Oxidizing Gas Sensing by SiC/ZnO Heterocontact

NO_x Sensing

Abstract

The oxidizing gas (NO_x 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 NO_x gas sensing characteristics, the presence of water vapor is needed but too much water vapor spoiled the NO_x 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.