scholarly journals Toward the Growth of Self-Catalyzed ZnO Nanowires Perpendicular to the Surface of Silicon and Glass Substrates, by Pulsed Laser Deposition

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4427
Author(s):  
Basma ElZein ◽  
Yingbang Yao ◽  
Ahmad S. Barham ◽  
Elhadj Dogheche ◽  
Ghassan E. Jabbour

Vertically-oriented zinc oxide (ZnO) nanowires were synthesized on glass and silicon substrates by Pulsed Laser Deposition and without the use of a catalyst. An intermediate c-axis oriented nanotextured ZnO seed layer in the form of nanowall network with honey comb structure allows the growth of high quality, self-forming, and vertically-oriented nanowires at relatively low temperature (<400 °C) and under argon atmosphere at high pressure (>5 Torr). Many parameters were shown to affect the growth of the ZnO nanowires such as gas pressure, substrate–target distance, and laser energy. Growth of a c-axis-crystalline array of nanowires growing vertically from the energetically favorable sites on the seed layer is observed. Nucleation occurs due to the matching lattice structure and the polar nature of the ZnO seed layer. Morphological, structural, and optical properties were investigated. X-ray diffraction (XRD) revealed highly c-axis aligned nanowires along the (002) crystal plane. Room temperature photoluminescence (PL) measurements showed a strong and narrow bandwidth of Ultraviolet (UV) emission, which shifts to lower wavelength with the increase of pressure.

1995 ◽  
Vol 395 ◽  
Author(s):  
R.D. Vispute ◽  
H. Wu ◽  
K. Jagannadham ◽  
J. Narayan

ABSTRACTAIN thin films have been grown epitaxially on Si(111) and Al2O3(0001) substrates by pulsed laser deposition. These films were characterized by FTIR and UV-Visible, x-ray diffraction, high resolution transmission electron and scanning electron microscopy, and electrical resistivity. The films deposited on silicon and sapphire at 750-800°C and laser energy density of ∼ 2 to 3J/cm2 are epitaxial with an orientational relationship of AIN[0001]║ Si[111], AIN[2 110]║Si[011] and AlN[0001]║Al2O3[0001], AIN[1 2 1 0]║ Al2O3[0110] and AIN[1010] ║ Al2O3[2110]. The both AIN/Si and AIN/Al2O3 interfaces were found to be quite sharp without any indication of interfacial reactions. The absorption edge measured by UV-Visible spectroscopy for the epitaxial AIN film grown on sapphire was sharp and the band gap was found to be 6.1eV. The electrical resistivity of the films was about 5-6×l013Ω-cm with a breakdown field of 5×106V/cm. We also found that the films deposited at higher laser energy densities ≥10J/cm2 and lower temperatures ≤650°C were nitrogen deficient and containing free metallic aluminum which degrade the microstructural, electrical and optical properties of the AIN films


2021 ◽  
pp. 126323
Author(s):  
Joseph A. De Mesa ◽  
Angelo P. Rillera ◽  
Melvin John F. Empizo ◽  
Nobuhiko Sarukura ◽  
Roland V. Sarmago ◽  
...  

Vacuum ◽  
2010 ◽  
Vol 84 (11) ◽  
pp. 1306-1309 ◽  
Author(s):  
Xiaofeng Xu ◽  
Yiqun Shen ◽  
Ning Xu ◽  
Wei Hu ◽  
Jushui Lai ◽  
...  

2000 ◽  
Vol 15 (10) ◽  
pp. 2249-2265 ◽  
Author(s):  
Jeanne M. McGraw ◽  
John D. Perkins ◽  
Falah Hasoon ◽  
Philip A. Parilla ◽  
Chollada Warmsingh ◽  
...  

We have found that by varying only the substrate temperature and oxygen pressure five different crystallographic orientations of V2O5 thin films can be grown, ranging from amorphous to highly textured crystalline. Dense, phase-pure V2O5 thin films were grown on SnO2/glass substrates and amorphous quartz substrates by pulsed laser deposition over a wide range of temperatures and oxygen pressures. The films' microstructure, crystallinity, and texturing were characterized by electron microscopy, x-ray diffraction, and Raman spectroscopy. Temperature and oxygen pressure appeared to play more significant roles in the resulting crystallographic texture than did the choice of substrate. A growth map summarizes the results and delineates the temperature and O2 pressure window for growing dense, uniform, phase-pure V2O5 films.


2019 ◽  
Vol 15 (34) ◽  
pp. 41-54
Author(s):  
Iqbal S. Naji

The influence of sintering and annealing temperatures on the structural, surface morphology, and optical properties of Ag2Cu2O4 thin films which deposited on glass substrates by pulsed laser deposition method have been studied. Ag2Cu2O4 powders have polycrystalline structure, and the Ag2Cu2O4 phase was appear as low intensity peak at 35.57o which correspond the reflection from (110) plane. Scan electron microscopy images of Ag2Cu2O4 powder has been showed agglomerate of oxide particles with platelets shape. The structure of thin films has been improved with annealing temperature. Atomic Force micrographs of Ag2Cu2O4 films showed uniform, homogenous films and the shape of grains was almost spherical and larger grain size of 97.85 nm has obtained for film sintered at 600 °C. The optical band gap was increase from 1.6 eV to 1.65 eV when sintering temperature increased to 300 °C and decrease to 1.45 eV at 600 °C for the films deposited at room temperature. Heat treatment of films has been increased the energy band with increasing sintering temperature. Hall coefficient of Ag2Cu2O4 films have a positive sign which means the charge carrier is a p-type. The electrical conductivity decreases with increasing of the sintering temperature for as deposited and annealed films.


2007 ◽  
Vol 88 (1) ◽  
pp. 31-34 ◽  
Author(s):  
A. Rahm ◽  
M. Lorenz ◽  
T. Nobis ◽  
G. Zimmermann ◽  
M. Grundmann ◽  
...  

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