Influence of the aluminum incorporation on the properties of electrodeposited ZnO thin films

Undoped and aluminum doped zinc oxide thin films were successfully deposited by electrodeposition technique from aqueous solution onto ITO substrates at optimized experimental conditions. The variations of the structural, electrical and optical properties with the doping concentration were investigated. X-ray diffraction analysis showed typical patterns of the hexagonal ZnO structure for both doped and undoped films. The films are single phase and polycrystalline with the (002) preferred orientation. The grain size, texture coefficient and optical band gap values were evaluated for different aluminum salt concentrations. The films, obtained from a 10− 7 M aluminum electrolyte, exhibit the highest crystallographic quality and lowest electrical resistivity of 2 × 10− 4 Ω·cm with an energy band gap of 3.35 eV.