Creation of 2D-Atomically-Thin-Layered Heterojunctions and their Applications to Novel Terahertz Photonic Devices

2019 Fiscal Year Annual Research Report

• Project/Area Number: 16H06361
• Research Institution: Tohoku University
• Principal Investigator: 尾辻 泰一 東北大学, 電気通信研究所, 教授 (40315172)
• Co-Investigator(Kenkyū-buntansha): 鈴木 哲 兵庫県立大学, 高度産業科学技術研究所, 教授 (00393744) ; 高村 真琴 日本電信電話株式会社NTT物性科学基礎研究所, 機能物質科学研究部, 研究主任 (00622250) ; 吹留 博一 東北大学, 電気通信研究所, 准教授 (10342841) ; Maxim・V Ryzhii 会津大学, コンピュータ理工学部, 上級准教授 (50254082) ; 佐藤 昭 東北大学, 電気通信研究所, 准教授 (70510410) ; 渡辺 隆之 東北大学, 電気通信研究所, 助教 (80771807)
• Project Period (FY): 2016-05-31 – 2021-03-31
• Keywords: グラフェン / 二次元原子薄膜 / テラヘルツ / 複合量子効果 / プラズモン

Outline of Annual Research Achievements

１．G-DGL(グラフェン二重層)構造プラットフォームの創製： 金属触媒を用いた新たなh-BN膜上グラフェンヘテロエピ成長法に挑んだ．h-BN上にNi等の金属触媒を蒸着し，グラフェンをCVD成長させ，その後金属触媒を除去することによりグラフェン/h-BN構造が製膜できることを確認できた．本手法ではh-BN－グラフェン界面が清浄に保たれ，触媒を用いても金属汚染のないヘテロエピ成長ができることを明らかにした．
2. プラズモン・トンネル二重共鳴のTHz増幅・発振素子応用： 独自の非対称二重回折格子ゲートの導入によって共鳴トンネルに寄与するTHzフォトンとグラフェン表面プラズモンポラリトン(SPP)との結合作用が得られ，ドレインバイアスが閾値以下ではグラフェンSPPに対応する共鳴吸収応答を示し，閾値以上では最大9%の共鳴増幅利得を得た昨年度実施の実験結果を説明しうる物理モデルの構築に成功した．DGLのプラズモンアシストトンネルの共鳴周波数をグラフェンSPPの共鳴周波数に合致させることによって格段の利得増強が期待される．
3. 新たな展開：　グラフェンと黒燐もしくは黒色ヒ素燐との積層構造をチャネルとする新たなトランジスタ構造を考案した．隣接する黒燐もしくは黒色ヒ素燐層を正孔供給層とし、利得媒質となるグラフェンに対して垂直方向から正孔を注入し，電子をサイドコンタクトから水平方向に注入するキャリア注入方式を新たに考案した．正孔注入層の光学フォノン散乱によって正孔の熱化が素子でき，通常のグラフェン面内方向からの電子・正孔同時注入に比較して，桁違いの高い負性微分導電率・THz利得が得られることを発見した．本成果は，室温下でも安定したTHz帯自励発振と非線形THz波動伝搬の能動的制御を可能にするものであり,本研究で懸案となっていた課題解決の見通しを得ることができた．大きな進展である．

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

1. G-DGL構造プラットフォームの創製　　【予定どおりの成果が見込まれる】
(1)剥離・転写法の高度化：　独自の二次元原子薄膜剥離・転写装置を開発し，半導体集積加工装置による金属電極形成プロセスとの連携によってG-DGLデバイスプロセス技術を完成した．(2)vdW ヘテロエピ成長法：均一大面積h-BN原子薄膜の成膜，およびh-BNドメインを一方向に揃えることに成功した．(3)h-BN上へのグラフェン再成長において，金属触媒を利用した金属汚染の無い成長実現の見通しを得た．(4)結晶品質・物性評価：独自のオペランド３次元局所場顕微分光法による結晶品質評価法を開発し，原子１層分以下の極限的空間分解能によって観測することに成功した．
2. プラズモン・トンネル二重共鳴のTHz増幅・検出素子応用　　【予定どおりの成果が見込まれる】 代表者らが考案した非対称二重回折格子ゲートの導入によって結合作用が得られることを擬似的な単純構造素子の試作によって実証した．実験で観測されたバンド間遷移にともなうグラフェン単層による吸収係数2.3%を大きく上回る最大9%の共鳴増幅利得は，プラズモンが光学導電率に与える実部と虚部の位相関係が一定条件を満たすときに得られること，その実現に電子ドリフト速度がプラズモン速度を超越する条件が必要とされた従来の定説を覆す物理が内在することを発見した．この結果，デバイスの設計論として工学的に物理現象を実装することが可能となり，DGLのプラズモンアシストトンネルが重畳された二重共鳴では格段に利得増強作用が得られる見通しが得られた．
3. 新たな展開　　【予定以上の成果が見込まれる】 グラフェンと黒燐もしくは黒色ヒ素燐との積層構造をチャネルとする新たな巨大負性微分抵抗のトランジスタ構造を考案し，本研究で懸案となっていた課題解決の見通しを得ることができた．

Strategy for Future Research Activity

１．G-DGL構造プラットフォームの創製：　(1) ヘテロエピ成長：引き続き無触媒CVD法および金属触媒利用によるヘテロエピ成長法による実現を目指す．炭素原子蒸気分子線エピタキシー(MBE)法によるh-BN上へのグラフェン再成長の目途を立てるとともに，成長面方位制御性，層数制御性，結晶品質を向上させる．(2) 結晶品質・物性評価：本研究で開発した原子一層分の極限的空間分解能を駆使して，DGL各層の物性を元素選択的かつ高空間分解
能評価し，素子特性との関係を引き続き解明する．(3)プロセス技術：本研究で開発した独自プロセス技術を援用してTHz利得の獲得に十分なGDGL基本素子構造の安定した実現を図る．
2. DGL構造によるフォトン・プラズモンアシスト共鳴トンネル型高効率THz機能素子：　本研究で考案創出したプラズモンアシスト共鳴トンネル型G-DGLをカスケード積層した構造を有する新しいTHz量子カスケードレーザー素子の試作に挑む．カスケード積層はプロセス的に挑戦性が極めて高いが，開発した二次元原子薄膜連続剥離・転写装置を第一ステップとして活用し，vdWヘテロエピCVD製膜装置の完成に受け継ぐ．
3. グラフェンSPP・DGLトンネル二重共鳴現象による超高効率THz機能素子：　(1)引き続き、DGLに非対称二重回折格子ゲート構造をドッキングした独自の素子構造で高効率THzレーザー発振の実現に挑む．(2)新規考案のグラフェン・黒燐のvdWヘテロ接合構造によるTHz帯非線形波動制御の原理検証に挑む．
４．最終年度にあたる本研究の集大成：　(1)グラフェンを中心とする二次元原子薄膜連続ヘテロエピタキシャル成長技術およびG-DGLプロセス技術を完成させる．(2)G-DGLの複合量子系とそのTHz非線形信号処理応用に関するデバイス設計論として体系化する

Research Products

• [Int'l Joint Research] Univ. Buffalo, SUNY/Rensselaer Polytechnic Inst.(米国)
  • Country Name: U.S.A.
  • Counterpart Institution: Univ. Buffalo, SUNY/Rensselaer Polytechnic Inst.
• [Int'l Joint Research] CNRS-Univ. Montpellier(フランス)
  • Country Name: FRANCE
  • Counterpart Institution: CNRS-Univ. Montpellier
• [Int'l Joint Research] CENTERA, Inst. High-Pressure Phys., PAS(ポーランド)
  • Country Name: POLAND
