scholarly journals Chlorosulfuric acid-assisted production of functional 2D materials

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohsen Moazzami Gudarzi ◽  
Maryana Asaad ◽  
Boyang Mao ◽  
Gergo Pinter ◽  
Jianqiang Guo ◽  
...  
Keyword(s):  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Real Life ◽  
Large Area ◽  
Polar Solvents ◽  
Aspect Ratios ◽  
Two Dimensional Materials ◽  
Liquid Phase Exfoliation

AbstractThe use of two-dimensional materials in bulk functional applications requires the ability to fabricate defect-free 2D sheets with large aspect ratios. Despite huge research efforts, current bulk exfoliation methods require a compromise between the quality of the final flakes and their lateral size, restricting the effectiveness of the product. In this work, we describe an intercalation-assisted exfoliation route, which allows the production of high-quality graphene, hexagonal boron nitride, and molybdenum disulfide 2D sheets with average aspect ratios 30 times larger than that obtained via conventional liquid-phase exfoliation. The combination of chlorosulfuric acid intercalation with in situ pyrene sulfonate functionalisation produces a suspension of thin large-area flakes, which are stable in various polar solvents. The described method is simple and requires no special laboratory conditions. We demonstrate that these suspensions can be used for fabrication of laminates and coatings with electrical properties suitable for a number of real-life applications.

scholarly journals In situ epitaxial engineering of graphene and h-BN lateral heterostructure with a tunable morphology comprising h-BN domains

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Dechao Geng ◽  
Jichen Dong ◽  
Lay Kee Ang ◽  
Feng Ding ◽  
Hui Ying Yang
Keyword(s):  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Chemical Vapor ◽  
Large Area ◽  
Atomic Lattice ◽  
Cvd Method ◽  
Wide Range ◽  
Tunable Morphology

Abstract Graphene and hexagonal boron nitride (h-BN), as typical two-dimensional (2D) materials, have long attracted substantial attention due to their unique properties and promise in a wide range of applications. Although they have a rather large difference in their intrinsic bandgaps, they share a very similar atomic lattice; thus, there is great potential in constructing heterostructures by lateral stitching. Herein, we present the in situ growth of graphene and h-BN lateral heterostructures with tunable morphologies that range from a regular hexagon to highly symmetrical star-like structure on the surface of liquid Cu. The chemical vapor deposition (CVD) method is used, where the growth of the h-BN is demonstrated to be highly templated by the graphene. Furthermore, large-area production of lateral G-h-BN heterostructures at the centimeter scale with uniform orientation is realized by precisely tuning the CVD conditions. We found that the growth of h-BN is determined by the initial graphene and symmetrical features are produced that demonstrate heteroepitaxy. Simulations based on the phase field and density functional theories are carried out to elucidate the growth processes of G-h-BN flakes with various morphologies, and they have a striking consistency with experimental observations. The growth of a lateral G-h-BN heterostructure and an understanding of the growth mechanism can accelerate the construction of various heterostructures based on 2D materials.

scholarly journals Tunable Photodetectors via In Situ Thermal Conversion of TiS3 to TiO2

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 711 ◽  
Author(s):  
Foad Ghasemi ◽  
Riccardo Frisenda ◽  
Eduardo Flores ◽  
Nikos Papadopoulos ◽  
Robert Biele ◽  
...  
Keyword(s):  
2D Materials ◽  
Optoelectronic Devices ◽  
Thermal Conversion ◽  
Wide Bandgap ◽  
Common Source ◽  
Many Body ◽  
Two Dimensional Materials ◽  
Materials Research ◽  
Titanium Trisulfide

