Borophosphene: A New Anisotropic Dirac Cone Monolayer with a High Fermi Velocity and a Unique Self-Doping Feature

Abstract

Two-dimensional (2D) Dirac cone materials exhibit linear energy dispersion at the Fermi level, where the effective masses of carriers are very close to zero and the Fermi velocity is ultrahigh, only 2 ~ 3 orders of magnitude lower than the light velocity. Such the Dirac cone materials have great promise in high-performance electronic devices. Herein, we have employed the genetic algorithms methods combining with first-principles calculations to propose a new 2D anisotropic Dirac cone material, that is, orthorhombic boron phosphide (BP) monolayer named as borophosphene. Molecular dynamics simulation and phonon dispersion have been used to evaluate the dynamic and thermal stability of borophosphene. Because of the unique arrangements of B-Band P-P dimers, the mechanical and electronic properties are highly anisotropic. Of great interest is that the Dirac cone of the borophosphene is robust, independent of in-plane biaxial and uniaxial strains, and can also be observed in its one-dimensional (1D) zigzag nanoribbons and armchair nanotubes. The Fermi velocities are ~ 10 5 m/s, the same order of magnitude with that of graphene.By using a tight-binding model, the origin of the Dirac cone of borophosphene is analyzed.Moreover, a unique feature of self-doping can be induced by the in-plane biaxial and uniaxial strains of borophosphene and the Curvature effect of nanotubes, which is great beneficial to realizing high speed carriers (holes). Our results suggest that the borophosphene holds a great promise in high-performance electronic devices, which could promote the experimental and theoretical studies to further explore the potential applications of other 2D Dirac cone sheets.

Dirac Semimetal Protected by Nonsymmorphic Mirror Symmetries in TPH‐Graphene

“…The calculated values of four constants C 11 , C 12 , C 22 , and C 44 are 311.1, 79.3, 306.6, and 34.5 N m À1 , which fulfill the requirements of mechanical stability for an orthorhombic 2D monolayer (C 11 > 0, C 22 > 0, C 44 > 0, and C 11 C 22 > C 2 12 ). [45] We can also obtain the in-plane Young's modulus and Poisson's ratio along an arbitrary direction θ (θ is the angle relative to the primitive vectorã in Figure 1a) by the following formula. [66] YðθÞ ¼…”

“…Besides hexagonal systems, the Dirac points can exist in 2D orthorhombic and tetragonal systems, including α-graphdiyne, [40] S-graphene, [41] palgraphyne, [10] and HOT graphene. [42] Further, azugraphene, [43] StoneÀWales graphene, [44] borophosphene, [45] cp-graphyne, [19] and circumcoro-graphyne [46] also exhibit linear band dispersion and associated Dirac points. However, most of the synthesized 2D carbon materials are protected by hexagonal symmetry.…”

Bonding, structure, and mechanical stability of 2D materials: the predictive power of the periodic table

“…Table 6 contains the cohesive energies and structural data of the groups of related monolayers BX, 131,[136][137][138][139][140][141][142] AlX, 131,142,143 GaX, 131,134,142,144,145 InX, 131,134,142,146,147 and TlX 131,148 with X = N, P, As, Sb, and Bi. As revealed in Fig.…”

Defects and Strain Engineering of Structural, Elastic, and Electronic Properties of Boron-Phosphide Monolayer: A Hybrid Density Functional Theory Study

“…Due to the periodic affinity sites and excellent surface electrochemical properties, boron-phosphide monolayers can be expected to use as anode materials for lithium-ion batteries and anchoring materials for lithium-ion batteries [14,15]. In addition, its isomer with orthorhombic symmetry was proposed using the genetic algorithm methods [16], which holds great promise in alkali metal ion battery [17,18]. Although the boron-phosphide monolayer has not been synthesized, many studies have shown its great potential in nanoelectronics.…”