Shuji Nakamura obtained B.E., M.S., and Ph.D. degrees in Electrical Engineering from the University of Tokushima, Japan in 1977, 1979, and 1994, respectively. He joined Nichia Chemical Industries Ltd in 1979. In 1993 and 1995 he developed the first group-III nitride-based high-brightness blue and green light-emitting diodes (LEDs). He also developed the first group-III nitride-based violet laser diodes (LDs) in 1995. Since 2000, he has been a professor of Materials and Electrical & Computer Engineering at the University of California, Santa Barbara. He is the 2014 Nobel Laureate in Physics for the invention of the efficient blue light-emitting diode which has enabled bright and energy-saving white light sources. 2014 Nobel Laureate in Physics Shuji Nakamura , Ph.D. LECTURES Make group lecture series reservations for: Name_____________________________________________________________________ Title ______________________________________________________________________ Organization _______________________________________________________________ Address __________________________________________________________________ City ___________________________________________ State ______ Zip ___________ Email _____________________________________________________________________ Business Phone (___ ___ ___)___ ___ ___-____ ____ ____ ____ Check events attending: ______ Public Lecture ______ Seminar Other participants from your organization: Name_____________________________________________________________________ Title ______________________________________________________________________ Name_____________________________________________________________________ Title ______________________________________________________________________ Reserved seats will only be held up until 15 minutes prior to the start of each lecture. Early submission recommended for reserved seating. Detach this card and send registration to: UW-L Foundation Inc. Cleary Alumni & Friends Center P.O. Box 1148 La Crosse, WI 54602-1148 USA 608.785.6803 Fax 608.785.6868 email: [email protected] Physics Seminar Development of InGaN/GaN Light Emitting Diodes (LEDs) and Laser Diodes for Energy Efficient Lighting and Displays LEDs fabricated from indium gallium nitride (InGaN) have led to the realization of high-efficiency white solid-state lighting. Currently, InGaN white LEDs exhibit luminous efficacy greater than 150 lm/W, and wall-plug efficiencies higher than 60%. This has enabled LEDs to compete with traditional lighting technologies such as incandescent and compact fluorescent lighting (CFL). Further improvements in materials quality and cost reduction are necessary for widespread adoption of LEDs for lighting. Tunnel junction (TJ) was used to improve the light extraction efficiency and the p-type contact in order to reduce the operating voltage of the LEDs. Peak wall-plug efficiency as high as 70% have been achieved. A review of the unique polarization anisotropy in GaN is included for the different crystal orientations. Emphasis on semipolar LEDs will highlight high-power violet and blue emitters and considers the effects of indium incorporation and polarization. Semipolar GaN materials have enabled the development of high-power blue lasers. Laser light sources show great promise for directional white illumination with efficiency as high as 87lm/W. This publication was funded by the University of Wisconsin-La Crosse Foundation Inc. Public Lecture The Invention Of High Efficient Blue LEDs And Future Lighting In the 1970s and 80s, a lack of suitable materials left efficient blue and green light-emitting diodes (LED) as the last missing elements for solid-state display and lighting technologies. By that time, III-nitride alloys were regarded as the least likely candidates due to various “impossible” difficulties. However, a series of unexpected breakthroughs in 1990’s totally changed peoples’ views. The first high-efficiency blue LEDs were invented and commercialized at the same time in 1993. Nowadays, III- nitride-based LEDs have become the most widely used light source in many applications. LED light bulbs have more than ten times the efficiency of incandescent bulbs, and they last for 50 years! At their current adoption rates, by 2020, LEDs can reduce the world’s need for electricity by the equivalent of nearly 60 nuclear power plants. The history of the invention of blue LED and future uses of their lighting will be described. Distinguished Lecture Series in PHYSICS