  • Counterpart Institution: CENTERA, Inst. High-Pressure Phys., PAS
• [Int'l Joint Research] Inst. Physics for Microstructures, RAS/Kotelnikov Inst. Radio Eng. Electron./Bauman-Moscow State Tech. Univ.(ロシア連邦)
  • Country Name: RUSSIA FEDERATION
  • Counterpart Institution: Inst. Physics for Microstructures, RAS/Kotelnikov Inst. Radio Eng. Electron./Bauman-Moscow State Tech. Univ.
  • # of Other Institutions: 1
• [Int'l Joint Research] Salamanca University(スペイン)
  • Country Name: SPAIN
  • Counterpart Institution: Salamanca University
• [Journal Article] Graphene plasmonics for terahertz applications (Invited) (2020)
  • Author(s): V. Ryzhii, T. Otsuji, and M.S. Shur
  • Journal Title: Appl. Phys. Lett. Volume: 116 Pages: 1-6
  • DOI: 10.1063/1.5140712
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Far-infrared photodetectors based on graphene/black-AsP heterostructures (2020)
  • Author(s): V. Ryzhii, M. Ryzhii, V. Mitin, M.S. Shur, and T. Otsuji
  • Journal Title: Opt. Exp. Volume: 28 Pages: 2480-2489
  • DOI: 10.1364/OE.376299
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Sub-terahertz FET detector with self-assembled Sn-nanothreads (2020)
  • Author(s): D.S. Ponomarev, D.V. Lavrukhin, A.E. Yachmenev, R.A. Khabibullin, I.E. Semenikhin, V.V. Vyurkov, K.V. Marem'yanin, V.I. Gavrilenko, M. Ryzhii, M.S. Shur, T. Otsuji and V. Ryzhii
  • Journal Title: J. Phys. D: Appl. Phys. Volume: 53 Pages: 75102-1-7
  • DOI: 10.1088/1361-6463/ab588f
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Optical pumping in graphene-based terahertz/far-infrared superluminescent and laser heterostructures with graded-gap black-Px As1-x absorbing-cooling layers (2019)
  • Author(s): M.Yu. Morozov, V.G. Leiman, V.V. Popov, V. Mitin, M.S. Shur, V.E. Karasik, M. Ryzhii, T. Otsuji, and V. Ryzhii
  • Journal Title: Opt. Eng. Volume: 59 Pages: 061606-1-11
  • DOI: 10.1117/1.OE.59.6.061606
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Terahertz plasmon-emitting graphene-channel transistor (2019)
  • Author(s): A. Dubinov, V. Aleshkin, S. Morozov, V. Ryzhii, and T. Otsuji
  • Journal Title: Opt. Electron. Rev. Volume: 27 Pages: 345-347
  • DOI: 10.1016/j.opelre.2019.11.003
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Physics and technology of graphene-based 2D heterostructures for current-injection terahertz lasers and amplifiers (Keynote) (2019)
  • Author(s): T. Otsuji
  • Journal Title: ISNTT2019: the International School and Symposium on Nanoscale Transport and phoTonics Proc., Atsugi R&D center, Kanagawa, Japan, Nov. 18-22 Volume: 1 Pages: 1-2
  • Peer Reviewed
• [Journal Article] Graphene-based van der Waals heterostructures towards a new type of terahertz quantum-cascade lasers (Invited) (2019)
  • Author(s): T. Otsuji
  • Journal Title: 5th EU-Japan Flagship Workshop on Graphene and 2D Materials Abstract Book, S4-1, Palazzo della Carovana, Scuola Normale Superiore, Pisa, Italy, Nov. 18-20 Volume: 1 Pages: 1
  • Peer Reviewed
• [Journal Article] Optical pumping of graphene-based heterostructures with black-arsenic-phosphorus absorbing-cooling layer for terahertz lasing (2019)
  • Author(s): M. Ryzhii, V. Ryzhii, T.Otsuji, V. Mitin, and M.S. Shur
  • Journal Title: COMCAS2019: IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems, Tel Aviv, Israel, Nov. 4-6 Volume: 1 Pages: 8958394-1-4
  • DOI: 10.1109/COMCAS44984.2019.8958394
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Asymmetric dual grating gate graphene-FETs for direct detection of THz radiation (2019)
  • Author(s): J.A. Delgado-Notario, V. Clerico, E. Diez, J.E. Velazquez-Perez, T. Taniguchi, K. Watanabe, T. Otsuji, and Y.M. Meziani
