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

• ; scanning tunneling microscopy and spectroscopy; Introduction Defects in lattices of two-dimensional (2D) materials are considered as promising building blocks for tailoring electronic and phononic band structures, magnetic texture, photon emission, and charge carrier concentration [1]. In addition

• , 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

• , Poland Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, E-50018 Zaragoza, Spain 10.3762/bjnano.15.18 Abstract Graphene is one of the most extensively studied 2D materials, exhibiting

Upscaling the urea method synthesis of CoAl layered double hydroxides

• Camilo Jaramillo-Hernández,
• Víctor Oestreicher,
• Martín Mizrahi and
• Gonzalo Abellán

Beilstein J. Nanotechnol. 2023, 14, 927–938, doi:10.3762/bjnano.14.76

• hydroxides; layered double hydroxide; layered materials; scale-up process; synthesis; two-dimensional materials; Introduction Since the discovery of graphene [1], research on two-dimensional (2D) materials has become one of the most relevant topics in physics, chemistry, and (nano)materials science [2][3][4

Ni, Co, Zn, and Cu metal-organic framework-based nanomaterials for electrochemical reduction of CO₂: A review

• Ha Huu Do and
• Hai Bang Truong

Beilstein J. Nanotechnol. 2023, 14, 904–911, doi:10.3762/bjnano.14.74

• (2D) MOFs represent a novel addition to the family of 2D materials. Particularly, 2D MOF nanolayers with several outstanding characteristics, such as high surface area and abundant exposed active sites, have been studied for CO2RR. As a case in point, Wu et al. prepared 2D Ni-based zeolitic imidazole

Transferability of interatomic potentials for silicene

• Marcin Maździarz

Beilstein J. Nanotechnol. 2023, 14, 574–585, doi:10.3762/bjnano.14.48

• –Weber, EDIP, ReaxFF, COMB, and machine-learning-based interatomic potentials. A quantitative systematic comparison and a discussion of the results obtained are reported. Keywords: 2D materials; DFT; force fields; interatomic potentials; mechanical properties; silicene; Introduction We are living in

• graphene has also sparked interest in other non-carbon 2D materials [1][2]. One of such materials is 2D silicon, called silicene [3][4]. Using first-principles methods with current computer resources enables us to model structures up to about a few hundred atoms. For larger systems, approximate methods are

• quantify the potentials under examination. For 2D materials, directional 2D Young’s moduli, 2D Poisson’s ratios, and the 2D shear modulus, are often used instead of elastic constants Cij. Because of the symmetry of hexagonal lattices, these reduce to one 2D Young’s modulus E and one 2D Poisson’s ratio ν

Carbon nanotube-cellulose ink for rapid solvent identification

• Tiago Amarante,
• Thiago H. R. Cunha,
• Claudio Laudares,
• Ana P. M. Barboza,
• Ana Carolina dos Santos,
• Cíntia L. Pereira,
• Vinicius Ornelas,
• Bernardo R. A. Neves,
• André S. Ferlauto and
• Rodrigo G. Lacerda

Beilstein J. Nanotechnol. 2023, 14, 535–543, doi:10.3762/bjnano.14.44

• and other 1D/2D materials have been employed as ink components with great potential for a broad range of applications, for example, in flexible electronics, photoconductors, transparent conductors, and gas sensors [44][45][46][47]. Carbon nanotube ink films have been reported as field-effect

On the use of Raman spectroscopy to characterize mass-produced graphene nanoplatelets

• Keith R. Paton,
• Konstantinos Despotelis,
• Naresh Kumar,
• Piers Turner and
• Andrew J. Pollard

Beilstein J. Nanotechnol. 2023, 14, 509–521, doi:10.3762/bjnano.14.42

• .14.42 Abstract Raman spectroscopy is one of the most common methods to characterize graphene-related 2D materials, providing information on a wide range of physical and chemical properties. Because of typical sample inhomogeneity, Raman spectra are acquired from several locations across a sample, and

