Intercalation of Si between MoS₂ layers

• Rik van Bremen,
• Qirong Yao,
• Soumya Banerjee,
• Deniz Cakir,
• Nuri Oncel and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2017, 8, 1952–1960, doi:10.3762/bjnano.8.196

• -dimensional materials; Introduction Since the discovery of graphene [1][2][3][4] interest has extended to the search for other 2D materials with properties similar to graphene. One appealing candidate is silicene, a graphene-like 2D allotrope of silicon. The first calculations of graphite-like allotropes of

Coexistence of strongly buckled germanene phases on Al(111)

• Weimin Wang and
• Roger I. G. Uhrberg

Beilstein J. Nanotechnol. 2017, 8, 1946–1951, doi:10.3762/bjnano.8.195

• model. Keywords: core-level spectroscopy; DFT; germanene; STM; Introduction The properties of two-dimensional (2D) materials are currently subjected to intense experimental and theoretical studies. The research is focused on many important properties predicted by theory for various conceivable 2D

• materials. In similarity with graphene, some other materials are also predicted to show a linear electron dispersion near the Fermi level. Other important properties/phenomena that make 2D materials particularly interesting for incorporation in various devices are, magnetism, superconductivity, Rashba type

• spin-splitting, quantum spin Hall effect, amongst others. Based on the wealth of physical phenomena exhibited by various 2D materials, they are considered as important future materials of high potential for applications in nano-scale electronics and spintronics. A sub-group of 2D materials is graphene

α-Silicene as oxidation-resistant ultra-thin coating material

• Ali Kandemir,
• Fadil Iyikanat,
• Cihan Bacaksiz and
• Hasan Sahin

Beilstein J. Nanotechnol. 2017, 8, 1808–1814, doi:10.3762/bjnano.8.182

• intensively in surface protection for a long time [1][2], two-dimensional (2D) materials have become new candidates for nanoscale coatings for different material groups. Therefore, coating mechanisms at the nanoscale take are of high interest in nanotechnology, and new candidates for nanostructural protection

(Metallo)porphyrins for potential materials science applications

• Lars Smykalla,
• Carola Mende,
• Michael Fronk,
• Pablo F. Siles,
• Michael Hietschold,
• Georgeta Salvan,
• Dietrich R. T. Zahn,
• Oliver G. Schmidt,
• Tobias Rüffer and
• Heinrich Lang

Beilstein J. Nanotechnol. 2017, 8, 1786–1800, doi:10.3762/bjnano.8.180

• allow for the engineering of manifold extended 2D materials with novel transport properties. One major approach for surface-confined polymerization is the halogen-based Ullmann coupling reaction [42]. Thereby, the topography and also electronic properties of the covalent organic framework are determined

Adsorption and diffusion characteristics of lithium on hydrogenated α- and β-silicene

• Fadil Iyikanat,
• Ali Kandemir,
• Cihan Bacaksiz and
• Hasan Sahin

Beilstein J. Nanotechnol. 2017, 8, 1742–1748, doi:10.3762/bjnano.8.175

• barriers show that α- and β-silicene are promising platforms for Li-storage applications. Keywords: density functional theory; diffusion; Li atom; silicene; ultra-thin materials; Introduction Following the first synthesis of graphene, the family of two-dimensional (2D) materials have drawn extraordinary

• chalcogenides [18]. Structural stability, chemical versatility and electronic band gaps of 2D materials that cover the range from 0 to 5 eV make them attractive for current nanoscale device applications. In the large family of 2D materials, silicene deserves a special consideration due to its compatibility and

• for the hydrogenated forms of α- and β-silicene on a Ag(111) surface. The adsorption of alkali metal atoms provides various ways to modify the structural, electronic and magnetic properties of 2D materials. It was found that adsorption of alkali atoms is a proper way to dope carbon nanotubes

Group-13 and group-15 doping of germanane

• Nicholas D. Cultrara,
• Maxx Q. Arguilla,
• Shishi Jiang,
• Chuanchuan Sun,
• Michael R. Scudder,
• R. Dominic Ross and
• Joshua E. Goldberger

