Abstract
The atomic force microscopy (AFM) morphologies and electrical properties of the nanostructured Aluminium (Al) doped Zinc Oxide (ZnO) thin films prepared at various thicknesses were investigated. The films were prepared by sol-gel spin-coating method to fabricate ZnO-based sensors. The sensitivity upon exposure to methane (CH 4 ) gas at room temperature was investigated. The results show that the lowest resistivity of 0.752 × 10 6 Ω-cm was obtained for the ZnO nanostructures prepared at thickness of 170 nm. It also display highest sensitivity value which is 30%.