Structural and sensing properties of ethanol gas using Pd-doped SnO2 thick film gas sensor

In the present study, we fabricate undoped and 1 wt% palladium (Pd)-doped tin oxide (SnO2) films were deposited on alumina substrate using screen printing technology. The deposited sensing film is characterized and its microstructural properties are studied using X-ray diffraction (XRD) and atomic force microscope (AFM). The crystallite size, grain size, and roughness parameter decrease with Pd doping. It was similar to 23.5 nm and similar to 19.2 nm for undoped and Pd-doped SnO2 film samples. The response of fabricated thick film sensor for 1 wt% Pd-doped SnO2 is maximum (similar to 71) with varying concentrations of ethanol (5000 ppm) at operating temperature 473 K. The response/recovery time is observed and it is similar to 41 s/125 s. The reduction in crystallinity and roughness leads to improves sensing behavior towards ethanol gas. The sensing mechanism and response behavior is explained based on a theoretical model.

Automated summary

In this study, undoped and Pd-doped SnO2 films were fabricated on alumina substrate using screen printing technology. The microstructural properties of the deposited sensing film were characterized using XRD and AFM, showing a decrease in crystallite size, grain size, and roughness parameter with Pd doping. The response of the sensor to ethanol gas was found to be maximum for 1 wt% Pd-doped SnO2, with an observed response/recovery time of approximately 41 s/125 s. The improvement in sensing behavior towards ethanol gas was attributed to the reduction in crystallinity and roughness of the film.