A5065103996- GaN-based semiconductor devices and materials
- Ga2O3 and related materials
- ZnO doping and properties
- Semiconductor Quantum Structures and Devices
- Nanowire Synthesis and Applications
- Semiconductor Lasers and Optical Devices
- Metal and Thin Film Mechanics
- Solid State Laser Technologies
- Advanced Optical Sensing Technologies
- Spectroscopy and Laser Applications
- Photocathodes and Microchannel Plates
- Laser Design and Applications
- Water Quality Monitoring and Analysis
- 3D Modeling in Geospatial Applications
- Inclusion and Disability in Education and Sport
- Pediatric health and respiratory diseases
- Gas Sensing Nanomaterials and Sensors
- Chalcogenide Semiconductor Thin Films
- Acoustic Wave Resonator Technologies
- Perovskite Materials and Applications
- Photonic Crystals and Applications
- Advanced Materials Characterization Techniques
- Optical properties and cooling technologies in crystalline materials
- Thin-Film Transistor Technologies
- Family and Disability Support Research
Meijo University
2019-2023
Japan College of Social Work
2023
Koito Manufacturing (Japan)
2019-2022
Shimizu (Japan)
2020
Shizuoka University
2004
An impressive enhancement of cathodoluminescence was achieved in coaxial GaInN/GaN multiple-quantum-shells nanowires by employing an AlGaN undershell for trapping point defects.
Multi-color emission from coaxial GaInN/GaN MQS nanowire-based light-emitting diodes was identified. A modified epitaxial growth sequence with improved crystalline quality for MQSs applied to effectively narrow the EL peaks.
To light emitting diodes (LEDs), solving the common non-uniform current injection and efficiency degradation issues in (0001) plane micro-LED is essential. Herein, we investigated emission characteristics of various mesa sizes different p-electrode areas toward realization coaxial GaInN/GaN multi-quantum-shell (MQS) nanowires (NWs)-based micro-LEDs. As area was reduced, leakage decreases, further reduction showed a possibility realizing with less leakage. The large path mainly associated...
Broadened emission was demonstrated in coaxial GaInN/GaN multiple quantum shell (MQS) nanowires that were monolithically grown by metalorganic chemical vapor deposition. The non-polar structures coaxially on n-core with combinations of three different diameters and pitches. To broaden the band these nanowire patterns, we varied triethylgallium (TEG) flow rate growth temperature barriers wells, investigated their effects In incorporation during MQS growth. At higher TEG rates, promoted,...
High crystalline quality coaxial GaInN/GaN multiple quantum shells (MQSs) grown on dislocation-free nanowires are highly in demand for efficient white-/micro-light-emitting diodes (LEDs). Here, we propose an effective approach to improve the MQS during selective growth by metal-organic chemical vapor deposition. By increasing temperature of GaN barriers, cathodoluminescent intensity yielded enhancements 0.7 and 3.9 times samples with AlGaN spacers, respectively. Using spacer before barrier...
A multi-quantum-shell (MQS) grown on a GaN nanowire is promising three-dimensional active region and it expected to show excellent performance, compared with conventional nitride-based LEDs. However, there are no suitable simulators for calculating optical properties of MQS-LEDs, because their complex structure. In this study, hybrid simulation, which composed the finite-difference time-domain method, rigorous coupled wave analysis ray tracing developed. Applying useful tool calculation...
The aim of this research is to realize high‐efficiency light‐emitting diodes (LEDs) with a 3D core‐shell GaN nanowire. This article describes the growth nanowires, formation indium tin oxide (ITO) around p‐GaN outer shell and characteristics fabricated nanowire‐LED (NW‐LED). structural properties n‐GaN core, GaInN/GaN multiquantum (MQS), shell, ITO electrode are investigated by scanning electron microscopy transmission microscopy. In addition, optical electrical NW‐LEDs evaluated. findings...
Abstract The superior crystalline quality of coaxial GaInN/GaN multiple-quantum shell (MQS) nanowires (NWs) was demonstrated by employing an AlGaN undershell during metal-organic chemical vapor deposition. Scanning transmission electron microscopy (STEM) results reveal that the NW structure consists distinct regions on different positions NWs and cores were dislocation-free. High-resolution atomic contrast STEM images verified importance undershells in trapping point defects diffused from...