Beilstein J. Nanotechnol. 2017, 8, 1642–1648, doi:10.3762/bjnano.8.164

• layered van der Waals materials [20][21][22]. Germanane, a hydrogen-terminated graphane analogue of germanium, has garnered considerable attention in the field of 2D materials on account of its direct band gap [5][23][24], large predicted electron mobility, and the ability to controllably tune the

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• that nanocomposite formation of semiconductors with such 2D materials effectively improves the photocatalytic processes. In addition, these 2D materials possess several extraordinary properties, which makes them more advantageous over other materials as summarized below [39]: high specific surface area

• . Carbon-based 2D materials Graphene Since the discovery of graphene in 2004, it has attracted great attention because of its fascinating electrical, thermal, optical and mechanical properties. Basically, graphene consists of a single layer of sp2 hybridized carbon atoms densely packed into an atomically

• leads to the efficient separation of the photogenerated charge carriers and thereby enhances the visible light photocatalytic H2 production activity of the nanocomposite. As discussed in the introduction section regarding the significance of 2D materials in photocatalytic applications, Chen et al. [147

3D continuum phonon model for group-IV 2D materials

• Morten Willatzen,
• Lok C. Lew Yan Voon,
• Appala Naidu Gandi and
• Udo Schwingenschlögl

Beilstein J. Nanotechnol. 2017, 8, 1345–1356, doi:10.3762/bjnano.8.136

• ) based codes. One of the earliest applications to group-IV elemental 2D materials was for the important prediction of the stability of silicene and germanene [1]. These are complex calculations and prone to qualitative errors due to the various approximations such as convergence criteria and use of

• approaches, by starting with the elastic and electric equations, and taking into account the full crystalline symmetry and piezoelectric couplings when allowed by symmetry. We apply the theory to obtain the phonons in group-IV elemental 2D materials. Given that there are two fundamental structures for the

• phonons for all the group-IV elemental 2D materials. Application: MoS2 While the primary focus of this paper is on the properties of phonons of the group-IV elemental materials, it is important to know if there are properties of the phonons that are due to these being elemental. Hence, we will now

The integration of graphene into microelectronic devices

• Guenther Ruhl,
• Sebastian Wittmann,
• Matthias Koenig and
• Daniel Neumaier

Beilstein J. Nanotechnol. 2017, 8, 1056–1064, doi:10.3762/bjnano.8.107

• hand graphene and other 2D materials consist only of surface and every surface modification changes the materials properties. This property allows the use of graphene as an environmental sensor, but is detrimental to fabricating stable devices. In the following review we highlighted the most crucial

Ion beam profiling from the interaction with a freestanding 2D layer

• Ivan Shorubalko,
• Kyoungjun Choi,
• Michael Stiefel and
• Hyung Gyu Park

Beilstein J. Nanotechnol. 2017, 8, 682–687, doi:10.3762/bjnano.8.73

• interaction with 2D materials contains information about beam profiles [14][17][18]. Here we show that it is possible to fabricate pores in graphene membranes smaller than the ion beam diameter by carefully tailoring the exposure dose. The pore diameters directly depend on the time for which individual pixels

Advances in the fabrication of graphene transistors on flexible substrates

• Gabriele Fisichella,
• Stella Lo Verso,
• Silvestra Di Marco,
• Vincenzo Vinciguerra,
• Emanuela Schilirò,
• Salvatore Di Franco,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Amaia Zurutuza,
• Alba Centeno,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2017, 8, 467–474, doi:10.3762/bjnano.8.50

• substrates and the discovery of new materials suitable for bending, stretching or conformably shaping [1], such as in the case of many 2D materials [2], paved the way to a huge number of stretchable, foldable or form factor reconfigurable demonstrators. Such devices can be considered for various applications

In-situ monitoring by Raman spectroscopy of the thermal doping of graphene and MoS₂ in O₂-controlled atmosphere

• Aurora Piazza,
• Filippo Giannazzo,
• Gianpiero Buscarino,
• Gabriele Fisichella,
• Antonino La Magna,
• Fabrizio Roccaforte,
• Marco Cannas,
• Franco Mario Gelardi and
• Simonpietro Agnello

Beilstein J. Nanotechnol. 2017, 8, 418–424, doi:10.3762/bjnano.8.44

• measurements. The formation of MoO3 on the edges of the flakes is observed indicative of the oxygen-activated transformation. Keywords: two-dimensional (2D) materials; graphene; MoS2; Raman spectroscopy; thermal doping; Introduction A wide interest for two-dimensional (2D) materials has grown in recent years

