M M Bagheri-Mohagheghi
Articles written in Pramana – Journal of Physics
Volume 77 Issue 4 October 2011 pp 679-688 Research Articles
In this work, some structural and optical properties of the zinc oxide (ZnO) nanoparticles were studied. The highly crystalline ZnO nanoparticles were produced by the hydrothermal and sol–gel methods. The analyses of the XRD patterns, STEM images and UV spectroscopy showed that the size of the nanoparticles prepared by oxalic acid was smaller than the ones by urea. The properties of oxalic acid and urea were also investigated to determine the most effective crystallization process of ZnO nanoparticles. It has been shown that pH, decomposition temperature and activity coefﬁcient of the complexing agent have certain effects on crystallization process.
Volume 78 Issue 4 April 2012 pp 625-634 Research Articles
In this work, ZnO thin ﬁlms have been prepared by spray pyrolysis deposition method on the glass substrates. The effect of deposition parameters, such as deposition rate, substrate temperature and solution volume has been studied by X-ray diffraction (XRD) method, UV–Vis–NIR spectroscopy, scanning electron microscopy (SEM), and electrical measurements. The XRD patterns indicate polycrystalline wurtzite structure with preferred direction along (0 0 2) planes. Thin ﬁlms have transparency around 90% in the visible range. The optical band gap was determined at 3.27 eV which did not change signiﬁcantly. Evolution of electrical results containing the carriers' density, sheet resistance and resistivity are in agreement with structural results. All the results suggest the best deposition parameters are: deposition rate, $R = 3$ ml/min, substrate temperature, $T_s = 450^\circ$C and thickness of the thin ﬁlms $t = 110–130$ nm.
Volume 93 | Issue 5
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