공증발과 열산화로 제조한 Ag-CuO-SnO2 박막에서 미세조직과 CO 가스 감지특성 |
지인걸, 한규석, 오재희, 고태경 |
인하대학교 신소재공학부 |
Microstructure and CO Gas Sensing Properties of Ag-CuO-SnO2 Thin Films Prepared by Co-Evaporation and Thermal Oxidation |
In-Geol Ji, Kyu-Suk Han, Jae-Hee Oh, Tae-Gyung Ko |
Division of Materials Science and Engineering, Inha University |
|
|
|
ABSTRACT |
In this study, we investigated microstructure and the CO gas sensing properties of Ag-CuO-$SnO_2$ thin films prepared by co-evaporation and subsequently thermal oxidation at air atmosphere. The sensitivity of a Cu-Sn films, thermally oxidized at $600^{circ}C$, is strongly affected by the amount of Cu. At Cu:7 wt%-Sn:93 wt%, the film exhibited a maximum sensitivity of ${sim}2.3$ to CO gas of 1000 ppm at $300^{circ}C$. In contrast, the sensitivity of a Sn-Ag film did not change significantly with the amount of Ag. An enhanced sensitivity of ${sim}3.7$ was observed in the film with a composition of Ag:3 wt%-Cu:4 wt%-Sn:93 wt%, when thermally oxidized at $600^{circ}C$. In addition, this thin film shows a response time of ${sim}80$ sec and a recovery time of ${sim}450$ sec to 1000 ppm CO gas. The results demonstrate that the CO sensitivity of the Ag-CuO-$SnO_2$ thin films may be closely associated with coexistence of $SnO_2$ and SnO phase, decrease in average particle size, and a porous microstructure. We also suggest that co-evaporation and followed by thermal oxidation is a very simple and effective method to prepare oxide gas sensor thin films. |
Key words:
$SnO_2$, Catalyst, CO gas sensor, Co-evaporation, Thermal oxidation |
|