Properties of Al-doped ZnO thin films deposited by a chemical spray process

Chemically sprayed aluminum-doped zinc oxide thin films were deposited on glass substrates. The effect of the deposition conditions and the post annealing treatment in vacuum on the electrical, optical, structural and morphologic properties have been analyzed. The films were prepared using two Zn reactants, namely zinc acetate A(Zn) and zinc pentanedionate P(Zn). Aluminum pentanedionate P(Al) was used as the dopant source in both cases. The results show that the doping and annealing of the ZnO thin films enhance mainly the electrical properties. Under optimum deposition conditions a low resistivity and a high optical transmittance of the order of 1.8 × 10? 2 ? cm and 85%, respectively, were obtained. No significant changes in the optical properties were observed as a consequence of the annealing treatments. All the films show a crystalline structure with a preferred (002) growth i.e. the c-axis is oriented normal to the substrate plane in all the cases.