OTANI NAOKI
Faculty of Science and Engineering Department of Electronics
Professor
Last Updated :2019/09/26

Researcher Profile and Settings

Research Interests

  • Light-emitting diodes
  • Dye-sensitized solar cells
  • Optical devices
  • semiconductor photo-physics
  • nano-structures
  • quntum dots
  • multi-quantum wells
  • organic-EL

Research Areas

  • Electrical and electronic engineering/Electron device/Electronic equipment
  • Electrical and electronic engineering/Electronic materials/Electric materials
  • Nano/Micro science/Nanostructural physics

Research History

  • 1994-2001 Research on ultra-fast optical switching devices and photo-physics of semiconductor nano-structures
  • 2001-2005 Research on semiconductor lasers and and photo-physics of semiconductor nano-structures

Academic & Professional Experience

  • Communications Research Laboratory, Leader of research group, 2001 - 2005
  • ATR Laboratories, Visiting researcher, 1994 - 2001

Education

  • Hokkaido University, Graduate School, Division of Engineering, 1994
  • Tokyo University of Agriculture and Technology, Faculty of Engineering, 1989

Academic Degrees

  • Doctor of Engineering, Hokkaido University
  • Master of Engineering, Hokkaido University

Association Memberships

  • THE JAPAN SOCIETY OF APPLIED PHYSICS

Awards & Honors

  • IEDMS2015 Best Paper Award
    2015

Published Papers

  • Fabrication and Characterization of Carbon Nitride Fluorescent Material Using Annealed Melamine
    K. Wada and N. Ohtani
    Physica Status Solid (b), 256(6)1800521 , Jun. 2019, English, Research paper (scientific journal)
  • Optical properties and carrier transport in a biased GaAs/AlAs asymmetric quintuple-quantum-well superlattice
    K. Yoshida, S. Goto, R. Wang, M. Hosoda, K. Akahane, and N. Ohtani
    Key Engineering Materials, 777(8)121 - 125, Aug. 2018, English, Research paper (scientific journal)
  • All solution-processed quintuple-layer organic light-emitting diodes containing organic-inorganic hybrid active layers fabricated by sol-gel method
    Y. Jitsui and N. Ohtani
    Key Engineering Materials, 777(8)113 - 120, Aug. 2018, English, Research paper (scientific journal)
  • Fabrication of aluminum and gallium codoped ZnO multilayer transparent conductive films by spin coating method and discussion about improving their performance
    Y. Morita and N. Ohtani
    Japanese Journal of Applied Physics, 57(2)02CB03-1 - 02CB03-6, Feb. 2018, English, Research paper (scientific journal)
  • Evidence for various higher subband resonances and interferences in a GaAs/AlAs asymmetric quadruple-quantum-well superlattice analyzed from its photoluminescence properties
    K. Hata, M. Hosoda, K. Akahane, and N. Ohtani
    Physical Review B, 95(2)075309-9 , Feb. 2017, English, Research paper (scientific journal)
  • Improvement of photoelectric conversion efficiencies of dye-sensitized solar cells consisting of hemispherical TiO2 films
    S. Izumi, A. Mizuno, and N. Ohtani
    physica status solidi (c), 14(6)1600186 , Feb. 2017, English, Research paper (scientific journal)
  • 半導体超格子における電界ドメインの非線形ダイナミクス
    M. Hosoda and N. Ohtani
    Oyo Butsuri, 84(6)508 , 2015, Japanese, Research paper (scientific journal)
  • Fabrication of silica glass thin films containing organic emissive materials and application to multi-layer organic light-emitting diodes
    R. Nakagawa, Y. Jitsui, A. Emoto, and N. Ohtani
    Molecular Crystals and Liquid Crystals, 641(1)111 , Dec. 2016, English, Research paper (scientific journal)
  • Enhancement of radiative efficiencies of near-ultraviolet organic light-emitting diodes by localized surface plasmon resonance effect
    A. Matsuoka, A. Emoto, and N. Ohtani
    Journal of Physics, 647(1)012058 , Oct. 2015, English, Research paper (scientific journal)
  • Improved photoluminescence lifetime of organic emissive materials embedded in organic-inorganic hybrid thin films fabricated by sol-gel method using Tetraethoxysilane
    N. Ohtani and M. Tonoi
    Molecular Crystals and Liquid Crystals, 599(1)132 , May 2014, English, Research paper (scientific journal)
  • Synthesis of Uniform and High Density Silver Nanoparticles by using Peltophorum pterocarpum flower Extract
    B. Matheswaran, S. Saravanan, and N. Ohtani
    Japanese Journal of Applied Physics, 53(5S1)05FB19 , May 2014, English, Research paper (scientific journal)
  • Structural and Photoluminescence Studies of Ni- doped ZnO Nanoparticles Synthesized by Simple Solution Combusting Method
    S. Murugesan, S. Saravanan, N. Ohtani and T. Soga
    Japanese Journal of Applied Physics, 53(5S1)05FB16 , May 2014, English, Research paper (scientific journal)
  • Fabrication and optical characterization of organic-inorganic hybrid films using ultraviolet curable silsesquioxanes
    H. Akiyama and N. Ohtani
    Japanese Journal of Applied Physics, 53(2S)02BC18 , Jan. 2014, English, Research paper (scientific journal)
  • Excitonic Rabi oscillations in self-assembled quantum dots in the presence of a local field effect
    K.Asakura, Y. Mitsumori, H. Kosaka, K. Edamatsu, K. Akahane, N. Yamamoto, M. Sasaki, and N. Ohtani
    Physical Review B, 87(24)241301(R) , Dec. 2013, English, Research paper (scientific journal)
  • White organic light emitting diodes using two phosphorescence materials in a starburst hole-transporting layer
    T. Inden, T. Hishida, M. Takahashi, M. Ohsumi, and N. Ohtani
    International Journal of Photoenergy, 2012703496 , Mar. 2012, English, Research paper (scientific journal)
  • Fabrication of near-infrared polymer light-emitting diodes using dispersed laser dye
    Y. Jitsui and N. Ohtani