In two-dimensional materials research, oxidation is usually considered as a common source for the degradation of electronic and optoelectronic devices or even device failure. However, in some cases a controlled oxidation can open the possibility to widely tune the band structure of 2D materials. In particular, we demonstrate the controlled oxidation of titanium trisulfide (TiS3), a layered semicon-ductor that has attracted much attention recently thanks to its quasi-1D electronic and optoelectron-ic properties and its direct bandgap of 1.1 eV. Heating TiS3 in air above 300 °C gradually converts it into TiO2, a semiconductor with a wide bandgap of 3.2 eV with applications in photo-electrochemistry and catalysis. In this work, we investigate the controlled thermal oxidation of indi-vidual TiS3 nanoribbons and its influence on the optoelectronic properties of TiS3-based photodetec-tors. We observe a step-wise change in the cut-off wavelength from its pristine value ~1000 nm to 450 nm after subjecting the TiS3 devices to subsequent thermal treatment cycles. Ab-initio and many-body calculations confirm an increase in the bandgap of titanium oxysulfide (TiO2-xSx) when in-creasing the amount of oxygen and reducing the amount of sulfur.

Steer the Rheology of Solvent with Little Surfactant to Exfoliate MoS2 Nanosheet by Liquid Phase Exfoliation Method

NANO ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. 2050118
Author(s):  
Dan Zhou ◽  
Jianzhong Yin
Keyword(s):  
High Speed ◽  
2D Materials ◽  
Ultrasonic Bath ◽  
Mos2 Nanosheet ◽  
Alcohol Mixtures ◽  
Liquid Phase Exfoliation ◽  
The Impact ◽  
Shear Thinning Fluid ◽  
Statistical Results

A surfactant system L64 and alcohol mixture was employed to exfoliate MoS2. To reduce the impact of surfactant on the quality of the nanosheet, the concentration of L64 was decreased to an extremely low value 0.0325 mM. Utilize common ultrasonic bath, the production yield of the nanosheet was increased to about 5% per hour, and statistical results from AFM showed that 40% of the nanosheet were less than 4 nm thick. Rheology characterization showed that surfactant alcohol mixtures were shear thinning fluid, yet the viscosity of L64 system varies directly with the shear rate in the high-speed shear region (higher than 400 s−1), and further affect the shear strength, therefore viscosity at high-speed shear can be considered as an indicator of the effectiveness for the exfoliation system. Exfoliated MoS2 was evaluated by hydrogen evolution reaction, and compared to the bulk MoS2, the 4 wt% Pt/FL-MoS2 improved the overpotential from 366 mV to 273 mV at 10 mA[Formula: see text]cm[Formula: see text]. This study presented a facile and effective route to fabricate 2D MoS2 with much less residue, and bring more opportunities to exploit clean and nontoxic system to exfoliate 2D materials.

Disentangling the liquid phase exfoliation of two-dimensional materials: an “in silico” perspective

2020 ◽  
Vol 22 (39) ◽  
pp. 22157-22179
Author(s):  
Titas Kumar Mukhopadhyay ◽  
Ayan Datta
Keyword(s):  
Liquid Phase ◽  
Molecular Simulation ◽  
In Silico ◽  
2D Materials ◽  
Two Dimensional ◽  
Simulation Techniques ◽  
Recent Advances ◽  
Two Dimensional Materials ◽  
Liquid Phase Exfoliation ◽  
Shed Light

In this perspective article, recent advances in molecular simulation techniques have been reviewed to shed light on the complexity of liquid phase exfoliation of 2D materials.

scholarly journals Large-area integration of two-dimensional materials and their heterostructures by wafer bonding

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Arne Quellmalz ◽  
Xiaojing Wang ◽  
Simon Sawallich ◽  
Burkay Uzlu ◽  
Martin Otto ◽  
...  
Keyword(s):  
Wafer Bonding ◽  
Semiconductor Manufacturing ◽  
Large Scale ◽  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
High Volume ◽  
Two Dimensional ◽  
Wafer Level ◽  
Large Area ◽  
Wide Range

