2DCC User Research Highlight

Project Summary: Molybdenum trioxide (a-MoO3) is a wide bandgap 2D layered oxide (Eg~3 eV) that is of interest for resistive switching-based nonvolatile memory devices.  It is difficult to produce large-area monolayer MoO3 through exfoliation of bulk crystals or other techniques. This study demonstrates a facile route to obtain wafer-scale monolayer amorphous MoO3 using monolayer 2D MoS2 grown by metalorganic chemical vapor deposition (MOCVD) as a starting material, following by UV-ozone oxidate at substrate temperatures as low as 120oC.

Project Summary: A multi-dimensional optical imaging technique that combines scattering  was developed to map subdiffractional distributions of doping and strain in MoS2 and MoS2/graphene vertical heterostructures.

Project Summary: Quasi-two-dimensional transition-metal dichalcogenides are a key platform for exploring emergent nanoscale phenomena arising from complex interactions. Access to the underlying degrees-of-freedom on their natural time scales motivates the use of advanced ultrafast probes sensitive to self-organized atomic-scale patterns.

Project Summary: Transition metal dichalcogenides (TMDCs) with van der Waals gaps (vdW) have been a subject under extensive studies, since 2D thin layers of these materials exhibit a plethora of technologically useful properties, e.g. large direct band gap and high

Project Summary: The topological Hall effect (THE) is a phenomenon that is a consequence of a Berry phase created by spin textures in real space. Interfacing a topological insulator with a magnetic insulator provides a model platform for studying this phenomenon in a well-controlled manner. This papers reports the first clear evidence for the THE in heterostructures that combine a model topological insulator (Bi2Se3) with a ferromagnetic insulator (BaFe12O19).

Project Summary: Remote epitaxy has drawn attention as it offers epitaxy of functional materials that can be released from the substrates with atomic precision, thus enabling production and heterointegration of flexible, transferrable, and stackable freestanding single-crystalline membranes. In this highlight, 2DCC and PARADIM team up to work with the inventor of remote epitaxy, Prof.

Project Summary: MnBi2Te4 has been established as the first intrinsic antiferromagnetic (AFM) topological insulator.

Project Summary: Azimuthal reflection high-energy electron diffraction (ARHEED) is demonstrated as a powerful technique to measure the symmetry, lattice constants and in-plane orientation domain dispersion in wafer-scale, continuous monolayer WSe2 epitaxially grown on c-plane sapphire by metalorganic chemical vapor deposition.

Project Summary: Nodal-line semimetals represent a new topological quantum state, which has attracted enormous interest. ZrSiTe is a distinct nodal-line semimetal, since it possesses a nodal line protected by nonsymmorphic symmetry very close to the Fermi energy. The Ross group at Texas A&M University recently utilized nuclear magnetic resonance (NMR) spectroscopy to study the distinctive network of nodal lines in ZrSiTe. Their experiments show that temperature induced changes lead the chemical potential to coincide with the protected node at low temperatures.

What Has Been Achieved: Multiscale/multiphysics models that couple continuum fluid mechanics and phase-field methods provide a means to map out how experimentally controllable macroscale (inlet velocity, temperature) and mesoscale (surface diffusion and deposition rates) parameters control the morphology of 2D materials, within the precise experimental growth geometries of the 2DCC, in a manner tha