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1

Demonstration Assessment of Light-Emitting Diode (LED) Freezer...  

Broader source: Energy.gov (indexed) [DOE]

Demonstration Assessment of Light-Emitting Diode (LED) Freezer Case Lighting Demonstration Assessment of Light-Emitting Diode (LED) Freezer Case Lighting This document is a report...

2

Demonstration Assessment of Light Emitting Diode (LED) Street...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Demonstration Assessment of Light Emitting Diode (LED) Street Lighting, Final Report Demonstration Assessment of Light Emitting Diode (LED) Street Lighting, Final Report This...

3

Depth of cure and compressive strength of dental composites cured with blue light emitting diodes (LEDs)  

E-Print Network [OSTI]

Depth of cure and compressive strength of dental composites cured with blue light emitting diodes with either a light emitting diode (LED) based light curing unit (LCU) or a conventional halogen LCU do reserved. Keywords: Blue light emitting diodes; Light curing unit; Composites; Irradiance; Spectrum; Depth

Ashworth, Stephen H.

4

Demonstration Assessment of Light-Emitting Diode (LED) Accent Lighting at the Field Museum in Chicago, IL  

SciTech Connect (OSTI)

This report reviews a demonstration of light-emitting diode (LED) accent lighting compared to halogen (typical) accent lighting in a gallery of the Field Museum in Chicago, IL.

Myer, Michael; Kinzey, Bruce R.

2010-12-10T23:59:59.000Z

5

Vehicle Traffic Control Signal Heads— Light Emitting Diode Circular Signal Supplement (VTCSH-LED). This replaced the so-called Interim LED Purchase Specifications,  

E-Print Network [OSTI]

Engineers ’ (ITE) specification for light-emitting diode (LED) circular traffic signals recently was updated (June 27, 2005) and published under the name

S. Behura

6

Demonstration Assessment of Light-Emitting Diode (LED) Parking Lot Lighting in Leavenworth, KS  

SciTech Connect (OSTI)

This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a commercial parking lot lighting application, under the U.S. Department of Energy (DOE) Solid-State Lighting Technology GATEWAY Demonstration Program. The parking lot is for customers and employees of a Walmart Supercenter in Leavenworth, Kansas and this installation represents the first use of the LED Parking Lot Performance Specification developed by the DOE’s Commercial Building Energy Alliance. The application is a parking lot covering more than a half million square feet, lighted primarily by light-emitting diodes (LEDs). Metal halide wall packs were installed along the building facade. This site is new construction, so the installed baseline(s) were hypothetical designs. It was acknowledged early on that deviating from Walmart’s typical design would reduce the illuminance on the site. Walmart primarily uses 1000W pulse-start metal halide (PMH) lamps. In order to provide a comparison between both typical design and a design using conventional luminaires providing a lower illuminance, a 400W PMH design was also considered. As mentioned already, the illuminance would be reduced by shifting from the PMH system to the LED system. The Illuminating Engineering Society of North America (IES) provides recommended minimum illuminance values for parking lots. All designs exceeded the recommended illuminance values in IES RP-20, some by a wider margin than others. Energy savings from installing the LED system compared to the different PMH systems varied. Compared to the 1000W PMH system, the LED system would save 63 percent of the energy. However, this corresponds to a 68 percent reduction in illuminance as well. In comparison to the 400W PMH system, the LED system would save 44 percent of the energy and provide similar minimum illuminance values at the time of relamping. The LED system cost more than either of the PMH systems when comparing initial costs. However, when the life-cycle costs from energy and maintenance were factored into the scenario, the LED system had lower costs at the end of a 10-year analysis period. The LED system had a 6.1 year payback compared to the 1000W PMH system and a 7.5 year payback versus the 400W PMH system. The costs reflect high initial cost for the LED luminaire, plus more luminaires and (subsequently) more poles for the LED system. The other major issue affecting cost effectiveness was that Leavenworth, Kansas has very low electricity costs. The melded rate for this site was $0.056 per kWh for electricity. However, if the national electricity rate of $0.1022/kWh was used the payback would change to between four and five years for the LED system. This demonstration met the GATEWAY requirements of saving energy, matching or improving illumination, and being cost effective. The project also demonstrated that the Commercial Building Energy Alliance (CBEA) specification works in practice. Walmart appreciated having an entire site lighted by LEDs to gain more experience with the technology. Walmart is reviewing the results of the demonstration as they consider their entire real estate portfolio.

Myer, Michael; Kinzey, Bruce R.; Curry, Ku'uipo

2011-05-06T23:59:59.000Z

7

Demonstration Assessment of Light-Emitting Diode (LED) Street Lighting Host Site: Lija Loop, Portland, Oregon  

SciTech Connect (OSTI)

This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a residential street lighting application, under the U.S. Department of Energy GATEWAY Solid-State Lighting Technology Demonstration Program. In this project, eight 100W (nominal) high-pressure sodium cobra head fixtures were replaced with a like number of LED street light luminaires manufactured by Leotek, Inc. The Leotek product achieved an estimated payback in the Lija Loop installation of about 20 years for replacement scenarios and a much shorter 7.6 years for new installations. Much of the associated energy savings (55%) supporting these payback periods, however, were achieved by reducing average horizontal photopic illuminance a similar amount (53%). Examined from a different perspective, the measured performance suggests that the Leotek product is at approximate parity with the HPS cobra head in terms of average delivered photopic illumination for a given power consumption. HPS comprises the second most efficacious street lighting technology available, exceeded only by low pressure sodium (LPS). LPS technology is not considered suitable for most street lighting applications due to its monochromatic spectral output and poor color rendering ability; therefore, this LED product is performing at an efficiency level comparable to its primary competition in this application.

Kinzey, Bruce R.; Myer, Michael

2009-11-01T23:59:59.000Z

8

Development of substrate-removal-free vertical ultraviolet light-emitting diode (RefV-LED)  

SciTech Connect (OSTI)

A vertical ultraviolet (UV) light-emitting diode (LED) that does not require substrate removal is developed. Spontaneous via holes are formed in n-AlN layer epitaxially grown on a high conductive n+Si substrate and the injected current flows directly from the p-electrode to high doped n{sup +} Si substrate through p-AlGaN, multi-quantum wells, n-AlGaN and spontaneous via holes in n-AlN. The spontaneous via holes were formed by controlling feeding-sequence of metal-organic gas sources and NH{sub 3} and growth temperature in MOCVD. The via holes make insulating n-AlN to be conductive. We measured the current-voltage, current-light intensity and emission characteristics of this device. It exhibited a built-in voltage of 3.8 V and emission was stated at 350 nm from quantum wells with successive emission centered at 400?nm. This UV LED can be produced, including formation of n and p electrodes, without any resist process.

Kurose, N., E-mail: kurose@fc.ritsumei.ac.jp; Aoyagi, Y. [The Research Organization of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)] [The Research Organization of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan); Shibano, K.; Araki, T. [Department of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)] [Department of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)

2014-02-15T23:59:59.000Z

9

Demonstration Assessment of Light Emitting Diode (LED) Commercial Garage Lights In the Providence Portland Medical Center, Portland, Oregon  

SciTech Connect (OSTI)

This U.S. Department of Energy GATEWAY Demonstration project studied the applicability of light-emitting diode (LED) luminaires for commercial parking garage applications. High-pressure sodium (HPS) area luminaires were replaced with new LED area luminaires. The project was supported under the U.S. Department of Energy (DOE) Solid State Lighting Program. Other participants in the demonstration project included Providence Portland Medical Center in Portland, Oregon, the Energy Trust of Oregon, and Lighting Sciences Group (LSG) Inc. Pacific Northwest National Laboratory (PNNL) conducted the measurements and analysis of the results. PNNL manages GATEWAY demonstrations for DOE and represents their perspective in the conduct of the work. Quantitative and qualitative measurements of light and electrical power were taken at the site for both HPS and LED light sources. Economic costs were estimated and garage users’ responses to the new light sources were gauged with a survey. Six LED luminaires were installed in the below-ground parking level A, replacing six existing 150W HPS lamps spread out over two rows of parking spaces. Illuminance measurements were taken at floor level approximately every 4 ft on a 60-ft x 40-ft grid to measure light output of these LED luminaires which were termed the “Version 1” luminaires. PNNL conducted power measurements of the circuit in the garage to which the 6 luminaires were connected and determined that they drew an average of 82 W per lamp. An improved LED luminaire, Version 2, was installed in Level B of the parking garage. Illuminance measurements were not made of this second luminaire on site due to higher traffic conditions, but photometric measurements of this lamp and Version 1 were made in an independent testing laboratory and power usage for Version 2 was also measured. Version 1 was found to produce 3600 lumens and Version 2 was found to produce 4700 lumens of light and to consume 78 Watts. Maximum and minimum light levels were measured for the HPS and LED Version 1 luminaires and projected for the Version 2 luminaires. Maximum light levels were 23.51 foot candles, 20.54 fc, and 26.7 fc respectively and minimum light levels were 1.49 fc, 1.45 fc, and 1.88 fc. These results indicate very similar or even slightly higher light levels produced by the LED lamps, despite the higher lumen output of the HPS lamp. The LED lamps provide higher luminaire efficacy because all of the light is directed down and out. None of it is “lost” in the fixture. Also the HPS luminaire had poorly designed optics and a plastic covering that tended to get dirty and cracked, further decreasing the realized light output.[is this an accurate way to say this?] Consumer perceptions of the Version 2 LED were collected via a written survey form given to maintenance and security personnel. More than half felt the LED luminaires provided more light than the HPS lamps and a majority expressed a preference for the new lamps when viewing the relamped area through a security camera. Respondents commented that the LED luminaires were less glary, created less shadows, had a positive impact on visibility, and improved the overall appearance of the area. PNNL conducted an economic analysis and found that the Version 1 lamp produced annual energy savings of 955 kWh and energy cost savings of $76.39 per lamp at electricity rates of 6.5 cents per kWh and $105.03 at 11 cents per kWh. PNNL found that the Version 2 lamp produced annual energy savings of 991 kWh and energy cost savings of $79.26 per lamp at electricity rates of 6.5 cents per kWh and $108.98 at 11 cents per kWh. PNNL also calculated simple payback and found that Version 1 showed paybacks of 5.4 yrs at 6.5c/kWh and 4.1 yrs at 11c/kWh while Version 2 showed paybacks of 5.2 yrs at 6.5c/kWh and 3.9 yrs at 11c/kWh.

