Fabrication of Organic Light Emitting Diodes in an Undergraduate Physics Course
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Overview of OLED: Structure and Operation
OLEDs: Modifiability and Applications Jill A. Rowehl 3.063- Polymer Physics 21 May 2007 1 "The dream is to get to the point where you can roll out OLEDs or stick them up like Post-it notes," --Janice Mahon, vice president of technical commercialization at Universal Display1 Take a look at your cell phone; do you see a display that saves your battery and doubles as a mirror? When you dream of your next TV, are you picturing an unbelievably thin screen that can be seen perfectly from any viewing angle? If you buy a movie two decades from now, will it come in a cheap, disposable box that continually plays the trailer? These three products are all applications of organic light emitting devices (OLEDs). OLEDs are amazing devices that can be modified through even the smallest details of chemical structure or processing and that have a variety of applications, most notably lighting and flexible displays. Overview of OLEDs: Structure and Operation The OLED structure is similar to inorganic LEDs: an emitting layer between an anode and a cathode. Holes and electrons are injected from the anode and cathode; when the charge carriers annihilate in the middle organic layer, a photon is emitted. However, there is sometimes difficulty in injecting carriers into the organic layer from the usually inorganic contacts. To solve this problem, often the structure includes an electron transport layer (ETL) and/or a hole transport layer (HTL), which facilitate the injection of charge carriers. All of 2 these layers must be grown on top of each other, with the first grown on a substrate (see Figure 1). -
M7 Electroluminescence of Polymers
Universität Potsdam Institute of Physics and Astronomy Advanced Physics Lab Course March 2020 M7 ELECTROLUMINESCENCE OF POLYMERS I. INTRODUCTION The recombination of holes and electrons in a luminescent material can produce light. This emitted light is referred to as electroluminescence (EL) and was discovered in organic single crystals by Pope, Magnante, and Kallmann in 1963.[1] EL from conjugated polymers was first reported by Burroughes et al.[2] The polymer used was poly(p-phenylenevinylene) (PPV). Since then, a variety of other polymers has been investigated. Organic EL devices have applications in a wide field ranging from multi-color displays and optical information processing to lighting. Polymers have the advantage over inorganic and monomolecular materials in the ease with which thin, structurally robust and large area films can be perpared from solutions. Using printing techniques, patterned structures can be produced easily. Even flexible displays can be produced because of the good mechanical properties of polymers. In this lab course, basic optical and electrical properties of conjugated polymers will be investigated. Advanced Lab Course: Electroluminescence of Polymers 2 EXPERIMENTAL TASKS Measure the absorption spectra of your polymers (thin films spin coated onto glass substrates). Characterize the setup used for luminescence measurements. Identify possible sources of error and collect data necessary for their correction. Measure the photoluminescence emission spectra for the polymer films, using suitable excitation wavelengths. Measure the photoluminescence excitation spectra for the polymer films, using suitable detection wavelengths. Measure the current through the OLEDs and the spectral radiant intensity of electroluminescence as a function of applied voltage (the current-radiance-voltage characteristics). -
Quantum Dot-Based Light Emitting Diodes (Qdleds): New Progress
DOI: 10.5772/intechopen.69014 Provisional chapter Chapter 3 Quantum Dot-Based Light Emitting Diodes (QDLEDs): QuantumNew Progress Dot-Based Light Emitting Diodes (QDLEDs): New Progress Neda Heydari, Seyed Mohammad Bagher NedaGhorashi Heydari,, Wooje Seyed Han Mohammad and Hyung-Ho Bagher Park Ghorashi, WoojeAdditional Han information and Hyung-Ho is available at Parkthe end of the chapter Additional information is available at the end of the chapter http://dx.doi.org/10.5772/intechopen.69014 Abstract In recent years, the display industry has progressed rapidly. One of the most important developments is the ability to build flexible, transparent and very thin displays by organic light emitting diode (OLED). Researchers working on this field try to improve this area more and more. It is shown that quantum dot (QD) can be helpful in this approach. In this chapter, writers try to consider all the studies performed in recent years about quantum dot-based light emitting diodes (QDLEDs) and conclude how this nanoparticle can improve performance of QDLEDs. In fact, the existence of quantum dots in QDLEDs can cause an excellent improvement in their efficiency and lifetime resulted from using improved active layer by colloidal nanocrystals. Finally, the recent progresses on the quantum dot-based light emitting diodes are reviewed in this chapter, and an important outlook into challenges ahead is prepared. Keywords: quantum dot, organic light emitting diode, efficiency, lifetime, active layer 1. Introduction Due to increased population and consumption of more energy, the people of Earth are faced with a serious shortage of energy resources. Therefore, the primary concern of researchers and manufacturers is closely linked to energy consumption. -
