Synthesis and properties of phosphorus nanostructures on Au(110).

Phosphorene, a semiconducting two-dimensional material, has recently attracted huge interest due to its potential applications in opto-electronics. The first attempts to synthesize phosphorene were based mainly on mechanical and chemical exfoliations. A few years later, different groups reported the synthesis of phosphorene using the molecular beam epitaxy process, which opened the way for research on physical properties.

Recent Advances in Phosphorene: Structure, Synthesis, and Properties.

Phosphorene is a 2D phosphorus atomic layer arranged in a honeycomb lattice like graphene but with a buckled structure. Since its exfoliation from black phosphorus in 2014, phosphorene has attracted tremendous research interest both in terms of synthesis and fundamental research, as well as in potential applications. Recently, significant attention in phosphorene is motivated not only by research on its fundamental physical properties as a novel 2D semiconductor material, such as tunable bandgap, strong in-plane anisotropy, and high carrier mobility, but also by the study of its wide range of potential applications, such as electronic, optoelectronic, and spintronic devices, energy conversion and storage devices.

Structural properties of Bi/Au(110).

Atomically thin bismuth films (2D Bi) are becoming a promising research area due to their unique properties and their wide variety of applications in spintronics, electronic and optoelectronic devices. We report on the structural properties of Bi on Au(110), explored by low-energy electron diffraction (LEED), scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. At a Bi coverage lower than one monolayer (1 ML) various reconstructions are observed, we focus on Bi/Au(110)-c(2 × 2) reconstruction (at 0.

Electron beam analysis induces Cl vacancy defects in a NaCl thin film.

This work reports on the electron-induced modification of NaCl thin film grown on Ag(110). We show using low energy electron diffraction that electron beam bombardment leads to desorption and formation of Cl vacancy defects on NaCl surface. The topographic structure of these defects is studied using scanning tunneling microscopy (STM) showing the Cl defects as depressions on the NaCl surface.

Flat epitaxial quasi-1D phosphorene chains.

The emergence of peculiar phenomena in 1D phosphorene chains (P chains) has been proposed in theoretical studies, notably the Stark and Seebeck effects, room temperature magnetism, and topological phase transitions. Attempts so far to fabricate P chains, using the top-down approach starting from a few layers of bulk black phosphorus, have failed to produce reliably precise control of P chains. We show that molecular beam epitaxy gives a controllable bottom-up approach to grow atomically thin, crystalline 1D flat P chains on a Ag(111) substrate.

Efficient production of few-layer black phosphorus by liquid-phase exfoliation.

Phosphorene is a new two-dimensional material that has recently attracted much attention owing to its fascinating electrical, optical, thermal and chemical properties. Here, we report on high-quality exfoliation of black phosphorus nanosheets, with controllable size produced in large quantities by liquid-phase exfoliation using -methyl-2-pyrrolidone (NMP) as a solvent under ambient conditions. The as-synthesized few layers show a great potential for solar energy conversion based on the optical results shown in this work.

Blue phosphorene reactivity on the Au(111) surface.

The synthesis of blue phosphorene by molecular beam epitaxy (MBE) has recently come under the spotlight due to its potential applications in electronic and optoelectronic devices. However, this synthesis remains a significant challenge. The surface reactivity between the P atoms and the Au atoms should be considered for the P/Au(111) system.

Phase transition and thermal stability of epitaxial PtSe nanolayer on Pt(111).

This work relates to direct synthesis of the two-dimensional (2D) transition metal dichalchogenide (TMD) PtSe using an original method based on chemical deposition during immersion of a Pt(111) surface into aqueous NaSe solution. Annealing of the sample induces significant modifications in the structural and electronic properties of the resulting PtSe film. We report systematic investigations of temperature dependent phase transitions by combining synchrotron based high-resolution X-ray photoemission (XPS), low temperature scanning tunnelling microscopy (LT-STM) and low energy electron diffraction (LEED).

Tip-induced oxidation of silicene nano-ribbons.

We report on the oxidation of self-assembled silicene nanoribbons grown on the Ag (110) surface using scanning tunneling microscopy and high-resolution photoemission spectroscopy. The results show that silicene nanoribbons present a strong resistance towards oxidation using molecular oxygen. This can be overcome by increasing the electric field in the STM tunnel junction above a threshold of +2.

Unoccupied electronic band structure of pentagonal Si nanoribbons on Ag(110).

Silicon nanoribbons - one dimensional silicon structures with a pentagonal atomic structure and mixed sp- and sp-hybridisation - grow on Ag(110) upon deposition of silicon. These nanostructures are viewed as promising candidates for modern day electronics as they are comprised of the same element as today's semiconductor devices. Even though they have been studied extensively over the last decade, only little is known about their unoccupied band structure which is important for possible future optoelectronics, semiconductor, and spintronics applications.

Epitaxial Synthesis of Blue Phosphorene.

Phosphorene is a new 2D material composed of a single or few atomic layers of black phosphorus. Phosphorene has both an intrinsic tunable direct bandgap and high carrier mobility values, which make it suitable for a large variety of optical and electronic devices. However, the synthesis of single-layer phosphorene is a major challenge.

Compelling experimental evidence of a Dirac cone in the electronic structure of a 2D Silicon layer.

The remarkable properties of graphene stem from its two-dimensional (2D) structure, with a linear dispersion of the electronic states at the corners of the Brillouin zone (BZ) forming a Dirac cone. Since then, other 2D materials have been suggested based on boron, silicon, germanium, phosphorus, tin, and metal di-chalcogenides. Here, we present an experimental investigation of a single silicon layer on Au(111) using low energy electron diffraction (LEED), high resolution angle-resolved photoemission spectroscopy (HR-ARPES), and scanning tunneling microscopy (STM).

Silicon sheets by redox assisted chemical exfoliation.

In this paper, we report the direct chemical synthesis of silicon sheets in gram-scale quantities by chemical exfoliation of pre-processed calcium disilicide (CaSi2). We have used a combination of x-ray photoelectron spectroscopy, transmission electron microscopy and energy-dispersive x-ray spectroscopy to characterize the obtained silicon sheets. We found that the clean and crystalline silicon sheets show a two-dimensional hexagonal graphitic structure.

Silicene structures on silver surfaces.

In this paper we report on several structures of silicene, the analog of graphene for silicon, on the silver surfaces Ag(100), Ag(110) and Ag(111). Deposition of Si produces honeycomb structures on these surfaces. In particular, we present an extensive theoretical study of silicene on Ag(111) for which several recent experimental studies have been published.

Silicon nano-ribbons on Ag(110): a computational investigation.

We report results of a computational investigation, based on density functional theory, of silicon self-assembled nano-ribbons (Si NRs) on Ag(110). These NRs present a honeycomb-like structure arched on the substrate and forming a closed-packed structure. The calculated STM images match the experimental ones, hinting to a possible new Si structure, mediated by the Ag substrate.

Burning match oxidation process of silicon nanowires screened at the atomic scale.

Silicon oxide nanowires hold great promise for functional nanoscale electronics. Here, we investigate the oxidation of straight, massively parallel, metallic Si nanowires. We show that the oxidation process starts at the Si NW terminations and develops like a burning match.