InGaNベース強磁性半導体による長波長円偏光半導体レ-ザ創製に関する研究

• Project Area: Optoelectronics Frontier by Nitride Semiconductor -Ultimate Utilization of Nitride Semiconductor Material Potential-
• Project/Area Number: 21016004
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Osaka University
• Principal Investigator: 朝日 一 大阪大学, 産業科学研究所, 教授 (90192947)
• Co-Investigator(Kenkyū-buntansha): 長谷川 繁彦 大阪大学, 産業科学研究所, 准教授 (50189528) ; 江村 修一 大阪大学, 産業科学研究所, 助教 (90127192) ; 周 逸凱 大阪大学, 産業科学研究所, 助教 (60346179)
• Project Period (FY): 2009 – 2010
• Project Status: Completed (Fiscal Year 2010)
• Budget Amount: ¥7,000,000 (Direct Cost: ¥7,000,000); Fiscal Year 2010: ¥3,500,000 (Direct Cost: ¥3,500,000); Fiscal Year 2009: ¥3,500,000 (Direct Cost: ¥3,500,000)
• Keywords: 窒化物半導体 / スピンエレクトロニクス / 光物性 / 結晶工学 / MBE

Research Abstract

長波長での円偏光半導体レーザを創製することを狙いとして、希土類金属Gdを添加したIII族窒化物希薄磁性半導体を分子線エピタキシ(MBE)法により成長し、その光学特性及び磁気特性を測定し、更にデバイス作製に向けて磁性制御に関して研究を行い、次の結果を得た。
(1)In濃度35%のInGaGdNが成長可能となり、InGaGdNからのフォトルミネセンス(PL)ピーク波長はIn組成の増加に対応した長波長シフトが観測された。PLの温度変化はInGaNと同様であった。室温で強磁性特性が観測された。
(2)Gd濃度6%のInGaGdNの飽和磁化はGd濃度1%のInGaGdNと比べ倍程度に増加することが分かった。ただし、Gd濃度を大きくし過ぎるとGaN等の析出が起こり、低下した。
(3)InGaGdNにSiを共添加すると、キャリア(電子)濃度が増加すると共に、磁化の増加が観測、された。キャリア誘起強磁性と理解される。
(4)InGaGdN/GaN多重量子井戸(MQW)構造を成長した。この構造では、同じ厚さのInGaGdN単層膜より磁化が増大することが分かった。InGaGdN/GaN MQW構造のGaN層にSiを添加した場合には更に磁化が増加することが確認された。いずれもバンドギャップの大きいGaN中のキャリアがInGaGdN層に流れ込むことによるキャリア誘起強磁性と理解される。
(5)InGaGdN/GaN MQW活性層をSiドープn形GaN、Mgドープp形GaNクラッド層で挟んだスピンLED構造を成長し、MQW活性層からのPL発光を観測した。

