First-Principles Investigation of Borophene as a Monolayer Transparent Conductor

Abstract

Two-dimensional boron is promising as a tunable monolayer metal for nano-optoelectronics. We study the optoelectronic properties of two likely allotropes of two-dimensional boron, β 12 and δ 6 , using first-principles density functional theory and many-body perturbation theory. We find that both systems are anisotropic metals, with strong energy-and thickness-dependent optical transparency and a weak (<1%) absorbance in the visible range. Additionally, using state-of-the-art methods for the description of the electron−phonon and electron− electron interactions, we show that the electrical conductivity is limited by electron−phonon interactions. Our results indicate that both structures are suitable as a transparent electrode.

2D Boron Sheets: Structure, Growth, and Electronic and Thermal Transport Properties

“…The electrical conductivity σ of δ 6 a) and β 12 b) boron sheets under different temperatures, and the referring line C is that of graphene. Reproduced with permission . Copyright 2018, American Chemical Society.…”

“…Therefore, borophene may be a transparent and flexible conductor. Adamska et al [23] calculated electrical conductivity using the BoltzWann package. [137] Comparing with the conductivity graphene which is red C line in Figure 29a,b, the conductivity of the explored borophene structures [138] are always lower than that graphene, indicating borophene indeed is an excellent conductor.…”

“…Most of the borophene sheets are metallic with remarkable anisotropy behaviors . They are proposed to be good electric conductors, even better than graphene according to theoretical calculations. Dirac cones are predicted to exist in β 12 , χ 3 and fully hydrogenated δ 6 borophene (borophane) sheets.…”

“…Besides, the outstanding and peculiar properties of borophene make them tempting platform for exploring novel physical phenomena and extensive applications.Most of the borophene sheets are metallic with remarkable anisotropy behaviors. [21,22] They are proposed to be good electric conductors, [23,24] even better than graphene according to theoretical calculations. Dirac cones are predicted to exist in β 12 , χ 3 and fully hydrogenated δ 6 borophene (borophane [25] ) sheets.…”

Solar‐Inspired Water Purification Based on Emerging 2D Materials: Status and Challenges

“…Recently, borophene came into researchers' sight because of its unique position close to carbon and it is the lightest Xenes. The polymorphism and anisotropic structure of borophene lead to many attractive properties, including the optical transparency, metallicity, phonon‐mediated superconductivity, photoluminescence in visible region (≈626 nm), efficient thermal transport, mechanical flexibility, etc. When considering its photothermal application, there is a drawback of weak absorption with extinction coefficient of ≈2.5 L g −1 cm −1 , making the application of photothermal evaporation full of challenge.…”