Rapidly responding room temperature NO2 gas sensor based on SnSe nanostructured film

Excess of NO2 in the environment has become a big problem for the lives of humans and animals. It is necessary to know its concentration in the atmosphere. SnSe is made from earth-abundant, non-toxic materials. SnSe nanostructured film was fabricated using an industrially viable thermal evaporation method. In-house grown SnSe powder was used for this purpose. For characterizing SnSe nanostructured film, X-ray diffraction (XRD), scanning electron microscope (SEM), and UV–visible spectroscopy was used. The SnSe nanostructured film-based gas sensor response was around 174% for 5 ppm NO2 at room temperature, and it showed a low limit of detection (LOD) of 345 ppb with 106% response. It showed a fast response time of 5 s, and the recovery time was around 232 s. The sensor showed good selectivity towards NO2 compared to NO, NH3, H2, and SO2 gases. Although the theoretical report on SnSe for NO2 detection is in the literature, this is the first experimental report on SnSe based NO2 gas sensors. Thus, the work opens up a new dimension for the SnSe material-based selective gas sensor.