Revolutionary Pixels for Tomorrow's OLED Displays
Revolutionary pixels for tomorrow’s OLED displays Intro Deck Max Lemaitre [email protected] (847) 269-3692 LCD TV Factory $6B USD (2008) 2 Confidential & Proprietary SHUTDOWN 2021 3 Confidential & Proprietary 90% Declining LCD Market share 80% 70% 60% 50% 40% OLED 30% Opportunity 20% 2018 2020 2022 2024 2026 4 Confidential & Proprietary LCD OLED TV Factory 5 Confidential & Proprietary We recycle aging LCD display factories and simplify manufacturing for more profitable OLED production Up to $900M in CAPEX savings per factory >25% reduction in panel manufacturing costs 6 Confidential & Proprietary The “OLED Backplane Problem” Conventional OLED Pixel Transistor (TFT) Backplane: Ø Supplies current to pixel and acts as the pixel’s internal “dimmer switch” Light-emitting Frontplane: Ø converts electrical current to light Transistor Light Backplane Zoom-in of a TV display OLED (array of OLED pixels) Frontplane Single Pixel Top View 7 Confidential & Proprietary The “OLED Backplane Problem” Conventional OLED Pixel BACKPLANE PROBLEM Transistor (TFT) Backplane: Complex Ø Supplies current to pixel and acts as pixel circuits the pixel’s internal “dimmer switch” In-pixel compensation 5 to 7 TFTs Light-emitting Frontplane: Ø converts electrical current to light Exotic Materials Quaternary alloy Narrow processing window Transistor Light sensitivity Light Backplane Expensive Equipment OLED Limited scalability Frontplane Inhomogeneity 8 Confidential & Proprietary Mattrix’s OLED Backplane SOLUTION Mattrix circumvents what is known as the “OLED backplane problem”, -
LCD Manufacturers Face Price Crisis
BUSINESS NEWS TECHNOLOGY FOCUS LCD manufacturers face price crisis fter months of price cuts, manufacturers Aof large-size liquid-crystal displays 60,000 (LCDs) are under pressure to reduce panel LCD-TV panels prices further, following a major build-up of LCD-TV set inventory. A recent report from US business analyst iSuppli revealed that the second quarter of 2010 saw the manufacture of 52 40,000 million large (ten inches and above) LCD television panel shipments, but the sale of only 38.7 million LCD television sets. The resulting imbalance between supply 20,000 and demand is having a strong impact on the sector. “This gap is higher than anything seen in 2009. Over-supply persisted in shipments (thousands of units) Total the first two months of the third quarter 0 9 0 0 -0 -1 -1 as buyers cut orders in July and August,” Q1 Q1-09 Q2 Q3-09 Q4-09 Q2 says iSuppli analyst Sweta Dash. “LCD ISUPPLI television brands are expected to lower prices more aggressively to reduce their An imbalance between supply and demand is causing prices to decline in the large-panel LCD industry. inventory levels, thus putting mounting pressure on panel suppliers to reduce and help to steady panel prices by the end of iPhone, iPad and other competing prices further.” the fourth quarter of 2010. products,” explains Jakhanwal. Dash points out that manufacturers of At the same time, rapidly rising sales of “Smart phone manufacturers are now monitor and notebook panels have been smart phones and tablet PCs are predicted adopting TFT LCDs that use in-plane reducing supply to mitigate excessive to see the global market for small- and switching technology, which supports inventory levels, and that panel prices are medium-size thin-film transistor (TFT) a wider viewing angle and better now stabilizing as a result. -
Active Matrix Organic Light Emitting Diode (AMOLED) Environmental Test Report
JSC-66638 National Aeronautics and RELEASE DATE: November 2013 Space Administration Active Matrix Organic Light Emitting Diode (AMOLED) Environmental Test Report ENGINEERING DIRECTORATE AVIONICS SYSTEMS DIVISION November 2013 National Aeronautics and Space Administration Lyndon B. Johnson Space Center Houston, TX 77058 JSC-66638 Active Matrix Organic Light Emitting Diode (AMOLED) Environmental Test Report November 2013 Prepared by Branch Chief Engineer Human Interface Branch/EV3 281-483-1062 Reviewed by: Glen F. Steele Electronics Engineer Human Interface Branch/EV3 281-483-0191 Approved by: Deborah Buscher Branch Chief Human Interface Branch/EV3 281-483-4422 ii JSC-66638 Table of Contents 1.0 AMOLED Environmental Test Summary ...... ................. .. .. ......... .... .. ... .... ..................... 1 2.0 References ... .......... ... ..... ... .. ...... .. .......................... 2 3.0 Introduction .. ... .. .......... ...... ..... .... ... .... ...... ......... ... ..... ................. ... 3 4.0 Test Article ... ... .... .. .... ... ... ... .. ... .. .. ... ................. .... ... ...... ...... ............. 4 5.0 Environmental Testing ....... ............. .... ... ..... .. ... ....................... .... .... ..... .. ..... ... ...... .. ..... ......... 7 5.1 Electromagnetic Interference (EMI) Test ............... .. .................... ..... .................. ...... 7 5.1.1 Test Description ....................................................... ........................ .. ... .. .... .............. 7 5.1 .2 Results -
QLED Vs. W-OLED: TV Display Technology Shoot-Out
