DOCSLIB.ORG

Blue LED and Solid State Lighting Hyeonsik Cheong Department of Physics Sogang University Nobel Prize in Physics 2014

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Blue LED and Solid State Lighting Hyeonsik Cheong Department of Physics Sogang University Nobel Prize in Physics 2014 Blue LED and Solid State Lighting Hyeonsik Cheong Department of Physics Sogang University Nobel Prize in Physics 2014 Isamu Akasaki (1929) Hiroshi Amano (1960) Shuji Nakamura (1954) “for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources” 2 Isamu Akasaki Born in 1929 1952 B.S. Kyoto Univ. 1959 Research Associate, Assistant and Associate Professor, Nagoya Univ. 1964 Dr. Eng., Nagoya Univ. 1964 Matsushita Research Institute 1981 Professor, Nagoya Univ. 1992 Professor Emeritus, Nagoya Univ. and Professor, Meijo Univ. 3 Hiroshi Amano Born in 1960 1983 B.E. Nagoya Univ. 1989 Dr. Eng. Nagoya, Univ. 1988 Research Associate, Nagoya Univ. 1992 Assistant, Associate, Professor, Meijo Univ. 2010 Professor, Nagoya Univ. 4 Shuji Nakamura Born in 1954 1977, 1979, BE and ME, Tokushima Univ. 1979 Nichia Corporation 1988 Visiting Scientist, Univ. of Florida 1994 Dr. Eng. Tokushima Unvi. 1999 Professor, UC Santa Barbara 5 Blue LED 6 7 Full-color Display (RGB) 8 Is it worth a Nobel Prize? History of Lighting 10 Electrical Lighting Incandescent lamp . Edison’s lamp: Carbon filament Tungsten filament . Electricity Heat Light Arc lamp (HID) . Electricity Gas Molecule Light Fluorescent lamp . Electricity Mercury vapor UV light Visible light LED . Electricity Light 11 Historical Development of Lighting 12 Comparison of Lamps Cost Comparison for 60 watt incandescent equivalent light bulb (U.S. residential electricity prices) LED LED Incandescent Halogen CFL LED (Cree) (EcoSmart clear) (Philips) Purchase price $0.41 $1.17 $0.99 $3.66 $1.50 $4.99 Watts 60 43 14 6.5 8.5 9.5 lumens (mean) 860 750 775 800 800 815 lumens/watt 14.3 17.4 55.4 123.1 94.1 85.8 Lifespan (hours) 1,000 1,000 10,000 15,000 10,000 25,000 Energy cost over 20 $289 $207 $67 $31 $41 $46 years @ 11 cents/kWh Total cost per 860 $307 $297 $78 $45 $52 $59 lumens over 20 years Comparison based on 6 hours use per day (43,800 hours over 20 yrs) 13 Energy Consumption 14 15 LED Monitor: LCD Display + White LED Lamp 16 Fluorescent Lamp 17 LED Lamp (White LED) Blue LED UV LED + + RGB LED Yellow Phosphor RGB Phosphor 18 LED Lighting 19 LED Lighting for Major League Baseball 20 21 History of Blue LED History of LED (Light Emitting Diode) 1907, H. J. Round (Marconi Electronics) . Observed light emission from SiC upon voltage 1927, Oleg Losev . Systematic study of electrical light emission from SiC Phil. Mag. 6, 1024 (1928). 23 History of LED 24 Visible Spectrum Wavelength Energy 25 Light Emitting Diode (LED) 26 Principle of LED p type n type Electrons (–) Band gap Hole(+) Photon Energy ~ Band Gap Energy 27 Elements for Semiconductors Band Gap . C (diamond), Si, Ge . GaAs, GaP, InP, GaN, AlN… . ZnO, ZnS, ZnSe, CdS, CdSe… 28 Band Gap Energy of Semiconductors 29 First Blue LED 1979 Matsushita Electric 30 High Power Blue LED Motivation: Blue Laser Diode (LD) Structure of Laser Laser Diode 31 High Power Blue LED Motivation: Blue Laser Diode (LD) Why Blue Laser Diode? . Optical Data Storage: CD, DVD, etc. 32 High Power Blue LED Motivation: Blue Laser Diode (LD) Why Blue Laser Diode? . Optical Data Storage: CD, DVD, etc. Data capacity ~ 1/휆 • Diffraction Limit Numerical Aperture (N.A.) 