  • Journal Title: RPGR2019: Recent Progress on Graphene and 2D Materials Abstracts, Matsue, Shimane, Japan, Oct. 7-9 Volume: 1 Pages: 7P_37-1-2
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Concepts of terahertz and infrared devices based on graphene/black phosphorus-arsenic heterostructures (2019)
  • Author(s): V. Ryzhii, T. Otsuji, M. Ryzhii, V. Leiman, V. Mitin, and M. S. Shur
  • Journal Title: RPGR2019: Recent Progress on Graphene and 2D Materials Abstracts, Matsue, Shimane, Japan, Oct. 7-9 Volume: 1 Pages: 8P_7-1-2
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Realization of the high-performance graphene transistor by controlling the interface between graphene and gate dielectric (2019)
  • Author(s): T. Komiyama, T. Watanabe, S. Morozov, M. Fadeev, V. Utochkin, H. Fukidome, A. Satou, and T. Otsuji,
  • Journal Title: RPGR2019: Recent Progress on Graphene and 2D Materials Abstracts, Matsue, Shimane, Japan, Oct. 7-9 Volume: 1 Pages: 7P_40-1-2
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Terahertz Light Amplification and Lasing in Current-Driven Graphene-Channel Transistor Structures (2019)
  • Author(s): S. Boubanga-Tombet, D. Yadav, A. Satou, W. Knap, V.V. Popov, and T. Otsuji
  • Journal Title: 2D MATERIALS 2019 - International Congress on Graphene, 2D Materials and Applications Abstracts, Sochi Olympic Park, Sochi, Russia, 30th Sept.- 04th Oct. Volume: 1 Pages: 1-2
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Graphene/Black Phosphorus-Arsenic Heterostructures and their terahertz and infrared device applications (2019)
  • Author(s): V. Ryzhii, M. Ryzhii, V. Leiman, V. Mitin, T.Otsuji, and M. S. Shur
  • Journal Title: 2D MATERIALS 2019 - International Congress on Graphene, 2D Materials and Applications Abstracts, Sochi Olympic Park, Sochi, Russia, 30th Sept.- 04th Oct. Volume: 1 Pages: 1-2
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Terahertz plasmonic graphene-channel transistor laser (2019)
  • Author(s): Y. Fuse, A. A. Dubinov, T. Watanabe, V. Ya. Aleshkin, S. V. Morozov, A. Satou, V. Ryzhii, and T. Otsuji
  • Journal Title: MTSA2019: The 5th International Symposium on Microwave/Terahertz Science and Applications Abstracts, Hanwha Resorts Haeundae Tivoli, Busan, Korea, Sept. 30-Oct. 3 Volume: 1 Pages: Ap2_4
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Negative terahertz conductivity and amplification of surface plasmons in graphene-black phosphorus injection laser heterostructures (2019)
  • Author(s): V. Ryzhii, T. Otsuji, M. Ryzhii, A.A. Dubinov, V. Ya. Aleshkin, V.E. Karasik, and M.S. Shur
  • Journal Title: Phys. Rev. B Volume: 100 Pages: 115436-1-13
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Negative terahertz conductivity at vertical carrier injection in a black-Arsenic-Phosphorus-Graphene heterostructure integrated with a light-emitting diode (2019)
  • Author(s): V. Ryzhii, M. Ryzhii, T. Otsuji, V.E. Karasik, V.G. Leiman, V. Mitin, and M.S. Shur
  • Journal Title: IEEE J. Select. Top. Quantum Electron. Volume: 25 Pages: 2000209-1-9
  • DOI: 10.1109/JSTQE.2019.2941922
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Optical pumping through a black-As absorbing-cooling layer in graphene-based heterostructure: thermo-diffusion model (2019)
  • Author(s): M.Yu. Morozov, V.V. Popov, M. Ryzhii, V.G. Leiman, V. Mitin, M.S. Shur, T. Otsuji, and V. Ryzhii
  • Journal Title: Opt. Mat. Exp. Volume: 9 Pages: 4061-4069
  • DOI: 10.1364/OME.9.004061
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Models of terahertz and infrared devices based on graphene/ black-AsP heterostructures (2019)