Public Information Display QLED vs. W-OLED: TV Display Technology Shoot-Out This year's display product introductions—from CES 2017 to the most recent IFA 2017 event—are pointing towards the fact that display technology is poised for evolution. There are two competing technologies that display manufacturers have been using to take the picture quality to the new heights: QLED and OLED. While the technologies are using similar acronyms, their working principles differ substantially. With the abundance of marketing materials around both, it could be hard to see the forest for the trees. Samsung Display team set out to take a step back from the advertising jargon and "look under the hood" to help you truly understand what solution best suits your industry and application. First and foremost, let's get the nomenclature straight. QLED – Quantum Dot LED QLED stands for Quantum Dot Light-Emitting Diode, also referred to as quantum dot-enhanced LCD screen. While similar in working principle to conventional LCDs, QLEDs are using the properties of quantum dot particles to advance color purity and improve display efficiency. Quantum dots are integrated with the backlight system of the LCD screen, most commonly with the help of Quantum Dot Enhancement Film (QDEF) that takes place of the diffuser film. Blue LEDs illuminate the film, and quantum dots output the appropriate color, based on their size. OLED – Organic LED OLED stands for Organic Light-Emitting Diode, which is self-emitting. Not all OLEDs are using the same tech though. The OLED technology used in phone screens is RGB-OLED, which is completely different from the White OLED (also referred to as W-OLED) used in TVs and large format displays. -
Low Voltage Organic Field Effect Light Emitting Transistors with Vertical Geometry
4th International Symposium on Innovative Approaches in Engineering and Natural Sciences SETSCI Conference November 22-24, 2019, Samsun, Turkey Proceedings https://doi.org/10.36287/setsci.4.6.112 4 (6), 437-440, 2019 2687-5527/ © 2019 The Authors. Published by SETSCI Low Voltage Organic Field Effect Light Emitting Transistors with Vertical Geometry Melek Uygun1*+, Savaş Berber2 1Occupational Health and Safety Program, Altınbas University, Istanbul, Turkey 2Physics Department, Gebze Technical University, Kocaeli, Turkey *Corresponding authors and +Speaker: [email protected] Presentation/Paper Type: Oral / Full Paper Abstract –The devices developed in the field of organic electronics in recent years are on the technological applications and development of organic electronic devices using organic semiconductor films. The main applications of the organic electronic revolution are; Electrochromic Device, Organic Light Emitting Diodes (OLED), Organic Field Effect Transistors (OFET). Among these devices, OLED technology has taken its place in the commercial market in the last five years and has started to be used in our daily life in a short time. The efficiency of OFET devices is related to the operation of the devices at low voltage. This is only possible if the load carriers in the channel of the OFET have a low distance. A new field of research is the ability to implement two or more features on a single device, in the construction of integrated devices. Light emitting transistors (OLEFET), where light emission and current modulation are collected in a single device, are the most intensively studied devices. In this study, ITO substrate, source and drain electrodes were made from aluminum electrode structured organic field effect OLEFETs. -
New Lighting—New Leds
New Lighting—New LEDs Aspects on light‐emitting diodes from social and material science perspectives Editors Mats Bladh & Mikael Syväjärvi Published by Linköping University Electronic Press, 2010 ISBN: 978‐91‐7393‐270‐7 URL: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva‐60807 © The Authors Contents Foreword ...................................................................................... 5 Authors ........................................................................................ 7 Introduction: A Paradigmatic Shift? Mats Bladh & Mikael Syväjärvi ................................................................................. 9 Materials and Growth Technologies for Efficient LEDs Mikael Syväjärvi, Satoshi Kamiyama, Rositza Yakimova & Isamu Akasaki ............... 16 Light Excitation and Extraction in LEDs Satoshi Kamiyama, Motoaki Iwaya, Isamu Akasaki, Mikael Syväjärvi & Rositza Yakimova ...................................................................................................... 27 ‘No Blue’ White LED Haiyan Ou, Dennis Corell, Carsten Dam‐Hansen, Paul‐Michael Petersen & Dan Friis .................................................................................................................... 35 User Responses to Energy Efficient Light Sources in Home Environments Monica Säter ............................................................................................................. 43 Prospects for LED from a Historical Perspective Mats Bladh ............................................................................................................... -
Whitepaper Head Mounted Displays & Data Glasses Applications and Systems
