Sol-gel fabrication of lithium doped zinc oxide thin films

Li doped zinc oxide thin films were deposited on glass substrates by a sol-gel technique. Acetates of zinc and lithium were used as metal sources. A homogeneous and stable solution was prepared by dissolving acetates in the solution of 2-propanol and ethanolamine. ZnO:Li thin films were obtained after preheating the spin coated films at 250degreesC for I minute after each coating. A post annealing between 450-600degreesC was applied after the deposition of the last layers. XRD analysis revealed ZnO with zincite structure (Card no: 36-1451) in all films. The thickness of the films was measured as 75 nm per layer. The optical band gap of the films increased as doping concentration of Li increased and decreased as the post-annealing temperature increased.