Novel encapsulated ITO/arc-ZnO:TiO2 antireflective passivating layer for TCO conducting substrate prepared by simultaneous radio frequency-magnetron sputtering
A thermally stable multilayered transparent conducting oxide utilizing nanocomposite ZnO:TiO2 antireflection thin film (arc-ZnO:TiO2) on an indiumtin oxide (ITO) substrate has been prepared by radio frequency-magnetron sputtering. The effects of post-deposition annealing on the morphological, structural, optical and electrical properties were investigated with the aim to find the best conditions for the antireflection substrate. The X-ray diffraction behaviors of mixed type crystalline structures preferred at [222] and [101] between ITO and ZnO were observed, respectively. The grain size increased from 37.9nm to 46.9nm due to the aggregation of smaller grain during the annealing process. Average transmittances of approximately 82% were observed for all the samples in the range between 440nm and 760nm. A corresponding reduction in the reflectance of about 11% and 3% compared to bare ITO was achieved. The refractive index increased from 1.82 up to 2.0 due to the change in the packing density. For all ranges of annealing conditions, the arc-ZnO:TiO2 layers conserved the low resistivity of ITO at 1.9610?4?. In other words, the oxygen consumed in the annealing process improved the crystallinity of the film without much change to the resistivity of the ITO-based substrate. The increment of the root mean square roughness from 2.12nm to 3.21nm evidenced by the atomic force microscopy analysis was supported by the increment of grain growth.
simultaneous radio frequency-magnetron sputtering nanocomposite indiumtin oxide antireflection coating encapsulated tio2 compact layer