A5068211089- 2D Materials and Applications
- Graphene research and applications
- Iron-based superconductors research
- Molecular Junctions and Nanostructures
- Topological Materials and Phenomena
- Surface and Thin Film Phenomena
- Surface Chemistry and Catalysis
- Electronic and Structural Properties of Oxides
- Rare-earth and actinide compounds
- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- MXene and MAX Phase Materials
- Magnetic and transport properties of perovskites and related materials
- Quantum and electron transport phenomena
- Catalytic Processes in Materials Science
- Multiferroics and related materials
- Quantum Dots Synthesis And Properties
- Advanced Thermoelectric Materials and Devices
- Corporate Taxation and Avoidance
- Intellectual Capital and Performance Analysis
- Machine Learning in Materials Science
- Semiconductor materials and interfaces
- Advanced Memory and Neural Computing
- Magnetic Properties and Applications
Shaanxi Normal University
2019-2025
Huazhong University of Science and Technology
2015-2024
Chinese Academy of Sciences
2002-2019
Tulane University
2019
Suzhou Institute of Nano-tech and Nano-bionics
2019
Oak Ridge National Laboratory
2006-2016
Center for Nanophase Materials Sciences
2013
Louisiana State University
2013
Institute of Physics
2004-2006
University of Tennessee at Knoxville
2005
Graphene is a two-dimensional network in which sp(2)-hybridized carbon atoms are arranged two different triangular sub-lattices (A and B). By incorporating nitrogen into graphene, its physico-chemical properties could be significantly altered depending on the doping configuration within sub-lattices. Here, we describe synthesis of large-area, highly-crystalline monolayer N-doped graphene (NG) sheets via atmospheric-pressure chemical vapor deposition, yielding unique N-doping site composed...
Single-layer black phosphorus (BP), or phosphorene, is a highly anisotropic two-dimensional elemental material possessing promising semiconductor properties for flexible electronics. However, the direct bandgap of single-layer predicted theoretically has not been directly measured, and its edges have considered in detail. Here we report atomic scale electronic variation related to strain-induced deformation puckered honeycomb structure freshly cleaved using high-resolution scanning tunneling...
Electrical and optoelectronic properties of few-layer black phosphorus field-effect transistors are investigated through spatial-, polarization-, gate-, bias-dependent photocurrent measurements.
Significance The gas-sensing performance of graphene could be remarkably enhanced by incorporating dopants into its lattice based on theoretical calculations. However, to date, experimental progress boron-doped (BG) is still very scarce. Here, we achieved the controlled growth large-area, high-crystallinity BG sheets and shed light their electronic features associated with boron at atomic scale. As a proof-of-concept, it demonstrated that doping in lead much sensitivity when detecting toxic...
N-doped graphene can be used as a substrate for different molecules to effectively enhance their Raman scattering signal.
The tungsten ditelluride WTe${}_{2}$ semimetal is known for if its extremely large magnetoresistance. authors measure the angular dependence of this magnetoresistance and find that when magnetic field applied parallel to chains (along $a$ axis), very (as high as 1200% at 15 T 2 K) no longer exhibits a conventional quadratic but rather linear dependence.
We report low-temperature scanning tunneling microscopy characterization of MoSe2 crystals and the fabrication electrical field-effect transistors on both SiO2 parylene-C substrates. find that multilayer devices show a room-temperature mobility close to bulk (100-160 cm(2) V(-1) s(-1)), which is significantly higher than substrates (≈50 s(-1)). The types are nearly thickness-independent. Our variable-temperature transport measurements reveal metal-insulator transition at characteristic...
Flat bands (FBs), presenting a strongly interacting quantum system, have drawn increasing interest recently. However, experimental growth and synthesis of FB materials been challenging remained elusive for the ideal form monolayer where arises from destructive interference as predicted in 2D lattice models. Here, we report surface self-assembled hydrogen-bond (H-bond) organic frameworks (HOFs) 1,3,5-tris(4-hydroxyphenyl)benzene (THPB) on Au(111) substrate observation FB. High-resolution...
We used scanning tunneling microscopy and spectroscopy (STM/S) techniques to analyze the relationships between edge shapes electronic structures in as-grown chemical vapor deposition (CVD) graphene nanoribbons (GNRs). A rich variety of single-layered exhibiting a width several 100 nm up 1 μm long were studied. High-resolution STM images highlight highly crystalline nanoribbon with well-defined clean edges. Theoretical calculations indicate clear spin-split states induced by electron-electron...
Using piezoresponse force microscopy in an ultrahigh vacuum, polarization switching has been detected and quantified epitaxial BiFeO${}_{3}$ films from 200 to about 4 unit cells thick. Local remnant was utilized probe both ferroelectric properties effects of imperfect electrical contacts. It found that the shape electromechanical hysteresis loops is strongly influenced by extrinsic dielectric gap, primarily through suppressing effect depolarizing field on spontaneous ultrathin films....
