A5068806728- ZnO doping and properties
- Electronic and Structural Properties of Oxides
- Ga2O3 and related materials
- Copper-based nanomaterials and applications
- GaN-based semiconductor devices and materials
- Semiconductor materials and devices
- Semiconductor Quantum Structures and Devices
- Gas Sensing Nanomaterials and Sensors
- Quantum Dots Synthesis And Properties
- Semiconductor Lasers and Optical Devices
- Microstructure and mechanical properties
- nanoparticles nucleation surface interactions
- Ferroelectric and Piezoelectric Materials
- Advanced Semiconductor Detectors and Materials
- Metal and Thin Film Mechanics
- Magnetic and transport properties of perovskites and related materials
- Ion-surface interactions and analysis
- Microstructure and Mechanical Properties of Steels
- Acoustic Wave Resonator Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Chalcogenide Semiconductor Thin Films
- Advanced Materials Characterization Techniques
- Graph Theory and Algorithms
- Ferroelectric and Negative Capacitance Devices
- Data Management and Algorithms
Coherent (United States)
2024
Huazhong University of Science and Technology
2022
The Ohio State University
2013-2015
University of Arkansas at Fayetteville
2010-2013
Material Sciences (United States)
2013
Chinese Academy of Sciences
2004-2011
Institute of Physics
2003-2011
National Laboratory for Superconductivity
2005-2007
Qufu Normal University
2004
High quality Bi2Te3 and Sb2Te3 topological insulators films were epitaxially grown on GaAs (111) substrate using solid source molecular beam epitaxy. Their growth behavior both vicinal non-vicinal substrates investigated by reflection high-energy electron diffraction, atomic force microscopy, X-ray high resolution transmission microscopy. It is found that better than a to provide films. Hall magnetoresistance measurements indicate p type n insulator can be directly substrate, which may pave...
In this paper, we introduce TigerVector, a system that integrates vector search and graph query within TigerGraph, Massively Parallel Processing (MPP) native database. We extend the vertex attribute type with embedding type. To support fast search, devise an MPP index framework interoperates efficiently engine. The language GSQL is enhanced to expressions enable compositions between results blocks. These advancements elevate expressive power analytical capabilities of databases, enabling...
Surface nitridation is used to eliminate O-polar inversion domains and control the growth of single-domain Zn-polar ZnO film on sapphire (0001) substrate by rf-plasma-assisted molecular-beam epitaxy. It found that temperature crucial for achieving quality AlN buffer layers films with cation polarity, as demonstrated ex situ transmission electron microscopy. Under optimal conditions, a 4×4 surface reconstruction was observed, which confirmed be characteristic structure films, can fingerprint...
Zn O ( 0001 ) ∕ Si 111 interface is engineered by using a three-step technique, involving low-temperature Mg deposition, oxidation, and MgO homoepitaxy. The double heterostructure of MgO(111)∕Mg(0001)∕Si(111) formed at −10°C prevents the surface from oxidation serves as an excellent template for single-domain ZnO epitaxy, which confirmed with in situ reflection high-energy electron diffraction observation ex characterization transmission microscopy, x-ray diffraction, photoluminescence....
We used a complement of photoemission and cathodoluminescence techniques to measure formation the BaTiO3 (BTO) on SrTiO3 (STO) heterojunction band offset grown monolayer by molecular beam epitaxy. X-ray spectroscopy (XPS) provided core level valence edge energies monitor in-situ as first few crystalline BTO monolayers formed STO substrate. Ultraviolet (UPS) measured Fermi positions within gap, work functions, ionization potentials growing film. Depth-resolved densities interface states at...
Well-defined cubic AlN ultrathin layers formed by nitridation of Al2O3 (0001) substrate at various temperatures were observed high-resolution transmission electron microscopy. The polarity the strongly depends on pretreatment and temperature. structure plays a key role in selection subsequent ZnO films, both Zn-polar O-polar films could be steadily obtained control layers.
We used molecular beam epitaxy (MBE) growth to control the density of oxygen vacancy-related (VO-R) defects at (Ba,Sr)TiO3/SrTiO3 heterojunctions along with depth-resolved cathodoluminescence spectroscopy (DRCLS), surface photovoltage and positron annihilation (PAS) identify their optical signature, energy levels spatial distribution. grew (Ba,Sr)TiO3 epilayers on SrTiO3 using plasma-assisted MBE under a range pressures temperatures designed extraction from substrate that feeds epilayer...
