Janus single-layer transition metal dichalcogenides, in which the two chalcogen layers have a different chemical nature, push chemical composition control beyond what is usually achievable with van der Waals heterostructures. Here, we report such a Janus compound, SPtSe, which is predicted to exhibit strong Rashba spin–orbit coupling. We synthetized it by conversion of a single-layer of PtSe2 on Pt(111)

Organometallic-halide perovskite solar cells (PSCs) are emerging as the most promising next generation solar cell devices. However, the stability is still the main bottleneck of their further development. Here, we introduce two-dimensional (2D) molybdenum chalcogenides (MoS2 and MoSe2) (MCs) nanoflakes as a buffer layer between perovskite layer and hole transport layer (HTL) to improve the stability

In contrast to the current research on two-dimensional (2D) materials, which is mainly focused on graphene and transition metal dichalcogenide-like structures, studies on 2D transition metal oxides are rare. By using ab initio calculations along with Monte Carlo simulations and nonequilibrium Green’s function method, we demonstrate that the transition metal oxide monolayer (ML) of Cr2O3 is an ideal

The exfoliation of two naturally occurring van der Waals minerals, graphite and molybdenite, arouse an unprecedented level of interest by the scientific community and shaped a whole new field of research: 2D materials research. Several years later, the family of van der Waals materials that can be exfoliated to isolate 2D materials keeps growing, but most of them are synthetic. Interestingly, in nature

Device and material reliability of 2-dimensional materials, especially CVD-grown MoS2, has remained un-addressed since 2011 when the first TMDC transistor was reported. For its potential application in next generation electronics, it is imperative to update our understanding of mechanisms through which MoS2 transistors’ performance degrades under long-term electrical stress. We report, for CVD-grown

Bilayer graphene (BLG) exhibits unique properties depending on a stacking angle between the two layers of graphene. Although it has been known that BLGs having stacking angles of 0° and 30° can be obtained by chemical vapor deposition (CVD), not much is known yet about the effect of copper (Cu) surface on the decision of stacking angle, through which further fine control of the stacking angle could

Due to the population explosion of the 21st century, nearly one billion people are over 64 years of age and bone fracture is one of the most frequent problems facing both sexes because of osteoporosis. However, difficulty in enhancing bone regeneration to repair bone fracture poses challenges and thus, a two-dimensional monolayer material (i.e. tungsten disulfide (WS2)) could be one of the candidates

Adopting black phosphorus (BP) as a material in electronic and optoelectronic device manufacturing requires the development and understanding of a large-scale synthesis technique. To that end, high-energy planetary ball milling is demonstrated as a scalable synthesis route, and the mechanisms and conversion kinetics of the BP phase transformation are investigated. During the milling process, media

Monolayer iron germanium telluride Fe3GeTe2, one of the typical two-dimensional ferromagnetic materials, hitherto, has only been studied by exfoliated micron-sized samples. We achieve high-quality wafer-scale growth of thin Fe3GeTe2 films by molecular beam epitaxy, greatly expanding the types of characterization tools employable and providing the possibility for its integration in devices like consumer

Single-stranded breaks in the DNA backbone caused by many endogenous and exogenous agents often lead to double-stranded breaks that are known causes of chromosomal instabilities leading to copious diseases. We describe a label-free detection technique using two-dimensional (2D) solid-state nanopore field-effect transistors (FETs) to sense and map site-specific nicks in the DNA backbone. We use all-atom

GaN-based semiconductors are promising materials for solid-state optoelectronic applications. However, the strong internal electrostatic field (IEF) along the [0001] direction is a serious problem that harms the efficiency of lighting devices based on GaN-based semiconductors due to the quantum confined Stark effect. Here we theoretically predict a method, reducing the dimensions from bulk to two-dimensional

Theory predicts that two-dimensional (2D) materials may only exist in the presence of out-of-plane deformations on atomic length scales, frequently referred to as ripples. While such ripples can be detected via electron microscopy, their direct observation via surface-based techniques and characterization in terms of interaction forces and energies remain limited, preventing an unambiguous study of