Research Products

• [Journal Article] Influence of Si-doping on the characteristics of InGaGdN/GaN MQWs, grown by MBE (2011)
  • Author(s): S.N.M.Tawil, D.Krishnamurthy, M.Ishimaru, S.Emura, S.Hasegawa, H.Asahi
  • Journal Title: Phys.Status Solidi (c) Volume: 8 Pages: 491-493
  • Peer Reviewed
• [Journal Article] Studies on the InGaGdN/GaN magnetic semiconductor heterostructures grown by plasma-assisted molecular-beam epitaxy (2011)
  • Author(s): S.N.M.Tawil, D.Krishnamurthy, R.Kakimi, S.Emura, S.Hasegawa, H.Asahi
  • Journal Title: J.Cryst.Growth Volume: (印刷中)
  • Peer Reviewed
• [Journal Article] Structural characterization of MBE grown InGaGdN/GaN and InGaN/GaGdN superlattice structures (2011)
  • Author(s): D.Krishnamurthy, S.N.M.Tawil, M.Ishimaru, S.Emura, Y.K.Zhou, S.Hasegawa, H.Asahi
  • Journal Title: Phys.Stat.Sol. Volume: (印刷中)
  • Peer Reviewed
• [Journal Article] Amealing effect in GaDyN on optical and magnetic properties (2010)
  • Author(s): Y.K Zhou, M.Takahashi, S.Emura, S.Hasegawa, H.Asahi
  • Journal Title: Journal of Superconductivity and Novel Magnetism Volume: 23 Pages: 103-105
  • Peer Reviewed
• [Journal Article] Structural and magnetic properties of GaGdN/GaN superlattice structures (2010)
  • Author(s): Y.K.Zhou, S.W.Choi, S.Kimura, S.Emura, S.Hasegawa, H.Asahi
  • Journal Title: Thin Solid Films Volume: 518 Pages: 5659-5661
  • Peer Reviewed
• [Journal Article] Characterization of InGaGdN layers prepared by molecular beam epitaxy (2010)
  • Author(s): S.N.M.Tawil, R.Kakimi, D.Krishnamurthy, M.Ishimaru, S.Emura, H.Tambo, S.Hasegawa, H.Asahi
  • Journal Title: Phys.Stat.Sol.Rap.Res.Lett. Volume: 4 Pages: 308-310
  • Peer Reviewed
• [Journal Article] Annealing effect in GaDyN on optical and magnetic properties (2010)
  • Author(s): Y.K Zhou, M.Takahashi, S.Emura, S.Hasegawa, H.Asahi
  • Journal Title: J.Phys. : Condens.Matter. 23 Pages: 103-105
  • Peer Reviewed
• [Journal Article] Structural and magnetic properties of GaGdN/GaN superlattice structures (2010)
  • Author(s): Y.K.Zhou, S.W.Choi, S.Kimura, S.Emura, S. Hasegawa, H.Asahi
  • Journal Title: J.Crystal Growth (印刷中)
  • Peer Reviewed
• [Journal Article] Formation of aligned CrN nanoclusters in Cr-delta-doped GaN (2009)
  • Author(s): Y.K.Zhou, S.Kimura, S.Emura, S.Hasegawa, H.Asahi
  • Journal Title: 14th International Conference on Modulated Semiconduct or Structures (MSS-14) 21
  • Peer Reviewed
• [Journal Article] Structural properties of AlCrN, GaCrN and InCrN (2009)
  • Author(s): S.Kimura, S.Emura, K.Tokuda, Y.K.Zhou, S.Hasegawa, H.Asahi
  • Journal Title: 5th Handai Nanoscinece and Nanotechnology International Symposium 311 Pages: 2046-2048
  • Peer Reviewed
• [Journal Article] Ferromagnetism and Luminescence of Diluted Magnetic Semiconductors GaGdN and AIGdN (2009)
  • Author(s): S.Emura, M.Takahashi, H.Tambo, A.Suzuki, T.Nakamura, Y.K.Zhou, S.Hasegawa, H.Asahi
  • Journal Title: 5th Handai Nanoscinece and Nanotechnology International Symposium 1111 Pages: 49-60
  • Peer Reviewed
• [Presentation] Crowth and characterization of transition-metal and rare-earth doped III-nitride semiconductors for spintronics (2010)
  • Author(s): H.Asahi, S.Hasegawa, Y.K.Zhou, S.Emura
  • Organizer: 2010 MRS Fall Meeting
  • Place of Presentation: ボストン(米国)(招待講演)
  • Year and Date: 2010-11-30
• [Presentation] Studies on the InGaGdN/GaN magnetic semiconductor heterostructures grown by plasma-assisted molecular-beam epitaxy (2010)
  • Author(s): S.N.M.Tawil, D.Krishnamurthy, R.Kakimi, S.Emura, S.Hasegawa, H.Asahi
  • Organizer: 16th International Conference on Molecular Beam Epitaxy
  • Place of Presentation: ベルリン(ドイツ)
  • Year and Date: 2010-08-25
• [Presentation] Influence of Si-doping on the Characteristics of InGaGdN/GaN MQWs Grown by MBE (2010)
  • Author(s): S.N.M.Tawil, D.Krishnamurthy, R.Kakimi, M.Ishimaru, S.Emura, S.Hasegawa, H.Asahi
  • Organizer: 37th International Symposium on Compound Semiconductor
  • Place of Presentation: 高松シンボルタワー(高松)
  • Year and Date: 2010-06-01
• [Presentation] Synthesis and Characterization of Gd-doped InGaN Thin Films and Superlattice Structure (2010)
  • Author(s): S.N.M. Tawil, D.Krishnamurthy, R.Kakimi, M.Ishimaru, S.Emura, S.Hasegawa, H.Asahi
  • Organizer: IEEE International NanoElectronics Conference (INEC 2010)
  • Place of Presentation: 香港(中国)
  • Year and Date: 2010-01-06
• [Presentation] Growth and characterization of GaN-based room-temperature ferromagnetic semiconductors for semiconductor spintronics (INVITED) (2009)
  • Author(s): H.Asahi, S.Hasegawa, Y.K.Zhou, S.Emura
  • Organizer: 11th Takayanagi Kenjiro Memorial Symposium
  • Place of Presentation: 静岡大学(静岡県)
  • Year and Date: 2009-11-13
• [Presentation] Large Zeeman splitting in low-temperature-grown GaDyN (2009)
  • Author(s): Y.K.Zhou, H.Ichihara, S.Emura, S.Hasegawa, H.Asahi
  • Organizer: International Symposium of Post-Silicon Materials and Devices Research Alliance Project
  • Place of Presentation: 大阪大学(大阪府)
  • Year and Date: 2009-09-05
• [Presentation] Growth and characterization of GaGdN/AIGaN heterostructures (2009)
  • Author(s): M.Kin, S.Hasegawa, D.Abe, H.Asahi
  • Organizer: Journal of Superconductivity and Novel Magnetism
  • Place of Presentation: 大阪大学(大阪府)
  • Year and Date: 2009-09-02
• [Presentation] Structural and optical properties of rare-earth element Gd doped GaN (2009)
  • Author(s): H.Tani, S.Hasegawa Y.K.Zhou S.Emura, H.Asahi
  • Organizer: Thin Solid Films
  • Place of Presentation: 大阪大学(大阪府)
  • Year and Date: 2009-09-02
• [Presentation] Enhancement of saturation magnetization in GaGdN/AIGaN multiple quantum wells grown by PA-MBE (2009)
  • Author(s): S.Hasegawa, H.Tani, M.Kin, Y.K.Zhou, H.Asahi
  • Organizer: Mater.Res.Soc.Symp.Proc.Ser.
  • Place of Presentation: 神戸国際会議場(兵庫県)
  • Year and Date: 2009-07-21
• [Remarks]
  • URL: http://www.sanken.osaka-u.ac.jp/labs/pem/
• [Remarks]
  • URL: http://www.sanken.osaka-u.ac.jp/labs/pem/