Recent Progress on Room Temperature Gas Sensors for NO2 Detection

Abstract

Air pollution is nowadays a big issue regarding the survival of mankind . The development of high-performance, reliable and low-cost NO 2 sensors are urgently needed. Recently, semiconductor gas sensors that do not need any heating element for high-temperature operation have received extensive attention. These sensors present many advantages: low power consumption, low manufacturing cost, as well as moderate stability and safety. Typically, wide bandgap semiconductors have weak, very slow or no response to NO 2 gases at room temperature. Therefore, some enhancing methods like light illumination, organic sensitization, formation of heterojunctions, preparation of composites with 2D materials and introduction of oxygen vacancies in high concentrations have been used to improve the sensing performance according to the published works. These methods and research progress are presented and discussed in this paper.