Tsuyoshi Nakagawa, Shun‐ichi Gonda, Shūichi Emura, Saburo Shimizu,
The dependence of the composition x of AlxIn1−xAs on the arsenic pressure and substrate temperature in molecular beam epitaxy is investigated. At a growth temperature of 540°C, the composition scarcely depends on the arsenic pressure, but at 580°C the Al composition decreases with increasing arsenic pressure under a constant flux ratio of group III elements. The dependence of composition x on the arsenic pressure and substrate temperature can be explained semiquantitatively using a modified thermodynamical ...
Tópico(s): Chalcogenide Semiconductor Thin Films
1988 - Elsevier BV | Journal of Crystal Growth
Sae Gonda, Shuichi Matsumura, Shoichiro Saito, Yasuhiro Go, Hiroo Imai,
The extraoral presence of taste signal transduction proteins has recently been reported in rodents and humans. Here, we report for the first time the presence of these signal transduction proteins in the caecum of a non-human primate, the common marmoset. Quantitative RT-PCR data on the gene expression of taste signal transduction molecules (gustducin and TRPM5) in common marmosets suggested high expression in the caecum, which was not observed in other non-human primates. Immunohistochemical analysis ...
Tópico(s): Advanced Chemical Sensor Technologies
2013 - Royal Society | Biology Letters
H. Asahi, Shūichi Emura, S. Gonda, Yuichi Kawamura, Hidenao Tanaka,
Raman scattering from InGaAlP layers on (100) GaAs substrates grown by molecular-beam epitaxy (MBE) is studied. Compositional dependencies of Raman shifts show two-mode behavior for InAlP and partial three-mode behavior for InGaAlP. The empirical expressions for the compositional variations of LO and TO phonon frequencies are presented. Enhancement of the Raman peak intensities for AlP- and InP-like LO phonons is observed for the composition range when the direct band-gap E0 is close to the photon ...
Tópico(s): Semiconductor materials and devices
1989 - American Institute of Physics | Journal of Applied Physics
Shiping Yu, H. Asahi, J. Takizawa, K. Asami, Shūichi Emura, S. Gonda, Hiroshi Kubo, Chihiro Hamaguchi, Y. Hirayama,
The disordering and compositional change of the InGaAs/InP superlattice by the Ga ion beam was investigated, and using the effect, quantum wires were fabricated by focused Ga ion beam. The analysis of Raman scattering shows that in the implanted region intermixing, i.e., alloying takes place in such a way that the intermixed In1−xGaxAsyP1−y alloy has the compositions of alloy with the lattice constant nearly equal to that of InP, although at higher doses the compositions x and y become smaller due ...
Tópico(s): Integrated Circuits and Semiconductor Failure Analysis
1991 - American Institute of Physics | Journal of Vacuum Science & Technology B Microelectronics and Nanometer Structures Processing Measurement and Phenomena
Shūichi Emura, Shun‐ichi Gonda, Yūichi Matsui, Hideki Hayashi,
Raman spectra of ${\mathrm{In}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As are observed over a wide range of composition. A GaAs-like mode frequency \ensuremath{\omega} is found to vary with the composition x as \ensuremath{\omega}=-32.4${x}^{2}$-18.6x+290.0 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. The internal stresses due to lattice mismatch are evaluated from the deviation of the GaAs-like LO mode frequency from the above experimental equation for small lattice mismatch. An ...
Tópico(s): Semiconductor materials and interfaces
1988 - American Physical Society | Physical review. B, Condensed matter
Soon Jae Yu, H. Asahi, Shūichi Emura, Shun‐ichi Gonda, Kiichi Nakashima,
Interdiffusion process of InGaAs/InP superlattice structures by thermal annealing of 700–850 °C is studied by Raman spectroscopy. Peak intensities and peak energies of InAs-, GaAs-, and InP-like longitudinal optical (LO) phonon modes change with thermal annealing temperature and time. Depth profiles of the group III and group V atoms are estimated quantitatively by measuring the variations of the peak energies of the LO phonon modes and the ratios of the mode intensities. The energy shift of the GaAs- ...
