A5100767726- Graphene research and applications
- 2D Materials and Applications
- Semiconductor materials and devices
- Plasma Diagnostics and Applications
- Topological Materials and Phenomena
- Diamond and Carbon-based Materials Research
- Electronic and Structural Properties of Oxides
- Vacuum and Plasma Arcs
- Advancements in Battery Materials
- High voltage insulation and dielectric phenomena
- Surface and Thin Film Phenomena
- Graphene and Nanomaterials Applications
- Quantum and electron transport phenomena
- MXene and MAX Phase Materials
- Power Transformer Diagnostics and Insulation
- Plasma Applications and Diagnostics
- Physics of Superconductivity and Magnetism
- Boron and Carbon Nanomaterials Research
- Carbon Nanotubes in Composites
- Electrochemical sensors and biosensors
- Nanowire Synthesis and Applications
- Electrohydrodynamics and Fluid Dynamics
- Advanced Antenna and Metasurface Technologies
- Chalcogenide Semiconductor Thin Films
- Electromagnetic wave absorption materials
Pennsylvania State University
2018-2025
Xi'an Jiaotong University
2014-2024
Park University
2024
Guangxi University
2023
China XD Group (China)
2020
Remote epitaxy has drawn attention as it offers of functional materials that can be released from the substrates with atomic precision, thus enabling production and heterointegration flexible, transferrable, stackable freestanding single-crystalline membranes. In addition, remote interaction atoms adatoms through two-dimensional (2D) in allows investigation utilization electrical/chemical/physical coupling bulk (3D) via 2D (3D–2D–3D coupling). Here, we unveil respective roles impacts...
Abstract The functionality of atomic quantum emitters is intrinsically linked to their host lattice coordination. Structural distortions that spontaneously break the symmetry strongly impact optical emission properties and spin-photon interface. Here we report on direct imaging charge state-dependent breaking two prototypical in mono- bilayer MoS 2 by scanning tunneling microscopy (STM) non-contact force (nc-AFM). By changing built-in substrate chemical potential, different states sulfur...
Two-dimensional (2D) materials are popular for fundamental physics study and technological applications in next-generation electronics, spintronics, optoelectronic devices due to a wide range of intriguing physical chemical properties. Recently, the family 2D metals semiconductors has been expanding rapidly because they offer properties once unknown us. One challenges fully access their is poor stability ambient conditions. In first half this Review, we briefly summarize common methods...
Graphene-enhanced Raman scattering (GERS) offers great opportunities to achieve optical sensing with a high uniformity and superior molecular selectivity. The GERS mechanism relies on charge transfer between molecules graphene, which is difficult manipulate by varying the band alignment graphene molecules. In this work, we synthesized few atomic layers of metal termed two-dimensional (2D) precisely deterministically modify Fermi level. Using copper phthalocyanine (CuPc) as representative...
Defects in graphene are important nanoscale pathways for metal atoms to enter the interface between epitaxial and SiC order form stable ultrathin layers with new exotic physical properties. However, atomic-scale details of defects that mainly govern intercalation process remain modest. In this work, we present first atomic investigation point generated by oxygen plasma treatment on grown using low-temperature scanning tunneling microscopy, corroborated density functional theory calculations....
While multiple studies have explored the mechanism for DC and AC microscale gas breakdown, few assessed pulsed voltage breakdown at microscale. This study experimentally analytically investigates gap widths from 1 μm to 25 μm. Using an electrical-optical measurement system with a spatial resolution of temporal 2 ns, we measure voltages determine morphology as function width. An empirical fit shows that varies linearly distance smaller gaps, agreeing analytical theory coupling field emission...
Forming long wavelength moir\'e superlattices (MSL) at small-angle twist van der Waals (vdW) bilayers has been a key approach to creating flat bands. The twist, however, leads strong lattice reconstruction, causing domain walls and disorders, which pose considerable challenges in engineering such platforms. At large angles, the rigid lattices render more robust, but shorter MSL, making it difficult engineer Here, we depict novel tailoring robust super-moir\'e (SM) structures that combines...