Ton, My K.; Richman, Eric E.; Gilbride, Theresa L.

2008-11-11T23:59:59.000Z

10

Highly Efficient Silicon Light Emitting Diode  

E-Print Network [OSTI]

silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap

Leminh Holleman Wallinga; P. Leminh; J. Holleman; H. Wallinga

2000-01-01T23:59:59.000Z

11

Demonstration Assessment of Light-Emitting Diode (LED) Retrofit Lamps at the Lobby of the Bonneville Power Administration, Portland, OR  

SciTech Connect (OSTI)

This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in the lobby of the Bonneville Power Administration (BPA) headquarters building in Portland, Oregon. The project involved a simple retrofit of 32 track lights used to illuminate historical black-and-white photos and printed color posters from the 1930s and 1940s. BPA is a federal power marketing agency in the Northwestern United States, and selected this prominent location to demonstrate energy efficient light-emitting diode (LED) retrofit options that not only can reduce the electric bill for their customers but also provide attractive alternatives to conventional products, in this case accent lighting for BPA's historical artwork.

Miller, Naomi

2011-07-01T23:59:59.000Z

12

Photonic crystal light emitting diode.  

E-Print Network [OSTI]

?? This master's thesis describe electromagnetic simulations of a gallium antimonide (GaSb) light emitting diode, LED. A problem for such devices is that most of… (more)

Leirset, Erlend

2010-01-01T23:59:59.000Z

13

Efficient Driver for Dimmable White LED Lighting.  

E-Print Network [OSTI]

??A high efficiency driver circuit is proposed for Light Emitting Diode (LED) lamps with dimming feature. The current regulation is accomplished by processing partial power… (more)

Yang, Wen-ching

2011-01-01T23:59:59.000Z

14

Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting at the I-35W Bridge, Minneapolis, MN  

SciTech Connect (OSTI)

This report describes the process and results of a demonstration of solid-state lighting (SSL) technology conducted in 2009 at the recently reconstructed I-35W bridge in Minneapolis, MN. The project was supported under the U.S. Department of Energy (DOE) Solid-State Lighting GATEWAY Technology Demonstration Program. Other participants in the demonstration project included the Minnesota Department of Transportation (Mn/DOT), Federal Highways Administration (FHWA), and BetaLED™ (a division of Ruud Lighting). Pacific Northwest National Laboratory (PNNL) conducted the measurements and analysis of the results. DOE has implemented a three-year evaluation of the LED luminaires in this installation in order to develop new longitudinal field data on LED performance in a challenging, real-world environment. This document provides information through the initial phase of the I-35W bridge project, up to and including the opening of the bridge to the public and the initial feedback received on the LED lighting installation from bridge users. Initial findings of the evaluation are favorable, with minimum energy savings level of 13% for the LED installation relative to the simulated base case using 250W high-pressure sodium (HPS) fixtures. The LEDs had an average illuminance level of 0.91 foot candles compared to 1.29 fc for the HPS lamps. The LED luminaires cost $38,000 more than HPS lamps, yielding a lengthy payback period, however the bridge contractor had offered to include the LED luminaires as part of the construction package at no additional cost. One potentially significant benefit of the LEDs in this installation is avoiding rolling lane closures on the heavily-traveled interstate bridge for the purpose of relamping the HPS fixtures. Rolling lane closures involve multiple crew members and various maintenance and safety vehicles, diversion of traffic, as well as related administrative tasks (e.g., approvals, scheduling, etc.). Mn/DOT records show an average cost of relamping fixtures along interstate roadways of between $130-150 per pole. The previous bridge saw a lamp mortality rate of approximately 50% every two years, though the new bridge was designed to minimize many of the vibration issues. A voluntary Web-based feedback survey of nearly 500 self-described bridge users showed strong preference for the LED lighting - positive comments outnumbered negative ones by about five-to-one.

Kinzey, Bruce R.; Myer, Michael

2009-08-31T23:59:59.000Z

15

Demonstration Assessment of Light Emitting Diode (LED) Residential Downlights and Undercabinet Lights in the Lane County Tour of Homes, Eugene, Oregon  

SciTech Connect (OSTI)

In August 2008 the Pacific Northwest National Laboratory (PNNL) conducted a light emitting diode (LED) residential lighting demonstration project for the U.S. Department of Energy (DOE), Office of Building Technologies, as part of DOE’s Solid State Lighting (SSL) Technology Demonstration Gateway Program. Two lighting technologies, an LED replacement for downlight lamps (bulbs) and an LED undercabinet lighting fixture, were tested in the demonstration which was conducted in two homes built for the 2008 Tour of Homes in Eugene, Oregon. The homes were built by the Lane County Home Builders Association (HBA), and Future B Homes. The Energy Trust of Oregon (ETO) also participated in the demonstration project. The LED downlight product, the LR6, made by Cree LED Lighting Solutions acts as a screw-in replacement for incandescent and halogen bulbs in recessed can downlights. The second product tested is Phillips/Color Kinetics’ eW® Profile Powercore undercabinet fixture designed to mount under kitchen cabinets to illuminate the countertop and backsplash surfaces. Quantitative and qualitative measurements of light performance and electrical power usage were taken at each site before and after initially installed halogen and incandescent lamps were replaced with the LED products. Energy savings and simple paybacks were also calculated and builders who toured the homes were surveyed for their responses to the LED products. The LED downlight product drew 12 Watts of power, cutting energy use by 82% compared to the 65W incandescent lamp and by 84% compared to the 75W halogen lamp. The LED undercabinet fixture drew 10 watts, cutting energy use by 83% to 90% compared to the halogen product, which was tested at two power settings: a low power 60W setting and a high power 105W setting. The LED downlight consistently provided more light than the halogen and incandescent lamps in horizontal measurements at counter height and floor level. It also outperformed in vertical illuminance measurements taken on the walls, indicating better lateral dispersion of the light. The undercabinet fixture’s light output was midway between the low and high power halogen undercabinet fixture light outputs (35.8 foot candle versus 13.4 fc and 53.4 fc) but it produced a more uniform light (max/min ratio of 7.0 versus 10.8). The color correlated temperature (CCT, the blue or yellowness) of the LED light correlated well with the halogen and incandescent lights (2675 K vs 2700 K). The color rendering of the LED downlight also correlated well at 92 CRI compared to 100 CRI for the halogen and incandescent lamps. The LED undercabinet fixture had measures of 2880 K CCT and 71 CRI compared to the 2700 K and 100 CRI scores for the halogen undercabinet fixture. Builders who toured the homes were surveyed; they gave the LED downlight high marks for brightness, said the undercabinet improved shadows and glare and said both products improved overall visibility, home appearance, and home value. Paybacks on the LED downlight ranged from 7.6 years (assuming electricity cost of 11 c/kWh) to 13.5 years (at 5C/kWh). Paybacks on the LED undercabinet fixture in a new home ranged from 4.4 years (11c/kWh electricity) to 7.6 years (5c/kWh) based on product costs of $95 per LED downlight and $140 per LED undercabinet fixture at 3 hrs per day of usage for the downlight and 2 hrs per day for the undercabinet lighting.

Ton, My K.; Richman, Eric E.; Gilbride, Theresa L.

2008-11-10T23:59:59.000Z

16

LED Retrofit Project in TSH Basement On July 14 2014, McMaster Facilities Services completed an energy conservation lighting  

E-Print Network [OSTI]

replaced with the new LED (light emitting diode) tubes. LEDs have better lighting quality, lower energy

Haykin, Simon

17

LED Provides Effective and Efficient Parking Area Lighting at...  

Broader source: Energy.gov (indexed) [DOE]

White Light Options for Parking Area Lighting Demonstration Assessment of Light Emitting Diode (LED) Street Lighting, Final Report Guide to FEMP-Designated Parking Lot...

18

Demonstration Assessment of Light Emitting Diode (LED) Walkway Lighting at the Federal Aviation Administration William J. Hughes Technical Center, in Atlantic City, New Jersey  

SciTech Connect (OSTI)

This report documents the results of a collaborative project to demonstrate a solid state lighting (SSL) general illumination product in an outdoor area walkway application. In the project, six light-emitting diode (LED) luminaires were installed to replace six existing high pressure sodium (HPS) luminaires mounted on 14-foot poles on a set of exterior walkways and stairs at the Federal Aviation Administration (FAA) William J. Hughes Technical Center in Atlantic City, New Jersey, during December, 2007. The effort was a U.S. Department of Energy (DOE) SSL Technology Gateway Demonstration that involved a collaborative teaming agreement between DOE, FAA and Ruud Lighting (and their wholly owned division, Beta LED). Pre- and post-installation power and illumination measurements were taken and used in calculations of energy savings and related economic payback, while personnel impacted by the new lights were provided questionnaires to gauge their perceptions and feedback. The SSL product demonstrated energy savings of over 25% while maintaining illuminance levels and improving illuminance uniformity. PNNL's economic analysis yielded a variety of potential payback results depending on the assumptions used. In the best case, replacing HPS with the LED luminaire can yield a payback as low as 3 years. The new lamps were quite popular with the affected personnel, who gave the lighting an average score of 4.46 out of 5 for improvement.