    Journal of the Korean Physical Society, 60(10)1557 - 1559, May 2012, English, Research paper (scientific journal)
  • Fabrication of organic light-emitting diodes using photosynthetic-pigments extracted from spinach
    N. Ohtani, N. Kitagawa and T. Matsuda
    Nature Photonics, 50(1)01BC08 , Apr. 2011, English, Research paper (scientific journal)
  • Organic near-infrared photodiodes containing a wide-bandgap polymer and an n-type dopant in the active layer
    N. Ohtani, K. Nakajima, and K. Bando
    Physica Status Solidi (c), 8(9)2907 - 2910, Sep. 2011, English, Research paper (scientific journal)
  • Carrier Transport and Luminescent Properties in Organic Light-Emitting Diodes Containing Graded Co-Deposited Active Layer
    N. Ohtani and M. Murata
    Lecture Notes in Information Technology, 11162 - 166, Dec. 2011, English, Research paper (scientific journal)
  • Improvement of carrier transport and luminous efficiency of organic light-emitting diodes by introducing a co-deposited active layer
    N. Ohtani, M. Murata, K. Kashiwabara, and K. Kurata
    Journal of Physics, 1930121060 , Mar. 2010, English, Research paper (scientific journal)
  • Observation and numerical analysis of quantum subband energies from photoluminescence spectra of organic multiple quantum wells
    N. Ohtani, M. Murata, and T. Yamamoto
    Microelectronics Journal, 40(4-5)867 - 868, Jan. 2009, English, Research paper (scientific journal)
  • Experimental study on the condition of formation of electric-field domains in multiple finite superlattices
    N. Ohtani, S. Noma, K. Akahane, M. Hosoda, and K. Fujita
    Microelectronics Journal, 40(4-5)818 - 820, Jan. 2009, English, Research paper (scientific journal)
  • 4-(Dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM)-doping density dependence of luminescence spectra and white emission in polymer light-emitting diodes
    A. Inoue, T. Hosokawa, M. Haishi, and N. Ohtani
    Physica Status Solidi, 6(1)334 - 447, Jan. 2009, English, Research paper (scientific journal)
  • Influence of co-deposited active layers on carrier transport and luminescent properties in organic light emitting diodes
    M. Murata, T. Yamamoto, M. Haishi, T. Ando, and N. Ohtani
    Physica Status Solidi (c), 6(1)330 - 333, Jan. 2009, English, Research paper (scientific journal)
  • Photoluminescence properties of annealed InAs quantum dots capped by InGaAs layers
    S. Hiratsuka, S. Saravanan, T. Harayama, and N. Ohtani
    Physica Status Solidi, 6(1)189 - 192, Jan. 2009, English, Research paper (scientific journal)
  • Quantum size effect on photoluminescence and electroluminescence in organic multiple quantum wells
    T. Yamamoto, M. Murata, M. Haishi, T. Ando, and, N. Ohtani
    Journal of Physics, 109012036 , Apr. 2008, English, Research paper (scientific journal)
  • Electric-field-direction dependence of carrier injection into high-energy states in asymmetric GaAs/AlAs multiple-quantum wells embedded in an n-i-n diode
    H. Kitamura, S. Hiratsuka, M. Hosoda, K. Akahane, and, N. Ohtani
    Journal of Physics, 109012021 , Apr. 2008, English, Research paper (scientific journal)
  • Improvement of radiative efficiency and wavelength-tuning by TPD-doping in organic light emitting diode using Poly [methylmethacrylate-co- (7- (4-trifluoromethyl) coumarin acrylamide)] (PCA)
    M. Haishi, T. Yamamoto, M. Murata, and, N. Ohtani
    Journal of Physics, 109012011 , Apr. 2008, English, Research paper (scientific journal)
  • Various photoluminescence properties due to Gamma-X resonance in type-I GaAs/AlAs multi-quantum wells consisting of quantum wells with different thicknesses
    N. Ohtani, H. Endo, S. Hiratsuka, H. Kitamura, T. Takamatsu, and M. Hosoda
    Physica E, 40(6)2016 - 2018, Apr. 2008, English, Research paper (scientific journal)
  • Photoluminescence properties affected by carrier transport between X and different first excited states originating from interface imperfection in GaAs/AlAs multi-quantum wells
    H. Endo, S. Hiratsuka, H. Kitamura, T. Takamatsu, M. Hosoda, and N. Ohtani
    Japanese Journal of Applied Physics, 47(1)682 - 684, Jan. 2008, English, Research paper (scientific journal)
  • Strong optical emission from two-dimensional metal photonic crystals with semiconductor multiple quantum wells
    S. Gozu, K. Akahane, N. Yamamoto, A. Ueta, N. Ohtani, and M. Tsuchiya
    Journal of Applied Physics, 101(8)086107 , Aug. 2007, English, Research paper (scientific journal)
  • Metamorphic molecular beam epitaxy growth and selective wet etching in epitaxial lift-off of AlAsSb toward optical waveguides with high optical confinement
    S. Gozu, K. Akahane, N. Yamamoto, A. Ueta, N. Ohtani, and M. Tsuchiya
    Journal of Crystal Growth, 301(1)955 - 958, Apr. 2007, English, Research paper (scientific journal)
  • Growth of InGaSb Quantum Dot Structures on GaAs and Silicon Substrates
    N. Yamamoto, K. Akahane, S. Gozu, A. Ueta, N. Ohtani, and M. Tsuchiya
    Japanese Journal of Applied Physics, 46(4)2401 - 2404, Apr. 2007, English, Research paper (scientific journal)
  • Site control of very low density InAs QDs on patterned GaAs nano-wiresurfaces
    A. Ueta, K. Akahane, S. Gozu, N. Yamamoto, N. Ohtani, and M. Tsuchiya
    Journal of Crystal Growth, 301(1)846 - 848, Apr. 2007, English, Research paper (scientific journal)
  • (In)GaSb/AlGaSb quantum wells grown on Si substrates
    K. Akahane, N. Yamamoto, S. Gozu, A. Ueta, and N. Ohtani
    Thin Solid Films, 515(10)4467 - 4470, Mar. 2007, English, Research paper (scientific journal)
  • Various photoluminescence properties observed in a GaAs/AlAs asymmetric double-quantum-well superlattice
    N. Ohtani, and M. Hosoda
