Browse
Submit Data
Databases
API
Help

Dataset Information

36 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Universal shape and pressure inside bubbles appearing in van der Waals heterostructures.

ABSTRACT: Trapped substances between a two-dimensional (2D) crystal and an atomically flat substrate lead to the formation of bubbles. Their size, shape and internal pressure are determined by the competition between van der Waals attraction of the crystal to the substrate and the elastic energy needed to deform it, allowing to use bubbles to study elastic properties of 2D crystals and conditions of confinement. Using atomic force microscopy, we analysed a variety of bubbles formed by monolayers of graphene, boron nitride and MoS2. Their shapes are found to exhibit universal scaling, in agreement with our analysis based on the theory of elasticity of membranes. We also measured the hydrostatic pressure induced by the confinement, which was found to reach tens of MPa inside submicron bubbles. This agrees with our theory estimates and suggests that for even smaller, sub-10?nm bubbles the pressure can be close to 1?GPa and may modify properties of a trapped material.

SUBMITTER: Khestanova E

PROVIDER: S-EPMC5007416 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Universal shape and pressure inside bubbles appearing in van der Waals heterostructures.

Khestanova E E Guinea F F Fumagalli L L Geim A K AK Grigorieva I V IV

Nature communications 20160825

Trapped substances between a two-dimensional (2D) crystal and an atomically flat substrate lead to the formation of bubbles. Their size, shape and internal pressure are determined by the competition between van der Waals attraction of the crystal to the substrate and the elastic energy needed to deform it, allowing to use bubbles to study elastic properties of 2D crystals and conditions of confinement. Using atomic force microscopy, we analysed a variety of bubbles formed by monolayers of graphe ...[more]

PMID: 27557732

Similar Datasets

Multiferroicity in atomic van der Waals heterostructures.

Project description:Materials that are simultaneously ferromagnetic and ferroelectric - multiferroics - promise the control of disparate ferroic orders, leading to technological advances in microwave magnetoelectric applications and next generation of spintronics. Single-phase multiferroics are challenged by the opposite d-orbital occupations imposed by the two ferroics, and heterogeneous nanocomposite multiferroics demand ingredients' structural compatibility with the resultant multiferroicity exclusively at inter-materials boundaries. Here we propose the two-dimensional heterostructure multiferroics by stacking up atomic layers of ferromagnetic Cr2Ge2Te6 and ferroelectric In2Se3, thereby leading to all-atomic multiferroicity. Through first-principles density functional theory calculations, we find as In2Se3 reverses its polarization, the magnetism of Cr2Ge2Te6 is switched, and correspondingly In2Se3 becomes a switchable magnetic semiconductor due to proximity effect. This unprecedented multiferroic duality (i.e., switchable ferromagnet and switchable magnetic semiconductor) enables both layers for logic applications. Van der Waals heterostructure multiferroics open the door for exploring the low-dimensional magnetoelectric physics and spintronic applications based on artificial superlattices.

| S-EPMC6570651 | biostudies-literature

Moire excitons in defective van der Waals heterostructures.

Project description:Excitons can be trapped by moiré potentials in van der Waals (vdW) heterostructures, forming ordered arrays of quantum dots. Excitons can also be trapped by defect potentials as single photon emitters. While the moiré and defect potentials in vdW heterostructures have been studied separately, their interplay remains largely unexplored. Here, we perform first-principles calculations to elucidate the interplay of the two potentials in determining the optoelectronic properties of twisted MoS2/WS2 heterobilayers. The binding energy, charge density, localization, and hybridization of the moiré excitons can be modulated by the competition and cooperation of the two potentials. Their interplay can also be tuned by vertical electric fields, which can either de-trap the excitons or strongly localize them. One can further tailor the interplay of the two potentials via defect engineering to create one-dimensional exciton lattices with tunable orientations. Our work establishes defect engineering as a promising strategy to realize on-demand optoelectronic responses.

| S-EPMC8364154 | biostudies-literature

Heterostructures formed through abraded van der Waals materials.

Project description:To fully exploit van der Waals materials and their vertically stacked heterostructures, new mass-scalable production routes which are low cost but preserve the high electronic and optical quality of the single crystals are required. Here, we demonstrate an approach to realise a variety of functional heterostructures based on van der Waals nanocrystal films produced through the mechanical abrasion of bulk powders. We find significant performance enhancements in abraded heterostructures compared to those fabricated through inkjet printing of nanocrystal dispersions. To highlight the simplicity, applicability and scalability of the device fabrication, we demonstrate a multitude of different functional heterostructures such as resistors, capacitors and photovoltaics. We also demonstrate the creation of energy harvesting devices, such as large area catalytically active coatings for the hydrogen evolution reaction and enhanced triboelectric nanogenerator performance in multilayer films. The ease of device production makes this a promising technological route for up-scalable films and heterostructures.

| S-EPMC7297739 | biostudies-literature

Electrotunable artificial molecules based on van der Waals heterostructures.