• , although quantification of the amount remains approximate. We therefore recommend this approach as a robust methodology for reliable characterization of mass-produced graphene-related 2D materials using confocal Raman spectroscopy. Keywords: few-layer graphene; graphene; metrology; quality control; Raman

• spectroscopy; Introduction Graphene and related 2D materials (GR2Ms) are now well established with commercial products available across a range of sectors, from sports and leisure products [1][2], through mobile phones [3] to automotive applications [4]. There are also a large number of producers of these

Liquid phase exfoliation of talc: effect of the medium on flake size and shape

• Samuel M. Sousa,
• Helane L. O. Morais,
• Joyce C. C. Santos,
• Ana Paula M. Barboza,
• Bernardo R. A. Neves,
• Elisângela S. Pinto and
• Mariana C. Prado

Beilstein J. Nanotechnol. 2023, 14, 68–78, doi:10.3762/bjnano.14.8

• applications that have specific requirements. Keywords: 2D materials; atomic force microscopy; liquid phase exfoliation; nanomaterials; talc; Introduction Two-dimensional (2D) materials have attracted a lot of interest due to their outstanding properties [1]. However, large-scale production is still a

• challenge that needs to be addressed to integrate 2D materials into industrial applications. One approach to producing large quantities of few-layer flakes of a broad range of exfoliatable materials is liquid-phase exfoliation (LPE) [2][3][4][5]. This method relies on mechanical energy to exfoliate

Photoelectrochemical water oxidation over TiO₂ nanotubes modified with MoS₂ and g-C₃N₄

• Phuong Hoang Nguyen,
• Thi Minh Cao,
• Tho Truong Nguyen,
• Hien Duy Tong and
• Viet Van Pham

Beilstein J. Nanotechnol. 2022, 13, 1541–1550, doi:10.3762/bjnano.13.127

• expensive synthesis equipment [29][36][37][38]. In this study, we compare properties and PEC water splitting efficiency of TNAs combined with the typical 2D materials MoS2 and g-C3N4 obtained with the same synthesis procedure. Insightful studies about optical and electronic properties have been conducted to

• materials (Figure 1b). This agrees with the results of previous publications in which hydrothermal methods were applied [24][25][26]. The SEM image of the g-C3N4 material shows the uniform nanosheets that were fabricated by the melamine pyrolysis method (Figure 1c). After the deposition of 2D materials MoS2

• filter cutting at 380 nm. Results and Discussion Characterizations of materials Figure 1a displays the morphology of TNAs, which have a uniform distribution of nanotubes with average diameters ranging from 80–100 nm and a length of 500 nm (Figure 1b). The MoS2 material exhibits the stacked layers of 2D

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

• 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

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

• . Keywords: 2D materials; graphene transfer process; large-scale fabrication; microelectronics; poly(methyl methacrylate); Introduction Graphene and two-dimensional (2D) transition metal dichalcogenides (TMDCs) have been the focus of an intense research effort aimed at developing a new class of innovative

Efficient liquid exfoliation of KP₁₅ nanowires aided by Hansen's empirical theory

• Zhaoxuan Huang,
• Zhikang Jiang,
• Nan Tian,
• Disheng Yao,
• Fei Long,
• Yanhan Yang and
• Danmin Liu

Beilstein J. Nanotechnol. 2022, 13, 788–795, doi:10.3762/bjnano.13.69

• nanoparticles as anode materials to promote the rapid diffusion and electron transfer of lithium, and Rongjun Zhao prepared n-butanol gas sensors with one-dimensional In2O3 nanorods [1][2]. Different from 2D materials, 1D materials generally have a chain-like crystal structure and are easily exfoliated due to a

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

• no exfoliation experience to make use of widely available graphene materials. Keywords: 2D materials; cascade centrifugation; graphene; Langmuir–Blodgett deposition; transparent conductors; Introduction The interest in graphene and other 2D materials keeps growing, especially since the initial