  • Author(s): M. Ryzhii, T.Otsuji, V. Ryzhii, V. Leiman, V. Mitin, and M.S. Shur
  • Journal Title: EMSS2019: 31st European Modeling and Simulation Symposium, Lisbon, Portugal, Sep. 18-20 Volume: 1 Pages: 237-240
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Asymmetric dual grating gate graphene-based THz detectors (2019)
  • Author(s): J.A. Delgado Notario, V. Clerico, E.Diez, J.E. Velazquez Perez, T. Otsuji, and Y.M. Mezian
  • Journal Title: IRMMW-THz2019: International Conference on Infrared, Millimeter, and Terahertz Waves Abstracts Book, Paris, France, Sept. 2-6 Volume: 1 Pages: We_AM_6_5-1-3
  • DOI: 10.1109/IRMMW-THz.2019.8873834
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Graphene-based van der Waals heterostructures towards a new type of terahertz quantum-cascade lasers (Invited) (2019)
  • Author(s): T. Watanabe, D. Yadav, S. Boubanga-Tombet, A. Satou, A.A. Dubinov, V. Ryzhii, and T. Otsuji
  • Journal Title: Proc. SPIE [SPIE OPTICS+ Phootnics, Conf. OP412: Terahertz Emitters, Receivers, and Applications X, San Diego Convention Center, San Diego, CA, USA, Aug. 11-15] Volume: 11124 Pages: 1112406-1-7
  • DOI: 10.1117/12.2529016
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Current-driven plasmonic instability in graphene metasurfaces for terahertz applications (Invited) (2019)
  • Author(s): S. Boubanga-Tombet, D. Yadav, A. Satou, W. Knap, V.V. Popov, and T. Otsuji
  • Journal Title: AES2019: the 7th Advanced Electromagnetics Symposium Abstract Book, Lisbon, Portugal, July 23-26 Volume: 1 Pages: 1A6_1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Current-driven plasmonic instability in graphene metasurfaces for terahertz applications (Invited) (2019)
  • Author(s): S. Boubanga-Tombet, D. Yadav, A. Satou, W. Knap, V.V. Popov, and T. Otsuji
  • Journal Title: META2019: the 10th International Conference on Metamaterials, Photonic Crystals and Plasmonics, Lisbon, Portugal, July 23-26 Volume: 1 Pages: 2A36_6
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Vertical hot-electron terahertz detectors based on black-As1-xPx/graphene/black-As1-yPy heterostructures (2019)
  • Author(s): M. Ryzhii, V. Ryzhii, V. Mitin, M.S. Shur, and T. Otsuji
  • Journal Title: Sensors and Materials Volume: 31 Pages: 2271-2279
  • DOI: 10.18494/SAM.2019.2305
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Graphene-black Phosphorus/Arsenic heterostructures for novel terahertz and infrared devices (Keynote) (2019)
  • Author(s): V. Ryzhii, T. Otsuji, and M.S. Shur
  • Journal Title: METANANO2019: 9th International Conference on Metamaterials and Nanophotonics Proc., St. Petersburg, Russia, July 15-19 Volume: 1 Pages: 1-2
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Graphene/black AsxP1-x heterostructures for terahertz and Infrared devices (Plenary) (2019)
  • Author(s): V. Ryzhii, T. Otsuji, M. Ryzhii, V. Leiman, V.E. Karasik, D. Ponomarev, P.P. Matsev, V. Mitin, and M.S. Shur
  • Journal Title: RJUSE2019: 8th Russia-Japan-USA-Europe Symposium on Fundamental & Applied Problems of Terahertz Devices & Technologies, & GDR-I FIR-LAB Workshop Abstracts, Nizhny Novgorod, Russia, July 8-11 Volume: 1 Pages: Wed_1_1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Graphene-based van der Waals heterostructures towards a new type of terahertz quantum-cascade lasers (2019)
  • Author(s): T. Otsuji, D. Yadav, S. Boubanga-Tombet, T. Watanabe, A.A. Dubinov, and V. Ryzhii
  • Journal Title: RJUSE2019: 8th Russia-Japan-USA-Europe Symposium on Fundamental & Applied Problems of Terahertz Devices & Technologies, & GDR-I FIR-LAB Workshop Abstracts, Nizhny Novgorod, Russia, July 8-11 Volume: 1 Pages: Tu_1_1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Concepts of infrared and terahertz photodetectors based on vertical graphene van der Waals and HgTe-CdHgTe heterostructures (2019)
