Research for high-efficiency deep-UV emitting devices using quaternary InAlGaN nitride semiconductors

2010 Fiscal Year Final Research Report

• Project Area: Optoelectronics Frontier by Nitride Semiconductor -Ultimate Utilization of Nitride Semiconductor Material Potential-
• Project/Area Number: 18069014
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: HIRAYAMA Hideki The Institute of Physical and Chemical Research, テラヘルツ量子素子研究チーム, チームリーダー (70270593)
• Project Period (FY): 2006 – 2010
• Keywords: 深紫外LED / AlGaN / InAlGaN4元混晶 / 内部量子効率 / 貫通転位密度 / 結晶成長 / 外部量子効率 / 注入効率

Research Abstract

High-efficiency deep-ultraviolet (DUV) semiconductor light sources with emission wavelengths between 250-350 nm are in strong demand for various applications including sterilization, water purification, medicine, and biochemistry. In this work, we realized high-efficiency DUV light-emitting diodes (LEDs) by developing low threading-dislocation density AlN crystals using pulse gas feeding growth method, by realizing high internal-quantum efficiency (IQE) emitting layers using quaternary InAlGaN quantum wells (QWs) and by improving injection efficiency using multi-quantum barrier (MQB) electron-blocking layers (EBLs).

Research Products

• [Journal Article] Marked Enhancement in the Efficiency of Deep-Ultraviolet AlGaN Light-Emitting Diodes by Using a Multiquantum-Barrier Electron Blocking Layer (2010)
  • Author(s): H.Hirayama, Y.Tsukada, T.Maeda, N.Kamata
  • Journal Title: Appl.Phys.Express 3 Pages: 031002
• [Journal Article] 222-282nm AlGaN and InAlGaN based high-efficiency deep-UV-LEDs fabricated on high-quality AlN on sapphire (2009)
  • Author(s): H.Hirayama, N.Noguchi, S.Fujikawa, J.Norimatsu, T.Takano, K.Tsubaki, N.Kamata
  • Journal Title: Physica Status Solidi (a) 206 Pages: 1176-1182
• [Journal Article] 227 nm AlGaN light-emitting diode with 0.15 mW output power realized using thin quantum well and AlN buffer with reduced threading dislocation density (2008)
  • Author(s): H.Hirayama, N.Noguchi, T.Yatabe, N.Kamata
  • Journal Title: Appl.Phys.Express 1 Pages: 051101
• [Journal Article] 231-261nm AlGaN deep-ultraviolet light-emitting diodes fabricated on AlN multilayer buffers grown by ammonia pulse-flow method on sapphire (2007)
  • Author(s): H.Hirayama, T.Yatabe, N.Noguchi, T.Ohashi, N.Kamata
  • Journal Title: Appl.Phys.Lett. 91 Pages: 071901
• [Remarks] 受賞
• [Remarks] 第43回市村学術賞功績賞 平山秀樹 「AlGaN系精密結晶成長技術の開拓と深紫外LEDの先駆的研究」、2011年4月
• [Remarks] 第24回日本IBM科学賞エレクトロニクス部門 平山秀樹 「AlGaN系半導体結晶の高品質化と深紫外LEDの先導的開発」、2010年11月
• [Remarks] IWN国際会議ベストポスター賞 M.Akiba, H.Hirayama, Y.Tsukada N.Maeda and N.Kamata "Efficiency Enhancement in AlGaN Deep-UV LEDs using High-Reflectivity Al-based p-type Electrode"、2010年9月
• [Remarks] 新聞その他報道など
• [Remarks] 2007年9月21日、朝日新聞「紫外線発光ダイオード開発」
• [Remarks] 2008年7月7日、日刊工業新聞「殺菌用紫外線LED世界最高出力」
• [Remarks] 2010年2月26日、毎日新聞「殺菌力強いLED、紫外光実用化レベルへ」
• [Patent(Industrial Property Rights)] 窒化物半導体多重量子構造を有する発光素子及びその製造方法 (2010)
  • Inventor(s): 平山秀樹
  • Industrial Property Rights Holder: 独立行政法人理化学研究所
  • Industrial Property Number: 2010-038912
  • Filing Date: 2010-02-24
• [Patent(Industrial Property Rights)] 光半導体発光素子及びその製造方法 (2010)
  • Inventor(s): 平山秀樹、大橋智昭、鎌田憲彦
  • Industrial Property Rights Holder: 独立行政法人理化学研究所
  • Industrial Property Number: 4538476
  • Acquisition Date: 2010-06-25