• delve into fundamental properties was augmented with an outlook towards potential applications [1]. Over the past decades, a great number of different methods for the synthesis of graphene and other 2D materials has been proposed, including micromechanical cleavage [2], chemical vapor deposition (CVD

• then break up the bulk 2D materials into mono- and few-layer nanosheets [15][16]. The choice of solvent for LPE is made based on surface energy considerations, compatible solvents include NMP, dimethylformamide (DMF), N,N-dimethylacetamide (DMA), γ-butyrolactone (GBL), 1,3-dimethyl-2-imidazolidinone

Revealing local structural properties of an atomically thin MoSe₂ surface using optical microscopy

• Lin Pan,
• Peng Miao,
• Anke Horneber,
• Alfred J. Meixner,
• Pierre-Michel Adam and
• Dai Zhang

Beilstein J. Nanotechnol. 2022, 13, 572–581, doi:10.3762/bjnano.13.49

• dichalcogenide. Keywords: copper phthalocyanine; local structure; molybdenum diselenide; optical spectroscopy; surface-enhanced Raman spectroscopy; Introduction Two-dimensional (2D) materials have garnered interest for the next generation of optoelectronic and electrochemical devices, mainly owing to their

• single-molecule detection level [18][19]. The Raman enhancement originates from an electromagnetic mechanism, provided by the excitation of surface plasmons, and a chemical mechanism which is related to the modification of Raman polarizability of molecules [20]. It has been reported that 2D materials

• orientation and molecular energy levels in the vicinity of the Fermi level of graphene, the charge-transfer effect can become more pronounced [24][25]. In summary, the structural irregularities in 2D materials and molecular probe both can impact the strength of molecule–substrate interactions and then modify

Electrostatic pull-in application in flexible devices: A review

• Teng Cai,
• Yuming Fang,
• Yingli Fang,
• Ruozhou Li,
• Ying Yu and
• Mingyang Huang

Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32

• [61]. Schematic diagram of a flexible microvalve structure. Figure 8 was redrawn from [77]. Schematic diagram of a GR pump. Figure 9 was republished from [78] (D. Davidovikj et al., “Graphene gas pumps”, 2D Materials, vol. 5, article no. 031009, published on 11 May 2018; https://doi.org/10.1088/2053

Theoretical understanding of electronic and mechanical properties of 1T′ transition metal dichalcogenide crystals

• Seyedeh Alieh Kazemi,
• Sadegh Imani Yengejeh,
• Vei Wang,
• William Wen and
• Yun Wang

Beilstein J. Nanotechnol. 2022, 13, 160–171, doi:10.3762/bjnano.13.11

• to their composition and structural polytypes. However, experimental measurements of the electronic and mechanical properties of 2D materials face the challenge of synthesizing high-quality pristine crystals. Thus, numerical simulations have become a promising alternative due to the relatively good

Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries

• Marina Tabuyo-Martínez,
• Bernd Wicklein and
• Pilar Aranda

Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75

• phosphorous/graphene anode delivered 1095 mAh·g−1 after 200 cycles at 1C [81]. It has also triggered research in a wider range of 2D materials as suitable and low-expansion anodes, starting with layered black phosphorous [73][76]. From there, exfoliated sheets of 2D allotropes came to scrutiny, such as

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

• substrate and the organic building blocks. Recently, two-dimensional (2D) materials, including hexagonal boron nitride (hBN) [22][23], graphene [24][25][26][27], and MoS2 [28], have emerged as monatomically thin decoupling layers. Van der Waals 2D materials are generally well suited due to their chemical

• changing chemical environment. Next, we outline articles that use 2D materials and ultrathin dielectric layers as decoupling layers. While on the one hand, molecular functionalization is a powerful approach to tune the electronic and optical properties of 2D materials, in particular for many practical

• applications [78], 2D materials, on the other hand, offer an alternative way for decoupling molecular structures from metal substrates [24]. 2D van der Waals materials are generally inert and therefore, are potentially well suited for physical decoupling of molecular structures. However, moiré patterns present

