Trends

Trends

Technology | Apr 21, 2011
Theorists from UC Santa Barbara Claim that LED Efficiency Puzzle Is Solved
Theorists from UC Santa Barbara Claim that LED Efficiency Puzzle Is Solved Researchers at the University of California, Santa Barbara, say they’ve figured out the cause of a problem that’s made light-emitting diodes (LEDs) impractical for general lighting purposes. Their work will help engineers develop a new generation of high-performance, energy-efficient lighting that could replace incandescent and fluorescent bulbs. Read more »
Technology | Mar 16, 2011
From the OSRAM Laboratory: Efficiency Record for Warm White
From the OSRAM Laboratory: Efficiency Record for Warm White OSRAM Opto Semiconductors has set a new laboratory record of 142 lm/W for the efficiency of a warm white LED light source. With a correlated color temperature (CCT) of 2755 K the LED achieves a good color rendering index (CRI) of 81. Measurements were taken under standard conditions: room temperature and pulsed mode at an operating current density of 350 mA/mm². Read more »
Technology | Feb 15, 2011
Jewel-Toned Organic Phosphorescent Crystals: A New Class of Light-Emitting Material
Jewel-Toned Organic Phosphorescent Crystals: A New Class of Light-Emitting Material University of Michigan researcher Jinsang Kim and his colleagues have developed a new class of material that shines with phosphorescence—a property that has previously been seen only in non-organic compounds or organometallics. This pure organic compounds that glow in jewel tones could potentially lead to cheaper, more efficient and flexible display screens, among other applications. Read more »
Technology | Jan 31, 2011
A Material to Revolutionize Electronics - Small Transistors, LEDs and Solar Cells
A Material to Revolutionize Electronics - Small Transistors, LEDs and Solar Cells A discovery made at EPFL could play an important role in electronics, allowing us to make transistors that are smaller and more energy efficient. Research carried out in the Laboratory of Nanoscale Electronics and Structures (LANES) has revealed that molybdenite, or MoS2, is a very effective semiconductor. This mineral, which is abundant in nature, is often used as an element in steel alloys or as an additive in lubricants. But it had not yet been extensively studied for use in electronics. Read more »
Technology | Jan 26, 2011
Voiding Defects: New Technique Makes LED Lighting More Efficient
Voiding Defects: New Technique Makes LED Lighting More Efficient Light-emitting diodes (LEDs) are an increasingly popular technology for use in energy-efficient lighting. Researchers from North Carolina State University have now developed a new technique that reduces defects in the gallium nitride (GaN) films used to create LEDs, making them more efficient. Read more »
Technology | Jan 18, 2011
Intematix Introduces ChromaLit™ Remote Phosphor Lighting Systems
Intematix Introduces ChromaLit™ Remote Phosphor Lighting Systems ChromaLit™ leverages a phosphor composite precisely layered onto a substrate, separated from the blue LED energy source. The independent phosphor emits light when excited by blue light. Because the phosphor has been separated from the energy source and can now be made in any shape and any color, unidirectional light, hot spots, inconsistency and design limitations are no longer SSL challenges. Read more »
Technology | Dec 22, 2010
Quantum Dots Are Not Dots
Quantum Dots Are Not Dots Researchers from the Quantum Photonics Group at DTU Fotonik in collaboration with the Niels Bohr Institute, University of Copenhagen surprise the scientific world with the discovery that light emission from solid-state photon emitters, the so-called quantum dots, is fundamentally different than hitherto believed. The new insight may find important applications as a way to improve efficiency of quantum information devices. Their findings are published on December 19th 2010 in the prestigious journal Nature Physics. Read more »
Technology | Dec 15, 2010
Power Integrations Introduces Reference Design for 5 W LED Lamps with PFC and Flicker-Free TRIAC Dimming
Power Integrations Introduces Reference Design for 5 W LED Lamps with PFC and Flicker-Free TRIAC Dimming Power Integrations, the leader in high-voltage integrated circuits for energy-efficient solid-state lighting, today announced a new reference design (RDK-251) for a 5-watt offline LED driver that includes flicker-free TRIAC dimming and single-stage power factor correction (PFC). The reference design is based on Power Integrations' LNK457DG, a member of the innovative LinkSwitch-PL family of LED driver ICs optimized for compact, non-isolated installations. Read more »
Technology | Nov 22, 2010
MIT Study: Significant Energy Savings through User-Controlled Efficient Lighting Systems
MIT Study: Significant Energy Savings through User-Controlled Efficient Lighting Systems These days, in newer buildings it’s often hard even to find a plain old-fashioned light switch. Often, the only controls are automatic motion-detector switches that turn off lights when people have left a room — or when they sit too still — or else daunting control panels with arrays of sliders and buttons. But some researchers at the MIT Media Lab are aiming to put the controls back in people’s hands, in a way that provides sophisticated and continuous control and could slash lighting bills by more than half. Read more »