푁. 퐴. = 푛 sin 휗 33 High Power Blue LED Motivation: Blue Laser Diode (LD) Why Blue Laser Diode? . Optical Data Storage: CD, DVD, etc. 34 High Power Blue LD 35 High Power Blue LED For High Efficiency Light Emission . High quality semiconductor crystal . Easy doping: both n and p types Limitations of GaN . Difficult (almost impossible) to grow single crystals . No appropriate substrates Difficult to obtain high quality materials . Difficult to obtain p-type doping 36 Growth of High Quality GaN Metal Organic Vapor Phase Epitaxy (MOVPE, MOCVD) 37 Growth of High Quality GaN Low-Temperature Buffer Layer 38 P-type Doping 39 P-type Doping Mg doping followed by heat treatment 40 First High Brightness Blue LED 41 Blue Laser Diode! 42 Unfortunately,… Laser diodes are not as important as expected… 43 But, Solid state lighting exceeded everyone’s expectation! 44 Shuji Nakamura Born in 1954 1977, 1979, BE and ME, Tokushima Univ. 1979 Nichia Corporation 1988 Visiting Scientist, Univ. of Florida 1994 Dr. Eng. Tokushima Unvi. 1999 Professor, UC Santa Barbara 2000 Becomes US citizen 2001 Files lawsuit for $180 million against Nichia (settles for $9 million) 45 Words from the winners “Hold on to your dream. Don’t be afraid to make mistakes – experience is the best teacher.” – Isamu Akasaki “I think the most important thing is students have to find out is what you like, what I like, you know. And almost it's like a dream. And then, just work hard for your dream. I think that's the best way, you know, to a good invention.” – Shuji Nakamura 46 47.
Load more

Recommended publications
  • That You Want to Know About the Light Emitting Diodes Or Leds
    ALL THAT YOU WANT TO KNOW ABOUT THE LIGHT EMITTING DIODES OR LEDS LED=LIGHT EMITTING DIODE IS A SEMICONDUCTOR DEVICE WHICH EMITS LIGHT WHEN PROPERLY BIASED. LIKE THE BASIC SEMICONDUCTOR DIODE IN FORWARD BIAS, THE ELECTRONS AND THE HOLES IN THE LED COMBINE TO RELEASE ENERGY BY A PROCESS CALLED ELECTROLUMINESCENCE. THE COLOUR OF THE LIGHT IS DETERMINED BY THE ENERGY GAP OF THE SEMICONDUCTOR. A LIGHT EMITTING DIODE CONSISTS OF MULTIPLE LAYERS OF SEMI-CONDUCTING MATERIAL. WHEN THE DIODE IS BEING USED WITH DIRECT CURRENT, LIGHT IS PRODUCED IN THE ACTIVE LAYER. THE LIGHT PRODUCED IS DECOUPLED DIRECTLY OR BY REFLECTIONS. IN CONTRAST TO INCANDESCENT REFLECTOR LAMPS, WHICH EMIT A CONTINUOUS SPECTRUM, AN LED EMITS LIGHT IN A PARTICULAR COLOR. THE LIGHT'S COLOR DEPENDS ON THE SEMICONDUCTOR MATERIAL USED. TWO MATERIAL SYSTEMS ARE MAINLY USED, IN ORDER TO PRODUCE LEDS WITH A HIGH DEGREE OF BRIGHTNESS IN ALL COLORS FROM BLUE TO RED AND, BY MEANS OF LUMINESCENCE CONVERSION, ALSO IN WHITE. DIFFERENT VOLTAGES ARE NECESSARY, TO OPERATE THE DIODE IN FORWARD BIAS. LEDS ARE SEMICONDUCTOR CRYSTALS. DEPENDING ON THE COMPOSITION OF THE CRYSTAL COMPOUNDS, THEY EMIT LIGHT IN THE COLORS OF RED, GREEN, YELLOW OR BLUE, WHEN CURRENT FLOWS THROUGH THEM. WITH THE THREE RGB COLORS, ANY NUMBER OF COLOR TONES MAY BE MIXED BY VARYING THE PROPORTIONS OF THE INDIVIDUAL COLORS. IN THIS WAY, THE LED LIGHTING CAN CREATE FASCINATING WORLDS OF EXPERIENCE. HISTORY THE FIRST LED WAS INVENTED BY OLEG LOSE (1927), JAMES R. BIARD (1961), NICK HOLONYAK (1962) SEPARATELY. EARLY LEDS EMITTED LOW INTENSITY RED LIGHT, MODERN ONES ARE AVAILABLE ACROSS THE VISIBLE, ULTRAVIOLET AND INFRARED WAVELENGTHS WITH VERY HIGH BRIGHTNESS.
