الفهرس 
Theoretical conceptsOnly 14 pages are availabe for public view
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Abstract
Flower-shaped Zinc oxide (ZnO) nanowires were synthesized by sol-gel
dip-coating. Sol-gel was prepared with different concentrations: 0.003M,
0.005M, 0.007M, 0.01M, and 0.02M from aqueous solutions of zinc nitrate
hexahydrate and methenamine at different acidities: pH 7, pH 6, and pH 4. The
dip-coating process was performed on substrates: Si, and SiOR2R. The coating
time was varied from 30 min to 48 hours. The coating processes were done at
different temperatures: 70 P
o
PC, 80 P
o
PC, and 90 P
o
PC.
Characterization of the surface morphology and crystal structure of ZnO
thin films was carried out using many techniques: field emission scanning
electron microscopy (FESEM), high resolution transmission electron
microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron
spectroscopy (XPS), and Raman spectroscopy. The optical properties were also
studied by photoluminescence (PL) measurements.
FESEM showed that the product is hexagonal flower-shaped ZnO
nanowires. We found that the best times for coating ranges from 2 to 4 hours,
with increasing in the nanowires diameter as the coating time increases. Also,
there was an observable increase in diameter either with increasing the molar
concentration or with increasing the coating temperature. For low
concentrations there was a dramatic decrease in deposition of the nanowires at
70 P
o
PC and 80 P
o
PC. Preparation of the sol-gel in acidic solution (pH = 6 and pH =
4) doesn’t affect on the nanowires diameter but affects on their outer shape.
Nanowires prepared from acidic solutions were found to have a uniform
diameter from top to bottom, whereas those prepared from neutral sol yielded
non-uniform diameters; small at the top and large at the bottom.
The energy dispersive X-ray (EDX) showed that the composition of the
nanowires was zinc and oxygen with weight percentage of 78.03% and 21.97%
respectively, and atomic percentage of 46.51% and 53.49%, respectively.