• in oxygen at temperatures below 400 °C. It has also been shown that the effect of doping is sensitive to the ambient atmosphere. In particular, water molecules affect the doping stability [20][21]. Alongside Gr, the transition metal dichalcogenide MoS2 is one of the stable 2D materials of interest [1

• dichalcogenides and show that the thermal processes could be driven by analogous reactions [32]. In particular, these effects are of relevance for the application of 2D materials in ambient environments where the temperature could be increased during their use. Finally, the possibility that doping of central

Zigzag phosphorene nanoribbons: one-dimensional resonant channels in two-dimensional atomic crystals

• Carlos. J. Páez,
• Dario. A. Bahamon,
• Ana L. C. Pereira and
• Peter. A. Schulz

Beilstein J. Nanotechnol. 2016, 7, 1983–1990, doi:10.3762/bjnano.7.189

• mechanisms involve states at the interior of the nanoribbon, whereas the effect shown here requires one-dimensional states localized at the edges. Concomitant to the development of the fascinating physics of 2D materials, new extreme 1D systems, namely isolated atomic chains, either based on carbon [45] or

• from the other edge. If the constriction is narrow enough to promote coupling between edges, it gives rise to Fano-like resonances as well as antiresonances in the transmission spectrum. These effects are shown to mimic an atomic chain like behavior in a two dimensional atomic crystal. Keywords: 2D

• materials; constrictions; edge states; phosphorene nanoribbons; quantum dots; Introduction Low-dimensional systems have attracted attention over the past fifty years since the development of semiconductor epitaxial growth and deposition of metallic thin films [1]. The early scenario, back in the 1960s, as

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• of the system (Figure 13) [77]. It should be mentioned that graphene is not the only 2D material today that offers great performance for a wide range of applications [78]. Boron nitride and molybdenum disulfide are examples of other 2D materials that offer the possibility to tune material and device

Imaging of carbon nanomembranes with helium ion microscopy

• André Beyer,
• Henning Vieker,
• Robin Klett,
• Hanno Meyer zu Theenhausen,
• Polina Angelova and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2015, 6, 1712–1720, doi:10.3762/bjnano.6.175

• (CNMs) prepared from aromatic self-assembled monolayers constitute a recently developed class of 2D materials. They are made by a combination of self-assembly, radiation-induced cross-linking and the detachment of the cross-linked SAM from its substrate. CNMs can be deposited on arbitrary substrates

• recording the emitted secondary electrons generates the HIM images. The advantages of HIM are high resolution, high surface sensitivity and large depth of field. The effects of sample charging, imaging of multilayer CNMs as well as imaging artefacts are discussed. Keywords: 2D materials; carbon

• hexagonal boron nitride (h-BN), an insulating material that shares similarities with graphene, were imaged in a comparative study [23]. Therein, it is shown that HIM is more sensitive and consistent than SEM for characterizing the number of layers and the morphology of 2D materials. It was also shown that

Two-dimensional and tubular structures of misfit compounds: Structural and electronic properties

• Tommy Lorenz,
• Jan-Ole Joswig and
• Gotthard Seifert

Beilstein J. Nanotechnol. 2014, 5, 2171–2178, doi:10.3762/bjnano.5.226

• or more layers of these sheets results in a so-called misfit layer compound (MLC) [1][2], in which the difference in the compound layers leads to different effects. Figure 1a demonstrates the misfit-compound concept schematically: two different layered, 2D materials are stacked alternately in

• -dimensional (2D) materials gave access to the preparation of numerous misfit compounds. To date, three comprehensive reviews have dealt with planar [3][4] and tubular [6] misfit compounds, which were as well the foundation for the present overview. In the following, planar and tubular misfit structures are

Fabrication of carbon nanomembranes by helium ion beam lithography

• Xianghui Zhang,
• Henning Vieker,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2014, 5, 188–194, doi:10.3762/bjnano.5.20

• attachment; helium ion microscopy; ion beam-organic molecules interactions; self-assembled monolayers; Introduction Carbon nanomembranes (CNMs) with monomolecular thickness and macroscopic lateral size represent a new type of functional two-dimensional (2D) materials [1]. A universal scheme to fabricate