Photoresponse characteristics of nanostructured aluminum doped Zinc oxide thin films

Aluminium doped Zinc oxide (ZnO) thin films were prepared through sol gel dip coating technique with various doping concentrations from 0 to 1.5 at.%. The thin films were characterized using X-ray Diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM), UV-Vis-NIR spectrophotometer and current voltage (I-V) measurement system. From the XRD analysis, increasing of doping concentration affected structural properties of the thin film where c-axis orientation becomes weaker. FESEM shows a homogenous thin films in nanoscale while the UV-Vis-NIR spectra reveals all films exhibit high transmission (>;80 %) in UV-NIR region. Improvement in electrical properties with dopant concentrations is observed as shown by I-V measurement results. The lowest dark resistivity obtained was 1.44 Ω.cm, while the lowest resistivity under light illumination was 1.05 Ω.cm at 1 at.% of Al doping.