Kinzey, Bruce R.; Myer, Michael

2008-03-18T23:59:59.000Z

19

Today LED Holiday Lights, Tomorrow the World?  

SciTech Connect (OSTI)

This article for The APEM Advantage, the quarterly newsletter of the Association of Professional Energy Managers (APEM) describes the recent increase in the popularity of light emitting diode (LED) lighting and compares LED light output with that of incandescent and compact fluorescent lighting.

Gordon, Kelly L.

2004-12-20T23:59:59.000Z

20

LED Lighting Retrofit  

E-Print Network [OSTI]

? Municipal Street Lighting Consortium ? American Public Power Association (APPA) ? Demonstration in Energy Efficiency Development (DEED) ? Source of funding and database of completed LED roadway projects 6 Rules of the Road ESL-KT-11-11-57 CATEE 2011..., 2011 ? 9 Solar-Assisted LED Case Study LaQuinta Hotel, Cedar Park, Texas ? Utilizes 18 - ActiveLED Solar-Assisted Parking Lot Lights ? Utilizes ?power management? to extend battery life while handling light output ? Reduces load which reduces PV...

Shaw-Meadow, N.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting on Residential and Commercial Streets in Palo Alto, CA  

SciTech Connect (OSTI)

This report is part of a GATEWAY demonstration that replaced existing HPS streetlights with two different types of LED products and one induction product. Energy savings ranged from 6% to 44%.

Myer, Michael; Kinzey, Bruce R.; Tam, Christine

2010-06-24T23:59:59.000Z

22

The light-emitting diode (LED) is an fairly new kind of light source found currently in  

E-Print Network [OSTI]

this technology an ideal replacement for less efficient incandescent light sources, particularly in applications elevator lighting has the potential to achieve 25 percent greater efficiency than current incandescent ILLUMINATION LEVELS SIMILAR TO THOSE OF INCANDESCENT FIXTURES WHILE CUTTING ENERGY USE 45 PERCENT. ELEVATOR

23

Light emitting diode color rendition properties.  

E-Print Network [OSTI]

??This paper discusses the color rendition capabilities of light emitting diodes (LEDs) and their relationship with the current standard for color rendition quality. The current… (more)

Hood, Sean

2013-01-01T23:59:59.000Z

24

Commercial Lighting and LED Lighting Incentives  

Broader source: Energy.gov [DOE]

Incentives for energy efficient commercial lighting equipment as well as commercial LED lighting equipment are available to businesses under the Efficiency Vermont Lighting and LED Lighting...

25

Demonstration Assessment of Light-Emitting Diode (LED) Parking Lot Lighting at T.J.Maxx in Manchester, NH Phase I  

SciTech Connect (OSTI)

A report describing the process and results of replacing existing parking lot lighting, looking at a LED option with occupancy sensors, and conventional alternates. Criteria include payback, light levels, occupant satisfaction. This report is Phase I of II. Phase I deals with initial installation.

Myer, Michael; Goettel, Russell T.

2010-06-29T23:59:59.000Z

26

Potential Environmental Impacts from the Metals in Incandescent, Compact Fluorescent Lamp (CFL), and Light-Emitting Diode (LED)  

E-Print Network [OSTI]

the lighting products are to be categorized as hazardous waste under existing U.S. federal and California state in lighting products without compromising their performance and useful lifespan. INTRODUCTION The U.S. Energy to increase energy efficiency for general lighting. Therefore, consumers are replacing incandescent light

Short, Daniel

27

Demonstrating LED and Fiber Optic Lighting in Commissary Applications  

Broader source: Energy.gov [DOE]

Presentation—given at the Federal Utility Partnership Working Group (FUPWG) Fall 2008 meeting—covers goals of the project and applications for light-emitting diodes (LEDs) and fiber optic lighting.

28

White light emitting diode as liquid crystal display backlight ; High brightness light emitting diode as liquid crystal display backlight .  

E-Print Network [OSTI]

??The discovery of high brightness (white) light emitting diode (LED) is considered as a real threat to the current lighting industry in various applications. One… (more)

Soon, Chian Myau

2007-01-01T23:59:59.000Z

29

Water Cooling of High Power Light Emitting Diode Henrik Srensen  

E-Print Network [OSTI]

Water Cooling of High Power Light Emitting Diode Henrik Sørensen Department of Energy Technology and product lifetime. The high power Light Emitting Diodes (LED) belongs to the group of electronics

Berning, Torsten

30

Quantum Dot Light Emitting Diode  

SciTech Connect (OSTI)

The project objective is to create low cost coatable inorganic light emitting diodes, composed of quantum dot emitters and inorganic nanoparticles, which have the potential for efficiencies equivalent to that of LEDs and OLEDs and lifetime, brightness, and environmental stability between that of LEDs and OLEDs. At the end of the project the Recipient shall gain an understanding of the device physics and properties of Quantum-Dot LEDs (QD-LEDs), have reliable and accurate nanocrystal synthesis routines, and have formed green-yellow emitting QD-LEDs with a device efficiency greater than 3 lumens/W, a brightness greater than 400 cd/m2, and a device operational lifetime of more than 1000 hours. Thus the aim of the project is to break the current cost-efficiency paradigm by creating novel low cost inorganic LEDs composed of inorganic nanoparticles.

Keith Kahen

2008-07-31T23:59:59.000Z

31

Quantum Dot Light Emitting Diode  

SciTech Connect (OSTI)

The project objective is to create low cost coatable inorganic light emitting diodes, composed of quantum dot emitters and inorganic nanoparticles, which have the potential for efficiencies equivalent to that of LEDs and OLEDs and lifetime, brightness, and environmental stability between that of LEDs and OLEDs. At the end of the project the Recipient shall gain an understanding of the device physics and properties of Quantum-Dot LEDs (QD-LEDs), have reliable and accurate nanocrystal synthesis routines, and have formed green-yellow emitting QD-LEDs with a device efficiency greater than 3 lumens/W, a brightness greater than 400 cd/m{sup 2}, and a device operational lifetime of more than 1000 hours. Thus the aim of the project is to break the current cost-efficiency paradigm by creating novel low cost inorganic LEDs composed of inorganic nanoparticles.

Kahen, Keith

2008-07-31T23:59:59.000Z

32

Thermal pumping of light-emitting diodes  

E-Print Network [OSTI]

The work presented here is a study of thermally enhanced injection in light-emitting diodes (LEDs). This effect, which we refer to as "thermal pumping", results from Peltier energy exchange from the lattice to charge ...

Gray, Dodd (Dodd J.)

2011-01-01T23:59:59.000Z

33

Demonstration Assessment of Light-Emitting Diode (LED) Retrofit Lamps at Intercontinental Hotel in San Francisco, CA  

SciTech Connect (OSTI)

This document is a report of observations and results obtained from a lighting demonstration project conducted under the U.S. Department of Energy (DOE) GATEWAY Demonstration Program. The program supports demonstrations of high-performance solid-state lighting (SSL) products in order to develop empirical data and experience with in-the-field applications of this advanced lighting technology. The DOE GATEWAY Demonstration Program focuses on providing a source of independent, third-party data for use in decision-making by lighting users and professionals; this data should be considered in combination with other information relevant to the particular site and application under examination. Each GATEWAY Demonstration compares SSL products against the incumbent technologies used in that location. Depending on available information and circumstances, the SSL product may also be compared to alternate lighting technologies. Though products demonstrated in the GATEWAY program have been prescreened and tested to verify their actual performance, DOE does not endorse any commercial product or in any way guarantee that users will achieve the same results through use of these products.

Miller, Naomi J.; Curry, Ku'Uipo J.

2010-11-01T23:59:59.000Z

34

LEDs for Energy Efficient Greenhouse Lighting  

E-Print Network [OSTI]

Light energy is an important factor for plant growth. In regions where the natural light source, i.e. solar radiation, is not sufficient for growth optimization, additional light sources are being used. Traditional light sources such as high pressure sodium lamps and other metal halide lamps are not very efficient and generate high radiant heat. Therefore, new sustainable solutions should be developed for energy efficient greenhouse lighting. Recent developments in the field of light source technologies have opened up new perspectives for sustainable and highly efficient light sources in the form of light-emitting diodes, i.e. LEDs, for greenhouse lighting. This review focuses on the potential of LEDs to replace traditional light sources in the greenhouse. In a comparative economic analysis of traditional vs. LED lighting, we show that the introduction of LEDs allows reduction of the production cost of vegetables in the long-run of several years, due to the high energy efficiency, low maintenance cost and lon...

