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Optical investigations of microwave induced synthesis of zinc oxide thin-film

Ansari A. R., Hussain S., Imran M., Al-Ghamdi A. A., Chandan M. R.

Materials Science Poland

2018

Vol. 36, No. 2

304--309

In this article, ZnO thin-film deposition on a glass substrate was done using microwave induced oxygen plasma based CVD system. The prepared thin-films were tested in terms of crystallinity and optical properties by varying the microwave power. The effect of power variation on the morphology and size of final products was carefully investigated. The crystal structure, chemical composition and morphology of the final products were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy, Raman spectroscopy and photoluminescence (PL). This technique confirmed the presence of hexagonal ZnO nanocrystals in all the thin-films. The minimum crystallite grain size as obtained from the XRD measurements was ~9.7 nm and the average diameter was ~18 nm.

Influence of aluminium concentration in Zn0:9V0:1O nanoparticles on structural and optical properties

Sayari A., El-Mir L., Al-Heniti S., Al-Harbi T., Yaghmour S. J., Al-Ghamdi A. A.

Materials Science Poland

2015

Vol. 33, No. 1

198--204

The (V,Al) co-doped ZnO nano-structured powders (Zn0.9V0.1AlxO, where x = 0.02, 0.03 and 0.04) were synthesized via the sol-gel technique and their structural and optical properties were investigated. The effect of Al concentration on the structural and optical properties of the Zn0.9-xV0.1AlxO nanopowders was studied using various techniques. The XRD patterns indicate that the samples have a polycrystalline wurtzite structure. The crystallite size increases with increasing the Al content and lies in the range of 23 to 30 nm. The lattice strain, estimated by the Stokes-Wilson equation, decreases when Al content increases. SEM and TEM micrographs show that Zn0.9-xV0.1AlxO powders are the agglomeration of nanoparticles having spherical and hexagonal shapes with dimensions ranging from 20 to 30 nm. FT-IR spectra show a distinct absorption peak at about 500 cm-1 for ZnO stretching modes and other peaks related to OH and H2O bands. Raman spectra confirm the wurtzite structure of the Zn0.9-xV0.1AlxO nanoparticles. The direct band gaps of the synthesized Zn0.9-xV0.1AlxO nanopowders, estimated from the Brus equation and the crystallite sizes deduced from XRD, are around 3.308 eV. The decomposition process of the dried gel system was investigated by thermal gravimetric analysis (TGA).