Two-Dimensional Planar Penta-NiPN with Ultrahigh Carrier Mobility and Its Potential Application in NO and NO 2 Gas Sensing.

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-NiN 2 ( 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 (10 3 -10 5 cm 2 V -1 s -1 ). Furthermore, we systematically studied the adsorption properties of common gas molecules (CO, CO 2 , CH 4 , H 2 , H 2 O, H 2 S, N 2 , NO, NO 2 , NH 3 , and SO 2 ) 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 NO 2 molecules. The excellent electronic properties of and the unique selectivity of the penta-NiPN monolayer for NO and NO 2 adsorption suggest that it has high potential in advanced electronics and gas sensing applications.