Huitong Cao

Bio: Huitong Cao is an academic researcher. The author has contributed to research in topics: Nanotechnology & Thin film. The author has co-authored 1 publications.

Conductometric ethanol gas sensor based on a bilayer film consisting of SnO2 film and SnO2/ZnSnO3 porous film prepared by magnetron sputtering

Abstract: As one important type of the sensing material, the metal oxide film can realize accurate detection to the low concentration of ethanol. In this paper, a double-layer nano film was prepared by sputtering a SnO2 bottom layer and co-sputtering a SnO2/ZnSnO3 porous top layer with SnO2 and ZnO targets. Firstly, the effects of Zn content on the properties of the single-layer SnO2/ZnSnO3 porous film were investigated by changing sputtering power of ZnO and keep sputtering power of SnO2 constant. When the sputtering power of ZnO is 25 W, the single-layer SnO2/ZnSnO3 porous film has the best response to ethanol. To expose more adsorption sites to air, the SnO2/ZnSnO3 porous layer was deposited on a SnO2 thin film with thickness of 10 nm to form the double-layer sensing material. The double-layer thin film has response of 11.5–50 ppm ethanol at 290 °C, which is 2.1 times that of the single-layer SnO2/ZnSnO3 porous layer, and the response and recovery time of the double layer are 56 s and 666 s to 50 ppm ethanol at 290 °C, which are shortened by 63 s and 641 s compared to those of the single layer, respectively. In addition, the double-layer porous film also exhibits excellent long-term stability and good selectivity to ethanol. The n-n heterojunction formed between SnO2 and ZnSnO3 and unique double-layer porous structure are the main reasons for the excellent sensing performance.