Singh, Devesh; Meinhardt-Wollweber, Merve; Roth, Bernhard

2014-01-01T23:59:59.000Z

35

Broadband light-emitting diode  

DOE Patents [OSTI]

A broadband light-emitting diode. The broadband light-emitting diode (LED) comprises a plurality of III-V compound semiconductor layers grown on a semiconductor substrate, with the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps for generating light in a wavelength range of about 1.3-2 .mu.m. In one embodiment of the present invention, the active region may comprise a first-grown quantum-well layer and a last-grown quantum-well layer that are oppositely strained; whereas in another embodiment of the invention, the active region is formed from a short-period superlattice structure (i.e. a pseudo alloy) comprising alternating thin layers of InGaAs and InGaAlAs. The use a short-period superlattice structure for the active region allows different layers within the active region to be simply and accurately grown by repetitively opening and closing one or more shutters in an MBE growth apparatus to repetitively switch between different growth states therein. The broadband LED may be formed as either a surface-emitting LED or as an edge-emitting LED for use in applications such as chemical sensing, fiber optic gyroscopes, wavelength-division-multiplexed (WDM) fiber-optic data links, and WDM fiber-optic sensor networks for automobiles and aircraft.

Fritz, Ian J. (Albuquerque, NM); Klem, John F. (Sandia Park, NM); Hafich, Michael J. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

36

Broadband light-emitting diode  

DOE Patents [OSTI]

A broadband light-emitting diode is disclosed. The broadband light-emitting diode (LED) comprises a plurality of III-V compound semiconductor layers grown on a semiconductor substrate, with the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps for generating light in a wavelength range of about 1.3--2 {micro}m. In one embodiment of the present invention, the active region may comprise a first-grown quantum-well layer and a last-grown quantum-well layer that are oppositely strained; whereas in another embodiment of the invention, the active region is formed from a short-period superlattice structure (i.e. a pseudo alloy) comprising alternating thin layers of InGaAs and InGaAlAs. The use a short-period superlattice structure for the active region allows different layers within the active region to be simply and accurately grown by repetitively opening and closing one or more shutters in an MBE growth apparatus to repetitively switch between different growth states therein. The broadband LED may be formed as either a surface-emitting LED or as an edge-emitting LED for use in applications such as chemical sensing, fiber optic gyroscopes, wavelength-divisionmultiplexed (WDM) fiber-optic data links, and WDM fiber-optic sensor networks for automobiles and aircraft. 10 figs.

Fritz, I.J.; Klem, J.F.; Hafich, M.J.

1998-07-14T23:59:59.000Z

37

White light emitting diode as liquid crystal display backlight  

E-Print Network [OSTI]

The discovery of high brightness (white) light emitting diode (LED) is considered as a real threat to the current lighting industry in various applications. One of the most promising sectors would be using white LED to ...

Soon, Chian Myau

2007-01-01T23:59:59.000Z

38

Shelf life of five meat products displayed under light emitting diode or fluorescent lighting.  

E-Print Network [OSTI]

??Light emitting diode (LED) and fluorescent (FLS) lighting effects on enhanced pork loin chops, beef longissimus dorsi and semimembranosus steaks, ground beef, and ground turkey… (more)

Steele, Kyle Stover

2011-01-01T23:59:59.000Z

39

Metacapacitors for LED Lighting: Metacapacitors  

SciTech Connect (OSTI)

ADEPT Project: The CUNY Energy Institute is developing less expensive, more efficient, smaller, and longer-lasting power converters for energy-efficient LED lights. LEDs produce light more efficiently than incandescent lights and last significantly longer than compact fluorescent bulbs, but they require more sophisticated power converter technology, which increases their cost. LEDs need more sophisticated converters because they require a different type of power (low voltage direct current, or DC) than what's generally supplied by power outlets. The CUNY Energy Institute is developing sophisticated power converters for LEDs that contain capacitors made from new, nanoscale materials. Capacitors are electrical components that are used to store energy. CUNY's unique capacitors are configured with advanced power circuits to more efficiently control and convert power to the LED lighting source. They also eliminate the need for large magnetic components, instead relying on networks of capacitors that can be easily printed on plastic substrate. CUNY's prototype LED power converter already meets DOE's 2020 projections for the energy efficiency of LED power converters.

None

2010-09-02T23:59:59.000Z

40

Have You Used LED Lighting? Tell Us About It. | Department of...  

Broader source: Energy.gov (indexed) [DOE]

It. May 7, 2009 - 5:00am Addthis This week, John shared his experiences with light-emitting diode (LED) lighting. In a future blog, he'll share more about LED lighting. Have you...

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

LED Traffic Light as a Communications Device Grantham Pang, Thomas Kwan, Chi-Ho Chan, Hugh Liu.  

E-Print Network [OSTI]

:http://www.eee.hku.hk/~gpang Abstract The visible light from an LED (light emitting diode) traffic light can be modulated and encoded on the description of an audio information system made up of high brightness, visible light emitting diodes (LEDs messages 1. Introduction Recently, high intensity light emitting diodes for traffic signals are available

Pang, Grantham

42

Pousset, Obein, Razet, LED lighting quality with CQS samples CIE 2010 : Lighting Quality and Energy Efficiency, 14-17 March 2010, Vienna, Austria 1  

E-Print Network [OSTI]

A psychophysical experiment developed to evaluate light quality of Light Emitting Diodes (LEDs) is described. Keywords: Light Emitting Diode, quality of light, Color Rendering Index, Color Quality Scale, visual

Paris-Sud XI, Université de

43

Wire-shaped semiconductor light-emitting diodes for general-purpose lighting  

SciTech Connect (OSTI)

The object of this work is to develop and optimize a new type of light-emitting diode (LED) with a wire-shaped, cylindrical geometry.

Mauk, Michael G.

2002-10-28T23:59:59.000Z

44

Researchers Say They've Solved the Mystery of LED Lighting "Droop...  

Broader source: Energy.gov (indexed) [DOE]

Sciences Team. Despite being cool, ultra-efficient and long lasting, the light-emitting diode (LED) faces a problem called "efficiency droop." New findings from simulations...

45

LED Lighting | Department of Energy  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehicles »Exchange Visitors HistoryHybridInspectorInvestingJobsLED Lighting

46

Cree LED Lighting Solutions Formerly LED Lighting Fixtures LLF | Open  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160Benin:EnergyWisconsin:2003) |Cordova39. It isEnergy Information LED Lighting

47

Psychophysical evaluations of modulated color rendering for energy performance of LED-based architectural lighting  

E-Print Network [OSTI]

This thesis is focused on the visual perception evaluation of colors within an environment of a highly automated lighting control strategy. Digitally controlled lighting systems equipped with light emitting diodes, LEDs, ...

Thompson, Maria do Rosário

2007-01-01T23:59:59.000Z

48

Municipal Consortium LED Street Lighting Workshop Presentations...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Controls Norma Isahakian, City of Los Angeles Bureau of Street Lighting San Jose's "Smart" LED Streetlights: Controlled Amy Olay, City of San Jose Adaptive Lighting Controls...

49

E-Print Network 3.0 - algainp light-emitting diodes Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by sequentially adding components of different types. Six hundred AlGaInP GaAs light- emitting diode segments... of 600 AlGaInP GaAs light-emitting diodes (LEDs) onto device...

50

Multispectral imaging of the ocular fundus using light emitting diode illumination  

E-Print Network [OSTI]

Multispectral imaging of the ocular fundus using light emitting diode illumination N. L. Everdell,1 on light emitting diode LED illumination that produces multispectral optical images of the human ocular

Claridge, Ela

51

Light-Emitting Diodes in the Solid-State Lighting Systems  

E-Print Network [OSTI]

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.

Sparavigna, Amelia Carolina

2014-01-01T23:59:59.000Z

52

Thermo-electrically pumped semiconductor light emitting diodes  

E-Print Network [OSTI]

Thermo-electric heat exchange in semiconductor light emitting diodes (LEDs) allows these devices to emit optical power in excess of the electrical power used to drive them, with the remaining power drawn from ambient heat. ...

Santhanam, Parthiban

2014-01-01T23:59:59.000Z

53

spectroscopic techniques A Multi-Source Portable Light Emitting Diode Spectrofluorometer  

E-Print Network [OSTI]

spectroscopic techniques A Multi-Source Portable Light Emitting Diode Spectrofluorometer SAFWAN only 1.5 kg that uses multiple light emitting diodes (LEDs) as excitation sources was developed emitting diodes; LEDs; Animal forage; Excitation-emission matrices; EEM. INTRODUCTION Movement of chemical

54

A strategy for the use of light emitting diodes by autonomous underwater vehicles  

E-Print Network [OSTI]

Light Emitting Diode (LED) technology has advanced dramatically in a few short years. An expensive and difficult to manufacture LED array containing nearly 100 individual LEDs and measuring at least 5 cm² can now be replaced ...

Curran, Joseph R. (Joseph Robinson)

2004-01-01T23:59:59.000Z

55

LED Street Lighting Conversion Workshop Presentations  

Broader source: Energy.gov [DOE]

This page provides links to the presentations given at the National League of Cities Mobile Workshop, LED Street Lighting Conversion: Saving Your Community Money, While Improving Public Safety,...

56

LED Lighting Facts®  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10 DOEWashington, DCKickoffLDV HVAC ModelLED LightbulbsLED

57

Journal of Light Emitting Diodes Vol 2 N0 1, April 2010 1 Abstract--Semiconductor nanocrystal quantum dots (NQD)  

E-Print Network [OSTI]

Journal of Light Emitting Diodes Vol 2 N0 1, April 2010 1 Abstract-- Semiconductor nanocrystal convertors integrated on light-emitting diodes (LEDs). The use of nonradiative energy transfer, also known-LEDs for lighting applications. Index Terms-- Förster resonance energy transfer, light emitting diode, nanocrystal

Demir, Hilmi Volkan

58

LED Lighting Off the Grid  

Energy Savers [EERE]

D. & Kammen, D. M. Decentralized energy systems for clean electricity access. Nature Climate Change accepted, in press, (2015). Off-Grid Status Quo : Fuel Based Lighting...

