Two-Dimensional C₄N Global Minima: Unique Structural Topologies and Nanoelectronic Properties

Abstract

Atomically thin 2D materials have drawn great attention due to their many potential applications. We herein report two novel structures of 2D C4N identified by first-principles calculations in combination with a swarm structure search. These two structures (with symmetry of Pm and P2/m) are almost degenerate in energy (with only 4 meV/atom difference) and exhibit quite similar structural topologies, both consisting of alternative arrays of C–N hexagon and arrays of C–N pentagon–octagon–pentagon. The Pm structure is semiconducting with a direct band gap of 90 meV at HSE. In contrast, the P2/m structure is a zero-band-gap semimetal and possesses the distorted Dirac cone, showing the direction-dependent Fermi velocity and electronic properties. Thus the predicted C4N monolayers are promising for applications in nanoelectronics.

Stability, electronic, and optical properties of two‐dimensional phosphoborane

“…To analyze the chemical bonding pattern of the 2D‐B 4 P 2 sheet, the solid‐state adaptive natural density partitioning (SSAdNDP) algorithm was used . Previously it was shown that SSAdNDP is a powerful tool for analyzing chemical bonding in two‐dimensional periodic systems . A plane wave (PW) calculation was performed using 450 eV energy cut off with convergence threshold 10 −6 eV for total energy.…”

DFT-Guided Design and Fabrication of Carbon-Nitride-Based Materials for Energy Storage Devices: A Review

“…These two configurations of C 4 N are semiconductors in nature and display a narrow and zero bandgap (Fig. 4 k); however, this property can be tuned easily [ 24 , 26 ].…”

Half-Dirac semimetals and the quantum anomalous Hall effect in Kagome Cd2N3 lattices

“…It exhibits a unique electronic properties such as ballistic charge transport [30], high carrier mobility [31], and quantum Hall effect [32]. Subsequently, many 2D lattices such as germanene [33], carbon allotropes [34][35][36][37], boron allotropes [38], SiC 3 [27], and C 4 N [39], have been identified as Dirac materials. However, the Dirac cone in these materials is intrinsically spin-degenerated, which actually limits its utilization in massless spintronics.…”

“…Normally, HDSs can be divided into two types: type-I, the d-state HDSs, in which the Dirac state is contributed by d-orbital of transitional-metal atoms, and type-II, the p-state HDSs, whose states are from p-orbital of transitional-metal atoms. To date, the reported majority of HDS members are belong to type-I HDSs [39][40][41][42][43][44][45][46][47], while there has been barely any on 2D type-II HDS materials. It is highly desirable to design type-II HDSs with robust spin ordering and high Curie temperature simultaneously, which may make the experimental synthesis largely accessible.…”