Effect of proton irradiation on the sensitivity of CO₂ sensors based on SnO₂ and SnO-SnO₂ heterojunctions

Gas sensors are integral to space exploration and development projects. However, few studies have examined the effects of proton irradiation on the performance of semiconductor gas sensors. This study fills this gap by investigating the effect of proton irradiation on the sensitivity of CO₂ semiconducting sensors, specifically SnO₂ and SnO-SnO₂ heterojunction types. In SnO₂-based sensors, sensitivity was indicated to remain stable at low fluence and increase at higher fluences owing to proton-induced oxygen vacancy formations, mainly. Meanwhile, in SnO-SnO₂ heterojunction sensors, it was found to decrease at low fluences and increase significantly at higher fluences owing to changes in the electrical properties of SnO. These findings suggest that proton irradiation can enhance sensor sensitivity, enabling potential applications in radiation-prone environments, such as outer space. This study contributes to the understanding of the effects of proton irradiation on semiconductor gas sensors and paves the way for their development.