Two-Dimensional Tetragonal GaN as Potential MoleculeSensors for NO and NO2 Detection: A First-Principle Study

摘要

Properties of gas molecules (NO, NH3, and NO2) adsorbed on two-dimensional GaN with a tetragonal structure (T-GaN) are studied using first-principles methods. Adsorption energy, adsorption distance, Hirshfeld charge, electronic properties, electric conductivity, and recovery time are calculated. It is found that these three molecules are all chemisorbed on the T-GaN with reasonable adsorption energies and apparent charge transfer. The electronic properties of the T-GaN present dramatic changes after the adsorption of NO2 and NO molecules, especially its electric conductivity, but NH3 molecule hardly changes the electronic properties of the T-GaN. Furthermore, the recovery time of the T-GaN sensor at T = 300 K is estimated to be quite short for NO2 and NO but very long for NH3. Moreover, the magnetic properties of the T-GaN are changed obviously due to the adsorption of NO (or NO2) molecule. Therefore, we suggest that the T-GaN can be a prominent candidate for application as NO2 and NO molecule sensors.