59

Vertical Pillar-Superlattice Array and Graphene Hybrid Light Emitting Diodes  

E-Print Network [OSTI]

Vertical Pillar-Superlattice Array and Graphene Hybrid Light Emitting Diodes Jung Min Lee, Jae a class of light emitting diode (LED) with interesting mechanical, optical, and electrical characteristics, light-emitting diodes, 3D architectures, transparent electrodes V ertical arrays of one-dimensional (1D

Rogers, John A.

60

Pittsburgh LED Street Lighting Research Project Performance Criteria  

Broader source: Energy.gov [DOE]

A Pittsburgh LED Street Lighting Research Project document on Technical and Aesthetic Performance for Business District LED Lighting.

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Highly Efficient Silicon Light Emitting Diode  

E-Print Network [OSTI]

In this paper, we describe the fabrication, using standard silicon processing techniques, of silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap. The improved efficiency had been explained by the spatial confinement of charge carriers due to a local strain field that is formed by dislocation loop arrays. The dependence of device electroluminescent properties on the annealing conditions is carefully examined as a high temperature process has profound influence on these dislocations. Increased luminescent intensity at higher device temperature, together with pure diffusion current conduction mechanism evidently shows the influence of the dislocation loops. The electrical properties of the diode are reasonable with low leakage reverse current.

Leminh Holleman Wallinga; P. Leminh; J. Holleman; H. Wallinga

2000-01-01T23:59:59.000Z

62

Efficiency enhancement in a light-emitting diode with a two-dimensional surface grating photonic crystal  

E-Print Network [OSTI]

Efficiency enhancement in a light-emitting diode with a two-dimensional surface grating photonic 21 November 2003 We demonstrate a light-emitting diode exhibiting 1.7­2.7-fold enhancement in light light emitting diode LED , the ef- ficiency is limited to several percents by a low light extrac- tion

Baba, Toshihiko

63

LED traffic lights: New technology signals major energy savings  

SciTech Connect (OSTI)

Using light-emitting diode technology to replace incandescent lamps in traffic signals promises energy savings upwards of 60 percent for each of the estimated quarter of a million controlled intersections in the United States. LED units use only 9 to 25 watts instead of the 67 to 150 watts used by each incandescent lamp. Though their first cost is relatively high, energy savings result in paybacks of 1 to 5 years. LED retrofit kits are available for red signal disks and arrows, and installations in several states have proven successful, although minor improvements are addressing concerns about varying light output and controller circuitry. Retrofitting green lamps is not yet feasible, because color standards of the Institute of Traffic Engineers cannot be met with existing LED technology. Yellow lamps have such low duty factors (they`re on only 3 percent of the time) that retrofitting with LED signals is not cost-effective. LEDs last much longer than incandescents, allowing municipalities to not only reduce their electricity bills, but to save on maintenance costs as well. As further incentive, some utilities are beginning to implement rebate programs for LED traffic signal retrofits. Full approval of LED units is still awaited from the Institute of Traffic Engineers (ITE), the standard-setting body for traffic safety devices. Local and state governments ultimately decide what specifications to require for traffic lights, and the growing body of successful field experience with LEDs appears to be raising their comfort level with the technology. The California Department of Transportation is developing an LED traffic light specification, and two California utilities, Southern California Edison and Pacific Gas and Electric, have provided rebates for some pilot installations.

Houghton, D.

1994-12-31T23:59:59.000Z

64

Design and fabrication of high-index-contrast self-assembled texture for light extraction enhancement in LEDs  

E-Print Network [OSTI]

We developed a high-index-contrast photonic structure for improving the light extraction efficiency of light-emitting diodes (LEDs) by a self-assembly approach. In this approach, a two-dimensional grating can be ...

Sheng, Xing

65

Flip-chip light emitting diode with resonant optical microcavity  

SciTech Connect (OSTI)

A flip-chip light emitting diode with enhanced efficiency. The device structure employs a microcavity structure in a flip-chip configuration. The microcavity enhances the light emission in vertical modes, which are readily extracted from the device. Most of the rest of the light is emitted into waveguided lateral modes. Flip-chip configuration is advantageous for light emitting diodes (LEDs) grown on dielectric substrates (e.g., gallium nitride LEDs grown on sapphire substrates) in general due to better thermal dissipation and lower series resistance. Flip-chip configuration is advantageous for microcavity LEDs in particular because (a) one of the reflectors is a high-reflectivity metal ohmic contact that is already part of the flip-chip configuration, and (b) current conduction is only required through a single distributed Bragg reflector. Some of the waveguided lateral modes can also be extracted with angled sidewalls used for the interdigitated contacts in the flip-chip configuration.

Gee, James M.; Bogart, Katherine H.; Fischer, Arthur J.

2005-11-29T23:59:59.000Z

66

ECE 466: LED Lighting Systems -Incandescent lightings rise and  

E-Print Network [OSTI]

versus cost - Power Electronic Drives for CFL and LED light sources to achieve dimmable operation - Basic electric AC and DC circuits at Sophomore level or equivalents Absolutes Lighting System Requirements index as a metric of a light source - Power Electronic Energy sources driving light sources in a compact

Schumacher, Russ

67

Efficiency loss mechanisms in colloidal quantum-dot light-emitting diodes  

E-Print Network [OSTI]

Saturated and tunable emission colors make colloidal quantum-dot light-emitting diodes (QD-LEDs) interesting for the next generation of display and lighting technologies. However, there still remain various hurdles to the ...

Shirasaki, Yasuhiro

2013-01-01T23:59:59.000Z

68

Sustainable LED Fluorescent Light Replacement Technology  

SciTech Connect (OSTI)

Ilumisys and the National Center for Manufacturing Sciences (NCMS) partnered on a three-year project awarded by the United States (U.S.) Department of Energy (DOE), to quantify the impacts of LED lamps, incandescent lamps and fluorescent benchmark lamps over a product lifecycle – i.e. to develop a sustainable design and manufacturing strategy that addresses product manufacturing, use, recycling and disposal scenarios for LED-based lighting. Based on the knowledge gained from extensive product tear-down studies of fluorescent and screw-in lighting products, lifecycle assessment tools, and accelerated lifecycle testing protocols, an interactive Sustainable LED Design Guide has been developed to aid architectural and lighting designers and engineers in making design decisions that consider three important environmental impacts (greenhouse gas emissions, energy use and mercury emission) across all phases of the life of an LED lighting product. Critical information developed for the lifecycle analysis and product feature comparisons is the useful life of the lighting product as well as its performance. The Design Guide is available at www.ncms.org, and was developed based on operational and durability testing of a variety of lighting products including power consumption, light output, and useful life of a lamp in order to allow a more realistic comparison of lamp designs. This report describes the main project tasks, results and innovative features of the lifecycle assessment (LCA)-based design tools, and the key considerations driving the sustainable design of LED lighting systems. The Design Guide incorporates the following three novel features for efficiently evaluating LED lighting features in value-chains: • Bill-of-Materials (BOM) Builder – Designers may import process data for each component and supply functional data for the product, including power, consumption, lumen output and expected useful life. • Environmental Impact Review – Designs are comparable across lifecycle phases, subsystems, and environmental impact category, and can be normalized to a userdefined functional unit. • Drill-down Review – These provide an indepth look at individual lamp designs with the ability to review across subsystem or lifecycle phase.

None

2011-06-30T23:59:59.000Z

69

Coupled optical and electronic simulations of electrically pumped photonic-crystal-based light-emitting diodes  

E-Print Network [OSTI]

trade-offs in electrically pumped photonic-crystal-based light-emitting diodes. A finite- toelectronic devices, such as light-emitting diodes LEDs and lasers. It has been suggested that a thin slabCoupled optical and electronic simulations of electrically pumped photonic-crystal-based light-emitting

Dutton, Robert W.

70

Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors  

E-Print Network [OSTI]

Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors developed for the optimization of light-emitting diodes (LED) and solar thermal collectors. The surface a light-extraction efficiency of only 3.7%). The solar thermal collector we considered consists

Mayer, Alexandre

71

LED Light Fixture Project FC1 Director's Conference Room: Life Cycle Cost and Break-even Analysis  

E-Print Network [OSTI]

. A light-emitting diode (LED) is a solid-state lighting source that switches on instantly, is readilyLED Light Fixture Project ­ FC1 Director's Conference Room: Life Cycle Cost and Break-even Analysis light fixtures in existing or new buildings across campus. Scope of Work On August 27, 2012, the six

Johnston, Daniel

72

Conference 5739, SPIE International Symposium Integrated Optoelectronic Devices, 22-27 Jan 2005, San Jose, CA Development of high power green light emitting diode dies in  

E-Print Network [OSTI]

, San Jose, CA Development of high power green light emitting diode dies in piezoelectric Ga in green light emitting diodes is one of the big challenges towards all-solid- state lighting. The prime,3], and commercialization [4,5] of high brightness light emitting diodes LEDs has led to a 1.82 Billion-$/year world market

Wetzel, Christian M.

73

Poly (p-phenyleneacetylene) light-emitting diodes  

DOE Patents [OSTI]

Acetylene containing poly(p-phenyleneacetylene) (PPA) - based light-emitting diodes (LEDs) are provided. The LEDs are fabricated by coating a hole-injecting electrode, preferably an indium tin oxide (ITO) coated glass substrate, with a PPA polymer, such as a 2,5-dibutoxy or a 2,5-dihexoxy derivative of PPA, dissolved in an organic solvent. This is then followed by evaporating a layer of material capable of injecting electrons, such as Al or Al/Ca, onto the polymer to form a base electrode. This composition is then annealed to form efficient EL diodes. 8 figs.

