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is a Japanese scientist, specializing in the field of semiconductor technology and Nobel Prize laureate, best known for inventing the bright gallium nitride (GaN) p-n junction blue LED in 1989 and subsequently the high-brightness GaN blue LED as well.〔(【引用サイトリンク】title=Japanese Journal of Applied Physics )〕〔(【引用サイトリンク】title=Japanese Journal of Applied Physics )〕〔Hiroshi Amano, Masahiro Kito, Kazumasa Hiramatsu and Isamu Akasaki: "P-Type Conduction in Mg-doped GaN Treated with Low-Energy Electron Beam Irradiation (LEEBI)", Jpn. J. Appl. Phys. Vol. 28, No.12, December 1989, pp. L2112-L2114, (accepted for pub. Nov. 1989).〕〔I. Akasaki, H. Amano, M. Kito and K. Hiramatsu :”Photoluminescence of Mg doped p-type GaN and electroluminescence of GaN p-n junction LED” J. Cryst. Growth, Vol. 48&49 pp.666-670, 1991〕〔Isamu Akasaki, Hiroshi Amano, Kenji Itoh, Norikatsu Koide and Katsuhide Manabe: “GaN-based UV/blue light emitting devices”, Inst. Phys. Conf. Ser. No.129, pp. 851-856, 1992〕 For this and other achievements Isamu Akasaki was awarded the Kyoto Prize in Advanced Technology in 2009〔(【引用サイトリンク】title=INAMORI FOUNDATION )〕 and the IEEE Edison Medal in 2011.〔(【引用サイトリンク】title=IEEE Jack S. Kilby Signal Processing Medal Recipients )〕 He was also awarded the 2014 Nobel prize in Physics, together with Hiroshi Amano and Shuji Nakamura, "for the invention of efficient blue light-emitting diodes, which has enabled bright and energy-saving white light sources". ==Career== Born in Kagoshima Prefecture, Akasaki graduated from Kyoto University in 1952, and obtained a Dr.Eng. degree in Electronics from Nagoya University in 1964. He started working on GaN-based blue LEDs in the late 1960s. Step by step, he improved the quality of GaN crystals and device structures〔Y. Ohki, Y. Toyoda, H. Kobayasi and I. Akasaki: “Fabrication and properties of a practical blue-emitting GaN m-i-s diode. Inst. Phys. Conf. Ser. No. 63, pp. 479-484 (Proc. of the 9th Intl. Symposium on Gallium Arsenide and Related Compounds, 1981).〕 at Matsushita Research Institute Tokyo, Inc.(MRIT), where he decided to adopt metalorganic vapor phase epitaxy (MOVPE) as the preferred growth method for GaN. In 1981 he started afresh the growth of GaN by MOVPE at Nagoya University, and in 1985 he and his group succeeded in growing high-quality GaN on sapphire substrate by pioneering the low-temperature (LT) buffer layer technology.〔H. Amano, N. Sawaki I. Akasaki and Y. Toyoda: "Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer,"〕〔Isamu Akasaki, Hiroshi Amano, Yasuo Koide, Kazumasa Hiramatsu and Nobuhiko Sawaki: "Effects of AlN buffer layer on crystallographic structure and on electrical and optical properties of GaN and Ga1-xAl xN (0 They achieved stimulated emission from the GaN firstly at room temperature in 1990,〔H. Amano, T. Asahi and I. Akasaki: “Stimulated Emission Near Ultraviolet at Room Temperature from a GaN Film Grown on Sapphire by MOVPE Using an AlN Buffer Layer” Jpn. J. Appl. Phys. Vol. 29, pp. L205-L206, 1990.〕 and developed in 1995 the stimulated emission at 388 nm with pulsed current injection from high-quality AlGaN/GaN/GaInN quantum well device.〔Isamu Akasaki, Hiroshi Amano, Shigetoshi Sota, Hiromitsu Sakai, Toshiyuki Tanaka and Masayoshi Koike: "Stimulated Emission by Current Injection from an AlGaN/GaN/GaInN Quantum Well Device" Jpn. J. Appl. Phys., Vol. 34 (1995) pp. L1517-1519, Part 2, No.11B, 15 November 1995 (accepted for pub. October 16, 1995).〕 They verified quantum size effect (1991)〔K. Itoh, T. Kawamoto, H. Amano, K. Hiramatsu and I. Akasaki: “Metalorganic Vapor Phase Epitaxial Growth and Properties of GaN/Al0.1Ga0.9N Layered Structures” Jpn. J. Appl. Phys. Vol. 30, pp.1924-1927, 1991.〕 and quantum confined Stark effect (1997)〔T. Takeuchi, S. Sota, M. Katsuragawa, M. Komori, H. Takeuchi, H. Amano and I. Akasaki: “Quantum-Confined Stark Effect due to Piezoelectric Fields in GaInN Strained Quantum Wells” Jpn. J. Appl. Phys., Vol.36, Pt. 2, No. 4A, pp. L382-385, 1997.〕 in nitride system, and in 2000 showed theoretically the orientation dependence of piezoelectric field and the existence of non-/semi-polar GaN crystals,〔Tetsuya Takeuchi, Hiroshi Amano and Isamu Akasaki: "Theoretical Study of Orientation Dependence of Piezoelectric Effects in Wurtzite Strained GaInN/GaN Heterostructures and Quantum Wells", Jpn. J. Appl. Phys. Vol. 39, pp. 413-416, Part1, No.2A, Feb.2000. (accepted for pub., November 1, 1999).〕 which have triggered today’s world-wide efforts to grow those crystals for application to more efficient light emitters. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Isamu Akasaki」の詳細全文を読む スポンサード リンク
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