    [Show full text]
  • Light Pollution, Blue Light, Stress and Insomnia: Dark Sides of the LED Light? Laurent Canale
    Light Pollution, Blue Light, Stress and Insomnia: Dark Sides of the LED Light? Laurent Canale To cite this version: Laurent Canale. Light Pollution, Blue Light, Stress and Insomnia: Dark Sides of the LED Light?. International Journal of Electronics and Electrical Engineering Systems, Association Algérienne de Génie Electrique et Electronique, 2020, 3 (3). hal-03164045 HAL Id: hal-03164045 https://hal.archives-ouvertes.fr/hal-03164045 Submitted on 10 Mar 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Light Pollution, Blue Light, Stress and Insomnia: Dark Sides of the LED Light? Dr Laurent CANALE CNRS Research Engineer, IEEE Senior Member LAPLACE, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France 118, Route de Narbonne, 31062 Toulouse Cedex 9, France E-mail : [email protected] Abstract - During decades, for indoor applications, a bulb was replaced by the same bulb, 100W, 60W or less, incandescent or sometimes linear fluorescent, and only mattered the shape, the power or the type of socket... The LEDs is the ultimate home revolution in lighting technologies and, as every newcomer, it comes with its censors and detractors. Light pollution, photo-biological risk to the eye, environmental impact or insomnia are not exclusive to LED lamps; but its remarkable arrival, in a world where evolutions are discreet, focus questions and suspicions.
    [Show full text]
  • Secrecy in the USSR and German Democratic Republic Patent Systems Martens, John A
    www.ssoar.info Secrecy in the USSR and German Democratic Republic Patent Systems Martens, John A. Erstveröffentlichung / Primary Publication Arbeitspapier / working paper Empfohlene Zitierung / Suggested Citation: Martens, J. A. (2021). Secrecy in the USSR and German Democratic Republic Patent Systems.. https://nbn- resolving.org/urn:nbn:de:0168-ssoar-74323-8 Nutzungsbedingungen: Terms of use: Dieser Text wird unter einer CC BY Lizenz (Namensnennung) zur This document is made available under a CC BY Licence Verfügung gestellt. Nähere Auskünfte zu den CC-Lizenzen finden (Attribution). For more Information see: Sie hier: https://creativecommons.org/licenses/by/1.0 https://creativecommons.org/licenses/by/1.0/deed.de Secrecy in the USSR and German Democratic Republic Patent Systems John A. Martens Abstract Why did the Soviet Union and its East European allies establish patent offices? Patents, after all, create private property rights which may interfere with the goals of state ownership and central planning. The Soviet Union and its allies also established secret patents, but wouldn’t secret patents undermine the free flow of information, one of the purported advantages of state planning and the inventor’s cer- tificate, a socialist form of patent? Although most developed market economies had secret patents or rules on maintaining secrecy for patent applications judged important to national security, why did the Soviet Union and its allies believe they needed to do so too? Were the com- munist countries more or less secretive than the market economies? This article explores the above questions by examining the Soviet and GDR secret patent systems, comparing them to each other and to the systems in selected developed market economies (the FRG, United States, United Kingdom and France).
    [Show full text]
  • Leds: Everything You Wanted to Know
    White Paper LEDs: Everything You Wanted to Know John Barrington, Matthew Hildner, and Aarash Navabi Introduction The rapid pace of modern technology is making many types of products smaller and more powerful. Moore’s law predicts that the number of transistors in a dense integrated circuit doubles approximately every two years. However, this doesn’t apply only to integrated circuits; Moore’s law is also reflected in Light Emitting Diode (LED) technology. An LED is made up of many small dies. The same advancements that allow packing more transistors into an integrated circuit also allow LEDs to become brighter and more compact. LEDs are fast becoming the future of lighting. Their high light output and low power consumption make them ideal solutions for meeting the new requirements being enacted due to recent legislation. However, it isn’t possible to compare an LED light to traditional lighting sources using previous terminology, such as describing an LED’s light output in terms of wattage. LEDs also have different constraints on operating conditions, manufacturing, and the type of light produced. In short, LEDs are a new technology that is very different than older light sources. This document is meant to be a resource for understanding LED technology, offering a reference for designers, engineers, managers, and anyone else working with them for using and designing for them properly. Intro to LEDs (Light Emitting Diodes) As the name suggests, an LED is a type of diode that emits light. The principles on which LEDs operate were discovered by Russian scientist Oleg Losev in 1927, but he was unable to develop practical applications for them.