    Physica Status Solidi (c), 4(2)353 - 355, Feb. 2007, English, Research paper (scientific journal)
  • Optical Cavity Properties of Metal Mirror Microcavities with InAsSb Quantum Dots
    A. Ueta, K. Akahane, S. Gozu, N. Yamamoto, M. Tsuchiya, and N. Ohtani
    Japanese Journal of Applied Physics, 45(11)8650 - 8652, Nov. 2006, English, Research paper (scientific journal)
  • Residual carrier density in GaSb grown on Si substrates
    K. Akahane, N. Yamamoto, S. Gozu, A. Ueta, and N. Ohtani
    Thin Solid Films, 515(2)748 - 751, Oct. 2006, English, Research paper (scientific journal)
  • Numerical method for coherent electron dynamics with potential-dependent effective-mass distributions in semidonductor heterostructures
    T. Ando, Y. Ohtake, and N. Ohtani
    Physical Review E, 73(6)066702 , Jun. 2006, English, Research paper (scientific journal)
  • Study of InAsN quantum dots on GaAs substrates by molecular beam epitaxy
    A. Ueta, K. Akahane, S. Gozu, N. Yamamoto, and N. Ohtani
    Physica Status Solidi (B), 243(7)1514 - 1518, Jun. 2006, English, Research paper (scientific journal)
  • Nanoscale structure fabrication of multiple AlGaSb/InGaSb quantum wells by reactive ion etching with chlorine-based gases toward photonic crystals
    S. Gozu, K. Akahane, N. Yamamoto, A. Ueta, N. Ohtani, and M. Tsuchiya
    Journal of Vacuum Science and Technology B, 24(5)2291 - 2294, May 2006, English, Research paper (scientific journal)
  • Metamorphic InGaAs/AlAsSb quantum wells grown on GaAs substrates for intersubband devices operating toward short-wavelength region
    S. Gozu, A. Ueta, K. Akahane, N. Yamamoto, N. Ohtani, and M. Tsuchiya
    Electronics Letters, 42(10)601 - 602, May 2006, English, Research paper (scientific journal)
  • Optical communications waveband lasing from Sb-based quantum dot vertical-cavity laser
    . Yamamoto, K. Akahane, S. Gozu, A. Ueta, and N. Ohtani
    Physica E, 32(1+2)516 - 519, May 2006, English, Research paper (scientific journal)
  • Change in band configuration of In0.57Ga0.43As1-xSbx/AlAs0.48Sb0.52 quantum well from type-II to type-I by increasing Sb composition x
    S. Gozu, K. Akahane, N. Yamamoto, A. Ueta, and N. Ohtani
    Physica E, 32(1+2)230 - 233, May 2006, English, Research paper (scientific journal)
  • 1.5 micron emission from InAs quantum dots with InGaAsSb strain-reducing layer grown on GaAs substrates
    K. Akahane, N. Yamamoto, S. Gozu, A. Ueta, and N. Ohtani
    Physica E, 32(1+2)81 - 84, May 2006, English, Research paper (scientific journal)
  • Observation of subband resonances between higher energy states in a series of asymmetric double quantum well superlattice systems
    M. Hosoda, M. Sato, Y. Hirose, T. Shioji, C. Domoto, and N. Ohtani
    Physical Review B, 73(16)165329 , Apr. 2006, English, Research paper (scientific journal)
  • Selective formation of self-organized InAs QDs on atterned GaAs substrates by molecular beam epitaxy
    A. Ueta, K. Akahane, S. Gozu, N. Yamamoto, and N. Ohtani
    Japanese Journal of Applied Physics, 45(4)3556 - 3559, Apr. 2006, English, Research paper (scientific journal)
  • Interface states of AlSb/InAs heterointerfacee with AlAs like interface
    S. Gozu, K. Akahane, N. Yamamoto, A. Ueta, T. Ando, and N. Ohtani
    Japanese Journal of Applied Physics, 45(4)3540 - 3543, Apr. 2006, English, Research paper (scientific journal)
  • 1.55-micron-waveband emissions operation of Sb-based quantum-dot vertical-cavity sufrace-emitting lasers fabricated on GaAs substrate
    N. Yamamoto, K. Akahane, S. Gozu, A. Ueta, and N. Ohtani
    Japanese Journal of Applied Physics, 45(4)3423 - 3426, Apr. 2006, English, Research paper (scientific journal)
  • Electron scattering between X and L indirect valleys in type-I GaAs/AlAs semiconductor superlattices
    M. Hosoda, J. Nohgi, and N. Ohtani
    Physical Review B, 72(3)033317 , Jul. 2005, English, Research paper (scientific journal)
  • All-optical control of resonant-photon tunneling effect observed in GaAs/AlGaAs multilayered structures containing quantum dots
    N. Yamamoto, K. Akahane, S. Gozu, A. Ueta, and N. Ohtani
    Applied Physics Letters, 87(23)231119 , Dec. 2005, English, Research paper (scientific journal)
  • Initial growth stage of GaSb on Si(001) substrates with AlSb initiation layers
    K. Akahane, N. Yamamoto, S. Gozu, and N. Ohtani
    Journal of Crystal Growth, 283(3)297 - 302, Oct. 2005, English, Research paper (scientific journal)
  • Circular polarization switch by using photo-chemically etched silicon
    N. Yamamoto, N. Ohtani, T. Matsuno and H. Takai
    Japanese Journal of Applied Physics, 44(7A)4749 - 4751, Jul. 2005, English, Research paper (scientific journal)
  • Anomalous photoluminescence branches observed in an asymmetric double-quantum-well superlattice
    N. Ohtani, N. Yamamoto, J. Nohgi and M. Hosoda
    Physica Status Solidi (c), 2(8)3006 - 3009, Jul. 2005, English, Research paper (scientific journal)
  • Over 1.3-μm laser emission from InGaSb quantum-dot diode fabricated on GaAs substrates
    N. Yamamoto, K. Akahane, S. Gozu, and N. Ohtani
    Applied Physics Letters, 86(20)203118 , May 2005, English, Research paper (scientific journal)
  • Growth of InAsSb quantum dots on GaAs substrates using periodic supply epitaxy
    A. Ueta, S. Gozu, K. Akahane, N. Yamamoto, and N. Ohtani
    Japanese Journal of Applied Physics, 44(22)696 - 698, May 2005, English, Research paper (scientific journal)
  • Characteristics of coupled mode of excitonic quantum beat and coherent longitudinal optical phonon in GaAs/AlAs multiple quantum wells
    T. Furuichi, O. Kojima, K. Mizoguchi, K. Akahane, N. Yamamoto, N. Ohtani and M. Nakayama,