Whitepaper Head Mounted Displays & Data Glasses Applications and Systems Dr.-Ing. Dipl.-Kfm. Christoph Runde Virtual Dimension Center (VDC) Fellbach Auberlenstr. 13 70736 Fellbach www.vdc-fellbach.de © Competence Centre for Virtual Reality and Cooperative Engineering w. V. – Virtual Dimension Center (VDC) System classes Application fields Directions of development Summary Content . System classes Head Mounted Display (HMD) – Video glasses – Data glasses . Simulator disease / Cyber Sickness . Application fields HMDs: interior inspections, training, virtual hedging engineering / ergonomics . Application fields data glasses: process support, teleservice, consistency checks, collaboration . Directions of development: technical specifications, (eye) tracking, retinal displays, light field technology, imaging depth sensors . Application preconditions information & integration (human, IT, processes) . Final remark 2 SystemSystem classes classes Application fields Directions of development Summary Head Mounted Displays (HMDs) – Overview . 1961: first HMD on market . 1965: 3D-tracked HMD by Ivan Sutherland . Since the 1970s a significant number of HMDs is applied in the military sector (training, additional display) Table: Important HMD- projects since the 1970s [Quelle: Li, Hua et. al.: Review and analysis of avionic helmet-mounted displays. In : Op-tical Engineering 52(11), 110901, Novembre2013] 3 SystemSystem classes classes Application fields Directions of development Summary Classification HMD – Video glasses – Data glasses Head Mounted Display -
Lecture ˮincoherent Light Sources“ Summer Term 2008 Tim Pohle Electroluminescence Light Sources – Table of Contents
Lecture ˮIncoherent Light Sources“ Summer term 2008 Tim Pohle Electroluminescence Light Sources – Table of contents Table of contents . Overview of electroluminescence . LED (Light Emitting Diode) History of development Technical details Applications . OLED (Organic Light Emitting Diode) History of development Technical details Applications . Electroluminescent strings and foils – Light Emitting Capacitor History of development Technical details Applications Incoherent Light Sources 2008 Tim Pohle 2 Electroluminescence Light Sources – Overview of Electroluminescence Overview of Electroluminescence [6] [3] . It depeds on luminescence [1] . It is distinct from fluorescence3/phosphorescence, [2] chemoluminescence2, sonoluminescence5, bioluminescence1, superluminescence6, triboluminescnece4, etc. [4] [5] . It is an optical/electrical phenomenon . Material emits light in response to an electric current passed through it, or to a strong electric field CB . It is result of radiative recombination of electrons and holes in a material VB Incoherent Light Sources 2008 Tim Pohle 3 Electroluminescence Light Sources – LED LED (Light Emitting Diode) History of development 1907 Henry Joseph Round (Marconi Labs) „invents the LED“. He finds out that some inorganic substances glow if a electric voltage is impress on them. He publishted his observation in the journal „Electrical World“ 1921 Ignorant of Round`s invention, Oleg Vladimirovich Losev makes the same observations 1927- Losev investigates this effect 1942 and guesses that it is the inversion of Einstein„s photoelectrical effect Incoherent Light Sources 2008 Tim Pohle 4 Electroluminescence Light Sources – LED 1951 Satisfactory explanation of the light emission due to the semiconductor and transistor development 1961 Bob Biard and Gary Pittman (Texas Instruments) find out that gallium arsenide (GaAs) give off infrared radiation when electric current is applied. -
Properties of Light Library Document
Light + Air North America Properties of Light Library Document 2 Properties Library Document of Light Properties of Light Light as energy The other way of representing light is as a wave phenomenon. This is somewhat more difficult for most people to understand, but Light is remarkable. It is something we take for granted every day, perhaps an analogy with sound waves will be useful. When you play but it is not something we stop and think about very often or even a high note and a low note on the piano, they both produce sound, try to define. Let us take a few minutes and try to understand but the main thing that is different between the two notes is the some things about light. Simply stated, light is nature’s way frequency of the vibrating string producing the sound waves--the of transferring energy through space. We can complicate it by faster the vibration the higher the pitch of the note. If we now shift talking about interacting electric and magnetic fields, quantum our focus to the sound waves themselves instead of the vibrating mechanics and all of that, but just remember, light is energy. Light string, we would find that the higher pitched notes have shorter travels very rapidly, but it does have a finite velocity. In vacuum, wavelengths, or distances between each successive wave. Likewise the speed of light is 186,282 miles per second (or nearly 300,000 (and restricting ourselves to optical light for the moment), blue kilometers per second), which is really humming along! However, light and red light are both just light, but the blue light has a higher when we start talking about the incredible distances in astronomy, frequency of vibration (or a shorter wavelength) than the red light.