Sensing of CO and NO on Cu-Doped MoS2Monolayer-Based Single Electron Transistor: A First Principles Study

Owing to the large surface area, 2-D materials are being used for sensing gas molecules, which are important for environmental protection and human health. Using first principle calculations, adsorption of CO and NO gas molecules on Cu-substituted monolayer MoS2is studied in terms of energy, charge transfer, and density of states. Further, the behavior of CO and NO on Cu-substituted monolayer MoS2-based single electron transistor (SET) is explored. Strong interaction between Cu metal and MoS2sheet suggests the stability of the Cu-doped MoS2system at ambient conditions. It is further found that on doping Cu into MoS2sheet, the adsorption strength of CO and NO molecules got enhanced as compared with the pristine MoS2sheet and, hence, possesses better sensing capability. The sensing response of the Cu-doped MoS2sheet in the SET environment toward these molecules is studied from the calculated charge stability diagram that serves as a unique fingerprint of each adsorbed molecule. The charging energy is reduced when Cu impurity is added to MoS2for CO/NO adsorption, which makes such system more suitable in low-powered SET devices. The results show that SET based on Cu-doped MoS2can essentially detect hazardous molecules and is proved to have potential application in gas sensors.