Effect of open air annealing on spin coated aluminum doped ZnO nanostructure

• Aluminum doped ZnO thin film nanostructures were prepared by sol–gel deposition.
• Optimized film nanostructures with a low resistivity of 2.11 × 10−1 Ω-cm were obtained.
• Atomic force microscopy (AFM) shows mountain and valley like nanostructure.

Aluminum doped ZnO thin film nanostructures were prepared by spin coating deposition on glass and silicon substrates. Electrical, optical and structural properties of these films were analyzed in order to investigate their dependence on post annealing temperature and number of coating cycles. Ultraviolet–Visible spectrophotometry and X-Ray diffraction (XRD) analysis confirmed that the films are optically transparent and polycrystalline in nature. Scanning electron microscopy (SEM) reveals worm like homogeneous morphology. Chemical analysis was carried out by Fourier transform infrared spectroscopy (FTIR). Atomic force microscopy (AFM) showed mountain and valley like nanostructure. Optimized films with a low resistivity of 2.11 × 10−1 Ω cm were obtained at open air annealing temperature of 375 °C.