    Journal of Luminescence, 112(1)142 - 145, Apr. 2005, English, Research paper (scientific journal)
  • Strong photoluminescence and laser operation of InAs quantum dot covered by GaAsSb strain reduced layer
    K. Akahane, N. Yamamoto, S. Gozu, and N. Ohtani
    Physica E, 26(1)395 - 399, Feb. 2005, English, Research paper (scientific journal)
  • High quality GaSb/AlGaSb quantum well grown on Si substrate
    K. Akahane, N. Yamamoto, S. Gozu, and N. Ohtani
    Japanese Journal of Applied Physics, 44(1)15 - 17, Jan. 2005, English, Research paper (scientific journal)
  • Over 1.3 micron CW laser-emission from an InGaSb quantum-dot vertical-cavity surface-emitting laser on GaAs substrate
    N. Yamamoto, K. Akahane, S. Gozu, and N. Ohtani
    Electronics Letters, 40(18)1120 - 1121, Sep. 2004, English, Research paper (scientific journal)
  • Growth of InAs quantum dots on a low lattice-mismatched AlGaSb
    N. Yamamoto, K. Akahane, S. Gozu, and N. Ohtani
    Solid-State Phenomena, 99(1)49 - 52, Aug. 2004, English, Research paper (scientific journal)
  • Coupled mode of the coherent optical phonon and excitonic quantum beat in GaAs/AlAs multiple quantum wells
    K. Mizoguchi, O. Kojima, T. Furuichi, M. Nakayama,
    Physical Review B, 69(23)233302 , Jun. 2004, English, Research paper (scientific journal)
  • All-optical switching and memorizing devices using resonant photon tunneling effect in multi-layered GaAs/AlGaAs structures
    N. Yamamoto, and N. Ohtani
    Japanese Journal of Applied Physics, 43(4A)1393 - 1397, Apr. 2004, English, Research paper (scientific journal)
  • Formation of electric-field domains in an asymmetric double-quantum-well GaAs/AlAs superlattice
    N. Ohtani, Y. Hirose, T. Nishimura, T. Aida, and M. Hosoda
    Semiconductor Science and Technology, 19(4)89 - 90, Apr. 2004, English, Research paper (scientific journal)
  • Uniaxial-strain-induced transition from type-II to type-I band configuration of quantum well microtubes
    N. Ohtani, Y. Kishimoto, K. Kubota, S. Saravanan, Y. Sato, P. Vaccaro, T. Aida, and M. Hosoda
    Physica E, 21(2)732 - 736, Mar. 2004, English, Research paper (scientific journal)
  • Growth of high-density InGaSb quantum dots on silicon atoms irradiated substrate
    N. Yamamoto, K. Akahane, and N. Ohtani
    Physica E, 21(2)322 - 325, Mar. 2004, English, Research paper (scientific journal)
  • Long wavelength light emission from InAs quantum dots covered by GaAsSb grown on GaAs substrates
    K. Akahane, N. Yamamoto, and N. Ohtani
    Physica E, 21(2)295 - 299, Mar. 2004, English, Research paper (scientific journal)
  • Heteroepitaxial growth of GaSb on Si(001) substrates
    K. Akahane, N. Yamamoto, S. Gozu, and N. Ohtani
    Journal of Crystal Growth, 264(1)21 - 25, Mar. 2004, English, Research paper (scientific journal)
  • Self-consistent calculation of subbnad occupation and electron-hole plasma effects: Variational approach to quantum well states with Hartree and exchange-correlation interactions
    T. Ando, H. Taniyama, N. Ohtani, M. Hosoda and M. Nakayama
    Journal of Applied Physics, 94(7)4489 - 4501, Oct. 2004, English, Research paper (scientific journal)
  • Role of Al in spacer layer on the formation of stacked InAs quantum dot structures on InP(311)B
    K. Akahane, N. Yamamoto, N. Ohtani, Y. Okada, and M. Kawabe
    Journal of Crystal Growth, 256(1)7 - 11, Aug. 2003, English, Research paper (scientific journal)
  • Quantum-well microtube constructed from a free-standing thin quantum-well layer
    M. Hosoda, Y. Kishimoto, M. Sato, S. Nashima, K. Kubota, S. Saravanan, P. Vaccaro, T. Aida, and N. Ohtani
    Applied Physics Letters, 83(5)1017 - 1019, Aug. 2003, English, Research paper (scientific journal)
  • Photoluminescence property of uniaxially strained GaAs/AlGaAs quantum wells contained in a micro-tube
    N. Ohtani, K. Kubota, P. Vaccaro, T. Aida, and M. Hosoda
    Physica E, 17(1)391 - 392, Apr. 2003, English, Research paper (scientific journal)
  • Fabrication of ultra-high density InAs stacked quantum dots by strain controlled growth on InP(311)B substrate
    K. Akahane, N. Ohtani, Y. Okada, and M. Kawabe
    Journal of Crystal Growth, 245(1)31 - 36, Nov. 2002, English, Research paper (scientific journal)
  • Numerically stable and flexible method for solutions of the Schroedinger equation with self-interaction of carriers in quantum wells
    T. Ando, H. Taniyama, N. Ohtani, M. Hosoda and M. Nakayama
    IEEE Journal of Quantum Electronics, 38(10)1372 - 1383, Oct. 2002, English, Research paper (scientific journal)
  • Photoluminescence from higher Γ-electron subbands and intersubband electroluminescence using X-G carrier injection in a simple GaAs/AlAs superlattice
    C. Domoto, T. Nishimura, N. Ohtani, K. Kuroyanagi, P. O. Vaccaro, T. Aida, H. Takeuchi, and M. Nakayama
    Japanese Journal of Applied Physics, 41(8)5073 - 5077, Aug. 2002, English, Research paper (scientific journal)
  • Photoluminescence of GaAs/AlGaAs micro-tubes containing uniaxially strained quantum wells
    K. Kubota, P. Vaccaro, N. Ohtani, Y. Hirose, M. Hosoda, and T. Aida
    Physica E, 13(2)313 - 316, Mar. 2002, English, Research paper (scientific journal)
  • Excitation of right- and left-circularly polarized photoluminescence in silicon-based luminescent materials
    N. Yamamoto, I. Hosako, M. Akiba, N. Ohtani, and H. Takai
    Journal of Applied Physics, 91(5)2725 - 2728, Mar. 2002, English, Research paper (scientific journal)
  • Formation process of high-field domain in superlattices observed by photoluminescence spectra branch
    M.~Hosoda, N.~Ohtani, C.~Domoto, and T.~Aida:
    Japanese Journal of Applied Physics, 40(4B)3023 - 3031, Apr. 2001, English, Research paper (scientific journal)
  • Population inversion between subbands in simple periodical GaAs/AlAs superlattice
    C. Domoto, P. Vaccaro, and N. Ohtani
    IEE Proceedings: Optoelectronics, 147(3)225 - 227, Jun. 2000, English, Research paper (scientific journal)
  • Intersubband electroluminescence using X-G carrier injection in a GaAs/AlAs superlattice
    C. Domoto, N. Ohtani, K. Kuroyanagi, P. Vaccaro, H. Takeuchi, M. Nakayama, and T. Nishimura
    Applied Physics Letters, 77(6)848 - 850, Jun. 2000, English, Research paper (scientific journal)
  • Electric-field effects on photoluminescence properties in a GaAs/AlAs marginal type-I superlattice
    N. Ohtani, C. Domoto, N. Egami, H. Mimura, M. Ando, M. Nakayama, and M. Hosoda
    Physica E, 7(3-4)586 - 589, May 2000, English, Research paper (scientific journal)
  • Anomalous photoluminescence originating from resonance between X and intermediate states in GaAs/AlAs superlattices
    N. Ohtani, C. Domoto, K. Kuroyanagi, N. Egami, and M. Hosoda
    Journal of Luminescence, 87(1)415 - 417, May 2000, English, Research paper (scientific journal)
  • Photoluminescence and carrier-transport properties via the intersubband scattering in a GaAs/AlAs superlattice under applied electric field
    M. Ando, M. Nakayama, H. Takeuchi, H. Nishimura, N.Ohtani, N. Egami, M. Hosoda, and H. Mimura
    Journal of Luminescence, 87-89(1)411 - 414, May 2000, English, Research paper (scientific journal)
  • Carrier transport in GaAs/AlAs type-II superlattices under electric field: Switch from X-X to G-G transfer
    M. Hosoda, N. Ohtani, K. Kuroyanagi, and C. Domoto
    Applied Physics Letters, 76(14)1866 - 1868, Apr. 2000, English, Research paper (scientific journal)
  • Electric-field-induced combination of Wannier-Stark localization and type-I-type-II crossover in a marginal type-I GaAs/AlAs superlattice
    N. Ohtani, C. Domoto, N. Egami, H. Mimura, M. Ando, M. Nakayama, and M. Hosoda
    Physical Review B, 61(11)7505 - 7510, Mar. 2000, English, Research paper (scientific journal)
  • Phase diagram of static- and dynamic-domain formation in weakly coupled GaAs/AlAs superlattices
    N. Ohtani, N. Egami, H. T. Grahn, and K. H. Ploog
    Physical Review B, 61(8)5097 - 5100, Feb. 2000, English, Research paper (scientific journal)
  • Phase diagram of static- and dynamic-domain formation in semiconductor superlattices
    N. Ohtani, N. Egami, H. T. Grahn, and K. H. Ploog
    Physica B, 272(1)205 - 208, Dec. 1999, English, Research paper (scientific journal)
  • Light-hole Stark-ladder photoluminescence induced by the heavy-hole-light-hole resonance in GaAs/InAlAs superlattice
    K. Kuroyanagi, N. Ohtani, N. Egami, K. Tominaga, M. Hosoda, and M. Nakayama
    Physica B, 272(1)198 - 201, Dec. 1999, English, Research paper (scientific journal)
  • Controllable bistabilities and bifurcation scenarios in an undoped, photoexcited GaAs/AlAs superlattice
    K. J. Luo, S. W. Teitsworth, H. Kostial, H. T. Grahn, and N. Ohtani
    Applied Physics Letters, 74(25)3845 - 3847, Jun. 1999, English, Research paper (scientific journal)
  • Influence of strain effect on hole-subband resonances in GaAs/InAlAs superlattices
    K. Kuroyanagi, N. Ohtani, N. Egami, K. Tominaga, and M. Nakayama
    Applied Surface Science, 142(1)633 - 636, 1999, English, Research paper (scientific journal)
  • G-X transfer in GaAs/AlAs type-I superlattices
    H. Mimura, M. Hosoda, N. Ohtani, Y. Yokoo
    Applied Surface Science, 142(1)624 - 628, 1999, English, Research paper (scientific journal)
  • Electroluminescence in undoped GaAs/AlAs superlattices due to avalanche breakdown
    C. Domoto, N. Ohtani, K. Kuroyanagi, P. Vaccaro, and N. Egami
    Japanese Journal of Applied Physics, 38(4B)2577 - 2579, Apr. 1999, English, Research paper (scientific journal)
  • Transition between static and dynamic electric-field domain formation in weakly coupled GaAs/AlAs superlattices
    N. Ohtani, N. Egami, H. T. Grahn, K. H. Ploog, and L. L. Bonilla
    Physical Review B, 58(12)7528 - 7531, Sep. 1998, English, Research paper (scientific journal)
  • Carrier transport affected by G-X transfer in type-I GaAs/AlAs superlattices
    M. Hosoda, N. Ohtani, H. Mimura, K. Tominaga, T. Watanabe, H. Inomata, and K. Fujiwara
    Physical Review B, 58(11)7166 - 7180, Sep. 1998, English, Research paper (scientific journal)
  • Photoluminescence detection of X-electron resonance in a GaAs/AlAs type-II superlattice
    M. Nakayama, M. Ando, Y. Kumamoto, H. Nishimura, N. Ohtani, N. Egami, K. Fujiwara, and M. Hosoda
    Physical Review B, 58(11)7216 - 7221, Sep. 1998, English, Research paper (scientific journal)
  • Carrier density dependence of transitions between chaotic and periodic photocurrent oscillations in undoped GaAs/AlAs superlattices
    N. Ohtani, N. Egami, H. T. Grahn, and K. H. Ploog
    Physica B, 249(1)878 - 881, Apr. 1998, English, Research paper (scientific journal)
  • Carrier transport and photoluminescence affected by G-X resonance in GaAs/AlAs type-I superlattice
    H. Mimura, M. Hosoda, N. Ohtani, K. Fujiwara, K. Yokoo
    Physica E, 2(1)308 - 312, Jul. 1998, English, Research paper (scientific journal)
  • Photocurrent self-oscillations in undoped GaAs/AlAs superlattices modulated by an external ac voltage
    N. Ohtani, N. Egami, K. Fujiwara, and H. T. Grahn
    Solid State Electronics, 42(7)1509 - 1513, Jul. 1998, English, Research paper (scientific journal)
  • Wavefunction delocalization of strongly-localized Stark-ladder states in a GaAs/AlAs superlattice
    M. Ando, M. Nakayama, H. Nishimura, M. Hosoda, N. Ohtani, N. Egami, and K. Fujiwara
