Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• , defects profoundly impact, in a beneficial or detrimental manner, characteristic properties of 2D materials [2]. A prominent 2D material is graphene. Intact graphene, the 2D sp2 arrangement of C atoms in a honeycomb mesh, is well known for its appealing electronic and mechanical properties [3][4]. However

Graphene removal by water-assisted focused electron-beam-induced etching – unveiling the dose and dwell time impact on the etch profile and topographical changes in SiO₂ substrates

• Aleksandra Szkudlarek,
• Jan M. Michalik,
• Inés Serrano-Esparza,
• Zdeněk Nováček,
• Veronika Novotná,
• Piotr Ozga,
• Czesław Kapusta and
• José María De Teresa

Beilstein J. Nanotechnol. 2024, 15, 190–198, doi:10.3762/bjnano.15.18

• : direct writing; dwell time; electron dose; etching; graphene; maskless lithography; nanopatterning; Introduction The discovery of extraordinary and controllable electrical conductivity in graphene back in 2004 made it the most recognized 2D material [1]. The newly discovered phenomena, such as

Analytical and numerical design of a hybrid Fabry–Perot plano-concave microcavity for hexagonal boron nitride

• Felipe Ortiz-Huerta and
• Karina Garay-Palmett

Beilstein J. Nanotechnol. 2022, 13, 1030–1037, doi:10.3762/bjnano.13.90

• , followed by a transfer matrix model used to find the resonant modes of the microcavity, which are then corroborated by FDTD simulations. Results and Discussion Fabrication design Hybrid plano-concave microcavity By using a quarter-wavelength DBR with a multilayer 2D material on top (Figure 2a), we designed

• our system (2D material + DBR stack) to have a maximum reflectivity at the center wavelength of 637 nm. The selected wavelength of our system falls within the typical emission rates of the zero-phonon line (ZPL) of SPEs in hBN (500–800 nm). A quarter-wavelength thickness is conveniently chosen for the

• hBN where its value falls between experimentally achievable thicknesses of multilayer 2D materials [6]. A 3D concave shape polymer then could be fabricated on top of the 2D material (Figure 2b) by a direct laser writing system (e.g., Photonic Professional, Nanoscribe GmbH) by use of a 2PP process

Self-assembly of C₆₀ on a ZnTPP/Fe(001)–p(1 × 1)O substrate: observation of a quasi-freestanding C₆₀ monolayer

• Guglielmo Albani,
• Michele Capra,
• Alessandro Lodesani,
• Alberto Calloni,
• Gianlorenzo Bussetti,
• Marco Finazzi,
• Franco Ciccacci,
• Alberto Brambilla,
• Lamberto Duò and
• Andrea Picone

Beilstein J. Nanotechnol. 2022, 13, 857–864, doi:10.3762/bjnano.13.76

• layer of 2D material, such as graphene [27][28], hexagonal boron nitride [29][30][31] and MoS2 [32][33]. Moreover, an organic layer inserted between the substrate and the overlayer has been shown to be effective in improving the order of the molecular film [34][35] or restoring its original electronic

Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• a wide range of 2D material-based devices and heterostructures, especially in optoelectronics [7][8][9]. At present, one of the remaining challenges in the fabrication of graphene-based devices lies in the reproducibility: More than the CVD itself, the transfer process from the growth substrate (e.g

Reliable fabrication of transparent conducting films by cascade centrifugation and Langmuir–Blodgett deposition of electrochemically exfoliated graphene

• Teodora Vićentić,
• Stevan Andrić,
• Vladimir Rajić and
• Marko Spasenović

Beilstein J. Nanotechnol. 2022, 13, 666–674, doi:10.3762/bjnano.13.58

• with lateral sizes larger than 1 µm are preferred [23]. On the other hand, thinner (thus also laterally smaller [24]) flakes have a higher transparency, with potential use in transparent conductors. Size selection of 2D material flakes in solution has thus become a key challenge for the practical use

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• inertness and the low density of states near the Fermi level. However, the electronic decoupling efficiency also depends on the electronic structure of the 2D material. Sometimes, only molecular states in the bandgap of the 2D material can be decoupled. Moreover, ultrathin organic spacer layers can

