A5076127424- ZnO doping and properties
- Gas Sensing Nanomaterials and Sensors
- Ga2O3 and related materials
- Diamond and Carbon-based Materials Research
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Ferroelectric and Piezoelectric Materials
- Ion-surface interactions and analysis
- Copper-based nanomaterials and applications
- Metal and Thin Film Mechanics
- Microwave Dielectric Ceramics Synthesis
- GaN-based semiconductor devices and materials
- High-pressure geophysics and materials
- Nuclear materials and radiation effects
- Analytical Chemistry and Sensors
- Advancements in Solid Oxide Fuel Cells
- Transition Metal Oxide Nanomaterials
- Acoustic Wave Resonator Technologies
- Advanced ceramic materials synthesis
- Physics of Superconductivity and Magnetism
- Luminescence Properties of Advanced Materials
- Thin-Film Transistor Technologies
- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced Chemical Sensor Technologies
National Institute for Materials Science
2016-2025
Kyushu University
2008-2023
University of East Asia
2021
Tokyo Institute of Technology
2014-2021
The University of Tokyo
1998-2021
Saitama University
2021
John Wiley & Sons (United Kingdom)
2021
Interface (United Kingdom)
2021
John Wiley & Sons (United States)
2021
Tokyo University of Science
2001-2021
ZnO micropatterning under very mild conditions is presented. Photolysis (using a mask) of Si–C bonds in self-assembled phenylsilane layer yields patterned phenyl/hydroxy surface. selectively deposited at 55 °C on the phenyl domains by electroless deposition using Pd catalyst adhered to The viability pattern as phosphor illustrated visible light cathodoluminescence image shown Figure and cover.
Diamond has always been adored as a jewel. Even more fascinating is its outstanding physical properties; it the hardest material known in world with highest thermal conductivity. Meanwhile, when we turn to electrical properties, diamond rather featureless insulator. However, boron doping, becomes p-type semiconductor, acting charge acceptor. Therefore recent news of superconductivity heavily boron-doped synthesized by high pressure sintering was received considerable surprise. Opening up new...
Evidence for the donor nature of sulfur in diamond was obtained by introducing hydrogen sulfide into microwave assisted plasma chemical vapor deposition process. The successfully doped homoepitaxial (100) films, which exhibit n-type conduction Hall-effect measurements temperature range 250--550 K. mobility electrons at room 597 ${\mathrm{cm}}^{2}$ ${\mathrm{V}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$. ionization energy 0.38 eV determined measuring carrier...
A pulse-modulated plasma irradiation technique was applied to hydrogenation of ZnO. Three kinds ZnO samples were employed investigate the electronic state hydrogen in Secondary-ion-mass-spectroscopy analysis using isotope tracer revealed that surface layer 100 nm doped with after and its concentration order 1016 cm−3. The efficiency band edge emission increased by hydrogenation. However, degree improvements depended on impurity defect original samples. It concluded passivates deep donor...
The effect of hydrogen doping on luminescence properties ZnO was investigated. Hydrogen incorporated in the crystal by irradiation with an inductively coupled plasma (ICP), particular, pulse modulated mode operation ICP, and spectra concentration resultant samples were analyzed. A hydrogenated region 20–100 nm formed at sample surface 1017–1018 cm−3. improved ultraviolet emission efficiency all samples, degree improvement depended initial state (impurity concentration) original samples. most...
Effect of Al-substitution for Co on the electrode properties LiCoO2 is investigated in a sulfide solid electrolyte. The substitution decreases resistance and thus improves high-rate capability. Investigation post-annealing effect revealed that, although crystal structure or morphology LiAlxCo1–xO2 are not significantly changed by post-annealing, highly dependent conditions, which suggests that improvement capability comes from change surface particles (i.e., self-organized core–shell...
We investigated roles of hydrogen on physical properties a-IGZO films and thin-film transistors (TFTs) by comparing standard ultra-high vacuum (UHV) sputtering systems. It was confirmed that the impurity hydrogens come mainly from residual gas in deposition chamber molecules adsorbed to surface target. found has unfavorable effects as follows; (i) enhances selective Zn desorption during film deposition, (ii) weakens chemical bonds resulting film, causing temperature instability. On other...
For monitoring of air quality and medical diagnosis, metal-oxide-semiconductor particles with high sensitivity to detect small amount gases are desirable. Herein, we report the fabrication ZnO pyramid-shaped remarkably ethanol gas. The were synthesized solvothermally under agitation from solution zinc acetate anhydride, hexamethylenetetramine, ethylene glycol, water. Gas sensing response was evaluated as ratio electrical resistance particulate layer in that ethanol. during solvothermal...
The surface conditions favoring a negative electron affinity (NEA) on hexagonal boron nitride (h-BN) grown by radio-frequency plasma-assisted chemical vapor deposition (CVD) have been investigated ultraviolet photoelectron spectroscopy. NEA condition the h-BN film appears to be resistant oxygen-plasma or in-vacuo atomic oxygen treatment. It is not certain whether segregation of bulk hydrogen onto helps promote NEA; depth profile deposited reveals about 0.01%–0.1% concentration hydrogen. High...