    Solid State Electronics, 42(7)1499 - 1503, Jul. 1998, English, Research paper (scientific journal)
  • Influence of G-X resonance on current-voltage characteristics in GaAs/InAlAs strained superlattices
    K. Kuroyanagi, N. Ohtani, N. Egami, K. Tominaga, M. Ando, and M. Nakayama
    Japanese Journal of Applied Physics, 37(3B)1650 - 1653, Mar. 1998, English, Research paper (scientific journal)
  • Photocurrent and photoluminescence affected by G-X electron transfer in type-I GaAs-AlAs superlattices
    H. Mimura, M. Hosoda, N. Ohtani, and K. Yokoo
    Japanese Journal of Applied Physics, 37(3B)1650 - 1653, Mar. 1998, English, Research paper (scientific journal)
  • Influence of G-X mixing on carrier transport and photoluminescence in GaAs/AlAs type-I superlattices
    N. Ohtani, M. Hosoda, H. Mimura, K. Tominaga, T. Watanabe, and K. Fujiwara
    Superlattices and Microstructures, 23(1)19 - 22, Jan. 1998, English, Research paper (scientific journal)
  • Investigation of X levels in GaAs/InAlAs strained superlattices
    K. Kuroyanagi, N. Ohtani, N. Egami, K. Tominaga, M. Ando, and M. Nakayama
    Nonlinear Optics, 18(2)261 - 264, 1997, English, Research paper (scientific journal)
  • Current self-oscillations in undoped, photoexcited GaAs/AlAs type-I superlattices
    N. Ohtani, N. Egami, K. Kuroyanagi, M. Ando, M. Hosoda, H. T. Grahn and K. H. Ploog
    Physica Status Solidi (b), 204(1)489 - 492, Nov. 1997, English, Research paper (scientific journal)
  • Photoluminescence from the barrier-X state in a GaAs/InAlAs strained superlattice under applied-bias voltages
    K. Kuroyanagi, N. Ohtani, N. Egami, K. Tominaga, M. Ando, and M. Nakayama
    Physica Status Solidi (b), 204(1)187 - 190, Nov. 1997, English, Research paper (scientific journal)
  • Avalanche breakdown mechanism originating from G-X-G transfer in GaAs/AlAs superlattices
    M. Hosoda, K. Tominaga, N. Ohtani, K. Kuroyanagi, N. Egami, H. Mimura, K. Kawashima and K. Fujiwara
    Applied Physics Letters, 71(19)2827 - 2829, Nov. 1997, English, Research paper (scientific journal)
  • Anomalously large negative differential resistance due to G-X resonances in type-I GaAs/AlAs superlattices
    M. Hosoda, N. Ohtani, K. Tominaga, H. Mimura, and T. Watanabe
    Physical Review B, 56(11)6432 - 6435, Sep. 1997, English, Research paper (scientific journal)
  • Subband-resonance oscillations in Undoped GaAs/AlAs Type-II Superlattices under Photoexcitation
    H. Mimura, M. Hosoda, N. Ohtani, H. T. Grahn, and K. Yokoo
    Applied Surface Science, 113(1)85 - 89, 1997, English, Research paper (scientific journal)
  • Observation of Γ-X resonances in type-I GaAs-AlAs semiconductor superlattices: Anomaly in photoluminescence
    M. Hosoda, H. Mimura, N. Ohtani, K. Tominaga, K. Fujita, T. Watanabe, H. Inomata, and M. Nakayama
    Physical Review B, 55(20)13689 - 13696, May 1997, English, Research paper (scientific journal)
  • Stark ladder photoluminescence of X states in GaAs/AlAs type-I superlattices
    N. Ohtani, M. Hosoda, H. Mimura, K. Tominaga, and T. Watanabe
    Japanese Journal of Applied Physics, 36(3B)1184 - 1187, Mar. 1997, English, Research paper (scientific journal)
  • Influence of G-X resonances on G ground state electron occupation in type-I GaAs/AlAs superlattice
    M. Hosoda, K. Tominaga, N. Ohtani, H. Mimura, and M. Nakayama
    Applied Physics Letters, 70(12)1581 - 1583, Mar. 1997, English, Research paper (scientific journal)
  • Photocurrent self-oscillations in a direct-gap GaAs-AlAs superlattice
    N. Ohtani, M. Hosoda, and H. T. Grahn
    Applied Physics Letters, 70(3)375 - 377, Jan. 1997, English, Research paper (scientific journal)
  • Structural and optical investigations of high quality InGaAs/InAlAs short period superlattices grown on an InGaAs
    K. Tominaga, M. Hosoda, N. Ohtani, T. Watanabe, H. Inomata, and K. Fujiwara
    Journal of Applied Physics, 80(10)5915 - 5920, Nov. 1996, English, Research paper (scientific journal)
  • Electric field domain formation in type-II superlattices
    H. Mimura, M. Hosoda, N. Ohtani, K. Tominaga, K. Fujita, T. Watanabe, H. T. Grahn, and K. Fujiwara
    Physical Review B, 54(4)2323 - 2326, Jul. 1996, English, Research paper (scientific journal)
  • Anomalously delayed carrier transport in GaAs/AlAs thin-barrier superlattices
    N. Ohtani, H. Mimura, K. Tominaga, M. Hosoda, T. Watanabe, G. Tanaka, and K. Fujiwara
    Solid State Electronics, 40(1)759 - 762, May 1996, English, Research paper (scientific journal)
  • Influence of type-I to type-II transition by an applied electric field on photoluminescence and carrier transport in
    N. Ohtani, H. Mimura, M. Hosoda, K. Tominaga, T. Watanabe, and K. Fujiwara
    Japanese Journal of Applied Physics, 35(2B)1302 - 1305, Feb. 1996, English, Research paper (scientific journal)
  • Delayed photocurrent affected by G-X resonance in GaAs/AlAs type-I short-period superlattices
    H. Mimura, N. Ohtani, M. Hosoda, K. Tominaga, T. Watanabe, G. Tanaka, and K. Fujiwara
    Applied Physics Letters, 67(22)3292 - 3294, Nov. 1995, English, Research paper (scientific journal)
  • Evidence for G-X transport in type-I GaAs/AlAs semiconductor superlattices
    M. Hosoda, N. Ohtani, H. Mimura, K. Tominaga, P. Davis, T. Watanabe, G. Tanaka, and K. Fujiwara
    Physical Review Letters, 75(24)4500 - 4503, Dec. 1995, English, Research paper (scientific journal)
  • Current self-oscillations in photoexcited type-II GaAs-AlAs superlattices
    M. Hosoda, H. Mimura, N. Ohtani, K. Tominaga, T. Watanabe, K. Fujiwara, and H. T. Grahn
    Applied Physics Letters, 69(4)500 - 502, Jul. 1996, English, Research paper (scientific journal)

