High Temperature and High Sensitive NOx Gas Sensor with Pt/SnO₂/SiC/Ni Heterojunction Structure

Abstract

In order to develop a high temperature (200°C˜400°C) and high sensitive NOx gas sensor with SiC based junction structure, a hetero-junction structure, Pt/SnO₂/SiC/Ni, was investigated and compared with the catalytic metal gate Schottky structure (Pt/SiC/Ni) sensor. It was found that the hetero-junction device showed much higher sensitivity to NO₂ gas compared with the Schottky junction structure sensor, whereas Schottky structure device had better sensitivity to NO gas than a hetero-junction structure sensor. These results suggest that selective detection of NO and NO₂ gases may be attained with these different structure devices.