2D Materials - IOPscience

2D Materials - IOPscience
2D Materials
Purpose-led Publishing
is a coalition of three not-for-profit publishers in the field of physical sciences: AIP Publishing, the American Physical Society and IOP Publishing.
Together, as publishers that will always put purpose above profit, we have defined a set of industry standards that underpin high-quality, ethical scholarly communications.
We are proudly declaring that science is our only shareholder.
SUPPORTS OPEN ACCESS
2D Materials
™ is a multidisciplinary, electronic-only journal devoted to publishing fundamental and applied research of the highest quality and impact covering all aspects of graphene and related two-dimensional materials.
Submit
an article
opens in new tab
Track my article
opens in new tab
RSS
Sign up for new issue notifications
Median submission to first decision before peer review
7 days
Median submission to first decision after peer review
42 days
Impact factor
4.3
Citescore
9.3
Full list of journal metrics
The following article is
Open access
The 2D materials roadmap
Wencai Ren
et al
2026
2D Mater.
13
021501
View article
, The 2D materials roadmap
PDF
, The 2D materials roadmap
Over the past two decades, two-dimensional (2D) materials have rapidly evolved into a diverse and expanding family of material platforms. Many members of this materials class have demonstrated their potential to deliver transformative impact on fundamental research and technological applications across different fields. In this roadmap, we provide an overview of the key aspects of 2D material research and development, spanning synthesis, properties and commercial applications. We specifically present roadmaps for high impact 2D materials, including graphene and its derivatives, transition metal dichalcogenides, MXenes as well as their heterostructures and moiré systems. The discussions are organized into thematic sections covering emerging research areas (e.g. twisted electronics, moiré nano-optoelectronics, polaritronics, quantum photonics, and neuromorphic computing), breakthrough applications in key technologies (e.g. 2D transistors, energy storage, electrocatalysis, filtration and separation, thermal management, flexible electronics, sensing, electromagnetic interference shielding, and composites) and other important topics (computational discovery of novel materials, commercialization and standardization). This roadmap focuses on the current research landscape, future challenges and scientific and technological advances required to address, with the intent to provide useful references for promoting the development of 2D materials.
figure placeholder
The following article is
Open access
Production and processing of graphene and related materials
Claudia Backes
et al
2020
2D Mater.
022001
View article
, Production and processing of graphene and related materials
PDF
, Production and processing of graphene and related materials
We present an overview of the main techniques for production and processing of graphene and related materials (GRMs), as well as the key characterization procedures. We adopt a ‘hands-on’ approach, providing practical details and procedures as derived from literature as well as from the authors’ experience, in order to enable the reader to reproduce the results.
Section I is devoted to ‘bottom up’ approaches, whereby individual constituents are pieced together into more complex structures. We consider graphene nanoribbons (GNRs) produced either by solution processing or by on-surface synthesis in ultra high vacuum (UHV), as well carbon nanomembranes (CNM). Production of a variety of GNRs with tailored band gaps and edge shapes is now possible. CNMs can be tuned in terms of porosity, crystallinity and electronic behaviour.
Section II covers ‘top down’ techniques. These rely on breaking down of a layered precursor, in the graphene case usually natural crystals like graphite or artificially synthesized materials, such as highly oriented pyrolythic graphite, monolayers or few layers (FL) flakes. The main focus of this section is on various exfoliation techniques in a liquid media, either intercalation or liquid phase exfoliation (LPE). The choice of precursor, exfoliation method, medium as well as the control of parameters such as time or temperature are crucial. A definite choice of parameters and conditions yields a particular material with specific properties that makes it more suitable for a targeted application. We cover protocols for the graphitic precursors to graphene oxide (GO). This is an important material for a range of applications in biomedicine, energy storage, nanocomposites, etc. Hummers’ and modified Hummers’ methods are used to make GO that subsequently can be reduced to obtain reduced graphene oxide (RGO) with a variety of strategies. GO flakes are also employed to prepare three-dimensional (3d) low density structures, such as sponges, foams, hydro- or aerogels. The assembly of flakes into 3d structures can provide improved mechanical properties. Aerogels with a highly open structure, with interconnected hierarchical pores, can enhance the accessibility to the whole surface area, as relevant for a number of applications, such as energy storage. The main recipes to yield graphite intercalation compounds (GICs) are also discussed. GICs are suitable precursors for covalent functionalization of graphene, but can also be used for the synthesis of uncharged graphene in solution. Degradation of the molecules intercalated in GICs can be triggered by high temperature treatment or microwave irradiation, creating a gas pressure surge in graphite and exfoliation. Electrochemical exfoliation by applying a voltage in an electrolyte to a graphite electrode can be tuned by varying precursors, electrolytes and potential. Graphite electrodes can be either negatively or positively intercalated to obtain GICs that are subsequently exfoliated. We also discuss the materials that can be amenable to exfoliation, by employing a theoretical data-mining approach.
The exfoliation of LMs usually results in a heterogeneous dispersion of flakes with different lateral size and thickness. This is a critical bottleneck for applications, and hinders the full exploitation of GRMs produced by solution processing. The establishment of procedures to control the morphological properties of exfoliated GRMs, which also need to be industrially scalable, is one of the key needs. Section III deals with the processing of flakes. (Ultra)centrifugation techniques have thus far been the most investigated to sort GRMs following ultrasonication, shear mixing, ball milling, microfluidization, and wet-jet milling. It allows sorting by size and thickness. Inks formulated from GRM dispersions can be printed using a number of processes, from inkjet to screen printing. Each technique has specific rheological requirements, as well as geometrical constraints. The solvent choice is critical, not only for the GRM stability, but also in terms of optimizing printing on different substrates, such as glass, Si, plastic, paper, etc, all with different surface energies. Chemical modifications of such substrates is also a key step.
Sections IV–VII are devoted to the growth of GRMs on various substrates and their processing after growth to place them on the surface of choice for specific applications. The substrate for graphene growth is a key determinant of the nature and quality of the resultant film. The lattice mismatch between graphene and substrate influences the resulting crystallinity. Growth on insulators, such as SiO
2,
typically results in films with small crystallites, whereas growth on the close-packed surfaces of metals yields highly crystalline films. Section IV outlines the growth of graphene on SiC substrates. This satisfies the requirements for electronic applications, with well-defined graphene-substrate interface, low trapped impurities and no need for transfer. It also allows graphene structures and devices to be measured directly on the growth substrate. The flatness of the substrate results in graphene with minimal strain and ripples on large areas, allowing spectroscopies and surface science to be performed. We also discuss the surface engineering by intercalation of the resulting graphene, its integration with Si-wafers and the production of nanostructures with the desired shape, with no need for patterning.