Misc

  • Observation of G-X resonances in type-I GaAs-AlAs semiconductor superlattices: Anomaly in photoluminescence
    Physical Review B, 55(20)13689 - 13696, 1997
  • Photoluminescence from higher G-electron subbands and intersubband electroluminescence using X-G carrier injection in a simple GaAs/AlAs superlattice
    Japanese Journal of Applied Physics, 41(8)5073 - 5077, 2002
  • Over 1.3-micron laser emission from InGaSb quantum-dot diode fabricated on GaAs substrates
    Applied Physics Letters, 86(20)203118 , 2005

Conference Activities & Talks

  • Preparation of carbon nitride thin films alginate gel for application to water decomposition by photocatalytic effect
    K. Mizuno and N. Ohtani
    The 3rd International Symposium on Recent Progress of Energy and Environmental Photocatalysis, Nov. 2019, English, Oral presentation(general)
  • Influence of strong acid on structural and photoluminescence properties of nano-amorphous graphitic carbon nitride dispersed in nitric acid
    T. Watanabe, M. Hirai, K. Takarabe, and N. Ohtani
    The 9th Asia-Pacific Workshop on Widegap Semiconductors, Nov. 2019, English, Oral presentation(general)
  • Fabrication of organic-inorganic hybrid thin films by sol-gel processusing metal-alkoxide
    R. Kasuga and N. Ohtani
    The 7th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2019), 20 Jun. 2019, English, Oral presentation(general)
  • Study of isolation method of green fluorescent pigments contained in cherry tomatoes using column chromatography
    A. Noma and N. Ohtani
    The 7th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2019), 20 Jun. 2019, English, Oral presentation(general)
  • Separation of blue fluorescent pigments contained in Fraxinus lanuginosa f. serrata using reverse-phase column chromatography and investigation of luminescent properties
    T. Ohtsu, Y. Kinoe, and N. Ohtani
    The 7th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2019), 20 Jun. 2019, English, Oral presentation(general)
  • Preparation of organic-inorganic hybrid emissive thin films by sol-gel reaction using photo-curing binary crosslinking
    Y. Jitsui and N. Ohtani
    XX International Sol-Gel Conference (Sol-gel 20), Jun. 2019, English, Oral presentation(general)
  • Fabrication of nano-amorphous graphitic carbon nitride dispersion and preparation of thin films by electrostatic-spraying method
    T. Watanabe, M. Hirai, K. Takarabe, and N. Ohtani
    The 7th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies} (EM-NANO 2019), Jun. 2019, English, Oral presentation(general)
  • Improvement of resistance of solution-processed ZnO Film by controlling annealing condition
    T. Nojiri and N. Ohtani
    The 7th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies} (EM-NANO 2019), Jun. 2019, English, Oral presentation(general)
  • Preparation of colloidal fluorescent quantum dot thin films by electrostatic spraying deposition
    R. Yamada, D. Kim, and N. Ohtani
    Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2019), Jun. 2019, English, Oral presentation(general)
  • Photoluminescence properties of emissive polymer MEH-PPV affected by antioxidant effect of natural beta-carotene extracted from spinach
    Y. Magata, S. Imada and N. Ohtani
    Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2019), Jun. 2019, English, Oral presentation(general)
  • Preparation of Graphitic Carbon Nitride Thin Films by Evaporating Melamine
    S. Minato and N. Ohtani
    the International Workshop on Nitride Semiconductors (IWN2018), Nov. 2018, English, Poster presentation
  • Fabrication of nano-amorphous graphitic carbon nitride thin film by wet process and its optical properties
    T. Watanabe, M. Hirai, K. Takarabe and N. Ohtani
    the International Workshop on Nitride Semiconductors (IWN2018), Nov. 2018, English, Poster presentation
  • Modulation of photoluminescence properties of emissive polymers induced by mixing of beta-carotene
    S. Imada and N. Ohtani
    the International Conference on Organic Materials for Electronics and Photonics (KJF-ICOMEP 2018), Sep. 2018, English, Poster presentation
  • Study on extraction method of blue emissive pigments contained in fraxinus lanuginose
    Y. Kinou and N. Ohtani
    the International Conference on Organic Materials for Electronics and Photonics (KJF-ICOMEP 2018), Sep. 2018, English, Poster presentation
  • Fabrication and Characterization of Carbon Nitride Fluorescent Material Using Annealed Melamine
    K. Wada and N. Ohtani
    the 34th International Conference on the physics of semiconductors (ICPS34), Jul. 2018, English, Poster presentation
  • Natural dye-sensitized solar cells containing anthocyanin dyes extracted from frozen blueberry using column chromatography method
    A. Mizuno, G. Yamada, and N. Ohtani
    the 7th World Conference on Photovoltaic Energy Conversion (WCPEC-7), Jun. 2018, English, Poster presentation
  • Antioxidant effect of β-carotene and lutein isolated and purified from spinach on photoluminescence lifetime of organic emissive materials
    S. Imada, T. Ito, and N. Ohtani
    The 6th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2017), Jun. 2017, English, Poster presentation
  • Blue-color photoluminescence from natural pigments extracted from Fraxinus lanuginosa
    Y. Kinou and N. Ohtani
    The 6th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2017), Jun. 2017, English, Poster presentation
