An overview of room temperature Fe2O3 gas sensors

Abstract

Resistive gas sensors have many advantages compared to other sensing materials such as graphene and its derivatives in term of much higher sensitivity, stability and faster dynamics. Nonetheless, one of the most serious problems of metal oxide sensors is their high sensing temperatures which leads to extensive power consumption and limit their widespread applications in places with energy shortage and remote areas. Thus, development of room temperature (RT) metal oxide gas sensors is of importance. N-type semiconducting α-Fe₂O₃ is one of the popular sensing candidates thanks to its non-toxicity, abundance, high stability, simple synthesis, and high mobility of charge carriers. Also, γ-Fe₂O₃ is another polymorph of iron oxide with n-type nature with less thermal stability. For gas sensing applications, often the sensing temperatures of both α-Fe₂O₃ and γ-Fe₂O₃ are high thanks to their relatively high electrical resistance at RT. However, there are some reports about RT gas sensing features of Fe₂O₃-based sensors. In this review paper, we are discussing those gas sensors in detail. We believe that this review paper can deliver new idea and strategies for design and development of Fe₂O₃ gas sensors with possibility of working at RT.