Effect of different dopant elements (Al, Mg and Ni) on microstructural, optical and electrochemical properties of ZnO thin films deposited by spray pyrolysis (SP)

In the present work we studied the influence of the dopant elements and concentration on the microstructural and electrochemical properties of ZnO thin films deposited by spray pyrolysis. Transparent conductive thin films of zinc oxide (ZnO) were prepared by the spray pyrolysis process using an aqueous solution of zinc acetate dehydrate [Zn(CH3COO)(2)center dot 2H(2)O] on soda. glass substrate heated at 400 +/- 5 degrees C. AlCl3, MgCl2 and NiCl2 were used as dopant. The effect of doping percentage (2-4%) has been investigated. Afterwards the samples were thermally annealed in an ambient air during one hour at 500 degrees C. X-ray diffraction showed that films have a wurtzite structure with a preferential orientation along the (002) direction for doped ZnO. The lattice parameters a and c are estimated to be 3.24 and 5.20 angstrom, respectively. Transmission allowed to estimate the band gaps of ZnO layers. The electrochemical studies revealed that the corrosion resistance of the films depended on the concentration of dopants. (C) 2012 Elsevier Ltd. All rights reserved.