Tópico(s): Semiconductor materials and interfaces
1991 - American Institute of Physics | Journal of Applied Physics
H. Asahi, Kumiko Asami, Tetsuya Watanabe, Soon Jae Yu, Tadaaki Kaneko, Shūichi Emura, Shun‐ichi Gonda,
Short period GaP/AlP superlattices are grown on GaP and GaAs substrates at 600 °C by gas source molecular beam epitaxy with growth interruption. Alternating monolayer growth of GaP and AlP is confirmed by the observation of the reflection high-energy electron diffraction intensity oscillations during growth. The formation of short period superlattice structures and the zone-folded LO phonons are observed in the x-ray diffraction rocking curves and Raman spectra, respectively.
Tópico(s): Advanced Semiconductor Detectors and Materials
1991 - American Institute of Physics | Applied Physics Letters
Koun Shirai, Shūichi Emura, Shun‐ichi Gonda, Y. Kumashiro,
Amorphous boron carbide (a-B1−xCx) is believed to have an icosahedron-based random network. In this paper, vibrational properties of a-B1−xCx films are studied by IR and Raman spectra, placing particular emphasis on the interpretation of the most prominent 1100-cm−1 band associated with the B–C bond. The 1100-cm−1 band appears in both IR and Raman spectra, and the frequency variation and the intensity as a function of the C content are examined, together with evaluation of the absolute absorption ...
Tópico(s): Thin-Film Transistor Technologies
1995 - American Institute of Physics | Journal of Applied Physics
H. Asahi, Teruaki Kohara, R. K. Soni, Nobuyuki Takeyasu, Kumiko Asami, Shūichi Emura, Shun‐ichi Gonda,
Abstract InGaAs/InP heterostructures having atomically controlled interfaces are grown by gas source migration-enhanced epitaxy (GS MEE) on (001)InP substrates at 350°C. RHEED intensity oscillations persisted for over 1 h with the same amplitude and phase during the growth of InGaAs and InP for appropriate supply times of Group III and Group V atoms and proper supply interruption times. The RHEED intensity traces during the growth of InGaAs/InP superlattices as well as Raman spectra from InGaAs/InP ...
Tópico(s): Quantum Dots Synthesis And Properties
1992 - Elsevier BV | Applied Surface Science
Shūichi Emura, Tsuyoshi Nakagawa, Shun‐ichi Gonda, Saburo Shimizu,
Raman study of the lattice vibrations of a ternary alloy AlxIn1−xAs on InP substrate over the whole range of compositions is reported. The Raman spectra show a two-mode-type behavior involving AlAs- and InAs-like longitudinal optical-phonon modes. The frequency of the AlAs-like mode strongly depends on the composition, but frequency of the InAs-like mode is almost independent of composition. A disorder-induced scattering by acoustic vibrations is also observed.
Tópico(s): Quantum and electron transport phenomena
1987 - American Institute of Physics | Journal of Applied Physics
Soon Jae Yu, H. Asahi, Shūichi Emura, Hitoshi Sumida, Shun‐ichi Gonda, H. Tanoue,
The damage of Sn-doped InP by Ga ion implantation with fluences ranging from 1×1013 to 5×1014 cm−2 and annealing effects (150–650 °C) are investigated by means of Raman scattering. The shift and asymmetrical broadening of a longitudinal optical phonon peak and the appearance of transverse optical mode and disorder-activated acoustic modes show that the damage effect by Ga ion implantation is very large, and the crystalline structure becomes amorphouslike at a fluence as low as 1×1014 cm−2. The damaged ...
Tópico(s): Thin-Film Transistor Technologies
1989 - American Institute of Physics | Journal of Applied Physics
S. G. Kim, H. Asahi, Masumichi Seta, J. Takizawa, Shūichi Emura, R. K. Soni, S. Gonda, H. Tanoue,
Recovery process in GaSb crystals with Ga ion implantation and subsequent annealing by rapid thermal annealing (RTA) or furnace annealing (FA) methods are studied by Raman scattering. The intensity of the GaSb LO phonon mode decreases with increasing ion implantation fluence. It is found that the threshold fluence to the amorphization for the Ga ion implanted GaSb is 5×1013 cm−2. It is much lower than that for InP (1×1014 cm−2). In the face-to-face FA, the recovery processes in the Ga ion implanted ...
