Highly stable and selective H2 gas sensors based on light-activated a-IGZO thin films with ZIF-8 selective membranes

Abstract

Metal-organic frameworks (MOFs) have emerged as promising selective membranes in oxide semiconductor gas sensors. However, their susceptibility to high temperatures poses significant challenges to the long-term stability of gas sensors. This paper proposes a novel approach for improving long-term stability by employing a lightactivated technique on amorphous InGaZnO (a-IGZO) films with a ZIF-8 membrane. Under 360 nm LED illumination, UV light can penetrate the ZIF membrane and be absorbed by a-IGZO, leading to a substantial number of photogenerated carriers in the IGZO film for gas reaction. The a-IGZO film with a ZIF-8 membrane shows an excellent selective response for H2 over CO, NO2, and O3. This light-activated film maintains a gas response comparable to that of thermal-activated counterparts while significantly improving its long-term stability. Our findings underscore the potential of light-activated a-IGZO sensors as a platform for future integration with an MOF selective membrane, ensuring long-term stability.