Technology | Oct 04, 2010
Using Nanostructures to Improve LED Light Emission
Using Nanostructures to Improve LED Light Emission Application of nanosphere lithography to create uniform surface roughness on an optical device sample promotes light extraction and collection efficiency. In recent years, nanopattern definition has become a subject of extensive exploration owing to its ability to improve device performance in electronics and optoelectronics. The literature proposes a variety of techniques, including electron-beam lithography, which gives uniform nanopatterns but is expensive, and self-assembled metal nanomasks, which scatter nonuniformly on the sample. As an alternative, we have developed a technology called nanosphere lithography that creates nanopatterns by spin-coating a monolayer of nanospheres on top of the device surface. We have used the technology to fabricate nanopatterns on gallium nitride (GaN)-based LEDs to improve light extraction and collection efficiency. Read more »
Technology | Sep 08, 2010
Philips Demonstrates World’s First Mains-Powered White-Light OLED Module
Philips Demonstrates World’s First Mains-Powered White-Light OLED Module Scientists from Philips Research have developed the first-ever organic light emitting diode (OLED) module that can be powered directly from a mains electricity supply. The prototype opens the door to OLED systems that can be directly plugged into standard power outlets without the need for bulky power management circuitry. This will reduce the bill of materials and simplify luminaire design for future OLED-based systems aimed at mass-market general illumination applications. Read more »
Technology | Aug 06, 2010
LED Failure Modes and Methods for Analysis
LED Failure Modes and Methods for Analysis LED’s open the way to new applications and markets in various different fields with a broad spectrum of requirements. Beneath other beneficial characteristics, in general, LED’s provide a high reliability, and a lifetime of more than 50;000 hours can be reached. Poor workmanship in manufacturing and unfavorable operational conditions may reduce the reliability significantly. To avoid failures or to achieve fast resolutions of existing problems a good knowledge of the failure mechanisms and suitable analytical methods is required. Objective of this article is to provide an overview of state of the art techniques in LED-Failure analysis. Read more »
Technology | Aug 06, 2010
LED Source Modeling Method Evaluations
LED Source Modeling Method Evaluations Producing accurate simulations of LED based optical systems requires accurate source models. This means the source models must not only produce the correct distribution of light in a far field measurement, they must also produce the correct near field behavior since secondary LED optics are often employed in very close proximity to the LED. Accurate simulations are vital to the design process especially with lens optics commonly used on LEDs given the high cost and long lead times for lens tooling. The data presented in this paper is a direct result of the lessons learned by one manufacturer about the importance of simulation accuracy. Read more »
Technology | Aug 04, 2010
Thermally Activated Degradation of Phosphor-Converted White LEDs
Thermally Activated Degradation of Phosphor-Converted White LEDs The increasing performances and long lifetime of High Brightness LEDs are still limited by the high temperatures involved. This work shows the results of several accelerated lifetime tests on 1W white LEDs. Two different tests have been carried out: a pure thermal storage at different temperatures and an electrical aging obtained by biasing the LEDs. The impact of high temperatures has been evaluated in terms of flux decay, chromatic properties modification, increase of forward voltage and thermal resistance. A picture of the main degradation mechanisms detected has been provided in detail. Read more »
Technology | Jul 29, 2010
Method May Help Optimize Light-emitting Semiconductors
Method May Help Optimize Light-emitting Semiconductors Physicists at JILA have demonstrated an ultrafast laser technique for "seeing" once-hidden electronic behavior in semiconductors, which eventually could be useful in more predictable design of optoelectronic devices, including semiconductor lasers and white light-emitting diodes. Read more »
Technology | Jul 29, 2010
Paint-on semiconductor outperforms chips
Paint-on semiconductor outperforms chips Researchers at the University of Toronto have created a semiconductor device that outperforms today's conventional chips -- and they made it simply by painting a liquid onto a piece of glass. Read more »
Technology | Jul 29, 2010
Novel Nano-Etched Cavity Makes LEDs 7 Times Brighter
Novel Nano-Etched Cavity Makes LEDs 7 Times Brighter Researchers at the National Institute of Standards and Technology (NIST) have made semiconductor light-emitting diodes (LEDs) more than seven times brighter by etching nanoscale grooves in a surrounding cavity to guide scattered light in one direction. Read more »
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