• due to the lattice mismatch between 2D material and its substrate might serve as structural templates for molecular adsorption and self-assembly [79][80][81][82]. The electronic decoupling depends on the electronic properties of the 2D materials as they can be insulators, semiconductors, semimetals

• . The significantly reduced resonance width allowed for resolving vibronic states in both frontier orbitals on graphene/Pt(111) by STS. The semiconducting 2D material MoS2 may act as a decoupling layer for molecules from the underlying metal substrate if the molecular resonances lie within the MoS2

The role of convolutional neural networks in scanning probe microscopy: a review

• Ido Azuri,
• Irit Rosenhek-Goldian,
• Neta Regev-Rudzki,
• Georg Fantner and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2021, 12, 878–901, doi:10.3762/bjnano.12.66

• classification task. AutoSiM was shown to yield results nearly equivalent to manual selection in much shorter time. Masubuchi et al. developed a deep learning-based, autonomous robotic system for exfoliated 2D material detection in a motorized optical microscope. Efficient detection of various exfoliated 2D

Prediction of Co and Ru nanocluster morphology on 2D MoS₂ from interaction energies

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2021, 12, 704–724, doi:10.3762/bjnano.12.56

• materials, which often differ from their bulk equivalent, as well as the flexibility in fabrication afforded by an ultrathin material [17]. The majority of applications are built on an interaction between a metal and the 2D material. There are multiple studies in this regard that involve the adsorption of

• or doping with transition metals [4][5][18][19][20][21][22], alkali and alkali earth metals [23][24][25], and non-metals [25] on MoS2 and other 2D materials. While experimental studies can be used to probe the performance of the 2D material in a device or some of the interfacial interactions between

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• curvatures in the beam path, use the local dose optimization to achieve a uniform target depth. To demonstrate the capabilities of FIB-o-mat, three different 2D material systems were patterned. Multilayers of Co/Pt were modified regarding their local magnetic response without changing their topography

Nanomechanics of few-layer materials: do individual layers slide upon folding?

• Ronaldo J. C. Batista,
• Rafael F. Dias,
• Ana P. M. Barboza,
• Alan B. de Oliveira,
• Taise M. Manhabosco,
• Thiago R. Gomes-Silva,
• Matheus J. S. Matos,
• Andreij C. Gadelha,
• Cassiano Rabelo,
• Luiz G. L. Cançado,
• Ado Jorio,
• Hélio Chacham and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2020, 11, 1801–1808, doi:10.3762/bjnano.11.162

• carbon nanotubes [13][14]. The interlayer slip is also intimately related to the dependence of κ on the thickness or the number of layers of a 2D material, which, in the case of very thin 2D materials, may be very different from that obtained from classical theories [12]. The quantification and

• small force or mass changes [16]. It is important to emphasize that the quality factor of the resonator depends on its maximum resonant frequency, which is intrinsically related to the flexural properties of the employed 2D material. As an example of an application based on the folds of a 2D material

• number of layers [34]. In this work, we present a method to obtain interlayer and 2D material/substrate adhesion energies and the bending stiffness of 2D materials by experimentally probing the mechanical response of folded edges to deformation. A folded edge is defined as an edge region of the 2D

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• memory to build an example future quantum network [64]. This should preferably be in a monolithic structure to reduce manufacturability limitations and materials mismatch. In an ultrathin 2D material like h-BN, however, conventional characterization is difficult due to the sensitivity limited to large

• long. Here the SPE is attributed to effects similar to SPEs from TMC flakes except that BNNT has a large bandgap (5.95 eV) that is not affected by the geometry and their operation is at room temperature. When the BNNT diameter increases, the material can be assimilated into a 2D material, and as such

• , it can be considered a hybrid 1D and 2D material. In [116], commercially available BNNTs were fabricated using a catalyst-free high-temperature pressure method, and the laser heating method was studied in terms of SPEs. Non-treated BNNTs provided photostable SPEs down to the single nanotube, either

Correction: Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1922–1922, doi:10.3762/bjnano.10.187

• and Opto-Electronics Engineering, Tianjin University, 92 Weijin road, Tianjin 300072, China 10.3762/bjnano.10.187 Keywords: 1T'-WTe2; 2D material; anisotropic; light polarization; optoelectrical; The authors wish to add the following sentence to the Acknowledgement section: The optical anisotropic

