Zinc-oxide-deposited Carbon Nanowalls for Acetone Sensing

Abstract The acetone level in diabetic patients is double that in healthy people, and is important not only for biosensors but also for gas sensors. In this study, carbon nanowall (CNW) was grown on a substrate using a microwave-plasma-enhanced chemical vapor deposition system with a mixture of methane (CH4) and hydrogen (H2) gases for acetone sensing. Zinc oxide (ZnO) and aluminum-doped ZnO (AZO) were deposited on the CNW using a radio frequency magnetron sputtering system with 4-inch AZO and ZnO targets. The surface structures of the AZO/CNW and ZnO/CNW were confirmed through Raman spectroscopy and field emission scanning electron microscopy. The detection characteristics were then confirmed using a current multimeter. A 200 mV voltage was applied to the electrode corresponding to the source and drain of each sample, and the organic matter was evaporated to confirm the acetone gas selectivity through the electrical variation of the samples.