  • Fabrication of Carbon Nitride-based Emissive Thin Films by Wet Process Using Annealed Melamine
    K. Wada and N. Ohtani
    The 6th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2017), Jun. 2017, English, Poster presentation
  • Carrier transport and photoluminescence properties in GaAs/AlAs asymmetric multiple-quantum well superlattices affected by resonances and scatterings between higher subband energies
    N. Ohtani and M. Hosoda
    the XXV International Materials Research Congress (IMRC), Aug. 2016, English, Oral presentation(invited, special)
  • Fabrication of emissive thin films using nano-amorphous graphitic carbon nitride powders
    T. Watanabe, M. Hirai, K. Takarabe and N. Ohtani
    The 6th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2017), Jun. 2017, English, Poster presentation
  • Photoluminescence properties affected by subband resonances and scatterings in GaAs/AlAs asymmetric sevenfold multiple quantum wells
    R. Wang, K. Hada, K. Yoshida, M. Hosoda, K. Akahane, and N. Ohtani
    the 33rd International Conference on the Physics of Semiconductors (ICPS2016), Jun. 2016, English, Poster presentation
  • Fabrication of organic light-emitting diodes and dye-sensitized solar cells using pigments extracted from plants
    OHTANI Naoki
    the 2015 International Electron Devices and Materials Symposium (IEDMS 2015), Nov. 2015, English, Poster presentation
  • Evaluation of Antioxidant Effect of Carotenoids Extracted from Spinach Using Column Chromatography Method for Improving Photoluminescence Lifetime of Organic Emissive Materials
    T. Ito, A. Emoto, and N. Ohtani
    the 2015 KJF International Conference on Organic Materials for Electronics and Photonics (KJF-ICOMEP 2015), Sep. 2015, English, Poster presentation
  • Dye sensitized solar cells containing anthocyanin dyes extracted from frozen red cabbages
    D. Isoda, S. Togo, A. Emoto, and N. Ohtani
    the 1st International Caparica Conference on Chromogenic and Emissive Materials} (IC3EM), Sep. 2014, English, Poster presentation
  • Inorganic-organic hybrid light-emitting diodes driven by low dc voltage containing CdSe-ZnS core-shell quantum dot emitters
    N. Ohtani, Y. Hagimoto, and S. Yoshikawa
    the 32nd International Conference on the Physics of Semiconductors (ICPS-32) , Aug. 2014, English, Poster presentation
  • Optical properties of pigments extracted from vegetables and application to light-emitting diodes
    N. Ohtani, T. Morikawa, Y. Katano, Y. Nishida, and A. Emoto
    the 25th Conference of the Condensed Matter Division of the EPS (CMD25), Aug. 2014, English, Poster presentation
  • Improved light emission properties and operation lifetime of multi-layered organic light-emitting diodes using dyes extracted from spinach
    Y. Nishida and N. Ohtani
    the 8th International Symposium on Organic Molecular Electronics (ISOME 2014), May 2014, English, Poster presentation
  • High efficient carrier injection into wide-bandgap polymer emissive materials and application to light-emitting diodes operating in the ultraviolet region
    N. Ohtani and M. Takahashi
    the 18th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON18), Jul. 2013, English, Poster presentation
  • Evaluation of antioxidant effect of carotenoid extracted from plants on the operating lifetime of organic light-emitting diodes
    Y. Nishida and N. Ohtani
    the 4th International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2013), Jun. 2013, English, Poster presentation
  • Transmission electron microscope observation of organic-inorganic hybrid thin active layers of light-emitting diodes
    Y. Jitsui, and N. Ohtani
    the International Conference on Superlattices, Nanostructures, and Nanodevices 2012 (ICSNN2012), Jul. 2012, English, Poster presentation
  • Organic light-emitting diodes consisting of SiO2 active layer in which emissive organic materials are dispersed
    Y. Jitsui, S. Kimura, and N. Ohtani
    the 31st International Conference on the Physics of Semiconductors (ICPS2012), Jul. 2012, English, Poster presentation
  • Organic near-infrared photodiodes containing a wide-bandgap polymer and an n-type dopant in the active layer
    N. Ohtani, K. Nakajima, and K. Bando
    the 4th International Conference on Optical, Optoelectronic and Photonic Materials and Applications (ICOOPMA10), Aug. 2010, English, Poster presentation
  • Excitonic Rabi oscillations in semiconductor quantum dot observed by photon echo spectroscopy
    K. Asakura, Y. Mitsumori, H. Kosaka, K. Edamatsu, K. Akahane, N. Yamamoto, M. Sasaki, and N. Ohtani
    the 30th International Conference on the Physics of Semiconductors (ICPS-30), Jul. 2010, English, Poster presentation
  • Fabrication of organic light-emitting diodes using photosynthetic-pigments extracted from spinach
    N. Ohtani, N. Kitagawa and T. Matsuda
    the 3rd International Symposium on Organic and Inorganic Electronic Materials and Related Nanotechnologies (EM-NANO 2010), Jun. 2010, English, Poster presentation

Research Grants & Projects

  • Compound semiconductor photonic devices, organic electroluminescence, nano-technology

Research Seeds

  • Two-dimensional birefringence profiler capable of real-time measuring
    Affiliation/Name: Akira Emoto:Naoki Ohtani

    Patent Information: 特願 2014-171159
  • Organic EL element activated in the ultraviolet wavelengh region
    Affiliation/Name: Naoki Ohtani