Abstract Improving current injection into r - and m -planes of nanowires (NWs) is essential to realizing efficient GaInN/GaN multiple quantum shell (MQS) NW-based light-emitting diodes (LEDs). Here, we present the effects different p -GaN growth conditions on emission characteristics MQS NW-LEDs. Firstly, a comparison between cathodoluminescence (CL) electroluminescence (EL) spectra indicates that in NW-LEDs originates from top region NWs. By growing thick shells, variable peak at around 600...
Core-shell GaInN/GaN multiquantum shell (MQS) nanowires (NWs) are gaining great attention for high-efficiency micro-light-emitting diodes (micro-LEDs) owing to the minimized etching region on their sidewall, nonpolar or semipolar emission planes, and ultralow density of dislocations. In this study, we evaluated changes in NW morphologies corresponding device properties induced by superlattice (SL) structures. The cathodoluminescence intensities samples with 20 40 pairs SLs were about 2.2 3.4...
The morphology and crystalline quality of p-GaN shells on coaxial GaInN/GaN multiple quantum shell (MQS) nanowires (NWs) were investigated using metal-organic chemical vapor deposition. By varying the trimethylgallium (TMG) flow rate, Mg doping, growth temperature, it was verified that TMG supply temperature dominant parameters in control shape NWs. Specifically, a sufficiently high enabled formation pyramid-shaped NW structure with uniform shell. ratio rate between c- m-planes NWs...
A GaInN/GaN multiquantum shell (MQS) structure grown over GaN nanowires can be utilized as active regions in optoelectronic devices because of its advantages such high crystalline quality and the absence internal polarization. To improve current injection toward sidewall MQS regions, a tunnel junction (TJ) n‐GaN‐embedded cap layer are adopted without using an indium‐tin‐oxide film. light‐emitting diode (LED) composed n‐GaN nanowires, TJs, is demonstrated for first time. Without activation...
In this study, the room-temperature pulsed operation of a nitride nanowire-based multi-quantum shell laser diode with thick p-type GaN cap layer grown on conventional c-face substrate was demonstrated using metalorganic chemical vapor phase epitaxy method. The threshold current density approximately 62 kA cm−2, and voltage at 14 V. Optical spectral characteristics two peak wavelengths, 403 417 nm, were observed.
Here, we systematically investigated the growth conditions of an n-GaN cap layer for nanowire-based light emitters with a tunnel junction. Selective-area multiple quantum shell (MQS)/nanowire core–shell structures on patterned n-GaN/sapphire substrate was performed by metal–organic vapor phase epitaxy, followed p-GaN, n++/ p++-GaN junction, and layer. Specifically, two-step carried out under various to determine optimal flat Scanning transmission electron microscopy characterization revealed...
GaInN/GaN multi-quantum-shell (MQS) nanowires (NWs) are gaining increasing attention as promising materials for developing highly efficient long-wavelength micro-light emitting diodes (LEDs). To improve the emission properties in MQS NWs, it is necessary to suppress from (0001)
Introduction: Many children with disabilities and latent characteristics are cared for in nursery schools (daycare centres). Paediatricians commissioned by our previous survey proved the occurrence of disabled abused schools. As parents alleged victims were likely to contact municipality, a municipalities managing childcare was requested.
 Methods: The target group local authorities' service management departments (public authorities). Questionnaires sent twice 1,742 from late 2012...
Abstract This study aimed to investigate and analyze the impurity doping characteristics in tunnel junctions (TJs) grown on core–shell structures, comprising GaInN/GaN multiple-quantum-shells (MQSs) GaN nanowires. To this end, impurity, structural, electrical properties of samples were characterized by scanning electron microscopy, transmission atom probe tomography (APT), nanoscale secondary ion mass spectrometry (NanoSIMS), electroluminescence device which was fabricated for a prototype...
Herein, the growth mechanism and defect structure of GaN‐based nanowire multiple‐quantum‐shells (NW‐MQSs) with cap layers combining tunnel junctions n‐GaN are investigated in detail. In NW‐MQS structure, structures formed three regions: (i) From c ‐plane active layer at tip NW because low crystal quality layer. (ii) Basal‐plane stacking faults (BSFs) partial dislocations (PDs) generated from m ‐planes NW‐MQSs; these defects triggered by silicon nitride (SiN x ) on surface. While some...