High Temperature and High Sensitive NOx Gas Sensor with Hetero-Junction Structure using Laser Ablation Method

In order to develop a high temperature (200 degrees C similar to 400 degrees C) and high sensitive NOx gas sensor, we developed a new structure of SiC-based hetero-junction device Pt/SnO2/SiC/Ni and Pt/WO3/SiC/Ni using a laser ablation method for the preparation of both metal (Pt) electrode and metal-oxide film. It was found that Pt/SnO2/SiC/Ni sensor show higher sensitivity to NO2 gas compared with the Pt/WO3/SiC/Ni sensor, whereas the Pt/WO3/SiC/Ni sensor had better sensitivity to NO gas. These results suggest that selective detection of NO and NO2 gases may be obtained by choosing different metal oxide films.