Oxidizing Gas Sensing by SiC/ZnO Heterocontact

Abstract

The oxidizing gas (NOx or Cl2) gas sensing characteristics of SiC/ZnO heterocontact were investigated. The current through the interface of SiC and ZnO under forward bias (SiC+, ZnO-) was decreased by the introduction of NO or NO2 gas. For the generation of the NOx gas sensing characteristics, the presence of water vapor is needed but too much water vapor spoiled the NOx sensing characteristics. That is similar to the chlorine gas sensing characteristics of SiC/ZnO heterocontact reported previously. The present results suggest that the oxidizing power of the molecules is a key point for explaining the gas sensing mechanism of SiC/ZnO heterocontact at room temperature.