  • Author(s): M. Ryzhii, V.V. Mitin, V. Karasik, A. Dubinov, V. Aleshkin, M. Shur, T. Otsuji, V. Leiman, and V. Ryzhii
  • Journal Title: Opt. Electron. Rev. Volume: 27 Pages: 219-223
  • DOI: 10.1016/j.opelre.2019.06.002
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Terahertz current-driven lasing and amplification in graphene-based vdW heterostructures (Invited) (2019)
  • Author(s): T. Otsuji
  • Journal Title: CCMR: 2019 Collaborative Conference on Materials Research Proc., the Kintex, Goyang Gyeonggi, South Korea, June 3-7 Volume: 1 Pages: 1-2
  • Peer Reviewed
• [Journal Article] Terahertz light amplification stimulated by current-driven plasmon instability in graphene-channel transistors (Invited) (2019)
  • Author(s): S. Boubanga-Tombet, W. Knap, A. Satou, D. But, V.V. Popov, and T. Otsuji
  • Journal Title: GSMM: the 12th Global Symposium onMillimeter Waves Proc., Sendai, Japan, May 22-24 Volume: 1 Pages: 1-4
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Terahertz light emission and lasing in current-driven graphene-based 2D nano- and plasmonic-structures (Keynote) (2019)
  • Author(s): T. Otsuji
  • Journal Title: EuroSciCon Joint Event on Laser Optics, Quantum & Plasma Physics Abstract Book, Stockholm, Sweden, May 5-10 Volume: 1 Pages: 1
  • Peer Reviewed / Open Access
• [Journal Article] Terahertz light amplification of stimulated emission of radiation in current-injection graphene channel transistor (Invited) (2019)
  • Author(s): T. Otsuji , S. Boubanga-Tombet, D. Yadav, T. Watanabe, A. Satou, and V. Ryzhii
  • Journal Title: Proc. SPIE [SPIE Int. Conf. Defence+ Commercial Sensing, Conf.-10982 on Micro- and Nanotechnol. Sens., Sys., Appl. XI, Baltimore, Maryland, USA, April 14-18] Volume: 10982 Pages: 109822V-1-6
  • DOI: 10.1117/12.2520092
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Terahertz light amplification stimulated by current-driven plasmon instability in grating-gate graphene transistor structures (Invited) (2019)
  • Author(s): S. Boubanga-Tombet, W. Knap, D. Yadav, A. Satou, D. but, V.V. Popov, and T. Otsuji
  • Journal Title: FGTC: French-German Terahertz Conference 2019 Abstract Book, Kaiserslautern, Germany, April 2-5 Volume: 1 Pages: 1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Characteristics of vertically stacked graphene-layer infrared photodetectors (2019)
  • Author(s): M. Ryzhii, T. Otsuji, V. Karasik, V. Leiman, M.S. Shur, V. Ryzhii, and V. Mitin
  • Journal Title: Solid State Electron. Volume: 155 Pages: 123-128
  • DOI: 10.1016/j.sse.2019.03.021
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Growth process of hexagonal boron nitride in the diffusion and precipitation method studied by X-ray photoelectron spectroscopy (2019)
  • Author(s): Satoru Suzuki and Yuichi Haruyama
  • Journal Title: Jpn. J. Appl. Phys. Volume: 58 Pages: SIIB15-1-4
  • DOI: 10.7567/1347-4065/ab203a
  • Peer Reviewed / Open Access
• [Journal Article] Direct formation of solution-based Al2O3 on epitaxial graphene surface for sensor applications (2019)
  • Author(s): K.S. Kim, H. Fukidome, and M. Suemitsu
  • Journal Title: Sensors and Materials Volume: 31 Pages: 2291-2301
  • DOI: 10.18494/SAM.2019.2317
  • Peer Reviewed / Open Access
• [Journal Article] Modulation of Electronic States near Electrodes in Graphene Transistors Observed by Operando Photoelectron Nanospectroscopy (2019)
  • Author(s): H. Fukidome, K. Funakubo, N. Nagamura, K. Horiba, Y. Tateno, M. Oshima, and M. Suemitsu