Project description:Quantum confinement has made it possible to detect and manipulate single-electron charge and spin states. The recent focus on two-dimensional (2D) materials has attracted significant interests on possible applications to quantum devices, including detecting and manipulating either single-electron charging behavior or spin and valley degrees of freedom. However, the most popular model systems, consisting of tunable double-quantum-dot molecules, are still extremely difficult to realize in these materials. We show that an artificial molecule can be reversibly formed in atomically thin MoS2 sandwiched in hexagonal boron nitride, with each artificial atom controlled separately by electrostatic gating. The extracted values for coupling energies at different regimes indicate a single-electron transport behavior, with the coupling strength between the quantum dots tuned monotonically. Moreover, in the low-density regime, we observe a decrease of the conductance with magnetic field, suggesting the observation of Coulomb blockade weak anti-localization. Our experiments demonstrate for the first time the realization of an artificial quantum-dot molecule in a gated MoS2 van der Waals heterostructure, which could be used to investigate spin-valley physics. The compatibility with large-scale production, gate controllability, electron-hole bipolarity, and new quantum degrees of freedom in the family of 2D materials opens new possibilities for quantum electronics and its applications.

| S-EPMC5650488 | biostudies-literature

Spin photovoltaic effect in magnetic van der Waals heterostructures.

Project description:[Figure: see text].

| S-EPMC8442881 | biostudies-literature

Superconducting Quantum Interference in Twisted van der Waals Heterostructures.

Project description:We demonstrate the formation of both Josephson junctions and superconducting quantum interference devices (SQUIDs) using a dry transfer technique to stack and deterministically misalign mechanically exfoliated flakes of NbSe2. The current-voltage characteristics of the resulting twisted NbSe2-NbSe2 junctions are found to be sensitive to the misalignment angle of the crystallographic axes, opening up a new control parameter for optimization of the device performance, which is not available in thin-film-deposited junctions. A single lithographic process has then been implemented to shape Josephson junctions into SQUID geometries with typical loop areas of ∼25 μm2 and weak links ∼600 nm wide. At T = 3.75 K in an applied magnetic field, these devices display large stable current and voltage modulation depths of up to ΔIc ∼ 75% and ΔV ∼ 1.4 mV, respectively.

| S-EPMC8397396 | biostudies-literature

Exciton-assisted electron tunnelling in van der Waals heterostructures.

Project description:The control of elastic and inelastic electron tunnelling relies on materials with well-defined interfaces. Two-dimensional van der Waals materials are an excellent platform for such studies. Signatures of acoustic phonons and defect states have been observed in current-to-voltage measurements. These features can be explained by direct electron-phonon or electron-defect interactions. Here we use a tunnelling process that involves excitons in transition metal dichalcogenides (TMDs). We study tunnel junctions consisting of graphene and gold electrodes separated by hexagonal boron nitride with an adjacent TMD monolayer and observe prominent resonant features in current-to-voltage measurements appearing at bias voltages that correspond to TMD exciton energies. By placing the TMD outside of the tunnelling pathway, we demonstrate that this tunnelling process does not require any charge injection into the TMD. The appearance of such optical modes in electrical transport introduces additional functionality towards van der Waals material-based optoelectronic devices.

| S-EPMC10465355 | biostudies-literature

Making van der Waals Heterostructures Assembly Accessible to Everyone.

Project description:Van-der Waals heterostructures assembled from one or few atomic layer thickness crystals are becoming increasingly more popular in condensed matter physics. These structures are assembled using transfer machines, those are based on mask aligners, probe stations or are home-made. For many laboratories it is vital to build a simple, convenient and universal transfer machine. In this paper we discuss the guiding principles for the design of such a machine, review the existing machines and demonstrate our own construction, that is powerful and fast-in-operation. All components of this machine are extremely cheap and can be easily purchased using common online retail services. Moreover, assembling a heterostructure out of exfoliated commercially available hexagonal boron nitride and tungsten diselenide crystals with a pick-up technique and using the microphotolumenescence spectra, we show well-resolved exciton and trion lines, as a results of disorder suppression in WSe2 monolayer. Our results thus show that technology of the two-dimensional materials and heterostructures becomes accessible to anyone.

| S-EPMC7700158 | biostudies-literature

Asymmetric electric field screening in van der Waals heterostructures.

Project description:A long-standing challenge facing the combination of two-dimensional crystals into heterojunction is the unknown effect of mixing layer of different electronic properties (semiconductors, metals, insulators) on the screening features of the fabricated device platforms including their functionality. Here we use a compelling set of theoretical and experimental techniques to elucidate the intrinsic dielectric screening properties of heterostructures formed by MoS2 and graphene layers. We experimentally observed an asymmetric field screening effect relative to the polarization of the applied gate bias into the surface. Surprisingly, such behavior allows selection of the electronic states that screen external fields, and it can be enhanced with increasing of the number of layers of the semiconducting MoS2 rather than the semi-metal. This work not only provides unique insights on the screening properties of a vast amount of heterojunction fabricated so far, but also uncovers the great potential of controlling a fundamental property for device applications.

| S-EPMC5871878 | biostudies-literature

Thermionic transport across gold-graphene-WSe2 van der Waals heterostructures.

Project description:Solid-state thermionic devices based on van der Waals structures were proposed for nanoscale thermal to electrical energy conversion and integrated electronic cooling applications. We study thermionic cooling across gold-graphene-WSe2-graphene-gold structures computationally and experimentally. Graphene and WSe2 layers were stacked, followed by deposition of gold contacts. The I-V curve of the structure suggests near-ohmic contact. A hybrid technique that combines thermoreflectance and cooling curve measurements is used to extract the device ZT. The measured Seebeck coefficient, thermal and electrical conductance, and ZT values at room temperatures are in agreement with the theoretical predictions using first-principles calculations combined with real-space Green's function formalism. This work lays the foundation for development of efficient thermionic devices.

| S-EPMC6839940 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data