A5088518571- Silicon Carbide Semiconductor Technologies
- Silicon and Solar Cell Technologies
- Thin-Film Transistor Technologies
- Semiconductor materials and devices
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and interfaces
- Photocathodes and Microchannel Plates
- Advanced ceramic materials synthesis
- Copper Interconnects and Reliability
- Solidification and crystal growth phenomena
- GaN-based semiconductor devices and materials
- Aluminum Alloys Composites Properties
- Silicon Nanostructures and Photoluminescence
- Electron and X-Ray Spectroscopy Techniques
- Lipid Membrane Structure and Behavior
- Induction Heating and Inverter Technology
- nanoparticles nucleation surface interactions
- Advanced Electron Microscopy Techniques and Applications
- Force Microscopy Techniques and Applications
- Advanced Surface Polishing Techniques
- Crystallization and Solubility Studies
- Thermal properties of materials
- Iron-based superconductors research
- Acoustic Wave Resonator Technologies
- Advancements in Semiconductor Devices and Circuit Design
Nagoya University
2015-2024
National Institute of Advanced Industrial Science and Technology
2018-2023
Hitachi (Japan)
2007-2022
SAGA Light Source
2021-2022
Institute for Sustainability
2021
Graduate School USA
2021
Advanced Device Technology (United States)
2020
Future Electronics (Netherlands)
2018-2019
RIKEN Center for Advanced Intelligence Project
2019
Aichi Science & Technology Foundation
2018
We report on the performance of solar cells with stacked self-assembled Ge dots in intrinsic region Si-based p-i-n diode. These were epitaxially grown p-type Si(100) substrate via Stranski–Krastanov growth mode by gas-source molecular beam epitaxy. Enhanced external quantum efficiency (EQE) infrared up to 1.45 μm was observed for compared that without dots. Furthermore, EQE found increase increasing number stacking. results show electron-hole pairs generated can be efficiently separated...
The formation of a supported planar lipid bilayer (SPLB) and its morphology on step-and-terrace rutile TiO2(100) surfaces were investigated by fluorescence microscopy atomic force microscopy. consisting steps flat terraces formed TiO2 single-crystal wafer wet treatment annealing under flow oxygen. An intact vesicular layer the surface when was incubated in sonicated vesicle suspension condition that full-coverage SPLB forms SiO2, as reported previous studies. However, full-coverage,...
The high-efficiency conversion of threading screw dislocations (TSDs) in 4H-SiC by solution growth provides an efficient method obtaining ultra high-quality SiC crystals. behavior TSDs on on-axis and off-axis 4H-SiC0001 seed crystals was investigated synchrotron X-ray topography. Almost all the Si-face crystal were converted to Frank-type stacking faults basal planes. ratio highly influenced surface polarity crystal. laterally propagate toward outside
A spin-polarized electron beam has been used as the probe in a transmission microscope by using photocathode gun with made of GaAs–GaAsP strained superlattice semiconductor negative affinity (NEA) surface. This system had spatial resolution order 1 nm for at 30 keV and it can generate an energy width 0.24 eV without employing monochromators. narrow suggests that NEA realize high energy-loss spectroscopy longitudinal coherence 3 × 10−7 m.
We report a marked reduction in the dislocation density of 4H-SiC crystal using high-efficiency conversion phenomenon. During solution growth, threading dislocations were efficiently converted to basal plane defects by step flow macrosteps. Utilizing this phenomenon, we achieved density. Consequently, screw was only 30 cm−2, which two orders magnitude lower than that seed crystal. The polytype replicated grown crystal, attributed spiral growth owing few remaining upstream flow.
The combination of the CFD simulation and machine learning thus makes it possible to determine optimized parameters for high-quality large-diameter crystals.
Evolution of threading screw dislocation (TSD) conversion during the solution growth 4H-SiC on a vicinal crystal 4H-SiC(0001) was investigated by synchrotron X-ray topography. Selecting appropriate wavelength and g vector, we can change penetration X-ray, behaviors with different depth were successfully observed. Evidently TSDs parallel to c-axis having c-component Burgers vector changed into defects (0001) basal planes same as TSDs, propagating...
Using a newly developed transmission-type photocathode, an electron beam of super-high brightness [(1.3±0.5)×107 A·cm-2·sr-1] was achieved. Moreover, the spin-polarization as high 90%. We fabricated photocathode based on GaAs–GaAsP strained superlattice GaP substrate in order to enhance and polarization greatly. In this system, laser is introduced through transparent substrate. The focused active layer with short focal length lens. Excited electrons are generated small area extracted from...
We have proposed a method to evaluate minority carrier lifetime through photovoltage measurements by photoassisted Kelvin probe force microscopy and applied it characterize polycrystalline silicon solar cell. The results indicate that the significantly decreases in vicinity of grain boundary material. distribution around is also discussed considering contribution both intrinsic surface potential lifetime.
Superconducting NdFeAs(O,F) thin films were grown on GaAs substrates by molecular beam epitaxy. Films with a sufficiently long growth time exhibited clear superconducting transition an onset temperature up to 48 K and zero resistance 42 without the need of ex situ annealing process. Electron probe microanalysis Hall coefficient measurements indicated that are doped fluorine, depth-profile analysis Auger electron spectroscopy revealed formation NdOF layer near surface, which is probably...
The brightness and interference fringes of a spin-polarized electron beam extracted from semiconductor photocathode excited by laser irradiation are directly measured via its use in transmission microscope. was 3.8 × 107 A cm−2 sr−1 for 30-keV energy with the polarization 82%, which corresponds to 3.1 108 200-keV energy. resulting exhibited long coherence length at specimen position due high parallelism (1.7 ± 0.3) 10−5 rad, generated representative first-order correlation using an biprism....
Li metal anodes are plagued by low coulombic efficiency due to their interfacial instability. Many approaches were proposed cope with this problem; however, little attention has been given the current collector of anodes. In study, we investigate crystal orientation dependence cycling stability on single-crystal Cu(111), (101), and (001) polycrystalline Cu collectors. Cyclic voltammetry (CV) electrochemical impedance spectroscopy (EIS) show that (111) achieved high resistance, while (101)...
We investigate the intensity interference between pairs of electrons using a spin-polarized electron beam having high polarization and narrow energy width. observe spin-dependent antibunching on basis coincident counts performed with transmission microscope, which could control spin-polarization without any changes in optics. The experimental results show that time correlation was only affected by spin polarization, demonstrating is associated fermionic statistics. coherent facilitates...
In order to produce a high brightness and spin polarization electron beam, pointlike emission mechanism is required for the photocathode of GaAs polarized source. For this purpose, laser spot size on must be minimized, which realized by changing direction injection light from front side back photocathode. Based concept, 20kV gun was constructed with transmission including an active layer GaAs–GaAsP superlattice layer. This system produces diameter as small 1.3μm 760–810nm wavelength. The...
Epitaxial films of NdFeAsO were grown on GaAs substrates by molecular beam epitaxy (MBE). All elements including oxygen supplied from solid sources using Knudsen cells. The x-ray diffraction pattern the film prepared with optimum growth condition showed no indication impurity phases. Only (00l) peaks observed, indicating that was c-axis perpendicular to substrate. window very narrow, but phase a good reproducibility. Despite absence any appreciable secondary phase, resistivity an increase...
We developed a spin-polarized low energy electron microscopy (SPLEEM) with highly polarized and high brightness spin gun in the present study. Magnetic structures of Co/W(110) were observed an acquisition time 0.02 s field view 6 µm. carried out dynamic observation magnetic SPLEEM during growth Co on W(110).