Opposite surface stress induced the distinctly different contact behaviors of monolayer and bilayer borophene on Ag(1 1 1)

Bridging Borophene and Metal Surfaces: Structural, Electronic, and Electron Transport Properties

“…Our BE results (Table 2) are comparable with those predicted for other 2D systems, for instance, MoS 2 /Ag-(111), 26,59 and can be classified as "potentially exfoliable". 60 Indeed, such an exfoliable nature of BBL(b) 1/4 adsorbed on Ag(111) was pointed out (very recently) by Xu et al, 22 where they found an E b of −107 meV/Å 2 using the Grimme formula (vdW-D2); meanwhile, Li et al 31 obtained an E b of 100 meV/ Å 2 and h = 2.26 Å using vdW-D3. 61 Here, indeed, using the same vdW-D2 approach, we found a BE of −111 meV/Å 2 .…”

“…A solid understanding of the structural and electronic properties of new materials is fundamental for the development of electronic devices. Here, computational simulations, based on first-principles methods, have been viewed as a promising solution for a comprehensive atomic-scale understanding of the electronic and structural properties of materials in general; for instance, in 2D systems like MoS 2 /metal, − phosphorene/metal, , and more recently BBL/metal interfaces. ,, …”

“…Here, computational simulations, based on first-principles methods, have been viewed as a promising solution for a comprehensive atomic-scale understanding of the electronic and structural properties of materials in general; for instance, in 2D systems like MoS 2 /metal, 25−28 phosphorene/metal, 29,30 and more recently BBL/metal interfaces. 24,31,32 Currently, the application of new materials in "twodimensional electronics" relies on critical issues like the understanding of the electronic and structural properties of metal/semiconductor interfaces and the emergence of electronic transport throughout 2D semiconductor channels. 33−35 In this work, we used first-principles calculations to investigate (i) the energetic, structural, and electronic properties of BBL on different metal surfaces (m-surf), specifically Ag(111), Au(111), and Al(111), denoted as BBL/m-surf, and (ii) the electronic transport properties through BBL channels (ch) under different BBL/m-surf top contacts (tc), which we describe as [BBL/m-surf] tc −[BBL] ch − [BBL/m-surf] tc .…”

Density Functional Theory Study of Bilayer Borophene-Based Anode Material for Rechargeable Lithium Ion Batteries

“…Similarly, large surface areas of bilayer boron atoms on the Ru(0001) surfaces are fabricated using surface segregation method and point out avenues for the application of high-quality bilayer borophene . On the theoretical aspect, abundant efforts have been devoted to find the stable atomic configurations and extraordinary properties of bilayer borophene. − Multiple boron bilayer sheets with different concentrations and distributions of pillars and hexagonal holes can effectively balance the excess electrons and are predicted to be stable under dynamic and thermal conditions, in which the lowest formation energy is only 0.35 eV/atom and much smaller than that of 0.50 eV/atom in its g 1/8 -sheet monolayer counterpart . The effect of substrates on bilayer borophene cannot be ignored when determining the stacking styles and the electronic properties. − The inert substrates of hexagonal boron nitride, MoS 2 and metal Al(111) with tiny tunneling barrier at the interface of the borophene–substrate systems have been predicted and are advantageous to the efficiency of carrier injection .…”

Structural Characterization of Boron Sheets beyond the Monolayer and Implication for Experimental Synthesis and Identification

“…Borophene, a novel 2D material with rich polymorphism and anisotropic metallic behavior, holds great promise for energy storage of ion batteries, − lithium–sulfur batteries, − and energy conversion of electrochemical catalysis, − and the performance is comparable to other common 2D materials. , The successful synthesis of monolayer borophene and the identification of atomic structures in experiments are inseparable from the above characterization methods. ,, After that, boron sheets beyond monolayer with higher stability and superior antioxidation are predicted in theory, which can be attributed to the formation of pillars and strong coupling strength between interlayers. − In addition, 3D-boron clusters intercalated into layered hydroxides could be utilized in superacid storage and dynamical disordering in MgB 2 materials in hydrogen storage performance . It is worth noting that recent experiments successfully fabricated quasi-freestanding bilayer borophene on Ag(111) and Cu(111) surfaces, and the metallicity is preserved. , In addition, the vibrational modes of bilayer borophene on the Ag(111) substrate found coupling interactions between boron sheets and substrate in visible and IR regions, and the strongest vibration occurred at the interlayer chemical bonds of boron atoms, further proposing the huge potential in optoelectronic devices.…”