Electronic and optical properties of boron-based hybrid monolayers

Abstract

Anisotropic 2D Dirac cone materials are important for the fabrication of nanodevices having direction-dependent characteristics since the anisotropic Dirac cones lead to different values of Fermi velocities yielding variable carrier concentrations. In this work, the feasibility of the B-based hybrid monolayers BX (X = As, Sb, and Bi), as anisotropic Dirac cone materials is investigated. Calculations based on density functional theory and molecular dynamics method find the stability of these monolayers exhibiting unique electronic properties. For example, the BAs monolayer possesses a robust self-doping feature, whereas the BSb monolayer carries the intrinsic charge carrier concentration of the order of 1012 cm−2 which is comparable to that of graphene. Moreover, the direction-dependent optical response is predicted in these B-based monolayers; a high IR response in the x-direction is accompanied with that in the visible region along the y-direction. The results are, therefore, expected to help in realizing the B-based devices for nanoscale applications.

Boron–pnictogen monolayers with a negative Poisson's ratio and excellent band edge positions for photocatalytic water splitting

“…Recently, different polymorphs of boron and group V elemental (pnictogens) binary materials, i.e., BX (X = P, As, Sb, Bi), have been widely explored, using computational methods, for their potential applications. [22][23][24][25][26] Boron-and-pnictogen-based 2D sheets are usually stable in the hexagonal crystal group (h-BX) with structural features akin to those of graphene. Hexagonal boron phosphide (h-BP) shows promising applications in hydrogen storage with a gravimetric capacity of 4.92 and 4.56% for the one-sided adsorption of H 2 and 7.40 and 6.45% for the double-sided adsorption of H 2 with Li and Na decoration, respectively.…”

“…31 By contrast, BX materials also exhibit different 2D polymorphs apart from h-BX. [22][23][24][25][26] Porous BN phases show outstanding permeability and selectivity for hydrogen purification. 32 Zhu et al have reported different forms (a 1 -BP, b 0 -BP, b 1 -BP and g-BP) for the allotropes of BP.…”