Improved semiconducting CuO/CuFe_2O_4 nanostructured thin films for CO_2 gas sensing

摘要

Promising results on the behavior of CuO/CuFe_2O_4 sputtered thin films as a sensing material under carbon dioxide atmospheres are presented in this article. More specifically, we report the effects of preparation parameters and microstructure of the sensing layer on the response to CO_2. FEG-SEM images and XPS measurements revealed the two-stacked layers rearrangement of samples after air annealing as a key parameter in gas sensing test. The influence of the sensing layer thickness and the influence of Ag as an additive in the film on the response are also reported. The best response was obtained at the optimal operating temperature of 250 ℃ with a thin film deposited under low argon pressure and low target-to-substrate distance, reaching 40% towards 5000 ppm of CO_2.