Tópico(s): Semiconductor materials and interfaces
1993 - American Institute of Physics | Journal of Applied Physics
H. Asahi, Teruaki Kohara, R. K. Soni, Kumiko Asami, Shūichi Emura, Shun‐ichi Gonda,
Abstract Atomically controlled InGaAs/InP SL structures having different types of heterointerfaces are grown on (001)InP substrates at 350°C gas source MEE (migration enhanced epitaxy). RHEED intensity traces exhibit the same shape at the positions of the same type of heterointerfaces, indicating the formation of the desired heterointerfaces. The Raman spectrum from the SL, having only the InAs-type heterointerfaces, is characterized by the absence of GaP-like LO phonon clearly suggesting the formation ...
Tópico(s): Quantum Dots Synthesis And Properties
1993 - Elsevier BV | Journal of Crystal Growth
K. Asami, T. Okuno, Shūichi Emura, S. Gonda, Seiji Mukai,
Electroreflectance (ER) measurements have been performed on an (AlxGa1−x)1−zInzPyAs1−y pentanary alloy grown on (100) GaAs in the energy range 1.3–3.8 eV at 300 K. Accurate band-gap energy has been determined from ER measurements. Photoluminescence (PL) spectra have been measured in the energy range 1.3–2.0 eV at 300 and 77 K. From the broadening parameters in ER spectra and the full width of half-maxima in PL spectra, the quality of AlGaInPAs has been discussed. The other optical features, E0+Δ0, E1, ...
Tópico(s): Semiconductor materials and devices
1987 - American Institute of Physics | Applied Physics Letters
H. Asahi, Soon Jae Yu, J. Takizawa, S.G. Kim, Yasutoshi Okuno, T. Kaneko, Shūichi Emura, S. Gonda, Hitoshi Kubo, Chihiro Hamaguchi, Y. Hirayama,
InGaAsP/InP quantum-wire structures are fabricated by focused Ga ion beam implantation onto InGaAs/InP single quantum well (QW) structures. It is found that InGaAsP layers produced by the intermixing of InGaAs/InP QW's by Ga ion implantation and subsequent thermal annealing are nearly lattice matched to the InP substrate. Fabricated quantum-wire structures exhibit photoluminescence spectra showing a large blue shift, which is induced by the carrier confinement into wire structures and the change ...
Tópico(s): Semiconductor materials and devices
1992 - Elsevier BV | Surface Science
R. K. Soni, Hirosuke Asahi, Shūichi Emura, Tetsuya Watanabe, K. Asami, S. Gonda,
Abstract e present Raman scattering characterization of short-period (GaP)n(AlP)m superlattices grown on GaAs (001) substrate by gas source MBE. Confined optical vibrations are observed in GaP and AlP layers which show strong sensitivity to the thickness. The measured confined frequencies are explained by considering an intermediate alloy layer in the interface plane due to short-range roughness. The influence of interface roughness on the behavior of confined vibrations is weak in thicker layer (n, ...
Tópico(s): Semiconductor materials and interfaces
1992 - Elsevier BV | Applied Surface Science
H. Asahi, Hitoshi Sumida, Soon Jae Yu, Shūichi Emura, Shun‐ichi Gonda, Masanori Komuro,
A high-electrical-resistance region as high as 1×10 4 Ω·cm can be formed in Si-doped InP ( n =1×10 18 cm -3 ) layers by 8×10 14 cm -2 Ga focused ion beam (FIB) implantation and 500–600°C annealing. The clear photoresponse is also observed in the Ga-FIB-implanted diode structures after annealing. A drastic carrier concentration decrease and the existence of residual defects are confirmed by Raman scattering measurement.
Tópico(s): Silicon Nanostructures and Photoluminescence
1989 - Institute of Physics | Japanese Journal of Applied Physics
Shūichi Emura, Shun‐ichi Gonda, Seiji Mukai,
The Raman scattering of (AlxGa1−x)1−zInzPyAs1−y (x<0.33, y<0.18) pentanary alloy semiconductor lattice matched to GaAs is investigated for the first time. Five Raman peaks are found in the composition range studied here, indicating that these materials display the multimode nature in the lattice mode character. The four peaks except the lowest one in frequency are assigned to InAs-, GaAs-, GaP-, and AlAs-like longitudinal optical modes, and the lowest one to disorder activated longitudinal ...