Section V deals with chemical vapour deposition (CVD) onto various transition metals and on insulators. Growth on Ni results in graphitized polycrystalline films. While the thickness of these films can be optimized by controlling the deposition parameters, such as the type of hydrocarbon precursor and temperature, it is difficult to attain single layer graphene (SLG) across large areas, owing to the simultaneous nucleation/growth and solution/precipitation mechanisms. The differing characteristics of polycrystalline Ni films facilitate the growth of graphitic layers at different rates, resulting in regions with differing numbers of graphitic layers. High-quality films can be grown on Cu. Cu is available in a variety of shapes and forms, such as foils, bulks, foams, thin films on other materials and powders, making it attractive for industrial production of large area graphene films. The push to use CVD graphene in applications has also triggered a research line for the direct growth on insulators. The quality of the resulting films is lower than possible to date on metals, but enough, in terms of transmittance and resistivity, for many applications as described in section V.
Transfer technologies are the focus of section VI. CVD synthesis of graphene on metals and bottom up molecular approaches require SLG to be transferred to the final target substrates. To have technological impact, the advances in production of high-quality large-area CVD graphene must be commensurate with those on transfer and placement on the final substrates. This is a prerequisite for most applications, such as touch panels, anticorrosion coatings, transparent electrodes and gas sensors etc. New strategies have improved the transferred graphene quality, making CVD graphene a feasible option for CMOS foundries. Methods based on complete etching of the metal substrate in suitable etchants, typically iron chloride, ammonium persulfate, or hydrogen chloride although reliable, are time- and resource-consuming, with damage to graphene and production of metal and etchant residues. Electrochemical delamination in a low-concentration aqueous solution is an alternative. In this case metallic substrates can be reused. Dry transfer is less detrimental for the SLG quality, enabling a deterministic transfer.
There is a large range of layered materials (LMs) beyond graphite. Only few of them have been already exfoliated and fully characterized. Section VII deals with the growth of some of these materials. Amongst them, h-BN, transition metal tri- and di-chalcogenides are of paramount importance. The growth of h-BN is at present considered essential for the development of graphene in (opto) electronic applications, as h-BN is ideal as capping layer or substrate. The interesting optical and electronic properties of TMDs also require the development of scalable methods for their production. Large scale growth using chemical/physical vapour deposition or thermal assisted conversion has been thus far limited to a small set, such as h-BN or some TMDs. Heterostructures could also be directly grown.
Section VIII discusses advances in GRM functionalization. A broad range of organic molecules can be anchored to the
sp
basal plane by reductive functionalization. Negatively charged graphene can be prepared in liquid phase (e.g. via intercalation chemistry or electrochemically) and can react with electrophiles. This can be achieved both in dispersion or on substrate. The functional groups of GO can be further derivatized. Graphene can also be noncovalently functionalized, in particular with polycyclic aromatic hydrocarbons that assemble on the
sp
carbon network by
stacking. In the liquid phase, this can enhance the colloidal stability of SLG/FLG. Approaches to achieve noncovalent on-substrate functionalization are also discussed, which can chemically dope graphene. Research efforts to derivatize CNMs are also summarized, as well as novel routes to selectively address defect sites. In dispersion, edges are the most dominant defects and can be covalently modified. This enhances colloidal stability without modifying the graphene basal plane. Basal plane point defects can also be modified, passivated and healed in ultra-high vacuum. The decoration of graphene with metal nanoparticles (NPs) has also received considerable attention, as it allows to exploit synergistic effects between NPs and graphene. Decoration can be either achieved chemically or in the gas phase. All LMs, can be functionalized and we summarize emerging approaches to covalently and noncovalently functionalize MoS
both in the liquid and on substrate.
Section IX describes some of the most popular characterization techniques, ranging from optical detection to the measurement of the electronic structure. Microscopies play an important role, although macroscopic techniques are also used for the measurement of the properties of these materials and their devices. Raman spectroscopy is paramount for GRMs, while PL is more adequate for non-graphene LMs (see section IX.2). Liquid based methods result in flakes with different thicknesses and dimensions. The qualification of size and thickness can be achieved using imaging techniques, like scanning probe microscopy (SPM) or transmission electron microscopy (TEM) or spectroscopic techniques. Optical microscopy enables the detection of flakes on suitable surfaces as well as the measurement of optical properties. Characterization of exfoliated materials is essential to improve the GRM metrology for applications and quality control. For grown GRMs, SPM can be used to probe morphological properties, as well as to study growth mechanisms and quality of transfer. More generally, SPM combined with smart measurement protocols in various modes allows one to get obtain information on mechanical properties, surface potential, work functions, electrical properties, or effectiveness of functionalization. Some of the techniques described are suitable for ‘
in situ
’ characterization, and can be hosted within the growth chambers. If the diagnosis is made ‘
ex situ
’, consideration should be given to the preparation of the samples to avoid contamination. Occasionally cleaning methods have to be used prior to measurement.
The following article is
Open access
The Computational 2D Materials Database: high-throughput modeling and discovery of atomically thin crystals
Sten Haastrup
et al
2018
2D Mater.
042002
View article
, The Computational 2D Materials Database: high-throughput modeling and discovery of atomically thin crystals
PDF
, The Computational 2D Materials Database: high-throughput modeling and discovery of atomically thin crystals
We introduce the Computational 2D Materials Database (C2DB), which organises a variety of structural, thermodynamic, elastic, electronic, magnetic, and optical properties of around 1500 two-dimensional materials distributed over more than 30 different crystal structures. Material properties are systematically calculated by state-of-the-art density functional theory and many-body perturbation theory (
and the Bethe–Salpeter equation for  ∼250 materials) following a semi-automated workflow for maximal consistency and transparency. The C2DB is fully open and can be browsed online (
) or downloaded in its entirety. In this paper, we describe the workflow behind the database, present an overview of the properties and materials currently available, and explore trends and correlations in the data. Moreover, we identify a large number of new potentially synthesisable 2D materials with interesting properties targeting applications within spintronics, (opto-)electronics, and plasmonics. The C2DB offers a comprehensive and easily accessible overview of the rapidly expanding family of 2D materials and forms an ideal platform for computational modeling and design of new 2D materials and van der Waals heterostructures.
The following article is
Open access
A review on transfer methods of two-dimensional materials
I Cheliotis and I Zergioti 2024
2D Mater.