Defect engineering in two-dimensional semiconductors has been exploited to tune the optoelectronic properties and introduce new quantum states band gap. Chalcogen vacancies transition metal dichalcogenides particular have found strongly impact charge carrier concentration mobility 2D transistors as well feature subgap emission single-photon response. In this Letter, we investigate layer-dependent charge-state lifetime of Se WSe_{2}. one monolayer WSe_{2}, observe ultrafast transfer from...
High harmonic generation (HHG) from 2D polar metal heterostructures (PMets) is described. Ag and Ga PMets were formed by confinement heteroepitaxy. High-temperature sublimation of Si atoms 6H-SiC epitaxial bilayer graphene/SiC (EG). Metal intercalation generated crystalline films monolayer in the confines graphene SiC interface, forming PMet heterostructure. HHG using a mid-infrared (5200 nm) laser to transduce fifth, seventh, ninth harmonics for both as well EG exhibited second-order...
The tunable optical properties of metals through size-dependent quantum effects have attracted attention due to synthesis chemically stable, ultrathin, and two-dimensional metals. Gate tunability, from the reduced screening low-dimensional metals, adds an additional route for control over properties. Here, (2D) Ga is synthesized via confinement heteroepitaxy patterned into electric-double-layer (EDL) gated transistors. 2D predicted out-of-plane permanent dipole moment resulting a...
Near-infrared-to-visible second harmonic generation from air-stable two-dimensional polar gallium and indium metals is described. The photonic properties of 2D metals, including the largest second-order susceptibilities reported for (approaching 10 nm/V), are determined by atomic-level structure bonding two-to-three-atom-thick crystalline films. bond character evolved covalent to metallic over a few atomic layers, changing out-of-plane metal–metal distances approximately ten percent (0.2 Å),...
Intercalation is the process of inserting chemical species into heterointerfaces two-dimensional (2D) layered materials. While much research has focused on intercalation metals and small gas molecules graphene, larger through basal plane graphene remains challenging. In this work, we present a new mechanism for intercalating large monolayer to form confined oxide materials at graphene-substrate heterointerface. We investigate phosphorus pentoxide (P2O5) directly from vapor phase confirm...
Abstract Contacting two-dimensional (2D) semiconductors with van der Waals semimetals significantly reduces the contact resistance and Fermi level pinning due to defect-free interfaces. However, depending on band alignment, a Schottky barrier remains. Here we study evolution of valence conduction edges in pristine heavily vanadium (0.44%), i.e., p -type, doped epitaxial WSe 2 quasi-freestanding graphene (QFEG) silicon carbide as function thickness. We find that increasing number layers gets...
Chemically stable quantum-confined 2D metals are of interest in next-generation nanoscale quantum devices. Bottom-up design and synthesis such could enable the creation materials with tailored, on-demand, electronic optical properties for applications that utilize tunable plasmonic coupling, nonlinearity, epsilon-near-zero behavior, or wavelength-specific light trapping. In this work, it is demonstrated electronic, superconducting, air-stable can be controllably tuned by formation alloys....
Abstract Novel confinement techniques facilitate the formation of non‐layered 2D materials. Here it is demonstrated that and properties oxides (GaO x , InO SnO ) at epitaxial graphene (EG)/silicon carbide (SiC) interface dependent on EG buffer layer prior to element intercalation. Using Ga, defects in lead Ga transforming GaO with non‐periodic oxygen a crystalline matrix via air oxidation room temperature. However, monolayer 2 bilayer O 3 ferroelectric wurtzite structure(FE‐WZ') can then be...
Abstract Intercalation forms heterostructures, and over 25 elements compounds are intercalated into graphene, but the mechanism for this process is not well understood. Here, de‐intercalation of 2D Ag Ga metals sandwiched between bilayer graphene SiC followed using photoemission electron microscopy (PEEM) atomistic‐scale reactive molecular dynamics simulations. By PEEM, “windows” (or defects) observed in both systems, processes follow distinctly different dynamics. Reversible de‐...