Visible spectrum of the WO3 thin film, it was found that the transmittance, reflectivity, and energy gap decreased (78%–53%), (9.63%–5.02%), and (3.40eV–2.63 eV), respectively. The X-ray diffraction of the WO3 film at the optimized was poly-crystalline and had a monoclinic phase, and the preferred orientation (hkl) was 200 at 2 = 24.19. From the image FESEM and EDX, it was found that it has a multi-fibrous network. The average diameter of the fiber is 266 nm, and the ratio of tungsten to oxygen (W/O) is 2.6, with a stoichiometric of 68.6% at the 80 mM concentration. The Atomic Force Microscopy shows that the WO3 thin layer has a nanostructure. The average surface roughness was 5.3 nm, and the Root Mean Square was 8.6 nm. The WO3 film had the lowest resistivity value of 2.393 × 108W cm, and the activation energy was 0.298 eV, among the parameter of the current voltage at substrate temperature and concentration optimum.
Zahraa M. Talib; Azhar I. Hassan; Jehan A. Saimon
Abstract
Graphene-ZnO nanohybrid thin films were prepared by spray pyrolysis technique at 350 °C. Different graphene nanoplate concentrations of 0.1, 0.2, 0.3, 0.4, and 0.5 wt.% were used to deposit films on quartz substrates. The Structural and optical properties of the nanohybrid films have been investigated. ...
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Graphene-ZnO nanohybrid thin films were prepared by spray pyrolysis technique at 350 °C. Different graphene nanoplate concentrations of 0.1, 0.2, 0.3, 0.4, and 0.5 wt.% were used to deposit films on quartz substrates. The Structural and optical properties of the nanohybrid films have been investigated. X-ray diffraction XRD results show that the films have a hexagonal wurtzite polycrystalline structure and no secondary phases were observed. The structural parameters of crystallite size, dislocation density, and microstrain have indicated that the addition of graphene has a strong effect on the microstructure of zinc oxide films. Surface morphological analysis of the ZnO-graphene films reveals that the graphene content effectively modifies the morphologies and grain growth of the ZnO microstructure. It was also found from the optical properties that the maximum energy gap for pure ZnO films was 3.4 eV which decreases to 2.7 eV as the concentration of graphene increases to 0.5 wt.%. Results confirmed that graphene can be used as an efficient modifier for band gap engineering and the microstructure of ZnO thin films for enhanced photovoltaic applications.