11
022004
View article
, A review on transfer methods of two-dimensional materials
PDF
, A review on transfer methods of two-dimensional materials
Over the years, two-dimensional (2D) materials have attracted increasing technological interest due to their unique physical, electronic, and photonic properties, making them excellent candidates for applications in electronics, nanoelectronics, optoelectronics, sensors, and modern telecommunications. Unfortunately, their development often requires special conditions and strict protocols, making it challenging to integrate them directly into devices. Some of the requirements include high temperatures, precursors, and special catalytic substrates with specific lattice parameters. Consequently, methods have been developed to transfer these materials from the growth substrates onto target substrates. These transfer techniques aim to minimize intermediate steps and minimize defects introduced into the 2D material during the process. This review focuses on the transfer techniques directly from the development substrates of 2D materials, which play a crucial role in their utilization.
The following article is
Open access
Emerging strategies for moiré systems: new knobs, dimensions, and materials
T Huynh
et al
2026
2D Mater.
13
022002
View article
, Emerging strategies for moiré systems: new knobs, dimensions, and materials
PDF
, Emerging strategies for moiré systems: new knobs, dimensions, and materials
Moiré superlattices in twisted van der Waals (vdW) heterostructures have motivated enormous interest by enabling the realization of novel quantum phases of matter such as unconventional superconductivity and new topological orders. Despite the rapid advances, moiré systems have largely remained constrained by the limited control over the moiré twist angle and reproducibility of fabricated devices. This obscures the microscopic origin of these quantum states and the development of scalable moiré-based technologies. In this Review, we explore the recently emerging strategies to address this challenge by developing novel control knobs to deterministically tune twist angles with ultra-high precision beyond the traditional ‘tear-and-stack’ approach. Next, we discuss the recent expansion of moiré engineering towards higher- and mixed-dimensional systems as well as non-vdW materials. These latter systems establish a robust platform to explore a new moiré phase space and gain new insights into the rich phenomenology of quantum states observed in conventional vdW moiré systems. Finally, we conclude with an outlook and future pathways towards scalable and highly uniform moiré platforms, particularly for their viable integration into next-generation technologies.
The following article is
Open access
theory for two-dimensional transition metal dichalcogenide semiconductors
Andor Kormányos
et al
2015
2D Mater.
022001
View article
, k·p theory for two-dimensional transition metal dichalcogenide semiconductors
PDF
, k·p theory for two-dimensional transition metal dichalcogenide semiconductors
We present
Hamiltonians parametrized by
ab initio
density functional theory calculations to describe the dispersion of the valence and conduction bands at their extrema (the
, and
points of the hexagonal Brillouin zone) in atomic crystals of semiconducting monolayer transition metal dichalcogenides (TMDCs). We discuss the parametrization of the essential parts of the
Hamiltonians for MoS
, MoSe
, MoTe
, WS
, WSe
, and WTe
, including the spin-splitting and spin-polarization of the bands, and we briefly review the vibrational properties of these materials. We then use
theory to analyse optical transitions in two-dimensional TMDCs over a broad spectral range that covers the Van Hove singularities in the band structure (the
points). We also discuss the visualization of scanning tunnelling microscopy maps.
The following article is
Open access
Electrical characterization of 2D materials-based field-effect transistors
Sekhar Babu Mitta
et al
2021
2D Mater.
012002
View article
, Electrical characterization of 2D materials-based field-effect transistors
PDF
, Electrical characterization of 2D materials-based field-effect transistors
Two-dimensional (2D) materials hold great promise for future nanoelectronics as conventional semiconductor technologies face serious limitations in performance and power dissipation for future technology nodes. The atomic thinness of 2D materials enables highly scaled field-effect transistors (FETs) with reduced short-channel effects while maintaining high carrier mobility, essential for high-performance, low-voltage device operations. The richness of their electronic band structure opens up the possibility of using these materials in novel electronic and optoelectronic devices. These applications are strongly dependent on the electrical properties of 2D materials-based FETs. Thus, accurate characterization of important properties such as conductivity, carrier density, mobility, contact resistance, interface trap density, etc is vital for progress in the field. However, electrical characterization methods for 2D devices, particularly FET-related measurement techniques, must be revisited since conventional characterization methods for bulk semiconductor materials often fail in the limit of ultrathin 2D materials. In this paper, we review the common electrical characterization techniques for 2D FETs and the related issues arising from adapting the techniques for use on 2D materials.
The following article is
Open access
Recent progress of the Computational 2D Materials Database (C2DB)
Morten Niklas Gjerding
et al
2021
2D Mater.
044002
View article
, Recent progress of the Computational 2D Materials Database (C2DB)
PDF
, Recent progress of the Computational 2D Materials Database (C2DB)
The Computational 2D Materials Database (C2DB) is a highly curated open database organising a wealth of computed properties for more than 4000 atomically thin two-dimensional (2D) materials. Here we report on new materials and properties that were added to the database since its first release in 2018. The set of new materials comprise several hundred monolayers exfoliated from experimentally known layered bulk materials, (homo)bilayers in various stacking configurations, native point defects in semiconducting monolayers, and chalcogen/halogen Janus monolayers. The new properties include exfoliation energies, Bader charges, spontaneous polarisations, Born charges, infrared polarisabilities, piezoelectric tensors, band topology invariants, exchange couplings, Raman spectra and second harmonic generation spectra. We also describe refinements of the employed material classification schemes, upgrades of the computational methodologies used for property evaluations, as well as significant enhancements of the data documentation and provenance. Finally, we explore the performance of Gaussian process-based regression for efficient prediction of mechanical and electronic materials properties. The combination of open access, detailed documentation, and extremely rich materials property data sets make the C2DB a unique resource that will advance the science of atomically thin materials.
The following article is
Open access
Roadmap on quantum magnetic materials
Antonija Grubišić-Čabo
et al
2025
2D Mater.
12
031501
View article
, Roadmap on quantum magnetic materials
PDF
, Roadmap on quantum magnetic materials
Fundamental research on two-dimensional (2D) magnetic systems based on van der Waals materials has been rapidly gaining traction since their recent discovery. With the increase of recent knowledge, it has become clear that such materials have also a strong potential for applications in devices that combine magnetism with electronics, optics, and nanomechanics. Nonetheless, many challenges still lay ahead. Several fundamental aspects of 2D magnetic materials are still unknown or poorly understood, such as their often-complicated electronic structure, optical properties, magnetization dynamics, and magnon spectrum. To elucidate their properties and facilitate integration in devices, advanced characterization techniques and theoretical frameworks need to be developed or adapted. Moreover, developing synthesis methods which increase critical temperatures and achieve large-scale, high-quality homogeneous thin films is crucial before these materials can be used for real-world applications. Therefore, the field of 2D magnetic materials provides many challenges and opportunities for the discovery and exploration of new phenomena, as well as the development of new applications. This Roadmap presents the background, challenges, and potential research directions across key topics in the field, including fundamentals, synthesis, characterization, and applications. We hope that this work can provide a strong starting point for young researchers in the field and provide a general overview of the key challenges for more experienced researchers.
figure placeholder
The following article is
Open access
Defect engineering of two-dimensional transition metal dichalcogenides
Zhong Lin
et al
2016
2D Mater.