Tópico(s): Semiconductor Quantum Structures and Devices
1988 - American Institute of Physics | Journal of Applied Physics
S. G. Kim, H. Asahi, Masumichi Seta, Shūichi Emura, Heiji Watanabe, S. Gonda, H. Tanoue,
Radiation damage and its recovery process of molecular-beam epitaxy grown AlSb implanted with Ga ions is studied using Raman scattering for Ga ion fluences ranging from 1×1013 to 5×1014 cm−2 and for annealing temperatures ranging from 300 to 600 °C. With increasing fluences the AlSb longitudinal optical (LO) phonon mode shifts to lower frequency and exhibits an asymmetric broadening. Recovery of radiation damages in the ion implanted AlSb is observed after annealing at as low as 300 °C. On the other ...
Tópico(s): Semiconductor Quantum Structures and Devices
1993 - American Institute of Physics | Journal of Applied Physics
Shūichi Emura, R. K. Soni, Shun‐ichi Gonda,
We study the effect of interfacial strain on the optical phonons in the strained-ultrathin-layer (InAs${)}_{2}$/(GaAs${)}_{1}$ superlattice by use of Raman scattering. A large softening of the vibrational frequencies, arising from a combined effect of phonon confinement and tensile stress in the GaAs layer, is observed. By comparing with an ${\mathrm{In}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ga}}_{\mathit{x}}$As alloy of equivalent composition, in which the composition dependence of the mode ...
Tópico(s): Advanced Semiconductor Detectors and Materials
1992 - American Physical Society | Physical review. B, Condensed matter
Takamitsu Hara, Manabu Iwadate, Shuichi Shiratori, Kenji Gonda, Tatsuo Shimura, Yoshihiro Nakagami, Masahiko Shibata, Satoshi Waguri, Seiichi Takenoshita,
... the radiotherapy. Citation Format: Takamitsu Hara, Manabu Iwadate, Shuichi Shiratori, Kenji Gonda, Tatsuo Shimura, Yoshihiro Nakagami, Masahiko Shibata, Satoshi Waguri, ...
Tópico(s): Cancer Research and Treatments
2013 - American Association for Cancer Research | Cancer Research
Shūichi Emura, Hitoshi Sumida, Shun‐ichi Gonda, Seiji Mukai,
Photoluminescence spectra of the pentanary alloy semiconductor (AlxGa1−x)1−zInzPyAs1−y (x<0.33, y<0.18, z<0.09) are observed at various temperatures between 300 and 13 K. The spectrum at higher temperatures is of a single peak, in which the line shape is well reproduced by an expression of C(E−Eg)1/2 exp[−(E−Eg)/kBT], where E is the photon energy, Eg the band gap, kB Boltzmann constant, and T temperature. At lower temperatures, a band on the lower energy side grows up rapidly. ...
Tópico(s): Electronic and Structural Properties of Oxides
1988 - American Institute of Physics | Journal of Applied Physics
Shuichi Yoshida, Ito Kenji, Shigeo Gonda,
Development of detection kit for sulfonylurea resistant
Tópico(s): Agriculture, Soil, Plant Science
2007 - The Weed Science Society of Japan | Journal of Weed Science and Technology
Soichiro Usui, Naotoshi Sugimoto, Noriko Takuwa, Satoru Sakagami, Shigeo Takata, Shuichi Kaneko, Yoh Takuwa,
... Scopus (288) Google Scholar, 29Okamoto H. Takuwa N. Gonda K. Okazaki H. Chang K. Yatomi Y. Shigematsu ...
Tópico(s): Lipid metabolism and biosynthesis
2004 - Elsevier BV | Journal of Biological Chemistry
Shūichi Emura, Yūichi Matsui, Shun‐ichi Gonda,
Phonon behavior in the strained (InAs)m/(GaAs)n ultrathin superlattices grown by molecular beam epitaxy has been investigated by means of Raman scattering spectroscopy. The phonon frequency in the GaAs layers shifts toward lower energy with increasing InAs layer thickness under fixed thickness of GaAs layers. The frequency in the InAs layers does not change significantly, as deduced from the behavior of the InAs-like mode in InxGa1−xAs alloys. These observed results are phenomenologically discussed ...
Tópico(s): Advanced Semiconductor Detectors and Materials
1995 - Elsevier BV | Journal of Crystal Growth
Shūichi Emura, K. Koto, Akira Yoshiasa, Hiroshi Itô, S. Gonda, Seiji Mukai,
Tópico(s): Thermodynamic and Structural Properties of Metals and Alloys
1989 - Springer Science+Business Media | Journal of Materials Science Letters