Semiconductors are the basis of many vital technologies such as electronics, computing, communications, optoelectronics, and sensing. Modern semiconductor technology can trace its origins to the invention of the point contact transistor in 1947. This demonstration paved the way for the development of discrete and integrated semiconductor devices and circuits that has helped to build a modern society

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2D semiconductors like Molybdenum disulfide (MoS2) still have issues in forming good metal electrode (Schottky and Ohmic) especially for mono layer (ML) to few layers thick due to strain and metallization issues. Here, we explore a 2D semi-metal, titanium disulfide (TiS2), for making different types of contacts with ML MoS2 using density functional theory (DFT). It is observed that ML TiS2 induces

Graphene/III–V semiconductor van der Waals (vdW) heterostructures offer potential access to physics, functionalities, and superior performance of optoelectronic devices. Nevertheless, the lack of a bandgap in graphene severely restricts the controllability of carrier properties and therefore impedes its applications. Here, we demonstrate the engineering of graphene bandgap in the graphene/GaAs heterostructure

Transverse electric graphene plasmons are generally weakly confined in the direction perpendicular to the graphene plane. They are featured by a skin depth δ, namely the penetration depth of their evanescent fields into the surrounding environment, much larger than the wavelength λ in free space (e.g., δ > 10λ). The weak spatial confinement of transverse electric graphene plasmons is now the key drawback

Photoelectrocatalysts that use sunlight to power the CO2 reduction reaction will be crucial for carbon-neutral power and energy-efficient industrial processes. Scalable photoelectrocatalysts must satisfy a stringent set of criteria, such as stability under operating conditions, product selectivity, and efficient light absorption. Two-dimensional materials can offer high specific surface area, tunability

Two-dimensional metal dichalcogenide/monochalcogenide thin flakes have attracted much attention owing to their remarkable electronic and electrochemical properties; however, chemical instability limits their applications. Chemical vapor transport (CVT)-synthesized SnTiS3 thin flakes exhibit misfit heterojunction structure and are highly stable in ambient conditions, offering a great opportunity to

Cavity-integrated transition metal dichalcogenide (TMDCs) excitons have recently emerged as a promising platform to study strong light–matter interactions and related cavity quantum electrodynamics phenomena. Although this exciton-cavity system is typically modeled as coupled harmonic oscillators, to account for the rich solid-state environment, the effect of exciton–phonon interaction needs to be

Layered semiconductors such as transition metal dichalcogenides (TMDs) offer endless possibilities for designing modern photonic and optoelectronic components. However, their optical engineering is still a challenging task owing to multiple obstacles, including the absence of a rapid, contactless, and the reliable method to obtain their dielectric function as well as to evaluate in situ the changes

Spintronics is expected to be the basis for future ultra-low-energy nanoelectronic devices. To operate such devices at room temperature, amplifiers, batteries, capacitors, as well as spin current sources are required. Here we report a chalcogenide superlattice composed of GeTe and Sb2Te3 layers that have a topologically protected spin diffusion length exceeding 100 μm at room temperature. A spin generator

Graphene doped by lithium atoms supports a strong Dirac plasmon, a weak acoustic plasmon and a strong interband plasmon Li(π + σ). Here we demonstrate that applying a positive or negative bias on the lithium-doped graphene causes the appearance (‘switching ON’) or disappearance (‘switching OFF’) of the Li(π + σ) plasmon and the ‘conversion’ of the Dirac plasmon into a strong acoustic plasmon. This

Spin Orbit Torque Magnetic RAM (SOT-MRAM) is emerging as a promising memory technology owing to its high endurance, reliability and speed. A critical factor for its success is the development of materials that exhibit efficient conversion of charge current to spin current, characterized by their spin Hall efficiency. In this work, it is experimentally demonstrated that the spin Hall efficiency of the

2D materials are attractive for nanoelectronics due to their ultimate thickness dimension and unique physical properties. A wide variety of emerging spintronic device concepts will greatly benefit from the use of 2D materials, leading a better way to manipulating spin. In this review, we discuss various 2D materials, including graphene and other inorganic 2D semiconductors, in the context of scientific

