A Novel Ultra-Sensitive Nitrogen Dioxide Sensor Based on Germanium Monosulfide Monolayer

Nitrogen dioxide (NO 2 ) is a representative toxic gas that plays a key role in variety of fields. Due to its extensive application, the demands for reliable sensors to detect NO 2 are extremely urgent. Here, we report the adsorption of N 2 , CO 2 , O 2 , and NO 2 molecules on the GeS monolayer from atomic scale to device scale by first principles and molecular dynamics method. The results indicate that the GeS monolayer is sensitive to NO 2 molecules with moderate adsorption energy and pronounced charge transfer. Remarkably, the sorption quantity of the GeS monolayer for NO 2 is 708.707 mg/g under the 101.33 kPa, which is much higher than other molecules. Additionally, the I-V characteristic reveals that when the NO 2 molecule is adsorbed, the resistance of the GeS monolayer is nontrivially and distinctly changed. The extraordinary sensitivity and selectivity of the GeS monolayer for NO 2 molecules suggests the GeS monolayer is a potential sensing material for NO 2 gas.