  • Journal Title: Sensors and Materials Volume: 31 Pages: 2303-2311
  • DOI: 10.18494/SAM.2019.2327
  • Peer Reviewed / Open Access
• [Journal Article] Influence of interface dipole layers on the performance of graphene field effect transistors (2019)
  • Author(s): N. Nagamura, H. Fukidome, K. Nagashio, K. Horiba, T. Ide, K. Funakubo, K. Tashima, A. Toriumi, M. Suemitsu, and M. Oshima
  • Journal Title: Carbon Volume: 152 Pages: 680-687
  • DOI: 10.1016/j.carbon.2019.06.038
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Ultrafast Unbalanced Electron Distributions in Quasicrystalline 30° Twisted Bilayer Graphene (2019)
  • Author(s): T. Suzuki, T. Iimori, S.-J. Ahn, Y. Zhao, M. Watanabe, J. Xu, M. Fujisawa, T, Kanai, N. Ishii, J. Itatani, Kento Suwa, H. Fukidome, S. Tanaka, J.-R. Ahn, K. Okazaki, S. Shin, F. Komori, and I. Matsuda
  • Journal Title: ACS Nano Volume: 13 Pages: 11981-11987
  • DOI: 10.1021/acsnano.9b06091
  • Peer Reviewed / Int'l Joint Research
• [Presentation] グラフェンを利用したバルク絶縁体のXASとPES (2020)
  • Author(s): 鈴木哲、春山雄一、山本知樹、石原マリ、住田弘祐、吉村真史、横山和司
  • Organizer: 2020年放射光学会、名古屋、日本、Jan. 12
• [Presentation] Physics and technology of graphene-based 2D heterostructures for current-injection terahertz lasers and amplifiers (Keynote) (2019)
  • Author(s): T. Otsuji
  • Organizer: ISNTT2019: International School and Symposium on Nanoscale Transport and phoTonics, Atsugi, Kanagawa, Japan, Nov. 18-22
  • Int'l Joint Research / Invited
• [Presentation] Graphene-based van der Waals heterostructures towards a new type of terahertz quantum-cascade lasers (Invited) (2019)
  • Author(s): T. Otsuji
  • Organizer: 5th EU-Japan Flagship Workshop on Graphene and 2D Materials, Palazzo della Carovana, Scuola Normale Superiore, Pisa, Italy, Nov. 18-20
  • Int'l Joint Research / Invited
• [Presentation] Optical pumping of graphene-based heterostructures with black-arsenic-phosphorus absorbing-cooling layer for terahertz lasing (2019)
  • Author(s): M. Ryzhii, V. Ryzhii, T.Otsuji, V. Mitin, and M.S. Shur
  • Organizer: COMCAS2019: IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems, Tel Aviv, Israel, Nov. 4-6
  • Int'l Joint Research
• [Presentation] Asymmetric dual grating gate graphene-FETs for direct detection of THz radiation (2019)
  • Author(s): J.A. Delgado-Notario, V. Clerico, E. Diez, J.E. Velazquez-Perez, T. Taniguchi, K. Watanabe, T. Otsuji, and Y.M. Meziani
  • Organizer: RPGR2019: Recent Progress on Graphene and 2D Materials, Matsue, Shimane, Japan, Oct. 7-9
  • Int'l Joint Research
• [Presentation] Concepts of terahertz and infrared devices based on graphene/black phosphorus-arsenic heterostructures (2019)
  • Author(s): V. Ryzhii, T. Otsuji, M. Ryzhii, V. Leiman, V. Mitin, and M. S. Shur
  • Organizer: RPGR2019: Recent Progress on Graphene and 2D Materials, Matsue, Shimane, Japan, Oct. 7-9
  • Int'l Joint Research
• [Presentation] Realization of the high-performance graphene transistor by controlling the interface between graphene and gate dielectric (2019)
  • Author(s): T. Komiyama, T. Watanabe, S. Morozov, M. Fadeev, V. Utochkin, H. Fukidome, A. Satou, and T. Otsuji,
  • Organizer: RPGR2019: Recent Progress on Graphene and 2D Materials, Matsue, Shimane, Japan, Oct. 7-9
  • Int'l Joint Research
• [Presentation] Terahertz Light Amplification and Lasing in Current-Driven Graphene-Channel Transistor Structures (Keynote) (2019)
  • Author(s): S. Boubanga-Tombet, D. Yadav, A. Satou, W. Knap, V.V. Popov, and T. Otsuji
  • Organizer: 2D MATERIALS 2019 - International Congress on Graphene, 2D Materials and Applications, Sochi, Russia, 30th Sept.- 04th Oct.