    [Show full text]
  • Stephanie Preißner, Christina Raasch, and Tim Schweisfurth
    A Service of Leibniz-Informationszentrum econstor Wirtschaft Leibniz Information Centre Make Your Publications Visible. zbw for Economics Preißner, Stephanie; Raasch, Christina; Schweisfurth, Tim Working Paper Is necessity the mother of disruption? Kiel Working Paper, No. 2097 Provided in Cooperation with: Kiel Institute for the World Economy (IfW) Suggested Citation: Preißner, Stephanie; Raasch, Christina; Schweisfurth, Tim (2017) : Is necessity the mother of disruption?, Kiel Working Paper, No. 2097, Kiel Institute for the World Economy (IfW), Kiel This Version is available at: http://hdl.handle.net/10419/172535 Standard-Nutzungsbedingungen: Terms of use: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Documents in EconStor may be saved and copied for your Zwecken und zum Privatgebrauch gespeichert und kopiert werden. personal and scholarly purposes. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle You are not to copy documents for public or commercial Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich purposes, to exhibit the documents publicly, to make them machen, vertreiben oder anderweitig nutzen. publicly available on the internet, or to distribute or otherwise use the documents in public. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, If the documents have been made available under an Open gelten abweichend von diesen Nutzungsbedingungen die in der dort Content Licence (especially Creative Commons Licences), you genannten Lizenz gewährten Nutzungsrechte. may exercise further usage rights as specified in the indicated licence. www.econstor.eu KIEL WORKING PAPER Is Necessity the Mother of Disruption? No. 2097 December 2017 Stephanie Preißner, Christina Raasch, and Tim Schweisfurth Kiel Institute for the World Economy ISSN 2195–7525 KIEL WORKING PAPER NO.
    [Show full text]
  • Semiconductor from Wikipedia, the Free Encyclopedia
    Semiconductor From Wikipedia, the free encyclopedia A semiconductor material has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Semiconductors are the foundation of modern electronics. Semiconducting materials exist in two types - elemental materials and compound materials.[1] The modern understanding of the properties of a semiconductor relies on quantum physics to explain the movement of electrons and holes in a crystal lattice.[2] The unique arrangement of the crystal lattice makes silicon and germanium the most commonly used elements in the preparation of semiconducting materials. An increased knowledge of semiconductor materials and fabrication processes has made possible continuing increases in the complexity and speed of microprocessors and memory devices. Some of the information on this page may be outdated within a year, due to the fact that new discoveries are made in the field frequently.[2] The electrical conductivity of a semiconductor material increases with increasing temperature, which is behaviour opposite to that of a metal. Semiconductor devices can display a range of useful properties such as passing current more easily in one direction than the other, showing variable resistance, and sensitivity to light or heat. Because the electrical properties of a semiconductor material can be modified by controlled addition of impurities, or by the application of electrical fields or light, devices made from semiconductors can be used for amplification, switching, and energy conversion. Current conduction in a semiconductor occurs through the movement of free electrons and "holes", collectively known as charge carriers. Adding impurity atoms to a semiconducting material, known as "doping", greatly increases the number of charge carriers within it.
    [Show full text]
  • Crystal Radio Receiver
    CRYSTAL RADIO RECEIVER Definition A Crystal radio receiver is a very simple radio receiver, popular in the early days of radio. It needs no battery or power source and runs on the power received from radio waves by a long wire antenna. It gets its name from its most important component, known as a crystal detector, originally made with a piece of crystalline mineral such as galena. This component is now called a diode. Basics The crystal radio receiver (also known as a crystal set) is a very simple kind of radio receiver. It needs no battery or power source except the power received from radio waves by a long outdoor wire antenna. Introduction Simple crystal radios are often made with a few hand made parts, like an antenna wire, tuning coil of copper wire, crystal detector and earphones. Because crystal radios are passive radio receivers, they are technically distinct from ordinary radios containing active powered amplifiers in many respects. This is because they must receive and preserve as much electrical power as possible from the antenna and convert it to sound power whereas ordinary radios amplify the weak electrical energy "signal" from the radio wave. Today making and operating crystal radios is a popular hobby for many reasons, including: Historical and nostalgic significance The astonishing results one can get from its utter simplicity The challenge of receiving weak distant signals without amplification Crystal radios can be designed to receive almost any radio frequency since there is no fundamental limit on the frequencies they will receive. The most common crystal radios are designed for the AM Broadcast Band and the 49- meter international short wave band, partly because the radio waves are stronger in those bands.