022002
View article
, Defect engineering of two-dimensional transition metal dichalcogenides
PDF
, Defect engineering of two-dimensional transition metal dichalcogenides
Two-dimensional transition metal dichalcogenides (TMDs), an emerging family of layered materials, have provided researchers a fertile ground for harvesting fundamental science and emergent applications. TMDs can contain a number of different structural defects in their crystal lattices which significantly alter their physico-chemical properties. Having structural defects can be either detrimental or beneficial, depending on the targeted application. Therefore, a comprehensive understanding of structural defects is required. Here we review different defects in semiconducting TMDs by summarizing: (i
the dimensionalities and atomic structures of defects; (ii) the pathways to generating structural defects during and after synthesis and, (iii
the effects of having defects on the physico-chemical properties and applications of TMDs. Thus far, significant progress has been made, although we are probably still witnessing the tip of the iceberg. A better understanding and control of defects is important in order to move forward the field of Defect Engineering in TMDs. Finally, we also provide our perspective on the challenges and opportunities in this emerging field.
The following article is
Open access
Ferroelectric
-In
Se
under pressure: reversible and irreversible phase transitions
Nada Alghofaili
et al
2026
2D Mater.
13
025025
View article
, Ferroelectric α-In Se under pressure: reversible and irreversible phase transitions
PDF
, Ferroelectric α-In Se under pressure: reversible and irreversible phase transitions
Ferroelectrics are important in many technological applications, from sensors and actuators to memory and fast-switching devices. The key to their versatility lies in the coupling between their electrical and mechanical properties, which can be controlled reversibly under different external conditions. Here, we report the effects of hydrostatic pressure on structural and ferroelectric phase transitions in the van der Waals material indium selenide
-In
Se
, as probed by Raman spectroscopy and imaging in a high-pressure diamond anvil cell. We demonstrate that 2H-
-In
Se
has a stronger ferroelectric phase stability than that reported in other polytype phases of polycrystalline In
Se
. Furthermore, we show that disorder is a key factor in the reversibility of the phase transition from ferroelectric 2H-
-In
Se
to paraelectric
-In
Se
The following article is
Open access
Theory of in-plane-magnetic-field-dependent excitonic spectra in atomically thin semiconductors
Michiel Snoeken
et al
2026
2D Mater.
13
025024
View article
, Theory of in-plane-magnetic-field-dependent excitonic spectra in atomically thin semiconductors
PDF
, Theory of in-plane-magnetic-field-dependent excitonic spectra in atomically thin semiconductors
The linear absorption spectrum of excitons in transition metal dichalcogenides monolayers under the influence of an in-plane magnetic field is theoretically studied. We demonstrate that in-plane magnetic fields induce a hybridization between spin-bright and spin-dark exciton transitions, resulting in a brightening of spin-dark excitons. We analytically investigate spectral features including resonance energy shifts, broadening and amplitudes ratios. In particular, for a MoSe
monolayer with linewidths dominated by reradiation, we find a complex interplay of dark-bright splitting and linewidth difference of both involved spin-bright and spin-dark excitons.
Incommensurate Moiré stacking and Landau quantization without external magnetic field in turbostratic graphene
Mona Garg
et al
2026
2D Mater.
13
025023
View article
, Incommensurate Moiré stacking and Landau quantization without external magnetic field in turbostratic graphene
PDF
, Incommensurate Moiré stacking and Landau quantization without external magnetic field in turbostratic graphene
Turbostratic multilayer graphene, composed of randomly twisted and stacked graphene sheets, offers a naturally disordered yet tunable platform for exploring moiré physics beyond tedious artificial stacking. Using scanning tunneling microscopy/spectroscopy and Raman analysis, we uncover a wide distribution of twist angles and stacking configurations spontaneously formed across large-area turbostratic films. In several regions, we identify overlapping incommensurate moiré patterns consistent with locally chiral trilayer stacking. We observe van Hove singularities and reconstructed Dirac-like spectra whose angle dependence supports strong interlayer electronic coherence. In the highly strained trilayered regions, we observe peaks in the local density-of-states with characteristic scaling of the quantized Landau levels strikingly even in the absence of a magnetic field. They arise from the strain-induced pseudo-magnetic fields (∼26 T), making turbostratic graphene a single natural platform to explore the physics of moiré structures as well as of the pseudo-electromagnetic fields.
Graphene inversion layer for enhanced photoresponse in layered two-dimensional materials-silicon Schottky diodes
Muhammad Malik
et al
2026
2D Mater.
13
025022
View article
, Graphene inversion layer for enhanced photoresponse in layered two-dimensional materials-silicon Schottky diodes
PDF
, Graphene inversion layer for enhanced photoresponse in layered two-dimensional materials-silicon Schottky diodes
Efficient conversion of photocarriers to electrical signal, prior to energy loss into the substrate, is essential for energy-efficient photodetection. However, carrier recombinations and thermal losses often limit the photoresponse and speed of the photodetection in these systems. In this work, we employed a van der Waals integration strategy to improve the photoresponse in layered 2D system-silicon junctions. We used
-doped graphene as an inversion layer in Schottky junctions of layered 2D materials on
-Si. This leads to increase in the Schottky barrier height and built-in interfacial electric field, suppressing dark current by two orders of magnitude and enhanced photoresponse up to 300%. We investigated this improvement in two different layered 2D systems, macroscopically-assembled graphene and MXene (Ti
) on silicon. This simple interfacial engineering strategy is CMOS-compatible and can be adapted to other layered 2D/3D hybrid systems, providing a universal strategy with broader implications in energy-efficient optoelectronics.
Evolution of electronic Y-branch junctions: from semiconductor heterostructures to 2D materials
Nayyar Abbas Shah
et al
2026
2D Mater.
13
022003
View article
, Evolution of electronic Y-branch junctions: from semiconductor heterostructures to 2D materials
PDF
, Evolution of electronic Y-branch junctions: from semiconductor heterostructures to 2D materials
Branch waveguides are essential elements in modern technologies that demand precise manipulation of electrical and optical signals to realize compact, efficient, and high-performance systems. They underpin applications such as passive optical networks and quantum key distribution. Among these, Y-branch junctions (YBJs), where one input channel divides into multiple output branches, serve as fundamental building blocks for directing and controlling signal flow. The rapid development of two-dimensional materials has opened new avenues for creating planar electronic waveguides that emulate fiber-optic functionality while enabling miniaturized optoelectronic switching. This review traces the evolution of YBJs from classical semiconductor architectures to atomically thin platforms, with emphasis on graphene-based implementations. It provides a comparative assessment of representative device concepts, including splitters, interferometers, and logic gates, summarizes theoretical progress and experimental demonstrations, and concludes with a perspective on key challenges and opportunities for future research in nanoscale signal control.