  • Int'l Joint Research / Invited
• [Presentation] Graphene/Black Phosphorus-Arsenic Heterostructures and their terahertz and infrared device applications (Keynote) (2019)
  • Author(s): V. Ryzhii, M. Ryzhii, V. Leiman, V. Mitin, T.Otsuji, and M. S. Shur
  • Organizer: 2D MATERIALS 2019 - International Congress on Graphene, 2D Materials and Applications, Sochi, Russia, 30th Sept.- 04th Oct.
  • Int'l Joint Research / Invited
• [Presentation] Terahertz plasmonic graphene-channel transistor laser (2019)
  • Author(s): Y. Fuse, A. A. Dubinov, T. Watanabe, V. Ya. Aleshkin, S. V. Morozov, A. Satou, V. Ryzhii, and T. Otsuji
  • Organizer: MTSA2019: 5th International Symposium on Microwave/Terahertz Science and Applications, Busan, Korea, Sept. 30-Oct. 3
  • Int'l Joint Research
• [Presentation] Models of terahertz and infrared devices based on graphene/ black-AsP heterostructures (2019)
  • Author(s): M. Ryzhii, T.Otsuji, V. Ryzhii, V. Leiman, V. Mitin, and M.S. Shur
  • Organizer: EMSS2019: 31st European Modeling and Simulation Symposium, Lisbon, Portugal, Sep. 18-20
  • Int'l Joint Research
• [Presentation] Asymmetric dual grating gate graphene-based THz detectors (2019)
  • Author(s): J.A. Delgado Notario, V. Clerico, E.Diez, J.E. Velazquez Perez, T. Otsuji, and Y.M. Mezian
  • Organizer: IRMMW-THz2019: International Conference on Infrared, Millimeter, and Terahertz Waves, Paris, France, Sept. 2-6
  • Int'l Joint Research
• [Presentation] Graphene-based van der Waals heterostructures towards a new type of terahertz quantum-cascade lasers (Invited) (2019)
  • Author(s): T. Watanabe, D. Yadav, S. Boubanga-Tombet, A. Satou, A.A. Dubinov, V. Ryzhii, and T. Otsuji
  • Organizer: SPIE OPTICS+ Phootnics, Conf. OP412: Terahertz Emitters, Receivers, and Applications X, San Diego, CA, USA, Aug. 11-15
  • Int'l Joint Research / Invited
• [Presentation] Current-driven plasmonic instability in graphene metasurfaces for terahertz applications (Invited) (2019)
  • Author(s): S. Boubanga-Tombet, D. Yadav, A. Satou, W. Knap, V.V. Popov, and T. Otsuji
  • Organizer: AES2019: 7th Advanced Electromagnetics Symposium, Lisbon, Portugal, July 23-26
  • Int'l Joint Research / Invited
• [Presentation] Current-driven plasmonic instability in graphene metasurfaces for terahertz applications (Invited) (2019)
  • Author(s): S. Boubanga-Tombet, D. Yadav, A. Satou, W. Knap, V.V. Popov, and T. Otsuji
  • Organizer: META2019: 10th International Conference on Metamaterials, Photonic Crystals and Plasmonics, Lisbon, Portugal, July 23-26
  • Int'l Joint Research / Invited
• [Presentation] Graphene-black Phosphorus/Arsenic heterostructures for novel terahertz and infrared devices (Keynote) (2019)
  • Author(s): V. Ryzhii, T. Otsuji, and M.S. Shur
  • Organizer: METANANO2019: 9th International Conference on Metamaterials and Nanophotonics, St. Petersburg, Russia, July 15-19
  • Int'l Joint Research / Invited
• [Presentation] Graphene/black AsxP1-x heterostructures for terahertz and Infrared devices (Plenary) (2019)
  • Author(s): V. Ryzhii, T. Otsuji, M. Ryzhii, V. Leiman, V.E. Karasik, D. Ponomarev, P.P. Matsev, V. Mitin, and M.S. Shur
  • Organizer: RJUSE2019: 8th Russia-Japan-USA-Europe Symp. on Fund. & Appl. Problems of THz Dev. & Technol., Nizhny Novgorod, Russia, July 8-11
  • Int'l Joint Research / Invited
• [Presentation] Graphene-based van der Waals heterostructures towards a new type of terahertz quantum-cascade lasers (2019)
  • Author(s): T. Otsuji, D. Yadav, S. Boubanga-Tombet, T. Watanabe, A.A. Dubinov, and V. Ryzhii
  • Organizer: RJUSE2019: 8th Russia-Japan-USA-Europe Symp. on Fund. & Appl. Problems of THz Dev. & Technol., Nizhny Novgorod, Russia, July 8-11