Photo-induced phase transitions (PIPTs) provide an ultrafast, energy-efficient way for precisely manipulating the topological properties of transition-metal ditellurides and can be used to stabilize a topological phase in an otherwise semiconducting material. Using first-principles calculations, we demonstrate that the PIPT in monolayer MoTe2 from the semiconducting 2H phase to the topological 1T′

Despite intensive studies on van der Waals heterostructures based on two-dimensional layered materials, isotype vdW heterojunctions, which consist of two different semiconductors with the same majority carrier, have received little attention. We demonstrate an n–n isotype field-effect heterojunction device composed of multilayer moly ditelluride (MoTe2) and tin disulfide (SnS2). The carrier transport

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have been the subject of sustained research interest due to their extraordinary electronic and optical properties. They also exhibit a wide range of structural phases because of the different orientations that the atoms can have within a single layer, or due to the ways that different layers can stack. Here we report a unique study involving

Two-dimensional materials (2DMs), with remarkably electronic, optical, and mechanical properties, exhibit both high scientific interest and huge application potential. Raman spectroscopy has been proven to be a fast, convenient, and nondestructive technique to characterize the fundamental properties of 2DMs at both laboratory and mass-production scales. In this review, we discuss recent advances in

Despite the improvement of the quality of CVD grown single-layer graphene on copper substrates, transferring the two-dimensional layer without introducing any unintentional defects still poses a challenge. While many approaches focus on optimizing the transfer itself or on necessary post-transfer cleaning steps, we have focused on developing a pre-treatment of the monolayer graphene on copper to improve

Trigonal-Tellurium (t-Te) has recently garnered interest in the nanoelectronics community because of its measured high hole mobility and low-temperature growth. However, a drawback of tellurium is its small bulk bandgap (0.33 eV), giving rise to large leakage currents in transistor prototypes. We analyze the increase of the electronic bandgap due to quantum confinement and compare the relative stability

Chemical vapour deposition (CVD) growth is capable of producing multiple single-crystal islands of atomically thin transition metal dichalcogenides (TMDs) over large areas. Subsequent merging of perfectly epitaxial domains can lead to single-crystal monolayer sheets, a step towards scalable production of high quality TMDs. For CVD growth to be effectively harnessed for such production it is necessary

Inter-layer excitons (IXs) in hetero-bilayers of transition metal dichalcogenides (TMDs) represent an exciting emergent class of long-lived dipolar composite bosons in an atomically thin, near-ideal two-dimensional (2D) system. The long-range interactions that arise from the spatial separation of electrons and holes can give rise to novel quantum, as well as classical multi-particle correlation effects

An unexploited property of graphene-based heterojunctions is the tunable doping of the junction via electrostatic gating. This unique property may be key in advancing electronic transport across interfaces with semiconductors. Here, we engineer transport in semiconducting TMDs by constructing a lateral heterostructure with epitaxial graphene and tuning its intrinsic doping to form a p–n junction between

Layered transition metal dichalcogenides (TMDs) are commonly classified as quasi-two-dimensional materials, meaning that their electronic structure closely resembles that of an individual layer, which results in resistivity anisotropies reaching thousands. Here, we show that this rule does not hold for 1T-TaS2—a compound with the richest phase diagram among TMDs. Although the onset of charge density

Two-dimensional/two-dimensional (2D/2D) heterojunctions form one of the most versatile technological solutions for building tunneling field effect transistors because of the sharp and potentially clean interfaces resulting from van der Waals assembly. Several evidences of room temperature band-to-band tunneling (BTBT) have been recently reported, but only few tunneling devices have been proven to break

We discuss the effect of the in-plane electric field on the Raman spectroscopy for few-layered MoS2. The characteristic Raman modes of MoS2 show gradual red shift, while the intensity increases by 45–50% as the electric field is increased, showing a large electro-optical effect. Structural analysis suggests that our few-layered MoS2 belongs to P6/m2 space group with broken inversion symmetry. We attribute

The Acknowledgments section of the original version of this Article did not acknowledge all of the relevant funding sources. This has now been corrected in the HTML and PDF versions of the Article.