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• and the possibility to open up new ways for applications of 2D materials for light polarization detection. Keywords: 1T’-WTe2; 2D material; anisotropic; light polarization; optoelectrical; Introduction The first exfoliation of graphene [1] attracted extensive interest in 2D materials such as black

Synthesis and characterization of quaternary La(Sr)S–TaS₂ misfit-layered nanotubes

• Marco Serra,
• Erumpukuthickal Ashokkumar Anumol,
• Dalit Stolovas,
• Iddo Pinkas,
• Ernesto Joselevich,
• Reshef Tenne,
• Andrey Enyashin and
• Francis Leonard Deepak

Beilstein J. Nanotechnol. 2019, 10, 1112–1124, doi:10.3762/bjnano.10.111

• interest of many researchers due to their electrical, optical, mechanical and thermoelectric properties [2] derived from their unique structure. WS2 nanotubes are nanostructures originating from the bending of a single layer of the 2D material tungsten disulfide along one axis, resulting in the

• ]. Typically, these nanostructures are synthesized by means of high-temperature reactions that allow the formation of different metal sulfide nanotubes [4][5]. Another type of hollow nanostructure, inorganic fullerene-like structures (IFs), is the result of bending of a 2D layer of WS2 or any other 2D material

Electronic properties of several two dimensional halides from ab initio calculations

• Mohamed Barhoumi,
• Ali Abboud,
• Lamjed Debbichi,
• Moncef Said,
• Torbjörn Björkman,
• Dario Rocca and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2019, 10, 823–832, doi:10.3762/bjnano.10.82

• external electric field to a rippled MoS2 monolayer [45] or a MoS2 nanoribbon [46][47] causes important changes in the electronic structure and reduces the bandgap. Also, applying an electric field to a 2D material mimics the presence of a gate voltage [48], and understanding the resulting changes in the

Choosing a substrate for the ion irradiation of two-dimensional materials

• Egor A. Kolesov

Beilstein J. Nanotechnol. 2019, 10, 531–539, doi:10.3762/bjnano.10.54

• , recoil atoms reaching the interface with a non-zero energy, and generation of hot electrons in close proximity of the interface. Additionally, the implantation of sputtered substrate atoms into the 2D material lattice is analyzed. This work is useful both for fundamental studies of irradiation of two

• a resultant defect yield [3]; on the other, it can participate in defect formation in the 2D material through energy transfer from sputtered substrate atoms moving through the monolayer [1][4]. When the energy is suitable, these atoms can become embedded into the 2D material crystal lattice, leading

• generation of hot electrons in the substrate within the close proximity of the interface can lead to a more intensive electronically stimulated surface atom desorption [13][14], which already occurs directly in a 2D material under ion irradiation [13][15]. In [16] it was shown by Raman spectroscopy and

Effects of post-lithography cleaning on the yield and performance of CVD graphene-based devices

• Eduardo Nery Duarte de Araujo,
• Thiago Alonso Stephan Lacerda de Sousa,
• Luciano de Moura Guimarães and
• Flavio Plentz

Beilstein J. Nanotechnol. 2019, 10, 349–355, doi:10.3762/bjnano.10.34

• electrical properties to surface phenomena and the existence of several routes for its surface functionalization, grant this 2D material plenty of application possibilities [1][2][3][4][5][6][7][8]. Among the several synthesis methods of high-quality graphene, chemical vapor deposition (CVD) stands out as

Contactless photomagnetoelectric investigations of 2D semiconductors

• Marian Nowak,
• Marcin Jesionek,
• Barbara Solecka,
• Piotr Szperlich,
• Piotr Duka and
• Anna Starczewska

Beilstein J. Nanotechnol. 2018, 9, 2741–2749, doi:10.3762/bjnano.9.256

• and holes induced by a back-gate voltage in graphene. Theoretical Description In the presented investigations, it was assumed that the 2D material is illuminated by a circular spot of TEM00 light with photon energy greater than its optical energy gap. The transport of electrons and holes through 2D

Two-dimensional semiconductors pave the way towards dopant-based quantum computing

