  Since the discovery of graphene, two-dimensional (2D) materials have paved a
new routine for designing high-performance nanoelectronic devices. To
facilitate the device applications, there are three key requirements for a
material: sizeable band gap, high carrier mobility and robust environmental
stability. However, for the hottest 2D materials studied in recent years,
graphene is gapless, transition metal dichalcogenides have low carrier
mobility, and black phosphorene is environmentally sensitive. So far, these
three characteristics can seldom be satisfied in one single material.
Therefore, it becomes a great challenge for finding an ideal 2D material to
overcome such a limitation. In this work, we theoretically predict a novel
planar 2D material: Penta-Pt2N4, which are designed by the fantastic Cario
pentagonal tiling as well as the rare nitrogen double bond. Most significantly,
the 2D Penta-Pt2N4 exhibits excellent intrinsic properties, including large
direct band gap up to 1.51 eV, high carrier mobility up to 105 cm2V-1s-1, giant
Young's module up to 0.70 TPa, and robust dynamic, thermal and chemical
stability. Moreover, Penta-Pt2N4 is a global minimal with PtN2 stoichiometry in
2D, so we also propose a CVD/MBE scheme to enable its experimental synthesis.
We envision that the 2D Penta-Pt2N4 may find a wide application for future
nanoelectronics.
