Impact of RF Sputtering Power on AZO Thin Films for Flexible Electro‐Optical Applications

Abstract

In the present work, fixed Al (2.5 wt%) doped zinc oxide (ZnO) thin films are fabricated at different radio frequency (RF) power on indium doped tin oxide‐coated polyethylene terephthalate substrate by sputtering techniques. From the X‐ray diffraction (XRD) results it has been observed that all thin films have polycrystalline nature with hexagonal structure. Stress of thin film calculated from XRD measurement is increased from −0.10 × 109 to 0.23 × 109 N m−2 with increase in RF sputtering power. The morphology analyzed by field electron microscopy is observed as irregular sphere for all samples. The estimated values of thickness are 440, 870, 913, and 1086 nm for the films grown at RF sputtering powers 130, 140, 150, and 160 W, respectively. On increasing the RF power from 130 to 160 W, the optical bandgap is decreased from 3.59 to 3.48 eV. The highest conductivity obtained is 2.43 × 102 S m−1 for the sample grown at sputtering power 160 W. The study reveals that there is an impact of sputtering power on the various properties of thin films grown on flexible substrates and these films have wide applications in flexible electro‐optical applications.