Shinar, J.; Swanson, L.S.; Lu, F.; Ding, Y.; Barton, T.J.; Vardeny, Z.V.

1994-10-04T23:59:59.000Z

74

Fabrication of poly(p-phenyleneacetylene) light-emitting diodes  

DOE Patents [OSTI]

Acetylene-containing poly(p-phenyleneacetylene) (PPA)-based light-emitting diodes (LEDs) are provided. The LEDs are fabricated by coating a hole-injecting electrode, preferably an indium tin oxide (ITO) coated glass substrate, with a PPA polymer, such as a 2,5-dibutoxy or a 2,5-dihexoxy derivative of PPA, dissolved in an organic solvent. This is then followed by evaporating a layer of material capable of injecting electrons, such as Al or Al/Ca, onto the polymer to form a base electrode. This composition is then annealed to form efficient EL diodes. 8 figs.

Shinar, J.; Swanson, L.S.; Lu, F.; Ding, Y.

1994-08-02T23:59:59.000Z

75

Poly (p-phenyleneneacetylene) light-emitting diodes  

DOE Patents [OSTI]

Acetylene containing poly(p-phenyleneacetylene) (PPA) - based light-emitting diodes (LEDs) are provided. The LEDs are fabricated by coating a hole-injecting electrode, preferably an indium tin oxide (ITO) coated glass substrate, with a PPA polymer, such as a 2,5-dibutoxy or a 2,5-dihexoxy derivative of PPA, dissolved in an organic solvent. This is then followed by evaporating a layer of material capable of injecting electrons, such as Al or Al/Ca, onto the polymer to form a base electrode. This composition is then annealed to form efficient EL diodes.

Shinar, Joseph (Ames, IA); Swanson, Leland S. (Ames, IA); Lu, Feng (Ames, IA); Ding, Yiwei (Ames, IA); Barton, Thomas J. (Ames, IA); Vardeny, Zeev V. (Salt Lake City, UT)

1994-10-04T23:59:59.000Z

76

Fabrication of poly(p-phenyleneacetylene) light-emitting diodes  

DOE Patents [OSTI]

Acetylene containing poly(p-phenyleneacetylene) (PPA) - based light-emitting diodes (LEDs) are provided. The LEDs are fabricated by coating a hole-injecting electrode, preferably an indium tin oxide (ITO) coated glass substrate, with a PPA polymer, such as a 2,5-dibutoxy or a 2,5-dihexoxy derivative of PPA, dissolved in an organic solvent. This is then followed by evaporating a layer of material capable of injecting electrons, such as A1 or A1/Ca, onto the polymer to form a base electrode. This composition is then annealed to form efficient EL diodes.

Shinar, Joseph (Ames, IA); Swanson, Leland S. (Ames, IA); Lu, Feng (Ames, IA); Ding, Yiwei (Ames, IA)

1994-08-02T23:59:59.000Z

77

(Expired) Nationwide Limited Public Interest Waiver for LED Lighting...  

Energy Savers [EERE]

(Expired) Nationwide Limited Public Interest Waiver for LED Lighting and HVAC Units: February 11, 2010 (Expired) Nationwide Limited Public Interest Waiver for LED Lighting and HVAC...

78

The Effect of Light Emitting Diode Phototherapy on the Rate of Orthodontic Tooth Movement - A Clinical Study.  

E-Print Network [OSTI]

??Increasing the rate of orthodontic tooth movement (OTM) can reduce risks such as periodontal disease and caries. This study investigated whether light emitting diode (LED)… (more)

Chung, Sean

2013-01-01T23:59:59.000Z

79

DOE Lighting Program Update: LED Validation Activities  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTieCelebratePartnersDepartmentforDOE Lighting Program Update LED

80

High efficiency III-nitride light-emitting diodes  

DOE Patents [OSTI]

Tailored doping of barrier layers enables balancing of the radiative recombination among the multiple-quantum-wells in III-Nitride light-emitting diodes. This tailored doping enables more symmetric carrier transport and uniform carrier distribution which help to reduce electron leakage and thus reduce the efficiency droop in high-power III-Nitride LEDs. Mitigation of the efficiency droop in III-Nitride LEDs may enable the pervasive market penetration of solid-state-lighting technologies in high-power lighting and illumination.

Crawford, Mary; Koleske, Daniel; Cho, Jaehee; Zhu, Di; Noemaun, Ahmed; Schubert, Martin F; Schubert, E. Fred

2013-05-28T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Development of ZnO Based Light Emitting Diodes and Laser Diodes.  

E-Print Network [OSTI]

??ZnO based homojunction light emitting diode, double heterojunction light emitting diode, embedded heterojunction random laser diode and Fabry-Perot nanowire laser devices were fabricated and characterized.… (more)

Kong, Jieying

2012-01-01T23:59:59.000Z

82

New and Underutilized Technology: High Bay LED Lighting  

Broader source: Energy.gov [DOE]

The following information outlines key deployment considerations for high bay LED lighting within the Federal sector.

83

Light source comprising a common substrate, a first led device and a second led device  

DOE Patents [OSTI]

At least one stacked organic or polymeric light emitting diode (PLEDs) devices to comprise a light source is disclosed. At least one of the PLEDs includes a patterned cathode which has regions which transmit light. The patterned cathodes enable light emission from the PLEDs to combine together. The light source may be top or bottom emitting or both.

Choong, Vi-En (Carlsbad, CA)

2010-02-23T23:59:59.000Z

84

Microcavity enhanced vertical-cavity light-emitting diodes U. Keller, G. R. Jacobovitz-Veselka, J. E. Cunningham, W. Y. Jan, B. Tell,  

E-Print Network [OSTI]

Microcavity enhanced vertical-cavity light-emitting diodes U. Keller, G. R. Jacobovitz-Veselka, J-cavity light-emitting diode (LED) by continuously changing the microcavity resonance with respect for optical interconnects seems to be the light emitting diode (LED), or better yet, the microcavity en

Keller, Ursula

85

Sandia National Laboratories: efficient LED lighting  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia, NRELdeep-waterbiofuels economicallyefficient LED lighting

86

Series Input Modular Architecture for Driving Multiple LEDs  

E-Print Network [OSTI]

, where each cell drives four 700 mA LEDs. Keywords ­ solid-state lighting, light emitting diodes, LED have been achieved over the past decade in solid state light emitting diodes (LEDs), leading to high

87

Room-temperature direct bandgap electroluminesence from Ge-on-Si light-emitting diodes  

E-Print Network [OSTI]

We report what we believe to be the first demonstration of direct bandgap electroluminescence (EL) from Ge/Si heterojunction light-emitting diodes (LEDs) at room temperature. In-plane biaxial tensile strain is used to ...

Sun, Xiaochen

88

Colloidal semiconductor nanocrystals as nanoscale emissive probes in light emitting diodes and cell biology  

E-Print Network [OSTI]

This thesis employs colloidal semiconductor nanocrystals (NCs) as nanoscale emissive probes to investigate the physics of light emitting diodes (LEDs), as well as to unveil properties of cells that conventional imaging ...

Huang, Hao, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

89

EECBG Success Story: Solar LED Light Pilot Project Illuminates...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Solar LED Light Pilot Project Illuminates the Way in Alabama EECBG Success Story: Solar LED Light Pilot Project Illuminates the Way in Alabama September 12, 2012 - 2:15pm Addthis...

90

Medical Applications of Space Light-Emitting Diode Technology--Space Station and Beyond  

SciTech Connect (OSTI)

Space light-emitting diode (LED) technology has provided medicine with a new tool capable of delivering light deep into tissues of the body, at wavelengths which are biologically optimal for cancer treatment and wound healing. This LED technology has already flown on Space Shuttle missions, and shows promise for wound healing applications of benefit to Space Station astronauts.

Whelan, H.T.; Houle, J.M.; Donohoe, D.L.; Bajic, D.M.; Schmidt, M.H.; Reichert, K.W.; Weyenberg, G.T.; Larson, D.L.; Meyer, G.A.; Caviness, J.A.

1999-06-01T23:59:59.000Z

91

Text-Alternative Version: Evaluating LED Street Lighting Solutions  

Broader source: Energy.gov [DOE]

Below is the text-alternative version of the Evaluating LED Street Lighting Solutions webcast, held July 20, 2010.

92

Light extraction from organic light-emitting diodes for lighting applications by sand-blasting  

E-Print Network [OSTI]

Light extraction from organic light-emitting diodes for lighting applications by sand@ust.hk Abstract: Light extraction from organic light-emitting diodes (OLEDs) by scattering the light is one of the effective methods for large-area lighting applications. In this paper, we present a very simple and cost

93

Municipal Consortium LED Street Lighting Workshop Presentations...  

Broader source: Energy.gov (indexed) [DOE]

A Rational View of LM-79 Reports, IES Files, and Product Variation Gary Steinberg, GE Lighting Solutions Solid-State Street Lighting: Calculating Light Loss Factors Dana Beckwith,...

94

Municipal Consortium LED Street Lighting Workshop Presentations...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

National Association of Energy Services Companies Calculating Light Loss Factors for Solid-State Lighting Systems Chad Stalker, Philips Lumileds Lighting Intro to MSSLC's...