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

• crystals (van der Waals heterostructures, graphene, hBN, MoS2, and WTe2) was demonstrated. The detection algorithm enables real-time detection of the 2D materials (running for 200 ms on a 1024 × 1024 optical image) and is insensitive to variations in microscopy conditions such as illumination and color

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

• gap in understanding thin film nucleation on 2D materials. In this paper, we present a density functional theory (DFT) study of the adsorption of small Co and Ru structures, with up to four atoms, on a monolayer of MoS2. We explore how the metal–substrate and metal–metal interactions contribute to the

• . Based on this understanding, we propose Co on MoS2 as a suitable candidate for advanced interconnects, while Ru on MoS2 is more suited to catalysis applications. Keywords: cobalt (Co); 2D materials; molybdenum disulfide (MoS2); ruthenium (Ru); thin film nucleation; Introduction Layered materials that

• 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

• function [30]. In several of these works, high-resolution scanning TEM (STEM) imaging has been performed to enable the analysis of the defects created on the atomic scale [26][29][30] (see, e.g., Figure 2c). Apart from 2D materials, thin-film samples have also been the subject of electronic property tuning

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• impacted graphene carrier concentration and strain. It is, therefore, possible to consider the use of NW substrates for defect engineering in graphene and probably in other 2D materials. SEM images of graphene on GaN NWs with different variations in height in N0 (a,d), N100 (b,e), and N500 (c,f) samples

Reconstruction of a 2D layer of KBr on Ir(111) and electromechanical alteration by graphene

• Zhao Liu,
• Antoine Hinaut,
• Stefan Peeters,
• Sebastian Scherb,
• Ernst Meyer,
• Maria Clelia Righi and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2021, 12, 432–439, doi:10.3762/bjnano.12.35

• reduced by the decoupling effect of graphene, thus yielding different electrical and mechanical properties of the top KBr layer. Keywords: DFT; graphene; Ir(111); KBr; KPFM; nc-AFM; surface reconstruction; Introduction Many two-dimensional (2D) materials have excellent optical, mechanical

Exploring the fabrication and transfer mechanism of metallic nanostructures on carbon nanomembranes via focused electron beam induced processing

• Christian Preischl,
• Linh Hoang Le,
• Elif Bilgilisoy,
• Armin Gölzhäuser and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2021, 12, 319–329, doi:10.3762/bjnano.12.26

• reduction of the iron structures. These results demonstrate that the fabrication of hybrids of metallic nanostructures onto organic 2D materials is an intrinsically complex procedure. The interactions among the metallic deposits, the substrate for the growth of the SAM, and the associated etching/dissolving

• agent need to be considered and further studied. Keywords: 2D materials; carbon nanomembranes (CNMs); focused electron beam-induced processing; metallic nanostructures; self-assembled monolayers; Introduction Focused electron beam-induced processing (FEBIP) is a powerful maskless “direct-write

• effects caused by secondary or backscattered electrons have minor influence on size and shape of the deposit. Recently, it could be demonstrated that FEBIP can be used to fabricate functional hybrid structures consisting of metallic nanostructures on top of organic 2D materials. The prototype of organic

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

• devices by design, that is, to tailor both material properties and device geometries according to a sophisticated blueprint. Thin layers and two-dimensional (2D) materials are especially interesting candidates for designer materials [1] as they are compatible with planar device geometries and may be

• , other challenges such as small sputter rates and large interaction volumes persist. Therefore, 2D materials are an ideal platform for ion beam machining with light ions. The lack (or non-relevance) of the interaction volume allows for a high spatial resolution, enabling the fabrication of structural

• features in the single-digit nanometer range where small sputter rates play a minor role. This holds true not only for monolayer 2D materials, such as graphene, but also for thin films forming quasi 2D geometries. The versatility of the corresponding materials opens a wide field of exciting applications