AbstractIntegrating two-dimensional (2D) materials into semiconductor manufacturing lines is essential to exploit their material properties in a wide range of application areas. However, current approaches are not compatible with high-volume manufacturing on wafer level. Here, we report a generic methodology for large-area integration of 2D materials by adhesive wafer bonding. Our approach avoids manual handling and uses equipment, processes, and materials that are readily available in large-scale semiconductor manufacturing lines. We demonstrate the transfer of CVD graphene from copper foils (100-mm diameter) and molybdenum disulfide (MoS2) from SiO2/Si chips (centimeter-sized) to silicon wafers (100-mm diameter). Furthermore, we stack graphene with CVD hexagonal boron nitride and MoS2 layers to heterostructures, and fabricate encapsulated field-effect graphene devices, with high carrier mobilities of up to $$4520\;{\mathrm{cm}}^2{\mathrm{V}}^{ - 1}{\mathrm{s}}^{ - 1}$$ 4520 cm 2 V − 1 s − 1 . Thus, our approach is suited for backend of the line integration of 2D materials on top of integrated circuits, with potential to accelerate progress in electronics, photonics, and sensing.

scholarly journals Device Applications of Metal-2D-Materials Interfaces A Short Review

2018 ◽  
Vol 3 (4) ◽  
pp. 1 ◽  
Author(s):  
Faisal Ahmad ◽  
Amir Mansoori ◽  
Sonia Bansal ◽  
Th. S. Dhahi ◽  
Shamim Ahmad
Keyword(s):  
Charge Carrier ◽  
Carrier Transport ◽  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Electronic Energy ◽  
Device Fabrication ◽  
Current Status ◽  
Large Area ◽  
Wide Range ◽  
Device Applications

The electronic energy band gaps of 2D-materials are known to spread over a wide range from zero in graphene to > 6eV in hexagonal boron nitride (h-BN). Various combinations of such engineered nanomaterials offer a number of novel device applications involving their unique optical, electronic, and thermal properties along with their higher charge carrier mobilities and saturation limited drift velocities. Structurally, these nanomaterials have single or multiple monolayers stuck together, which are not only suitable for flexible electron devices and circuits but also in preparing heterostructures (lateral as well as vertical configurations) that form super lattices with different kinds of band alignments. Such possibilities offer flexible control over the charge carrier transport in these materials via numerous types of exciton formations. Their extra sensitivity towards the presence of atomic, molecular and nanoparticulate species in their vicinity is the most significant aspect of these 2D-materials. This is the reason behind studying them in detail for detecting the presence of extremely low concentrations of the analyte that are not achievable in conventional sensors. For translating the above-said superlative properties of these fast emerging families of 2-D nanomaterials into usable devices and circuits, applying the conventional device fabrication technologies poses a real challenge. The experimental results reported in the context of forming usable interfaces between a metal and 2D-nanomaterial are examined here to assess their current status and future prospects. Their widespread applications are certainly anticipated in the fields like printed micro/nano sensors, large area electronics and printed intelligence with special reference to their emerging usages in Internet of Things (IoT) in the near future. 

scholarly journals Production and Mechanical Characterization of Graphene Micro-Ribbons

2019 ◽  
Vol 3 (2) ◽  
pp. 42
Author(s):  
Maria Giovanna Pastore Carbone ◽  
Georgia Tsoukleri ◽  
Anastasios C. Manikas ◽  
Eleni Makarona ◽  
Christos Tsamis ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Mechanical Characterization ◽  
Chemical Vapor ◽  
Large Area ◽  
Mechanical Investigation ◽  
Raman Spectral ◽  
Compressive Tests

Patterning of graphene into micro- and nano-ribbons allows for tunability in emerging fields such as flexible electronic and optoelectronic devices, and is gaining interest for the production of more efficient reinforcement for composite materials. In this work we fabricate micro-ribbons from graphene synthesized via chemical vapor deposition (CVD) by combining ultraviolet (UV) photolithography and dry etching oxygen plasma treatments. We used Raman spectral imaging to confirm the effectiveness of the patterning procedure, which is suitable for large-area patterning of graphene on wafer-scale, and confirms that the quality of graphene remains unaltered. The produced micro-ribbons were finally transferred and embedded into a polymeric matrix and the mechanical response was investigated by in-situ mechanical investigation combining Raman spectroscopy and tensile/compressive tests.