95

Thickness-dependent changes in the optical properties of PPV-and PF-based polymer light emitting diodes  

E-Print Network [OSTI]

the thickness-dependent optical properties of single layer polymer light emitting diodes for two materials, poly the electronic and optical properties of these materials in light emitting diode LED structures.2 OurThickness-dependent changes in the optical properties of PPV- and PF-based polymer light emitting

Carter, Sue

96

Junction temperature, spectral shift, and efficiency in GaInN-based blue and green light emitting diodes  

E-Print Network [OSTI]

Keywords: GaInN/GaN Light emitting diode temperature Micro-Raman Photoluminescence Electroluminescence well light emitting diode (LED) dies is analyzed by micro-Raman, photoluminescence, cathodoluminescenceJunction temperature, spectral shift, and efficiency in GaInN-based blue and green light emitting

Wetzel, Christian M.

97

THE LUMINA PROJECT http://light.lbl.gov  

E-Print Network [OSTI]

components for the LED lights. #12;2 Introduction Solid-state lighting based on light emitting diode (LED

Jacobson, Arne

98

LED Linear Lamps and Troffer Lighting  

Broader source: Energy.gov [DOE]

The CALiPER program performed a series of investigations on linear LED lamps. Each report in the series covers the performance of up to 31 linear LED lamps, which were purchased in late 2012 or 2013. The first report focuses on bare lamp performance of LED T8 replacement lamps and subsequent reports examine performance in various troffers, as well as cost-effectiveness. There is also a concise guidance document that describes the findings of the Series 21 studies and provides practical advice to manufacturers, specifiers, and consumers (Report 21.4: Summary of Linear (T8) LED Lamp Testing , 5 pages, June 2014).

99

Off-grid energy services for the poor: Introducing LED lighting in the Millennium Villages Project in Malawi  

E-Print Network [OSTI]

) powered by batteries, which are in turn charged by grid electricity or small solar panels, have emerged 2009 Keywords: Solar Lighting Development a b s t r a c t Lanterns that use light-emitting diodes (LEDs as a cost-competitive alternative to kerosene and other fuel-based lighting technologies, offering brighter

Modi, Vijay

100

High-Performance Organic Light-Emitting Diodes Using ITO  

E-Print Network [OSTI]

High-Performance Organic Light-Emitting Diodes Using ITO Anodes Grown on Plastic by Room,* Mark E. Madsen, Antonio DiVenere, and Seng-Tiong Ho Organic light-emitting diodes (OLEDs) fabricated

Ho, Seng-Tiong

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Integrated LED-based luminare for general lighting  

DOE Patents [OSTI]

Lighting apparatus and methods employing LED light sources are described. The LED light sources are integrated with other components in the form of a luminaire or other general purpose lighting structure. Some of the lighting structures are formed as Parabolic Aluminum Reflector (PAR) luminaires, allowing them to be inserted into conventional sockets. The lighting structures display beneficial operating characteristics, such as efficient operation, high thermal dissipation, high output, and good color mixing.

Dowling, Kevin J.; Lys, Ihor A.; Roberge, Brian; Williamson, Ryan C.; Roberts, Ron; Datta, Michael; Mollnow, Tomas; Morgan, Frederick M.

2013-03-05T23:59:59.000Z

102

C. Wetzel et al MRS Internet J. Nitride Semicond. Res. 10, 2 (2005) 1 Development of High Power Green Light Emitting Diode Chips  

E-Print Network [OSTI]

Power Green Light Emitting Diode Chips C. Wetzel and T. Detchprohm Future Chips Constellation Abstract The development of high emission power green light emitting diodes chips using GaInN/GaN multi production-scale implementation of this green LED die process. Keywords: nitrides, light emitting diode

Wetzel, Christian M.

103

Entangled Light Emission From a Diode  

SciTech Connect (OSTI)

Electrically-driven entangled photon generation is demonstrated for the first time using a single semiconductor quantum dot embedded in a light emitting diode structure. The entanglement fidelity is shown to be of sufficient quality for applications such as quantum key distribution.

Stevenson, R. M.; Shields, A. J. [Toshiba Research Europe Limited, 208 Cambridge Science Park, Cambridge CB4 0GZ (United Kingdom); Salter, C. L. [Toshiba Research Europe Limited, 208 Cambridge Science Park, Cambridge CB4 0GZ (United Kingdom); Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Farrer, I.; Nicoll, C. A.; Ritchie, D. A. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

2011-12-23T23:59:59.000Z

104

Considering LEDs for Street and Area Lighting  

Broader source: Energy.gov [DOE]

View Jim Brodrick's keynote video from the September 2009 IES Street and Area Lighting Conference in Philadelphia.

105

Demonstration Assessment of Light Emitting Diode (LED) Street Lighting,  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models | Department1 Prepared1217 Release NotesFinal Report | Department of

106

Diffusion injected multi-quantum well light-emitting diode structure  

SciTech Connect (OSTI)

The attention towards light-emitting diode (LED) structures based on nanowires, surface plasmon coupled LEDs, and large-area high-power LEDs has been increasing for their potential in increasing the optical output power and efficiency of LEDs. In this work we demonstrate an alternative way to inject charge carriers into the active region of an LED, which is based on completely different current transport mechanism compared to conventional current injection approaches. The demonstrated structure is expected to help overcoming some of the challenges related to current injection with conventional structures. A functioning III-nitride diffusion injected light-emitting diode structure, in which the light-emitting active region is located outside the pn-junction, is realized and characterized. In this device design, the charge carriers are injected into the active region by bipolar diffusion, which could also be utilized to excite otherwise challenging to realize light-emitting structures.

Riuttanen, L., E-mail: lauri.riuttanen@aalto.fi; Nykänen, H.; Svensk, O.; Suihkonen, S.; Sopanen, M. [Department of Micro- and Nanosciences, Aalto University, P.O. Box 13500, FI-00076 Aalto (Finland); Kivisaari, P.; Oksanen, J.; Tulkki, J. [Department of Biomedical Engineering and Computational Science, Aalto University, P.O. Box 12200, FI-00076 Aalto (Finland)

2014-02-24T23:59:59.000Z

107

LED Lighting Facts | Department of Energy  

Energy Savers [EERE]

results according to industry standards. For lighting buyers, designers, and energy efficiency programs, the program provides information essential to evaluating SSL products....

108

Have You Used LED Light Strings? | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

read about LED holiday light strings, which can use 90% less energy than regular incandescent light strings. You may even be able to save on the initial costs with rebates from...

109

White Light Emitting Diode Development for General Illumination Applications  

SciTech Connect (OSTI)

This report contains a summary of technical achievements during a 3-year project aimed at developing the chip and packaging technology necessary to demonstrate efficient, high flux light-emitting diode (LED) arrays using Cree's gallium nitride/silicon carbide (GaN/SiC) LED technology as the starting point. Novel chip designs and fabrication processes are described that led to high power blue LEDs that achieved 310 mW of light output at 350 mA drive current, corresponding to quantum and wall plug efficiencies of 32.5% and 26.5%, respectively. When combined with phosphor, high power white LEDs with luminous output of 67 lumens and efficacy of 57 lumens per watt were also demonstrated. Advances in packaging technology are described that enabled compact, multi-chip white LED lamp modules with 800-1000 lumens output at efficacies of up to 55 lumens per watt. Lamp modules with junction-to-ambient thermal resistance as low as 1.7 C/watt have also been demonstrated.

James Ibbetson

2006-05-01T23:59:59.000Z

110

Mid-ultraviolet light-emitting diode detects dipicolinic acid.  

SciTech Connect (OSTI)

Dipicolinic acid (DPA, 2,6-pyridinedicarboxylic acid) is a substance uniquely present in bacterial spores such as that from anthrax (B. anthracis). It is known that DPA can be detected by the long-lived fluorescence of its terbium chelate; the best limit of detection (LOD) reported thus far using a large benchtop gated fluorescence instrument using a pulsed Xe lamp is 2 nM. We use a novel AlGaN light-emitting diode (LED) fabricated on a sapphire substrate that has peak emission at 291 nm. Although the overlap of the emission band of this LED with the absorption band of Tb-DPA ({lambda}{sub max} doublet: 273, 279 nm) is not ideal, we demonstrate that a compact detector based on this LED and an off-the-shelf gated photodetection module can provide an LOD of 0.4 nM, thus providing a basis for convenient early warning detectors.

Bogart, Katherine Huderle Andersen; Lee, Stephen Roger; Temkin, Henryk (Texas Tech University, Lubbock, TX); Crawford, Mary Hagerott; Dasgupta, Purnendu K. (Texas Tech University, Lubbock, TX); Li, Qingyang (Texas Tech University, Lubbock, TX); Allerman, Andrew Alan; Fischer, Arthur Joseph

2005-06-01T23:59:59.000Z

111

Numerical Modelling of Light Emission and Propagation in (Organic) LEDs with the Green's Tensor  

E-Print Network [OSTI]

light emitting diodes, light emission, light extraction, dipole radiation, stratified media, layered surpasses incandescent sources by a factor of 2 and with further improvements light emitting diodes could on light extraction techniques from inorganic light emitting diodes we recommend chapter 5 in 1 . Organic

Floreano, Dario

112

Power Quality Improvements in Lighting Systems Mr. Ashish Shrivastava  

E-Print Network [OSTI]

from early incandescent lamps to present generation light emitting diodes (LEDs). Incandescent light

Kumar, M. Jagadesh

113

LED Lighting Facts | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10 DOEWashington, DCKickoffLDV HVAC ModelLED Lightbulbs

114

LED Lighting Forecast | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10 DOEWashington, DCKickoffLDV HVAC ModelLED

115

LED lamp  

DOE Patents [OSTI]

There is herein described a lamp for providing white light comprising a plurality of light sources positioned on a substrate. Each of said light sources comprises a blue light emitting diode (LED) and a dome that substantially covers said LED. A first portion of said blue light from said LEDs is transmitted through said domes and a second portion of said blue light is converted into a red light by a first phosphor contained in said domes. A cover is disposed over all of said light sources that transmits at least a portion of said red and blue light emitted by said light sources. The cover contains a second phosphor that emits a yellow light in response to said blue light. The red, blue and yellow light combining to form the white light and the white light having a color rendering index (CRI) of at least about 80.

