Two-Dimensional Planar Penta-NiPN with Ultrahigh Carrier Mobility and Its Potential Application in NO and NO₂ Gas...

Two-dimensional (2D) materials with novel structures and electronic properties are promising candidates for the next generation of micro- and nano-electronic devices. Herein, inspired by the recent experimental synthesis of penta-NiN₂ (ACS Nano, 2021, 15, 13539-13546), we propose for the first time a novel ternary penta-NiPN monolayer with high stability by partial element substitution. Our predicted penta-NiPN monolayer is a quasi-direct bandgap (1.237 eV) semiconductor with ultrahigh carrier mobilities (10³-10⁵ cm²V^-1s^-1). Furthermore, we systematically studied the adsorption properties of common gas molecules (CO, CO₂, CH₄, H₂, H₂O, H₂S, N₂, NO, NO₂, NH₃, and SO₂) on the penta-NiPN monolayer and its effects on electronic properties. According to the energetic, geometric, and electronic analyses, the penta-NiPN monolayer is predicted to be a promising candidate for NO and NO₂ molecules. The excellent electronic properties of and the unique selectivity of the penta-NiPN monolayer for NO and NO₂ adsorption suggest that it has high potential in advanced electronics and gas sensing applications.