Technology News - Light Generation

LEDs and OLEDs

Technology | Light Generation | Oct 07, 2014

And the Nobel Price 2014 Goes To ... The Inventors of the Blue LED

The blue LEDs, invented by the winners, are the basis for today's white LEDs like - following the latest trend - these chip-LEDs The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2014 to Isamu Akasaki from the Meijo University, Nagoya, Japan and Nagoya University, Japan, to Hiroshi Amano from the Nagoya University, Japan and to Shuji Nakamura from the University of California, Santa Barbara, CA, USA for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources. Read more »

Technology | Light Generation | Sep 25, 2014

Nanotechnology May Lead to Better, Cheaper LEDs

(a) Princeton researchers have used their expertise in nanotechnology to develop an economical new system that markedly increases the brightness, efficiency and clarity of LEDs, which are widely used in smartphones and other electronics. The illustration demonstrates how a conventional LED's structure traps most of the light generated inside the device; the new system, called PlaCSH, guides the light out of the LED. (lllustration courtesy of Stephen Chou et al.) (b) PlaCSH has a layer of light-emitting material about 100 nanometers thick that is placed inside a cavity with one surface made of a thin metal film (shown at left.) The key part of the device is a metal mesh (center) with incredibly small dimensions: it is 15 nanometers thick; and each wire is about 20 nanometers in width and 200 nanometers apart from center to center. An image of the experimental LED is shown at right. (Images courtesy of Stephen Chou et al.) Princeton University researchers have developed a new method to increase the brightness, efficiency and clarity of LEDs, which are widely used on smartphones and portable electronics as well as becoming increasingly common in lighting. Using a new nanoscale structure, the researchers, led by electrical engineering professor Stephen Chou, increased the brightness and efficiency of LEDs made of organic materials (flexible carbon-based sheets) by 57 percent. The researchers also report their ... Read more »

Technology | Light Perception | Sep 18, 2014

LpR 44 Article: Discomfort Glare Perception of Non-Uniform Light Sources in an Office Setting

Test setup of the different regions and luminance patterns under test LED based luminaires with different luminance patterns and recently with increasingly non-uniform luminance patterns are becoming mainstream. This trend makes discomfort due to glare an important topic. Based on an office setting and the comparison of results from three different regions, L. M. Geerdinck, J. R. Van Gheluwe and M.C.J.M. Vissenberg from Philips Research have reviewed the currently used formulae to predict discomfort glare to ascertain if they are still valid. Read more »

Technology | OLEDs | Sep 17, 2014

Printing Process of Metal Contacts for Reliable Contacting of Flexible OLEDs and Other Devices

Fraunhofer FEP works on cost-effective system solutions for flexible devices and presents results at Plastic Electronics 2014 A significant growth is predicted for the market of flexible devices. The topic “Wearables”, namely intelligent, wearable systems with several useful and funny features is currently one of the major discussion topics. To enjoy more comfort, exceptional designs and higher functionality manufacturers and users ask for flexible electronic devices, like displays, lighting elements or circuit boards. Read more »

Technology | Light Generation | White Paper | Aug 28, 2014

Osram Opto Demonstrates "3D nano LEDs" for White Light and Sees Series Maturity in Coming Years

Osram researchers make a 3D nano LED for white light shine on the wafer using two tiny, energized needles.The needles are pressed onto the contact surfaces of the chips, and the distance between the contact points corresponds approximately to the thickness of three sheets of stacked writing paper By making use of nanotechnology, Osram hopes to produce significantly more LED chips with its existing production plant. Osram researchers have for the first time succeeded in manufacturing a so-called "3D nano LED" for white light. The productivity boost is possible due to the special surface characteristics of the LED chip – in contrast to today's standard models, this is not smooth but consists of many adjacent, microscopically small columns with a three-dimensional structure, thus ... Read more »

Technology | Light Generation | Jul 03, 2014

Significant Technical Progress - BluGlass Demonstrates Best Ever RPCVD (p-GaN) Light Output

Demonstration of light emission at 473nm, with full width half maximum of 22nm, from a RPCVD p-GaN layer grown on a MOCVD partial structure Australian Cleantech innovator, BluGlass Limited, has announced today that it has been successful in demonstrating the best ever p-GaN light output using its propriety technology, Remote Plasma Chemical Vapour Deposition (RPCVD) on an MOCVD partial LED structure. This result is greater than a 10 fold improvement in LED efficiency over the first p-GaN demonstration data published by the company in December 2012, when the same measuring methodology is applied. This has been achieved by making ... Read more »

Technology | Light Generation | Apr 14, 2014

Developing Phosphor-Free White Light from Nanopyramid LEDs

Left: Fabrication schematic for phosphor-free nanopyramid LEDs by nanospherical-lens photolithography. Right: (a) Room-temperature photoluminescence spectra of nanopyramid LEDs with MQWs grown at different temperatures, along with reference structure grown on planar template. (b) Spectrum of ‘white LED’ (blue LED with yellow phosphors). (c) Electroluminescence spectrum of nanopyramid LEDs at 20mA; inset shows corresponding optical microphotograph Researchers in China have used nitride semiconductor nanopyramid structures to create light-emitting diodes (LEDs) with spectra that are similar to those provided by ‘white light’ LEDs with yellow phosphors [Kui Wu et al, J. Appl. Phys., vol115, p123101, 2014]. The researchers are at the Chinese Academy of Sciences’s institutes of Semiconductors and Mechanics, and Tsinghua University. A similar CAS/Tsinghua team previously reported such devices, using a polystyrene nanosphere mask to make holes ... Read more »