Evolution of electronic Y-branch junctions: from semiconductor heterostructures to 2D materials
Nayyar Abbas Shah
et al
2026
2D Mater.
13
022003
View article
, Evolution of electronic Y-branch junctions: from semiconductor heterostructures to 2D materials
PDF
, Evolution of electronic Y-branch junctions: from semiconductor heterostructures to 2D materials
Branch waveguides are essential elements in modern technologies that demand precise manipulation of electrical and optical signals to realize compact, efficient, and high-performance systems. They underpin applications such as passive optical networks and quantum key distribution. Among these, Y-branch junctions (YBJs), where one input channel divides into multiple output branches, serve as fundamental building blocks for directing and controlling signal flow. The rapid development of two-dimensional materials has opened new avenues for creating planar electronic waveguides that emulate fiber-optic functionality while enabling miniaturized optoelectronic switching. This review traces the evolution of YBJs from classical semiconductor architectures to atomically thin platforms, with emphasis on graphene-based implementations. It provides a comparative assessment of representative device concepts, including splitters, interferometers, and logic gates, summarizes theoretical progress and experimental demonstrations, and concludes with a perspective on key challenges and opportunities for future research in nanoscale signal control.
The following article is
Open access
Emerging strategies for moiré systems: new knobs, dimensions, and materials
T Huynh
et al
2026
2D Mater.
13
022002
View article
, Emerging strategies for moiré systems: new knobs, dimensions, and materials
PDF
, Emerging strategies for moiré systems: new knobs, dimensions, and materials
Moiré superlattices in twisted van der Waals (vdW) heterostructures have motivated enormous interest by enabling the realization of novel quantum phases of matter such as unconventional superconductivity and new topological orders. Despite the rapid advances, moiré systems have largely remained constrained by the limited control over the moiré twist angle and reproducibility of fabricated devices. This obscures the microscopic origin of these quantum states and the development of scalable moiré-based technologies. In this Review, we explore the recently emerging strategies to address this challenge by developing novel control knobs to deterministically tune twist angles with ultra-high precision beyond the traditional ‘tear-and-stack’ approach. Next, we discuss the recent expansion of moiré engineering towards higher- and mixed-dimensional systems as well as non-vdW materials. These latter systems establish a robust platform to explore a new moiré phase space and gain new insights into the rich phenomenology of quantum states observed in conventional vdW moiré systems. Finally, we conclude with an outlook and future pathways towards scalable and highly uniform moiré platforms, particularly for their viable integration into next-generation technologies.
The following article is
Open access
The 2D materials roadmap
Wencai Ren
et al
2026
2D Mater.
13
021501
View article
, The 2D materials roadmap
PDF
, The 2D materials roadmap
Over the past two decades, two-dimensional (2D) materials have rapidly evolved into a diverse and expanding family of material platforms. Many members of this materials class have demonstrated their potential to deliver transformative impact on fundamental research and technological applications across different fields. In this roadmap, we provide an overview of the key aspects of 2D material research and development, spanning synthesis, properties and commercial applications. We specifically present roadmaps for high impact 2D materials, including graphene and its derivatives, transition metal dichalcogenides, MXenes as well as their heterostructures and moiré systems. The discussions are organized into thematic sections covering emerging research areas (e.g. twisted electronics, moiré nano-optoelectronics, polaritronics, quantum photonics, and neuromorphic computing), breakthrough applications in key technologies (e.g. 2D transistors, energy storage, electrocatalysis, filtration and separation, thermal management, flexible electronics, sensing, electromagnetic interference shielding, and composites) and other important topics (computational discovery of novel materials, commercialization and standardization). This roadmap focuses on the current research landscape, future challenges and scientific and technological advances required to address, with the intent to provide useful references for promoting the development of 2D materials.
figure placeholder
Controlled growth and emergent properties of 2D high-entropy materials
Mengchen Wang
et al
2026
2D Mater.
13
022001
View article
, Controlled growth and emergent properties of 2D high-entropy materials
PDF
, Controlled growth and emergent properties of 2D high-entropy materials
Combining the rich chemical compositions of high-entropy materials (HEMs) with the quantum confinement effects of two-dimensional (2D) structures, 2D HEMs have emerged as a pivotal class of materials. The significance of synthesizing 2D HEMs lies in overcoming the driving force for phase separation while simultaneously maintaining the structural integrity and atomic flatness characteristic of 2D structures. This review categorizes recent progress in synthesizing 2D HEMs through thermodynamic, kinetic and their synergistic control, implemented by tuning critical preparation parameters and reaction conditions. We further summarize the mechanism of these parameters in modulating surface adsorption-desorption and reducing the energy barriers for atomic migration. Furthermore, we conclude the novel properties encompassing catalysis, energy storage, and physical properties. Finally, we outline a paradigm shift for the rational design of 2D HEMs with tailored functionalities, opening up fresh perspectives for future research on 2D HEMs.
Two-dimensional ferroelectric materials and their applications
Ateeb Naseer
et al
2026
2D Mater.
13
012004
View article
, Two-dimensional ferroelectric materials and their applications
PDF
, Two-dimensional ferroelectric materials and their applications
Ferroelectric materials are essential for advancing energy-efficient, high-speed field-effect transistors and high-density, nonvolatile memory technologies. However, as the demand for miniaturization increases, bulk ferroelectric materials face significant challenges owing to the reduction or loss of ferroelectric polarization due to enhanced depolarization fields at reduced thicknesses. This has shifted the research focus toward low-dimensional materials, particularly two-dimensional (2D) ferroelectrics, which offer promising solutions. 2D ferroelectric materials are atomically thin crystalline materials, typically consisting of a single layer or a few atomic layers, exhibiting spontaneous and switchable electric polarization. This polarization can arise either from ionic displacement or from interlayer sliding and can be altered by applying an external electric field. Recent theoretical and experimental research has uncovered a broad spectrum of 2D ferroelectric materials with substantial potential for advancing next-generation ferroelectric technology. Here, we present a comprehensive overview of the latest developments in the field of 2D ferroelectric materials, emphasizing their applications in cutting-edge technologies. Our review highlights the immense potential of 2D ferroelectric materials for enabling ultra-scaled logic, memory, and optoelectronic devices tailored for specific applications.
