Cu-Doped MoSi 2 N 4 Monolayer as a Potential NH 3 Sensor.

Cu doped MoSi 2 N 4 monolayer (Cu-MoSi 2 N 4 ) was firstly proposed to analyze adsorption performances of common gas molecules including O 2 , N 2 , CO, NO, NO 2 , CO 2 , SO 2 , H 2 O, NH 3 and CH 4 via density functional theory (DFT) combining with non-equilibrium Green's function (NEGF). The electronic transport calculations indicate that Cu-MoSi 2 N 4 monolayer has high sensitivity for CO, NO, NO 2 and NH 3 molecules. However, only NH 3 molecule adsorbs on the Cu-MoSi 2 N 4 monolayer with moderate strength (-0.55 eV) and desorbs at room temperature (2.36×10 -3  s). Thus, Cu-MoSi 2 N 4 monolayer is demonstrated as a potential NH 3 sensor.