• José Carlos Abadillo-Uriel,
• Belita Koiller and
• María José Calderón

Beilstein J. Nanotechnol. 2018, 9, 2668–2673, doi:10.3762/bjnano.9.249

• , some of the considered semiconductor 2D materials have no valley degeneracy, simplifying the experimental requirements of a scalable quantum computer. Schematic representation of the electronic distributions around two donors (represented in red) in a 2D material. Many of the 2D materials currently

Computational exploration of two-dimensional silicon diarsenide and germanium arsenide for photovoltaic applications

• Sri Kasi Matta,
• Chunmei Zhang,
• Yalong Jiao,
• Anthony O'Mullane and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1247–1253, doi:10.3762/bjnano.9.116

• (HSE) exchange–correlation functional [15][16] and Wannier90 package [17] implemented in the VASP code. The thermodynamic stability of the material is assessed by the formation energy for the 2D material and is indicated as “the difference in free energy of the 2D material and the lowest value of the

• formation of the 2D material from its bulk counterparts (green: experimentally synthesized 2D compound, red: not experimentally synthesized 2D compound, blue: possibility to synthesize 2D compound theoretically shown). Band structure for SiAs2 and GeAs2 calculated by the HSE-Wannier function method. The

Electro-optical interfacial effects on a graphene/π-conjugated organic semiconductor hybrid system

• Karolline A. S. Araujo,
• Luiz A. Cury,
• Matheus J. S. Matos,
• Thales F. D. Fernandes,
• Luiz G. Cançado and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2018, 9, 963–974, doi:10.3762/bjnano.9.90

• on optoelectronic devices possible. In another front, self-assembled monolayers (SAMs) on low-dimensional systems, such as a graphene (an archetypical 2D material), have attracted significant attention due to the myriad of applications in nanoelectronic devices [14][15][16]. Aiming at the improvement

• , with photohole–adsorbate recombination at the RA/graphene interface. In summary, the present work may promote new strategies in both organic electronics and 2D material applications due to potential interfacial-induced improvements within their hybrid systems. Experimental High-purity graphite flakes

Patterning of supported gold monolayers via chemical lift-off lithography

• Liane S. Slaughter,
• Kevin M. Cheung,
• Sami Kaappa,
• Huan H. Cao,
• Qing Yang,
• Thomas D. Young,
• Andrew C. Serino,
• Sami Malola,
• Jana M. Olson,
• Stephan Link,
• Hannu Häkkinen,
• Anne M. Andrews and
• Paul S. Weiss

Beilstein J. Nanotechnol. 2017, 8, 2648–2661, doi:10.3762/bjnano.8.265

• useful properties [14][15][16][17][18]. Here, we have investigated Au–alkanethiolate layers on PDMS that were produced during CLL specifically for their 2D material properties. The existence of Au on the PDMS stamp following lift-off was initially discovered using X-ray photoelectron spectroscopy (XPS

• experimental and computational strategies to characterize the hybrid Au–alkanethiolate 2D material formed at PDMS surfaces via lift-off lithography. Chemical lift-off lithography was used to pattern featureless (flat) PDMS substrates with Au–alkanethiolate monolayers, which enabled direct characterization of

Optical contrast and refractive index of natural van der Waals heterostructure nanosheets of franckeite

• Patricia Gant,
• Foad Ghasemi,
• David Maeso,
• Carmen Munuera,
• Elena López-Elvira,
• Riccardo Frisenda,
• David Pérez De Lara,
• Gabino Rubio-Bollinger,
• Mar Garcia-Hernandez and
• Andres Castellanos-Gomez

Beilstein J. Nanotechnol. 2017, 8, 2357–2362, doi:10.3762/bjnano.8.235

• available in the literature yet and it results crucial to further analysis of the optical properties of a material. For example, knowing the refractive index of a 2D material allows one to determine the substrate that optimizes its optical identification. This is done by calculating the optical contrast of

• to identify ultrathin flakes and to determine their thickness. Optical microscopy based identification methods have proven to be very resourceful ways to find ultrathin flakes produced by mechanical exfoliation [2][3][4][5][6][7][8][9][10][11][12][13][14]. In fact, nowadays each time a new 2D

• material is isolated one of the most urgent things is to establish a correlation between the thicknesses of the exfoliated flakes and their optical contrast (in order to be used as a calibration guide to identify ultrathin flakes optically) and to determine the optimal substrates to identify ultrathin