The discovery of ferromagnetism in two-dimensional (2D) van der Waals crystals has generated widespread interest. seeking robust 2D ferromagnets with high Curie temperature (Tc) is vitally important for next-generation spintronic devices. However, owing to the enhanced spin fluctuation and weak exchange interaction upon reduced dimensionalities, exploring Tc > 300 K highly demanded but remains challenging. In this work, we fabricated air-stable Cr5Te8/CrTe2 vertical heterojunctions above 400...
The nature of the anomalous metal state has been a major puzzle in condensed matter physics for more than three decades. Here, we report systematic investigation and modulation states high-temperature interface superconductor FeSe films on ${\mathrm{SrTiO}}_{3}$ substrate. Remarkably, under zero magnetic field, persists up to 20 K pristine films, an exceptionally high temperature standing out from previous observations. In stark contrast, with nanohole arrays, characteristic is considerably...
Supramolecular self-assembly on well-defined surfaces provides access to a multitude of nanoscale architectures, including clusters distinct symmetry and size. The driving forces underlying supramolecular structures generally involve both graphoepitaxy weak directional nonconvalent interactions. Here we show that functionalizing benzene molecule with an ethyne group introduces attractive interactions in 2D geometry, which would otherwise be dominated by intermolecular repulsion. Furthermore,...
Particularly in Sr2IrO4, the interplay between spin-orbit coupling, bandwidth and on-site Coulomb repulsion stabilizes a Jeff = 1/2 spin-orbital entangled insulating state at low temperatures. Whether this phase is Mott- or Slater-type, has been under intense debate. We address issue via spatially resolved imaging spectroscopic studies of Sr2IrO4 surface using scanning tunneling microscopy/spectroscopy (STM/S). STS results clearly illustrate opening an gap (150 ~ 250 meV) below Néel...
Based on recently synthesized Ni3C12S12 class 2D metal-organic frameworks, we predict electronic properties of M3C12S12 and M3C12O12, where M is Zn, Cd, Hg, Be, or Mg with no orbital contributions to bands near Fermi level. For M3C12S12, their band structures exhibit double Dirac cones different velocities that are n p type, respectively, which switchable by few-percent strain. The crossing two symmetry-protected be non-hybridizing, leading independent channels in node-line semimetals at the...
Half-Heusler alloys have recently received extensive attention because of their promising thermoelectric (TE) properties and great potential for applications requiring efficient thermoelectricity. Although the conversion efficiency these materials can be greatly improved by doping, it is still far away from real-life applications. Therefore, search better parent TE compounds deemed urgent. Using a high-throughput method based on first-principles calculations in newly proposed 378...
The interaction of oxygen with line defects Ti interstitials on a $\mathrm{Ti}{\mathrm{O}}_{2}(110)$ surface is investigated using scanning tunneling microscopy (STM) measurements and first-principles calculations. Ab initio molecular dynamics calculations show that an molecule dissociatively adsorbs row interstitials. Oxygen atoms subsequently surround interstitial to form the equatorial plane partially complete octahedron, basic building block for single- double-strand formation. Upon...
BaFe2As2 exhibits properties that are characteristic of the parent compounds newly discovered iron (Fe)-based high-T(C) superconductors. By combining real-space imaging scanning tunneling microscopy and spectroscopy (STM+STS) with momentum-space quantitative low-energy electron diffraction (LEED), we have identified surface plane cleaved crystals as As terminated Fe-As layer-the where superconductivity occurs. LEED STM+STS data on BaFe2As2(001) indicate an ordered arsenic (As) metallic...
We use multi-scale techniques to determine the extent of local inhomogeneity and superconductivity in Ca$_{0.86}$Pr$_{0.14}$Fe$_{2}$As$_{2}$ single crystal. The is manifested as a spatial variation praseodymium concentration, density states, superconducting order parameter. show that high-$T_{c}$ emerges from clover-like defects associated with Pr dopants. highest $T_{c}$ observed both tetragonal collapsed phases, its filamentary nature consequence non-uniform distribution develops...
The synthetic challenges of radialenes have precluded their practical applications. Here, we report a one-step protocol [4]radialene on copper surface. High-resolution scanning tunneling microscopy measurements reveal that such catalytic reaction proceeds readily with high selectivity at the temperature below 120 K. First-principles calculations show pathway is characterized by firstly cooperative inter-molecular hydrogen tautomerization and then C-C bond formation. feasibility...
The interplay between magnetism and crystal structures in three CaFe2As2 samples is studied. For the nonmagnetic quenched crystals, different crystalline domains with varying lattice parameters are found phases (orthorhombic, tetragonal collapsed tetragonal) coexist TS = 95 K 45 K. Annealing of crystals at 350°C leads to a strain relief through large (~1.3%) expansion c-parameter small (~0.2%) contraction a-parameter local ~0.2 Å displacements atomic-level. This annealing procedure results...
Unconventional quasiparticle excitations in condensed matter systems have become one of the most important research frontiers. Beyond two- and fourfold degenerate Weyl Dirac fermions, three-, six- eightfold symmetry protected degeneracies been predicted however remain challenging to realize solid state materials. Here, charge density wave compound TaTe4 is proposed hold fermionic excitation point energy bands. High quality single crystals are prepared, where revealed by directly imaging...