scholarly journals Layer-engineered large-area exfoliation of graphene

2020 ◽  
Vol 6 (44) ◽  
pp. eabc6601
Author(s):  
Ji-Yun Moon ◽  
Minsoo Kim ◽  
Seung-Il Kim ◽  
Shuigang Xu ◽  
Jun-Hui Choi ◽  
...  
Keyword(s):  
Large Scale ◽  
Metal Films ◽  
Thin Metal Film ◽  
Large Area ◽  
Exfoliated Graphene ◽  
Large Size ◽  
Measurement Analysis ◽  
Two Dimensional Materials ◽  
Mechanical Cleavage

The competition between quality and productivity has been a major issue for large-scale applications of two-dimensional materials (2DMs). Until now, the top-down mechanical cleavage method has guaranteed pure perfect 2DMs, but it has been considered a poor option in terms of manufacturing. Here, we present a layer-engineered exfoliation technique for graphene that not only allows us to obtain large-size graphene, up to a millimeter size, but also allows selective thickness control. A thin metal film evaporated on graphite induces tensile stress such that spalling occurs, resulting in exfoliation of graphene, where the number of exfoliated layers is adjusted by using different metal films. Detailed spectroscopy and electron transport measurement analysis greatly support our proposed spalling mechanism and fine quality of exfoliated graphene. Our layer-engineered exfoliation technique can pave the way for the development of a manufacturing-scale process for graphene and other 2DMs in electronics and optoelectronics.

Atomic-scale etching of hexagonal boron nitride for device integration based on two-dimensional materials

Nanoscale ◽  
2018 ◽  
Vol 10 (32) ◽  
pp. 15205-15212 ◽  
Author(s):  
Hamin Park ◽  
Gwang Hyuk Shin ◽  
Khang June Lee ◽  
Sung-Yool Choi
Keyword(s):  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Etching Rate ◽  
Atomic Scale ◽  
Two Dimensional ◽  
Two Dimensional Materials ◽  
Device Integration

We propose the atomic-scale etching of h-BN achieving an etching rate less than 1 nm min−1 for device integration based on 2D materials.

scholarly journals Two-Dimensional Nanomaterials-Based Polymer Composites: Fabrication and Energy Storage Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Wei Liu ◽  
Bakhtar Ullah ◽  
Ching-Ching Kuo ◽  
Xingke Cai
Keyword(s):  
Corrosion Resistance ◽  
Energy Storage ◽  
Polymer Composites ◽  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Low Cost ◽  
Lithium Ion ◽  
Two Dimensional ◽  
New Class ◽  
Two Dimensional Materials

Polymers have been widely used for their low density, low cost, corrosion resistance, easy design, and processing. The addition of nanomaterials into polymer matrices has been studied for a long history due to their enhancement on properties of polymers, such as the electrical conductivity, thermal conductivity, corrosion resistance, and wear resistance. Two-dimensional materials, a new class of nanomaterials, have been intensively studied as a filler for polymer composites in recent years, which can significantly enhance the performance at even extremely small loading. In this review, firstly, the preparing and modifying method of 2D materials, such as graphene, graphene oxide, and hexagonal boron nitride, as a filler for polymer composites are organized. The related dispersion methods of 2D materials in the polymers, surface treatments of 2D materials, interface bonding between 2D materials and polymers are discussed alongside. Secondly, the applications of 2D materials/polymer composites for energy storage in lithium ion battery separators and supercapacitors are summarized. Finally, we have concluded the challenges in preparing 2D materials/polymer composites, and future perspectives for using this class of new composites have also been discussed.

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