Effects of Cyclic Bending Parameters on Aluminum-Doped Zinc Oxide Thin Films for Flexible Device Applications

Aluminum-doped zinc oxide (AZO) presents an attractive option for cost-effective utilization as a transparent conductive oxide (TCO). Possessing favorable electrical and optical characteristics, AZO thin films hold potential, yet their dependability necessitates meticulous attention in both the manufacturing process and the practical deployment of flexible electronic devices. This article presents a comprehensive investigation into the influence of cyclic bending fatigue on AZO thin films deposited on polyimide Kapton substrates. The AZO thin films were meticulously prepared using radio frequency (RF) magnetron sputtering, with precise attention to factors such as substrate cleanliness, target purity, and deposition parameters. The experimental setup involved cyclic bending fatigue experiments on carefully prepared specimens, with a focus on electrical resistance and optical transmittance measurements. The analysis of variance (ANOVA) was performed to ascertain the impact of various factors on the percentage change in electrical resistance (PCER). The results revealed that the number of cycles and bending diameter significantly affect the PCER. Notably, a detailed examination of the relationship between significant factors and PCER was facilitated through main effect plots. The study elucidates the interplay between factors such as bending cycles, bending diameter, bending frequency, and sample width, shedding light on the development of cracks due to fatigue. These findings contribute to the understanding of thin-film behavior under cyclic bending conditions, with implications for applications such as flexible electronic packaging and solar cell technology.