Remarkable Evolution Of Electrical Conductivity In Al:Zno Films

We report here the investigation of Al-doped ZnO films fabricated by the RF magnetron deposition technique. The films show excellent crystalline quality with atomically smooth surface morphology. The Al-doped ZnO films have been characterized in detail using X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy UV-visible spectrophotometer and four probe technique. It was found that the morphological, structural, electrical and optical properties of Al-doped ZnO films are greatly dependent on substrate temperature. XRD patterns show that all the films are well crystallized with hexagonal wurtzite structure with preferred orientation along (0 0 2) plane. The electrical resistivity of Al-doped ZnO films decreases with increasing substrate temperature and was found to be close to 1.5 x 10(-3) ohm-cm and transmittance >85% in the visible region.