Preparation and characterization of Al doped ZnO thin films by spray pyrolysis

ZnO and Al-doped ZnO (AZO) thin films were prepared at 350°C on glass substrates by chemical spray pyrolysis method. In this contribution, the effects of aluminum doping on structural, optical and electrical properties are studied as function of dopant concentration, which was varied between 0 and 5 %. X-ray diffraction indicates that all the films exhibit hexagonal wurtzite structure and has polycrystalline nature. The preferential growth showed a variation depending on the doping ratios. Transmission measurements showed that for visible wavelengths, the AZO films have an average transmission of over 80%. The lowest resistivity was found to be 0.2 Ω.cm with a carrier concentration of 6.2 10²⁰ cm^-3 and high transmittance of 90 % at 550 nm after annealing.