The following article is
Open access
Magnetism of TbPc
on ferromagnetic iron oxide surface
Giaconi et al
View accepted manuscript
, Magnetism of TbPc2 on ferromagnetic iron oxide surface
PDF
, Magnetism of TbPc2 on ferromagnetic iron oxide surface
Thin inorganic films, such as metal oxides, are frequently employed as functional materials for decoupling or optimisation of the interaction between molecular magnetic layers and metallic surfaces. In the case of single-molecule magnet (SMM) deposits, an effective decoupling layer can reduce the hybridisation with the metallic substrate, which would otherwise suppress their intrinsic magnetic bistability. In this work, we investigate the potential of an ultra-thin Fe oxide layer as a substrate for the terbium(III) bis-phthalocyaninato (TbPc
) SMM in technological platforms. A multi-technique approach was employed to evaluate the integrity of a TbPc
sub-monolayer deposit and to determine the molecular adsorption geometry at the surface. Furthermore, large-scale facilities experiments were performed, and X-ray magnetic circular dichroism was used to probe the magnetic properties of the TbPc
sub-monolayer. Similar to what is observed on metallic surfaces, a suppression of the slow relaxation mechanisms in TbPc
is detected. The central finding is that while the magnetic moments and electronic configuration of the molecule are preserved, the characteristic slow magnetic relaxation is suppressed. This highlights the critical role of substrate phonon stiffness and tunnel barrier thickness in stabilizing the SMM behavior.
In-plane polarization induced ferroelectrovalley in a two-dimensional rare-earth halide
Bhardwaj et al
View accepted manuscript
, In-plane polarization induced ferroelectrovalley in a two-dimensional rare-earth halide
PDF
, In-plane polarization induced ferroelectrovalley in a two-dimensional rare-earth halide
We propose a mechanism where the valley splitting is caused by an in-plane polarization and is therefore coupled with it, making it possible to control the valley degree of freedom electrically. We show, by first-principles calculations, that the Eu
GdCl
monolayer exhibits an in-plane polarization coupled with a spontaneous valley splitting. Thus, unlike the conventional magnetic field switching of the valley degree of freedom, the valley polarization can be switched by an external electric field. We show that a similar ferroelectric-ferrovalley (FE-FV) coupling is also seen in the previously reported ferroelectric (CrBr
Li monolayer.
Advances in Direct CVD Growth of Twisted Two-Dimensional Materials
Liang et al
View accepted manuscript
, Advances in Direct CVD Growth of Twisted Two-Dimensional Materials
PDF
, Advances in Direct CVD Growth of Twisted Two-Dimensional Materials
Twisted two-dimensional (2D) materials, formed by stacking two monolayers with specific angles, exhibit a series of strongly correlated quantum phenomena, such as unconventional superconductivity, Wigner crystal and Mott-like insulating behavior owing to the electron flat band structure. This provides a new and controllable research platform for studying novel coupled electronic states by constructing artificial moiré superlattices. Utilizing moiré superlattices to modulate the band structure and introduce electron correlation facilitate the understanding of strongly correlated phenomena. Large-scale fabrication of twisted two-dimensional materials is the essential prerequisite for the application of these unique properties. Direct growth by chemical vapor deposition (CVD) is a promising approach for scalable fabrication of twisted 2D materials. However, it remains in its nascent stage as there are still challenges in achieving large size and precise twist angle in the CVD growth. In this review, we systematically summarize recent advances in CVD growth of twisted 2D materials. We offer a comprehensive overview of growth mechanism, modulation of growth conditions, technical advantages and limitations of the CVD synthetic strategy. This review further investigates the prospects for the development of twisted multilayer 2D materials,as well as the new changes brought about by artificial intelligence in this field.. This work will offer novel perspectives and inspiration for advanced research on twisted 2D materials, especially in the field of the fundamental research and device applications.
Colossal zero-field Nernst effect in topological pentagonal PB
Nuñez et al
View accepted manuscript
, Colossal zero-field Nernst effect in topological pentagonal PB2
PDF
, Colossal zero-field Nernst effect in topological pentagonal PB2
The generation of thermoelectric energy based on the anomalous Nernst effect is of great interest because of its flexibility, simplicity, and low production cost. This phenomenon has been widely studied in ferromagnetic metals, where a large Berry curvature has been associated with pronounced Nernst and anomalous Hall responses. Based on first-principles calculations, we evaluated the anomalous Hall and Nernst conductivities in a two-dimensional monolayer of PB
with a pentagonal pattern. We find that this material, a metal exhibiting p-orbital ferromagnetism, displays intense peaks in the Berry curvature arising from avoided band crossings near the Fermi level, leading to a strong anomalous Nernst response. Additionally, we demonstrate that under biaxial tensile strain, the avoided crossings are shifted closer to the Fermi level, giving rise to a colossal Nernst response at room temperature, which is significantly higher than the values found for most known materials. Specifically, a biaxial tensile strain of 2% allows a maximum Nernst coefficient of 23.9 µV/K at T = 300 K. A higher strain of 3.5% induces an even greater response of 39.41 µV/K at T = 100 K. These results indicate an avenue to engineering the thermoelectric response in monolayer penta-PB
through moderate mechanical strain.
Wafer-scale 2D materials: from single-crystalline epitaxy to artificial stacking
Ji et al
View accepted manuscript
, Wafer-scale 2D materials: from single-crystalline epitaxy to artificial stacking
PDF
, Wafer-scale 2D materials: from single-crystalline epitaxy to artificial stacking
Two-dimensional (2D) van der Waals (vdW) materials constitute a unique class of layered crystals in which adjacent layers are bonded through weak vdW interactions. Their orientation, stacking sequence, and twist angle can be precisely engineered, enabling atomic-level modulation of electronic structures and interfacial properties. This structural tunability has led to the discovery of diverse emergent phenomena in stacking, twisting, and heterointegration. Yet most of these findings rely on atomically defined local configurations, and extending such deterministic arrangements to wafer-scale level remains a central challenge for practical implementation. Recent years have witnessed major progress in the wafer-scale growth of single-crystalline vdW materials. Advances in symmetry-guided epitaxy, step-edge mediation, and interfacial engineering have elucidated how orientational selection, nucleation barriers, and seamless coalescence arise from substrate–film coupling. Meanwhile, stacking and twisting technologies have made notable progress in scalability and interfacial cleanliness, now enabling the assembly of large-area, deterministic vdW architectures. This Review provides a unified overview of the growth and stacking strategies that enable scalable deterministic atomic arrangements in vdW materials. Emphasis is placed on the correlations between structural configuration, interfacial characteristics, and functional performance in both homostructure stacking and lateral or vertical heterostructure fabrication. Finally, we highlight emerging directions—low-temperature epitaxy on non-epitaxial substrates, deterministic twist control for wafer-scale uniformity, and metrology connecting atomic order to device performance—toward rationally engineered, large-area vdW architectures.
