Gas Sensing Properties of Black Phosphorene-Like InP₃ Monolayer: A First-Principles Study

An anisotropic nature and layer-dependent bandgap energy are the unique properties that make phosphorene an attractive two-dimensional (2D) material to explore. Tremendous interest in unraveling other properties of phosphorene find application in energy conversion, photodetectors, electronic and optoelectronic devices, and gas sensing. The structural and dynamical stability and mechanical and electronic properties of phosphorene-like indium triphosphide monolayer (InP₃) are compared to pristine phosphorene (PP). Gaseous molecules of carbon dioxide (CO₂), carbon monoxide (CO), nitrogen dioxide (NO₂), nitrogen oxide (NO), hydrogen sulfide (H₂S), sulfur dioxide (SO₂), and ammonia (NH₃) are adsorbed on phosphorus (P), indium (In), and hollow (H) sites. The adsorption energies, differential charge densities (DCD), and electronic band structures of all molecules on each site are investigated. The adsorption energies of small gas molecules on the InP₃ monolayer show better performance than pristine phosphorene (PP) and indium-doped phosphorene (In@P). The computed adsorption energies of NO and NO₂ are −0.849 eV and −1.168 eV. The results prove that the most favorable adsorption site is on the top of the In atom. Therefore, the InP₃ monolayer is more sensitive to the NO₂ molecule. Graphical Abstract: [Figure not available: see fulltext.].