Fabrication of Transparent Conductive Al-doped ZnO Thin Films by Aerosol-assisted Chemical Vapour Deposition

Al-doped ZnO thin films were prepared by aerosol-assisted chemical vapour deposition (AACVD) on glass substrates. The effect of Al content (2at%−8at%) on the structural, optical and electrical properties of Al-doped ZnO thin films was investigated in detail. The samples were tested by XRD, SEM, EDAX and UV-Vis spectrophotometer. The results indicate that the AZO films have a hexagonal (wurtzite) structure without preferen- tial orientation along c-axis, and however no Al related phases are observed. The average transmittances of the AZO film is over 72% in the visible regions. The optical band gap for the AZO films becomes narrow with the increasing Al dopant. The four-point probe technique is used to characterize thin films electrically. The data shows that Al dopant decrease the sheet resistance. The ZnO films doped with 6at% Al exhibit a minimum of sheet resistance (18Ω/□).