    [Show full text]
  • Chronicle of a Cassandra the Dark Matters of Science Science And
    Chronicle of a Cassandra The Dark Matters of Science Science and Technology Exposed Written and Compiled by Alan Wade Copyright © 2012 Alan Wade Dedicated to my wife who first suggested that I write this book TABLE OF CONTENTS Introduction CHAPTER 1 Moon in their eyes Lunar Exploration and Newton©s Moon Madness CHAPTER 2 Wit©s End Logic Scepticism Rationale and Imagination CHAPTER 3 No More Wires Technology Radio (Wireless) CHAPTER 4 Science and Extraordinary Popular Delusions Technology Radio-astronomy CHAPTER 5 Television Personalities Technology Television CHAPTER 6 The Smithsonian Flying Circus Technology, science and the birth of aviation CHAPTER 7 Through a Glass Darkly Technology Tomography MRI the Nobel prize and an aether blast from the past. CHAPTER 8 Playing the Field Effect Technology Transistors and other semiconductors CHAPTER 9 It©s Not Rocket Science Technology Computer CHAPTER 10 Impossible Machinations New energy and perpetual scepticism CHAPTER 11 CHAPTER 12 Something is Under the Bedrock Anomalies of the Earth sciences and geology CHAPTER 13 The Abominable Showmen of Evolution References, Neo-Darwinism: time to reconsider. By Richard Milton Endnotes Chapter 1 to Chapter 13 List of illustrations Figures 1 to 5 Chronicle of a Cassandra A HISTORY OF SCIENCE AND TECHNOLOGY EVERYTHING IS A REMIX Introduction and Notes "It is a strange thought, but I believe a correct one, that twenty or thirty pages of ideas and information would be capable of turning the present-day world upside down, or even destroying it. I have often tried to conceive of what those pages might contain, but of course I am a prisoner of the present-day world, just as all of you are.
    [Show full text]
  • A New Approach to Control Electron Current in Unitary Quantum Theory
    International Journal of Applied Science and Technology Vol. 1 No. 6; November 2011 A New Approach to Control Electron Current in Unitary Quantum Theory Leo G. Sapogin Department of Physics Technical University (MADI) 64 Leningradsky pr. , A-319 125829, Moscow, Russia. V.A. Dzhanibekov Department of Cosmophysics Tomsk State Univesity 36 Lenina st., 634050 Tomsk, Russia. V.G. Sapogin Department of Physics Taganrog Institute of Technology Southern Federal University 44 Nekrasovsky str. GSP-17A, 347 928, Taganrog Russia. Abstract In the Unitary Quantum Theory a probability of tunneling effects controlled by initial phase. Mathematical model created for this phenomenon use equations with oscillating charge. This effect is absent in the Ordinary Quantum Mechanics and it may be useful for creation new electronics devices. Keywords: Unitary Quantum Theory, Tunneling effects, Electronic device, Tunneling diode, Control electron flow, Set of potential barriers, Oscillating charge. 1. Introduction In the world literature it is written that tunnel diode was constructed by Japanese researcher L.Esaki. However, at the end of forties in Soviet popular magazine “Radio” was published a series of articles about “crystadin” constructed by Russian ham Oleg Losev. He had used a falling sector of voltage-current characteristic of point contact between steel wire and homemade crystal FeS. Such diode had been made from mixture of iron filings and sulfur powder heated within test-tube. The coked mass obtained was then broken to pieces from which suitable crystal was chosen. That prototype of tunnel diode was used for oscillatory tuned-circuit Q-factor excursion in general crystal set. Articles described the way to do it at home.
