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SUMMARY:EE Distinguished Lecturer Seminar - 2014 Physics Nobel Prize: GaN 
 as a key material for establishing a sustainable society
DTSTART:20191014T121500
DTEND:20191014T131500
DTSTAMP:20260414T171505Z
UID:79aeee86afa8110e637706eb790b1d21a35a15890683fffa36c937ac
CATEGORIES:Conferences - Seminars
DESCRIPTION:Hiroshi Amano received his BE\, ME and DE degree in 1983\
 , 1985 and 1989\, respectively\, from Nagoya University. From 1988 to 199
 2\, he was a research associate at Nagoya University. In 1992\, he moved t
 o MeijoUniversity\, where he was an assistant professor\, associate profe
 ssor from 1998 till 2002\, and professor from 2002 till 2010. He moved to 
 Nagoya University\, where he was a professor of Graduate School of Enginee
 ring from 2011 till 2015. On Oct. 1\, 2015\, he became a director of Cente
 r for Integrated Research of Future Electronics\, Institute of Materials a
 nd Systems for Sustainability\, Nagoya University.  During his doctoral p
 rogram at the Nagoya University Graduate School of Engineering\, he was ab
 le to realize high-quality epitaxially grown GaN film with metal-organic v
 apor phase epitaxy (MOVPE)\, p-type GaN filmdoped with Mg while conducting
  research with Professor Akasaki.For the first time in history\, he establ
 ished the technology necessary for the production of blue LEDs\, thus perf
 orming a great achievement the development of the high-luminosity blue LED
 .  He is currently developing technologies for the fabrication of high-ef
 ficiency power semiconductor development and new energy-saving devices at 
 Nagoya University. He has over 560 publications. Prof. Amano shared the 
 Nobel Prizein Physics 2014 with Prof. Isamu Akasaki and Prof. Shuji Nakamu
 ra "for the invention of efficient blue light-emitting diodes which has en
 abled bright and energy-saving white light sources"\nAbstract : The most 
 important application of III nitrides is blue LEDs for full color displays
  and general lighting systems. Most of the commercially available blue are
  grown on foreign substrates such as sapphire\, Si or SiC. In spite of hig
 h dislocation density over 108cm-2\, wall plug efficiency (WPE) of blue LE
 Ds exceeds 50%\, which is extremely high compared with that of LEDs made b
 y other III-V compound semiconductors such as GaAs or GaP. In case of othe
 r LEDs\, WPE may be less than 1% if such a high density of dislocations ex
 ists in the crystal.One of the reason of high-efficiency of blue LEDs base
 d on III nitrides is short diffusion length of minority carriers in GaN an
 d InGaN. By 2020\, more than 70% of the general lighting system will be re
 placed from the conventional incandescent lamps or fluorescent lamps to LE
 D lamps\, by which about 7% of the total electricity consumption can be sa
 ved. In this presentation\, history and future prospects of the developmen
 t of the blue LEDs will be discussed. \nAlGaN-based deep-UV (DUV) LEDs on
  sapphire substrates are effective for the efficient and long-life devices
  for sterilization and purification of water compared with conventional UV
  germicidal lamps. UNICEF reported that 844 million people still lack acce
 ss to safe drinking water and 2.3 billion people do not use safe sanitatio
 n facilities. New water sterilization and purification systems have been c
 ommercialized\, in which AlGaN-based high-power DUV LEDs are installed. Ot
 her applications of DUV LEDs include as a sterilizer for sanitation facili
 ties\, resins and the curing of inks in large printers\, detecting forged 
 banknotes\, photolithography for manufacturing semiconductor devices\, and
  treating skin disease\, which is called dermatology. \nMicrowave high-el
 ectron mobility transistors (HEMT) based on AlGaN/GaN on SiC substrate wor
 ks well in spite of high dislocation density over 108cm-2because high-dens
 ity two-dimensional electron gas induced by polarization of these material
 s is used\, therefore Fermi level in the channel layer is very high and sc
 attering by the dislocation is small. Majority of high-power amplifier in 
 base station of smart phone have been replaced from multichip GaAs-based H
 EMT to single chip GaN-based HEMT.\nBreakdown field of GaN is one order of
  magnitude higher than that of Si. Therefore\, we can reduce not only the 
 size of the transistors\, but also power loss to one tenth. If we replace 
 all the Si based transistors such as insulated gate bipolar transistors to
  GaN based transistors in the invertor circuits\, we can reduce 9.8% of th
 e total electricity consumption in Japan. For power device applications\, 
 vertical structure is more feasible to operate high current. Low defect de
 nsity crystal is essential for realizing low current leakage at high volta
 ge. Therefore\, requirement specification for the substrate and epitaxial 
 layer is much higher than that of LEDs and microwave devices. In this pres
 entation\, substrate and epitaxy issues for the future power devices based
  on III nitrides will be discussed.\nThis research is supported by the Min
 istry of Education\, Culture\, Sports\, Science and Technology (MEXT)\, Ja
 pan\, through its “Program for research and development of next-generat
 ion semiconductor to realize energy-saving society.\n 
LOCATION:RLC E1 240 https://plan.epfl.ch/?room==RLC%20E1%20240
STATUS:CONFIRMED
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