More Accepted manuscripts
Trending on Altmetric
Isolation and characterization of few-layer black phosphorus
Andres Castellanos-Gomez
et al
2014
2D Mater.
025001
View article
, Isolation and characterization of few-layer black phosphorus
PDF
, Isolation and characterization of few-layer black phosphorus
Isolation and characterization of mechanically exfoliated black phosphorus flakes with a thickness down to two single-layers is presented. A modification of the mechanical exfoliation method, which provides higher yield of atomically thin flakes than conventional mechanical exfoliation, has been developed. We present general guidelines to determine the number of layers using optical microscopy, Raman spectroscopy and transmission electron microscopy (TEM) in a fast and reliable way. Moreover, we demonstrate that the exfoliated flakes are highly crystalline and that they are stable even in free-standing form through Raman spectroscopy and TEM measurements. A strong thickness dependence of the band structure is found by density functional theory (DFT) calculations. The exciton binding energy, within an effective mass approximation, is also calculated for different number of layers. Our computational results for the optical gap are consistent with preliminary photoluminescence results on thin flakes. Finally, we study the environmental stability of black phosphorus flakes finding that the flakes are very hydrophilic and that long term exposure to air moisture etches black phosphorus away. Nonetheless, we demonstrate that the aging of the flakes is slow enough to allow fabrication of field-effect transistors with strong ambipolar behavior. DFT calculations also give us insight into the water-induced changes of the structural and electronic properties of black phosphorus.
The following article is
Open access
The Computational 2D Materials Database: high-throughput modeling and discovery of atomically thin crystals
Sten Haastrup
et al
2018
2D Mater.
042002
View article
, The Computational 2D Materials Database: high-throughput modeling and discovery of atomically thin crystals
PDF
, The Computational 2D Materials Database: high-throughput modeling and discovery of atomically thin crystals
We introduce the Computational 2D Materials Database (C2DB), which organises a variety of structural, thermodynamic, elastic, electronic, magnetic, and optical properties of around 1500 two-dimensional materials distributed over more than 30 different crystal structures. Material properties are systematically calculated by state-of-the-art density functional theory and many-body perturbation theory (
and the Bethe–Salpeter equation for  ∼250 materials) following a semi-automated workflow for maximal consistency and transparency. The C2DB is fully open and can be browsed online (
) or downloaded in its entirety. In this paper, we describe the workflow behind the database, present an overview of the properties and materials currently available, and explore trends and correlations in the data. Moreover, we identify a large number of new potentially synthesisable 2D materials with interesting properties targeting applications within spintronics, (opto-)electronics, and plasmonics. The C2DB offers a comprehensive and easily accessible overview of the rapidly expanding family of 2D materials and forms an ideal platform for computational modeling and design of new 2D materials and van der Waals heterostructures.
The following article is
Open access
Recent progress of the Computational 2D Materials Database (C2DB)
Morten Niklas Gjerding
et al
2021
2D Mater.
044002
View article
, Recent progress of the Computational 2D Materials Database (C2DB)
PDF
, Recent progress of the Computational 2D Materials Database (C2DB)
The Computational 2D Materials Database (C2DB) is a highly curated open database organising a wealth of computed properties for more than 4000 atomically thin two-dimensional (2D) materials. Here we report on new materials and properties that were added to the database since its first release in 2018. The set of new materials comprise several hundred monolayers exfoliated from experimentally known layered bulk materials, (homo)bilayers in various stacking configurations, native point defects in semiconducting monolayers, and chalcogen/halogen Janus monolayers. The new properties include exfoliation energies, Bader charges, spontaneous polarisations, Born charges, infrared polarisabilities, piezoelectric tensors, band topology invariants, exchange couplings, Raman spectra and second harmonic generation spectra. We also describe refinements of the employed material classification schemes, upgrades of the computational methodologies used for property evaluations, as well as significant enhancements of the data documentation and provenance. Finally, we explore the performance of Gaussian process-based regression for efficient prediction of mechanical and electronic materials properties. The combination of open access, detailed documentation, and extremely rich materials property data sets make the C2DB a unique resource that will advance the science of atomically thin materials.
The following article is
Open access
theory for two-dimensional transition metal dichalcogenide semiconductors
Andor Kormányos
et al
2015
2D Mater.
022001
View article
, k·p theory for two-dimensional transition metal dichalcogenide semiconductors
PDF
, k·p theory for two-dimensional transition metal dichalcogenide semiconductors
We present
Hamiltonians parametrized by
ab initio
density functional theory calculations to describe the dispersion of the valence and conduction bands at their extrema (the
, and
points of the hexagonal Brillouin zone) in atomic crystals of semiconducting monolayer transition metal dichalcogenides (TMDCs). We discuss the parametrization of the essential parts of the
Hamiltonians for MoS
, MoSe
, MoTe
, WS
, WSe
, and WTe
, including the spin-splitting and spin-polarization of the bands, and we briefly review the vibrational properties of these materials. We then use
theory to analyse optical transitions in two-dimensional TMDCs over a broad spectral range that covers the Van Hove singularities in the band structure (the
points). We also discuss the visualization of scanning tunnelling microscopy maps.
Superior structural, elastic and electronic properties of 2D titanium nitride MXenes over carbide MXenes: a comprehensive first principles study
Ning Zhang
et al
2018
2D Mater.
045004
View article
, Superior structural, elastic and electronic properties of 2D titanium nitride MXenes over carbide MXenes: a comprehensive first principles study
PDF
, Superior structural, elastic and electronic properties of 2D titanium nitride MXenes over carbide MXenes: a comprehensive first principles study
The structural, elastic and electronic properties of two-dimensional (2D) titanium carbide/nitride based pristine (Ti
n+1
/Ti
n+1
) and functionalized MXenes (Ti
n+1
/Ti
n+1
, T stands for the terminal groups: –F, –O and –OH, n  =  1, 2, 3) are investigated by density functional theory calculations. Carbide-based MXenes possess larger lattice constants and monolayer thicknesses than nitride-based MXenes. The in-plane Young’s moduli of Ti
n+1
are larger than those of Ti
n+1
, whereas in both systems they decrease with the increase of the monolayer thickness. Cohesive energy calculations indicate that MXenes with a larger monolayer thickness have a better structural stability. Adsorption energy calculations imply that Ti
n+1
have stronger preference to adhere to the terminal groups, which suggests more active surfaces for nitride-based MXenes. More importantly, nearly free electron states are observed to exist outside the surfaces of –OH functionalized carbide/nitride based MXenes, especially in Ti
n+1
(OH)
, which provide almost perfect transmission channels without nuclear scattering for electron transport. The overall electrical conductivity of nitride-based MXenes is determined to be higher than that of carbide-based MXenes. The exceptional properties of titanium nitride-based MXenes, including strong surface adsorption, high elastic constant and Young’s modulus, and good metallic conductivity, make them promising materials for catalysis and energy storage applications.