    [Show full text]
  • Creativity Anoiko 2011
    Creativity Anoiko 2011 PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Sun, 27 Mar 2011 10:09:26 UTC Contents Articles Intelligence 1 Convergent thinking 11 Divergent thinking 12 J. P. Guilford 13 Robert Sternberg 16 Triarchic theory of intelligence 20 Creativity 23 Ellis Paul Torrance 42 Edward de Bono 46 Imagination 51 Mental image 55 Convergent and divergent production 62 Lateral thinking 63 Thinking outside the box 65 Invention 67 Timeline of historic inventions 75 Innovation 111 Patent 124 Problem solving 133 TRIZ 141 Creativity techniques 146 Brainstorming 148 Improvisation 154 Creative problem solving 158 Intuition (knowledge) 160 Metaphor 164 Ideas bank 169 Decision tree 170 Association (psychology) 174 Random juxtaposition 174 Creative destruction 175 References Article Sources and Contributors 184 Image Sources, Licenses and Contributors 189 Article Licenses License 191 Intelligence 1 Intelligence Intelligence is a term describing one or more capacities of the mind. In different contexts this can be defined in different ways, including the capacities for abstract thought, understanding, communication, reasoning, learning, planning, emotional intelligence and problem solving. Intelligence is most widely studied in humans, but is also observed in animals and plants. Artificial intelligence is the intelligence of machines or the simulation of intelligence in machines. Numerous definitions of and hypotheses about intelligence have been proposed since before the twentieth century, with no consensus reached by scholars. Within the discipline of psychology, various approaches to human intelligence have been adopted. The psychometric approach is especially familiar to the general public, as well as being the most researched and by far the most widely used in practical settings.[1] History of the term Intelligence derives from the Latin verb intelligere which derives from inter-legere meaning to "pick out" or discern.
    [Show full text]
  • Light-Emitting Diodes in the Solid-State Lighting Systems
    Light-Emitting Diodes in the Solid-State Lighting Systems Amelia Carolina Sparavigna 1 1Department of Applied Science and Technology, Politecnico di Torino, Torino, Italy Abstract: Red and green light-emitting diodes (LEDs) had been produced for several decades before blue emitting diodes, suitable for lighting applications, were widely available. Today, we have the possibility of combining the three fundamental colours to have a bright white light. And therefore, a new form of lighting, the solid-state lighting, has now become a reality. Here we discuss LEDs and some of their applications in displays and lamps. Keywords: Semiconductors, Light-Emitting Diodes, Solid-State Lighting Systems, LEDs, GaAs, GaN, InGaN. 1. Introduction nearly 100 times brighter of the previous LEDs [2]. The Royal Swedish Academy of Sciences has decided Nakamura’s group followed with a lower-cost doping to award the Nobel Prize in Physics for 2014 to Isamu method and several innovations that increased quality Akasaki, Hiroshi Amano and Shuji Nakamura, and brightness, so that Nakamura’s company was the because of their fundamental works on blue light- first to begin selling blue p-n junction LEDs [2]. emitting diodes (LEDs). In his will, Alfred Nobel dictated that the winners were persons who had The gallium nitride is then the semiconducting conferred great benefit to humankind. In the spirit of material, which is at the center of a new industry, that the founder then, this year the Prize is awarding the of the solid-state lighting (SSL), where solid-state creation of a new light source, which is more energy- devices are producing light.
    [Show full text]
  • Introduction to Lighting Technology: Led and Oled
    INTRODUCTION TO LIGHTING TECHNOLOGY: LED AND OLED М.І. Карпенко студент , Факультет елетроенерготехніки та автоматики Національний технічний університет України “ КПІ ” The light-emitting diode, or LED, is the basis for future lighting technology. This two-lead semiconductor produces light when being activated, and it is a very important device, because it finds wide application in the everyday life. Numerous indicators in our household appliances, for example, in remote controls, games- consoles, lamps, computers, etc. help us do work, communicate, and entertain ourselves. Many modern cars are equipped with LED indicators and brake lights. Also, we should not forget about traffic lights, signs, street lighting and so on. These diodes reveal the interconnection between electronics and photonics. In fact, the LED is a vital link to understanding these fields of science. The main reason why LED are so domination in these branches is that they are commonly used in broadband communication. Nowadays most people think that LED-technology has been recently discovered by US scientists. However, the light-emitting diode was actually invented by Henry Round, and Oleg Losev, one of the Russian scientists that are now forgotten, almost 100 years ago. 30 There are two main types of the light-emitting diodes – LEDs and OLEDs. There are also EL lamps (Electroluminescent Lamps), but there is a difference in the construction. The LED has special reflectors and other parts to make the light brighter and to focus it on one point. The OLED is different, because it’s a compound. The abbreviation OLED stands for “organic LED” and its layer consists of a mix of substances, just like in EL lamps, but it uses carbon molecules.
    [Show full text]