Adsorption of NO₂ molecules on armchair phosphorene nanosheet for nano sensor applications - A first-principles study

The electronic and NO₂ adsorption properties of hydrogenated armchair phosphorene nanosheet device is investigated through density functional theory (DFT) and non-equilibrium Green's function method (NEGF). The armchair phosphorene nanosheet is used for the detection of NO₂ gas in phosphorene molecular device. The DOS spectrum demonstrates the change in peak maxima due to transfer of electrons between NO₂ gas and phosphorene base material. The change in the peak amplitude is observed along the valance band as well as in the conduction band in the transmission spectrum of phosphorene device. I-V characteristics support the change in the current upon adsorption of NO₂ gas molecule on phosphorene molecular device. Using formation energy, structural stability of phosphorene nanosheet has been studied. The adsorption properties of NO₂ on phosphorene nanosheet have also been investigated with the help of adsorption energy, Mulliken charge and Bader charge analysis. In order to ascertain the selectivity of NO₂ gas along phosphorene molecular device in the ambient condition, the adsorption behavior of O₂ and CO₂ is also studied. The findings of the present work confirm that phosphorene molecular device can be used as a NO₂ gas sensor and also the influence of Al substitution in phosphorene nanosheet device is explored and reported.