The following article is
Open access
Transfer of large-scale two-dimensional semiconductors: challenges and developments
Adam J Watson
et al
2021
2D Mater.
032001
View article
, Transfer of large-scale two-dimensional semiconductors: challenges and developments
PDF
, Transfer of large-scale two-dimensional semiconductors: challenges and developments
Two-dimensional (2D) materials offer opportunities to explore both fundamental science and applications in the limit of atomic thickness. Beyond the prototypical case of graphene, other 2D materials have recently come to the fore. Of particular technological interest are 2D semiconductors, of which the family of materials known as the group-VI transition metal dichalcogenides (TMDs) has attracted much attention. The presence of a bandgap allows for the fabrication of high on–off ratio transistors and optoelectronic devices, as well as valley/spin polarized transport. The technique of chemical vapor deposition (CVD) has produced high-quality and contiguous wafer-scale 2D films, however, they often need to be transferred to arbitrary substrates for further investigation. In this review, the various transfer techniques developed for transferring 2D films will be outlined and compared, with particular emphasis given to CVD-grown TMDs. Each technique suffers undesirable process-related drawbacks such as bubbles, residue or wrinkles, which can degrade device performance by for instance reducing electron mobility. This review aims to address these problems and provide a systematic overview of key methods to characterize and improve the quality of the transferred films and heterostructures. With the maturing technological status of CVD-grown 2D materials, a robust transfer toolbox is vital.
On the origin of magnetic anisotropy in two dimensional CrI
J L Lado and J Fernández-Rossier 2017
2D Mater.
035002
View article
, On the origin of magnetic anisotropy in two dimensional CrI3
PDF
, On the origin of magnetic anisotropy in two dimensional CrI3
The observation of ferromagnetic order in a monolayer of CrI
has been recently reported, with a Curie temperature of 45 K and off-plane easy axis. Here we study the origin of magnetic anisotropy, a necessary ingredient to have magnetic order in two dimensions, combining two levels of modeling, density functional calculations and spin model Hamiltonians. We find two different contributions to the magnetic anisotropy of the material, favoring off-plane magnetization and opening a gap in the spin wave spectrum. First, ferromagnetic super-exchange across the ≃90 degree Cr–I–Cr bonds, are anisotropic, due to the spin–orbit interaction of the ligand I atoms. Second, a much smaller contribution that comes from the single ion anisotropy of the
=  3/2 Cr atom. Our results permit to establish the XXZ Hamiltonian, with a very small single ion anisotropy, as the adequate spin model for this system. Using spin wave theory we estimate the Curie temperature and we highlight the essential role played by the gap that magnetic anisotropy induces on the magnon spectrum.
Environmental instability of few-layer black phosphorus
Joshua O Island
et al
2015
2D Mater.
011002
View article
, Environmental instability of few-layer black phosphorus
PDF
, Environmental instability of few-layer black phosphorus
We study the environmental instability of mechanically exfoliated few-layer black phosphorus (BP). From continuous measurements of flake topography over several days, we observe an increase of over 200% in volume due to the condensation of moisture from air. We find that long term exposure to ambient conditions results in a layer-by-layer etching process of BP flakes. Interestingly, flakes can be etched down to single layer (phosphorene) thicknesses. BPʼs strong affinity for water greatly modifies the performance of fabricated field-effect transistors (FETs) measured in ambient conditions. Upon exposure to air, we differentiate between two timescales for changes in BP FET transfer characteristics: a short timescale (minutes) in which a shift in the threshold voltage occurs due to physisorbed oxygen and nitrogen, and a long timescale (hours) in which strong p-type doping occurs from water absorption. Continuous measurements of BP FETs in air reveal eventual degradation and break-down of the channel material after several days due to the layer-by-layer etching process.
The following article is
Open access
Defect engineering of two-dimensional transition metal dichalcogenides
Zhong Lin
et al
2016
2D Mater.
022002
View article
, Defect engineering of two-dimensional transition metal dichalcogenides
PDF
, Defect engineering of two-dimensional transition metal dichalcogenides
Two-dimensional transition metal dichalcogenides (TMDs), an emerging family of layered materials, have provided researchers a fertile ground for harvesting fundamental science and emergent applications. TMDs can contain a number of different structural defects in their crystal lattices which significantly alter their physico-chemical properties. Having structural defects can be either detrimental or beneficial, depending on the targeted application. Therefore, a comprehensive understanding of structural defects is required. Here we review different defects in semiconducting TMDs by summarizing: (i
the dimensionalities and atomic structures of defects; (ii) the pathways to generating structural defects during and after synthesis and, (iii
the effects of having defects on the physico-chemical properties and applications of TMDs. Thus far, significant progress has been made, although we are probably still witnessing the tip of the iceberg. A better understanding and control of defects is important in order to move forward the field of Defect Engineering in TMDs. Finally, we also provide our perspective on the challenges and opportunities in this emerging field.
Deterministic transfer of two-dimensional materials by all-dry viscoelastic stamping
Andres Castellanos-Gomez
et al
2014
2D Mater.
011002
View article
, Deterministic transfer of two-dimensional materials by all-dry viscoelastic stamping
PDF
, Deterministic transfer of two-dimensional materials by all-dry viscoelastic stamping
The deterministic transfer of two-dimensional crystals constitutes a crucial step towards the fabrication of heterostructures based on the artificial stacking of two-dimensional materials. Moreover, controlling the positioning of two-dimensional crystals facilitates their integration in complex devices, which enables the exploration of novel applications and the discovery of new phenomena in these materials. To date, deterministic transfer methods rely on the use of sacrificial polymer layers and wet chemistry to some extent. Here, we develop an all-dry transfer method that relies on viscoelastic stamps and does not employ any wet chemistry step. This is found to be very advantageous to freely suspend these materials as there are no capillary forces involved in the process. Moreover, the whole fabrication process is quick, efficient, clean and it can be performed with high yield.
Journal links
Submit an article
About the journal
Editorial Board
Author guidelines
Review for this journal
Publication charges
Awards
Journal collections
Pricing and ordering
Journal information
2014-present
2D Materials
doi: 10.1088/issn.2053-1583
Online ISSN: 2053-1583