A theoretical study of gas adsorption on tin arsenic and its application as a highly sensitive NO2 sensor

摘要

The sensing performance of tin arsenic (SnAs) monolayer with adsorption of different gas molecules at room temperature was systematically investigated by the first-principle calculations. The interaction of all studied gas molecules with SnAs monolayer shows physisorption nature. The moderate adsorption energy (- 0.76 eV) and large charge transfer (0.21 e) results demonstrated that the SnAs monolayer is ultra-sensitive to NO2. And the sensitivity of the SnAs layer for NO2 detecting is ultra-high reach to 67,500. Moreover, the SnAs monolayer cannot detect SO2 and NH3 gases, which could improve the reliability of the devices, comparing with other two-dimensional (2D) materials that are responsive to NO2, SO2, and NH3 gas molecules. The desorption time of the SnAs device is also short for NO2 molecules to meet the requirement of reuse. The study demonstrates the potential applications of SnAs in NO2 detecting with high selectivity and sensitivity at room temperature.