  • Int'l Joint Research / Invited
• [Presentation] Terahertz current-driven lasing and amplification in graphene-based vdW heterostructures (Invited) (2019)
  • Author(s): T. Otsuji
  • Organizer: CCMR 2019: Collaborative Conference on Materials Research, the Kintex, Goyang Gyeonggi, South Korea, June 3-7
  • Int'l Joint Research / Invited
• [Presentation] Terahertz light amplification stimulated by current-driven plasmon instability in graphene-channel transistors (Invited) (2019)
  • Author(s): S. Boubanga-Tombet, W. Knap, A. Satou, D. But, V.V. Popov, and T. Otsuji
  • Organizer: GSMM: 12th Global Symposium onMillimeter Waves, Sendai, Japan, May 22-24
  • Int'l Joint Research / Invited
• [Presentation] Terahertz light emission and lasing in current-driven graphene-based 2D nano- and plasmonic-structures (Keynote) (2019)
  • Author(s): T. Otsuji
  • Organizer: EuroSciCon Joint Event on Laser Optics, Quantum & Plasma Physics, Stockholm, Sweden, May 5-10
  • Int'l Joint Research / Invited
• [Presentation] Terahertz light amplification of stimulated emission of radiation in current-injection graphene channel transistor (Invited) (2019)
  • Author(s): T. Otsuji , S. Boubanga-Tombet, D. Yadav, T. Watanabe, A. Satou, and V. Ryzhii
  • Organizer: SPIE Int. Conf. Defence+ Commercial Sensing, Conf.-10982 on Micro- and Nanotechnol. Sens., Sys., Appl. XI, Baltimore, MD, USA, April 14-18
  • Int'l Joint Research / Invited
• [Presentation] Terahertz light amplification stimulated by current-driven plasmon instability in grating-gate graphene transistor structures (Invited) (2019)
  • Author(s): S. Boubanga-Tombet, W. Knap, D. Yadav, A. Satou, D. but, V.V. Popov, and T. Otsuji
  • Organizer: FGTC: French-German Terahertz Conference 2019, Kaiserslautern, Germany, April 2-5
  • Int'l Joint Research / Invited
• [Presentation] Wide tunability in plasmon reflection by carrier density pattern in graphene (2019)
  • Author(s): M. Takamura, N. Kumada, S. Wang, K. Kumakura, and Y. Taniyasu
  • Organizer: Graphene2019: 9th edition of Graphene Conference series, the Angelicum Congress Center, Rome, Italy, June 25-28
  • Int'l Joint Research
• [Presentation] Plasmonic Response in Graphene under Periodic Carrier Density Modulation (2019)
  • Author(s): N. Kumada, N. H. Tu, M. Takamura, Y. Ogawa, and S. Suzuki
  • Organizer: Graphene2019: 9th edition of Graphene Conference series, the Angelicum Congress Center, Rome, Italy, June 25-28
  • Int'l Joint Research
• [Presentation] 光励起多層グラフェンにおける広帯域テラヘルツ光放射の観測 (2019)
  • Author(s): 込山貴大, 渡辺隆之, Sergey Morozov, Mikhail Fadeev, Vladimir Utochkin, 吹留博一, 佐藤昭, 尾辻泰一
  • Organizer: 電子情報通信学会電子デバイス研究専門委員会(ED)・テラヘルツ応用システム時限研究専門委員会(THz)共催電子デバイス研究会, Dec. 23
• [Presentation] 東北大におけるテラヘルツ科学技術研究、ならびテラヘルツプラズモニックデバイスの創出（招待） (2019)
  • Author(s): 尾辻泰一
  • Organizer: 東北大学＆理研第1回連携ワークショップ-テラヘルツ光研究の新展開と産業応用への展望, 仙台, 日本, Oct. 23
  • Invited
• [Presentation] 二次元原子薄膜ヘテロ接合の光電子プラズモニック物性とそのテラヘルツ光電子デバイス応用（プレナリ） (2019)
  • Author(s): 尾辻泰一
  • Organizer: 徳島大学ポストLEDフォトニクス公開シンポジウム2019, 徳島大学 常三島けやきホール, 徳島市, Oct. 15
  • Invited
• [Presentation] Terahertz light amplification and lasing in graphene-channel transistor structures (in Japanese, Invited) (2019)
  • Author(s): T. Otsuji
  • Organizer: 64th RAP: Seminar on RIKEN Center for Advanced Photonics, RIKEN Sendai, Japan, Aug. 2
  • Invited
• [Presentation] グラフェンを利用した絶縁体試料のX線吸収分光と光電子分光（２） (2019)
  • Author(s): 鈴木 哲，春山 雄一，石原マリ，山本知樹，住田弘祐，吉村真史，横山和司
  • Organizer: 2019年秋応用物理学会、札幌、日本、Sep. 20
• [Remarks] Otsuji Laboratory, RIEC, Tohoku University
  • URL: http://www.otsuji.riec.tohoku.ac.jp/english/index_en.php