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

Sodium-ion batteries (SIBs) have attracted a great deal of attention as potential low-cost energy storage alternatives to Lithium-ion batteries (LIBs) due to the intrinsic safety and great abundance of sodium on Earth. For developing competitive SIBs, highly efficient anode materials with large capacity and rapid ion diffusion are indispensable. In this study, a two-dimensional (2D) Dirac monolayer, that is borophosphene, is proposed to be a promising anode material for high ...

Experimental realization of two-dimensional boron sheets was reported very recently by Feng et. al. using molecular beam epitaxy on silver (111) surface. These boron sheets possess promising electronic and transport properties. We performed the density functional theory (DFT) calculation to see the stability of two $\beta_{12}$ and $\chi$ polymorphs of boron under strain and further studied electronic and transport properties. We verified the directional dependency in electro...

Borophene (two-dimensional boron sheet) is a new type of two-dimensional material, which was recently grown successfully on single crystal Ag substrates. In this paper, we investigate the electronic structure and bonding characteristics of borophene by first-principle calculations. The band structure of borophene shows highly anisotropic metallic behaviour. The obtained optical properties of borophene exhibit strong anisotropy as well. The combination of high optical transpar...

Thin flakes of black phosphorus (BP) are a two-dimensional (2D) semiconductor whose energy gap is predicted being sensitive to the number of layers and external perturbations. Very recently, it was found that a simple method of potassium (K) doping on the surface of BP closes its band gap completely, producing a Dirac semimetal state with a linear band dispersion in the armchair direction and a quadratic one in the zigzag direction. Here, based on first-principles density fun...

Phosphorene, an emerging elemental two-dimensional (2D) direct band gap semiconductor with fascinating structural and electronic properties distinctively different from other 2D materials such as graphene and MoS2, is promising for novel nanoelectronic and optoelectronic applications. Phonons, as one of the most important collective excitations, are at the heart for the device performance, as their interactions with electrons and photons govern the carrier mobility and light-...

We report a previously unknown monolayer borophene allotrope and we call it super-B with a flat structure based on the ab initio calculations. It has good thermal, dynamical, and mechanical stability compared with many other typical borophenes. We find that super-B has a fascinating chemical bond environment consisting of standard sp, sp2 hybridizations, and delocalized five-center three-electron $\pi$ bond, called $\pi$(5c-3e). This particular electronic structure plays a pi...

A computation methodology based on ab initio evolutionary algorithms and the spin-polarized density functional theory was developed to predict two-dimensional (2D) magnetic materials. Its application to a model system borophene reveals an unexpected rich magnetism and polymorphism. A stable borophene with nonzero thickness was an antiferromagnetic (AFM) semiconductor from first-principles calculations, which can be further turned into a half metal by finite electron doping. I...

New crystal structures of fully hydrogenated borophene (borophane) have been predicted by first principles calculation. Comparing with the chair-like borophane (C-boropane) that has been reported in literature, we obtained four new borophane conformers with much lower total-energy. The most stable one, washboard-like borophane (W-borophane), has energy about 113.41 meV/atom lower than C-borophane. In order to explain the relative stability of different borophane conformers, t...

We report first principle calculations of electronic and mechanical properties of few-layer borophene with the inclusion of interlayer van der Waals (vdW) interaction. The anisotropic metallic behaviors are preserved from monolayer to few-layer structures. The energy splitting of bilayer borophene at $\Gamma$ point near the Fermi level is about 1.7 eV, much larger than the values (0.5--1 eV) of other layered semiconductors, indicating much stronger vdW interactions in metalli...

Carrier mobility is a crucial character for electronic devices since it domains power dissipation and switching speed. Materials with certain high carrier mobility, equally, unveil rich unusual physical phenomena elusive in their conventional counterparts. As a consequence, the methods to enhance the carrier mobility of materials receive immense research interests due to their potential applications in more effective electronic devices and enrichment of more unusual phenomena...