Technology | Light Generation | Mar 28, 2014

Osram To Demonstrate The World's Most Efficient LED Replacement Tube at Light+Building

Osram's record-breaking light source was developed by the central research department together with the optical semiconductor and lamp business units An Osram research team has succeeded in constructing the most efficient LED lamp in the world. The lamp in tubular form consumes only half the power of currently common fluorescent and LED tubes, and also achieves significantly superior colour rendering. Read more »

Technology | Light Generation | Mar 26, 2014

Cree Continues to Push the Boundaries of LED Performance by Breaking 300 Lumens-Per-Watt Barrier

According to Cree, the efficacy of the CCT 5150 K LED was measured applying a current of 350 mA at standard room temperature Cree, Inc. records another significant LED milestone with the demonstration of 303 lumens per watt from a white high power LED. Reaching the landmark achievement much faster than previously believed possible, this result surpasses Cree’s previous R&D industry best of 276 lumens per watt announced just over a year ago. Read more »

Technology | Light Generation | Mar 19, 2014

New Technique Makes LEDs Brighter, More Resilient

By coating polar gallium nitride with phosphonic groups, the researchers increased luminescence without increasing energy input (Image Credits: Stewart Wilkins) Researchers from North Carolina State University have developed a new processing technique that makes light emitting diodes (LEDs) brighter and more resilient by coating the semiconductor material gallium nitride (GaN) with a layer of phosphorus-derived acid. Read more »

Technology | Light Generation | White Paper | Mar 13, 2014

Quantum Materials Secures Los Alamos Thick-Shell Quantum Dot Technology to Increase Brightness

Quantum materials optioning Thick-Shell 'Giant' Quantum Dot patented technology promises improvement in solid-state brightness over conventional nanocrystal quantum dots (QD) Quantum Materials Corporation and Los Alamos National Laboratory's today announce Quantum Materials optioning Thick-Shell 'Giant' Quantum Dot patented technology with the potential of 10 to 100-fold improvement in solid-state brightness over conventional nanocrystal quantum dots (QD). High brightness leads to efficient use of materials and increased performance in electronic displays and solid state (LED) lighting. Read more »

Technology | Light Generation | Mar 11, 2014

Scientists Build Thinnest-Possible LEDs and Find It To Be Stronger, More Energy Efficient

The layers of the novel 2-D LED and how it emits light (Credits: U of Washington) Most modern electronics, from flat-screen TVs and smartphones to wearable technologies and computer monitors, use tiny light-emitting diodes, or LEDs. These LEDs are based off of semiconductors that emit light with the movement of electrons. As devices get smaller and faster, there is more demand for such semiconductors that are tinier, stronger and more energy efficient. Read more »

Technology | Light Generation | Mar 11, 2014

Two-Dimensional Material Shows Promise for Optoelectronics

In the team's experimental setup, electricity was supplied to a tiny piece of tungsten selenide (small rectangle at center) through two gold wires (from top left and right), causing it to emit light (bright area at center), demonstrating its potential as an LED material. Inset: Microscope image shows the teams experimental setup. (Images courtesy of Britt Baugher and Hugh Churchill) A team of MIT researchers has used a novel material that’s just a few atoms thick to create devices that can harness or emit light. This proof-of-concept could lead to ultrathin, lightweight, and flexible photovoltaic cells, light emitting diodes (LEDs), and other optoelectronic devices, they say. Read more »

Technology | Light Generation | Feb 24, 2014

A Roadmap to Efficient Green-Blue-Ultraviolet LEDs

This is a schematic description of processes responsible for light emitting diode (LED) operation. The thick black lines show the energy band diagram of the conventional (a) and proposed (b) LEDs based on GaN/AlN QWs. In the conventional GaN/AlN QW LEDs the polarization field in the GaN layer enhances strongly the rate of the nonradiative Auger processes leading to reduction of the photoluminescence quantum yield and, consequently, to the "droop" effect with increase of the electrical current. In the proposed LEDs (b) the electric field acting on holes in the QW is compensated by a gradual composition variation of the variable-gap GaAlN alloy resulting in a flat valence band potential. The Auger processes in these QWs are completely suppressed and no droop effect is expected to be seen in such LEDs. (Credit: U.S. Naval Research Laboratory) Scientists at the U.S. Naval Research Laboratory (NRL) have suggested a method that could significantly increase the efficiency of green-blue-ultraviolet light-emitting diodes based on GaInN/GaN, AlGaN/GaN, and AlInN/GaN quantum wells. Their approach could enable advances in solid state lighting and the creation of low threshold lasers and high power light emitting diodes (LEDs). Their research is published in the January 25 and November 26, 2013 issues of Applied Physics Letters. Read more »

Technology | OLEDs | White Paper | Feb 11, 2014

CPI Manufactures Flexible OLED Lighting Demonstrators

The Centre for Process Innovation (CPI) has produced a range of flexible Organic Light Emitting Diode (OLED) demonstrators on substrates with thickness ranging from 50µm to 125µm The Centre for Process Innovation (CPI) has produced a range of flexible Organic Light Emitting Diode (OLED) demonstrators. Manufactured on CPI’s OLED/OPV Prototyping Line, the devices have been built on a range of substrates with thickness ranging from 50µm to 125µm. The device structure consists of an Indium Tin Oxide anode, evaporated hole injection layer, co-evaporated emissive layer and a conventional cathode. The device chemistry can be modified to produce a variety of colours and is ... Read more »

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