heterojunctions made of p-SnSe/n-SnSe2 and SnSe2/AuPt , as well as few layers of SnSe2 have been explored for high performance NO2 detection. The sensor signal measured by Liu et. al and Shafiei et. al on SnS2-based devices at room temperature were 25.9 for 100 ppm and 85% for 11.9 ppm , respectively. For SnSe2-based devices, molecules, increasing the electronic interaction and consequently the devices' sensitivity.