Oxygen radicals pregrowth treatment and surface nitridation were used to eliminate Zn-polar inversion domains control the growth of single-domain O-polar ZnO film on sapphire (0001) substrate by rf plasma-assisted molecular beam epitaxy. We found that formation oxygen-terminated prior is crucial for achieving anion polarity in subsequent AlN layers, as demonstrated 3×3 reconstruction during ex situ determination. This method, general, can be applied other polar films, such II-VI oxides III-V...
GaAsBi/GaAs double quantum wells and well separate confinement heterostructures are grown at low temperatures using molecular beam epitaxy. Methods of achieving identical in structures without growth interruption proposed implemented. Cross-sectional transmission electron microscopy room temperature photoluminescence measurements indicate that the samples have excellent structural optical properties. The high quality is attributed to surfactant effect Bi throughout GaAs AlGaAs layers....
Surface modification of sapphire (0001) by Ga can eliminate multiple rotation domains in ZnO films. The existence at ZnO∕sapphire interface was confirmed x-ray energy dispersive spectroscopy a transmission electron microscope. Atomic detail mismatch dislocations imaged high resolution microscopy. Inside the film, there is density stacking fault. Both pure gliding ZnO(0001) plane and condensation vacancies or interstatials are possible mechanisms to generate
The rotation domain structures in ZnO films grown on sapphire substrates under different pre-treatment conditions have been investigated by situ reflection high-energy electron diffraction and ex x-ray (XRD). It was found that appropriate nitridation treatment, forming a thin AlN film the substrate, domains could be completely suppressed, full width at half maximum of only 180 arcsec observed (0 0 2) XRD rocking curves. mechanisms for elimination are discussed.
GaAsBi/GaAs/AlGaAs separate confinement heterostructures are grown using an asymmetric temperature profile due to the low optimal growth of GaAsBi; bottom AlGaAs barrier is at 610 °C, while GaAsBi quantum well and top 320 °C. Cross-sectional transmission electron microscopy room photoluminescence measurements indicate that this approach results in samples with excellent structural optical properties. The high quality attributed presence Bi on surface as indicated by a (1 × 3) reconstruction...
A magnesium wetting layer was used to modify the surface structure of MgAl2O4 (111) substrate achieve growth high-quality ZnO film by radio frequency plasma-assisted molecular beam epitaxy. It is found that this plays a crucial role in 30° rotation domain elimination, defect density reduction, and polarity control film, as demonstrated situ reflection high-energy electron diffraction ex transmission microscopy. Atomic force microscopy observation shows smooth surfaces with clearly resolved...
Self-assembly of bismuth droplets at nanoscale on GaAs(100) surface using molecular beam epitaxy was demonstrated. Fine control density and size achieved by varying growth temperature total deposition. Droplet tuned roughly 3 orders magnitude, the density-temperature dependence found to be consistent with classical nucleation theory. These results may extend flexibility droplet serving as templates for group V based epitaxy, which is in contrast conventional III encourage nanostructure...
Zn O ∕ ( La , Sr ) Al Ta 3 LSAT heterointerface is engineered to control the crystallographic orientation of ZnO films grown by plasmas-assisted molecular beam epitaxy. Lattice-matched in-plane alignment [112¯0]ZnO‖[112¯]LSAT has been realized using Mg modification substrate surface, which confirmed with in situ reflection high-energy electron diffraction observation, and ex characterization x-ray transmission microscopy. The low-temperature deposition high-temperature treatment layer on...
Transmission electron microscopy has been used to investigate the (1100) and (1103) inversion domain boundaries in a ZnO film prepared by molecular beam epitaxy. The was revealed dark-field images confirmed convergent-beam diffraction. Interacting with (0002) stacking fault, boundary plane alters its orientation from [0001] direction climbs on release strain energy. These features are characterized analysed high-resolution geometric phase method. findings significant for understanding...
Fabrication of GaAs/AlGaAs nano-ring structures by the droplet epitaxy technique is presented. Various double-ring shaped nanostructures are obtained crystallization Ga droplets with a varying As supply and characterized Atomic Force Microscopy. The formation mechanism nano-rings under influence flux has been deduced from morphology, revealing that evolution double caused combination migration nanodrilling effect.