Galvez, Miguel; Grossman, Kenneth; Betts, David

2013-11-12T23:59:59.000Z

116

Testimonials - Partnerships in LED Lighting - Philips Lumileds...  

Broader source: Energy.gov (indexed) [DOE]

lighting systems, followed by a computer screen with data, followed by a man wearing a blue lab coat and face mask is entering data in a computer in a laboratory. DOE has helped...

117

High Efficiency LED Lamp for Solid-State Lighting  

SciTech Connect (OSTI)

This report contains a summary of technical achievements during a three-year project to demonstrate high efficiency, solid-state lamps based on gallium nitride/silicon carbide light-emitting diodes. Novel chip designs and fabrication processes are described for a new type of nitride light-emitting diode with the potential for very high efficiency. This work resulted in the demonstration of blue light-emitting diodes in the one watt class that achieved up to 495 mW of light output at 350 mA drive current, corresponding to quantum and wall plug efficiencies of 51% and 45%, respectively. When combined with a phosphor in Cree's 7090 XLamp package, these advanced blue-emitting devices resulted in white light-emitting diodes whose efficacy exceeded 85 lumens per watt. In addition, up to 1040 lumens at greater than 85 lumens per watt was achieved by combining multiple devices to make a compact white lamp module with high optical efficiency.

James Ibbetson

2006-12-31T23:59:59.000Z

118

Light-emitting diode spherical packages: an equation for the light transmission efficiency  

E-Print Network [OSTI]

Virtually all light-emitting diodes (LEDs) are encapsulated with a transparent epoxy or silicone-gel. In this paper we analyze the optical efficiency of spherical encapsulants. We develop a quasi-radiometric equation for the light transmission efficiency, which incorporates some ideas of Monte-Carlo ray tracing into the context of radiometry. The approach includes the extended source nature of the LED chip, and the chip radiance distribution. The equation is an explicit function of the size and the refractive index of the package, and also of several chip parameters such as shape, size, radiance, and location inside the package. To illustrate the use of this equation, we analyze several packaging configurations of practical interest; for example, a hemispherical dome with multiple chips, a flat encapsulation as a special case of the spherical package, and approximate calculations of an encapsulant with a photonic crystal LED or with a photonic quasi crystal LED. These calculations are compared with Monte-Carl...

Moreno, Ivan; Avendano-Alejo, Maximino; 10.1364/AO.49.000012

2011-01-01T23:59:59.000Z

119

White emitting polyfluorene functionalized with azide hybridized on near-UV light emitting diode  

E-Print Network [OSTI]

White emitting polyfluorene functionalized with azide hybridized on near-UV light emitting diode@fen.bilkent.edu.tr Abstract: We develop and demonstrate high-quality white light generation that relies on the use of a single-UV LED platform. The high-quality white emission from the polyfluorene is achieved by using the azide

Demir, Hilmi Volkan

120

Enhanced coupling of light from organic light emitting diodes using nanoporous films  

E-Print Network [OSTI]

Enhanced coupling of light from organic light emitting diodes using nanoporous films H. J. Peng, Y the light extraction efficiency for organic light emitting diode OLED . Nanoporous alumina film was used by Bragg scattering. The corrugated light- emitting diode had two-times the efficiency as compared

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Matrix-addressable III-nitride light emitting diode arrays on silicon substrates by flip-chip technology.  

E-Print Network [OSTI]

??Matrix-addressable light emitting diode (LED) micro-arrays on sapphire substrates have been reported. In the fabrication process, complicated chemical-mechanical polishing after planarization with oxides, or conformal… (more)

Keung, Chi Wing

2007-01-01T23:59:59.000Z

122

Improved Cognitive Function After Transcranial, Light-Emitting Diode Treatments in Chronic, Traumatic Brain Injury: Two Case Reports  

E-Print Network [OSTI]

Objective: Two chronic, traumatic brain injury (TBI) cases, where cognition improved following treatment with red and near-infrared light-emitting diodes (LEDs), applied transcranially to forehead and scalp areas, are ...

Naeser, Margaret A.

123

LED Lighting Basics | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in3.pdfEnergy Health andofIanJennifer SomersKnown Challenges AssociatedLANLLED Lighting

124

Photoionization of optically trapped ultracold atoms with a high-power light-emitting diode  

SciTech Connect (OSTI)

Photoionization of laser-cooled atoms using short pulses of a high-power light-emitting diode (LED) is demonstrated. Light pulses as short as 30 ns have been realized with the simple LED driver circuit. We measure the ionization cross section of {sup 85}Rb atoms in the first excited state, and show how this technique can be used for calibrating efficiencies of ion detector assemblies.

Goetz, Simone; Hoeltkemeier, Bastian; Amthor, Thomas; Weidemueller, Matthias [Physikalisches Institut, Universitaet Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg (Germany)

2013-04-15T23:59:59.000Z

125

Light extraction analysis and enhancement in a quantum dot light emitting diode  

E-Print Network [OSTI]

Light extraction analysis and enhancement in a quantum dot light emitting diode Ruidong Zhu outcoupling and angular performance of quantum dot light emitting diode (QLED). To illustrate the design principles, we use a red QLED as an example and compare its performance with an organic light emitting diode

Wu, Shin-Tson

126

TRICOLOR LIGHT EMITTING DIODE DOT MATRIX DISPLAY SYSTEM WITHAUDIO OUTPUT  

E-Print Network [OSTI]

1 TRICOLOR LIGHT EMITTING DIODE DOT MATRIX DISPLAY SYSTEM WITHAUDIO OUTPUT Grantham Pang, Chi emitting diodes; tricolor display; audio communication. I. Introduction This paper relates to a tricolor broadcasting through the visible light rays transmitted by the display panel or assembly. Keywords: light

Pang, Grantham

127

LED Traffic Lights Get Buy American Stamp | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Traffic Lights Get Buy American Stamp November 30, 2010 - 10:19am Addthis Red. Yellow. Green. What LED traffic signals don't say: Made in USA. That is changing. Dialight...

128

WEBINAR: LED LIGHTING IN A PERFORMING ARTS BUILDING  

Broader source: Energy.gov [DOE]

Can LEDs render skin tones and makeup accurately in a dressing room? Can they provide the vertical footcandles in a studio to make dancers' bodies visible, or deliver acting studio lighting to...

129

Organic-Inorganic Hetero Junction White Light Emitting Diode.  

E-Print Network [OSTI]

?? The purpose of this thesis work is to design and fabricates organic-inorganic hetero junction White Light Emitting Diode (WLED). In this WLED, inorganic material… (more)

Lubuna Beegum, Shafeek

2008-01-01T23:59:59.000Z

130

City of Phildelphia: Light emitting diodes for traffic signal displays  

SciTech Connect (OSTI)

This project investigated the feasibility of using light emitting diodes (LEDs) for red traffic signals in a demonstration program at 27 signalized intersections in the City of Philadelphia. LED traffic signals have the potential to achieve significant savings over standard incandescent signals in terms of energy usage and costs, signal relamping costs, signal system maintenance costs, tort liability, and environmental impact. Based on successful experience with the demonstration program, the City of Philadelphia is currently developing funding for the conversion of all existing red incandescent traffic signals at approximately 2,700 intersections to LED signals. This program is expected to cost approximately $4.0 million and save about $850,000 annually in energy costs. During late 1993 and early 1994, 212 red LED traffic signals (134 8-inch signals and 78 12-inch signals) were installed at 27 intersections in Philadelphia. The first group of 93 signals were installed at 13 prototypical intersections throughout the City. The remaining group of signals were installed on a contiguous route in West Philadelphia consisting of standard incandescent signals and LED signals interspersed in a random pattern.

NONE

1995-12-01T23:59:59.000Z

131

Optimized Phosphors for Warm White LED Light Engines  

SciTech Connect (OSTI)

The objective of this program is to develop phosphor systems and LED light engines that have steady-state LED efficacies (using LEDs with a 60% wall-plug efficiency) of 105–120 lm/W with correlated color temperatures (CCT) ~3000 K, color rendering indices (CRI) >85, <0.003 distance from the blackbody curve (dbb), and <2% loss in phosphor efficiency under high temperature, high humidity conditions. In order to reach these goals, this involves the composition and processing optimization of phosphors previously developed by GE in combination with light engine package modification.

Setlur, Anant; Brewster, Megan; Garcia, Florencio; Hill, M. Christine; Lyons, Robert; Murphy, James; Stecher, Tom; Stoklosa, Stan; Weaver, Stan; Happek, Uwe; Aesram, Danny; Deshpande, Anirudha

2012-07-30T23:59:59.000Z

132

Optical manifold for light-emitting diodes  

DOE Patents [OSTI]

An optical manifold for efficiently combining a plurality of blue LED outputs to illuminate a phosphor for a single, substantially homogeneous output, in a small, cost-effective package. Embodiments are disclosed that use a single or multiple LEDs and a remote phosphor, and an intermediate wavelength-selective filter arranged so that backscattered photoluminescence is recycled to boost the luminance and flux of the output aperture. A further aperture mask is used to boost phosphor luminance with only modest loss of luminosity. Alternative non-recycling embodiments provide blue and yellow light in collimated beams, either separately or combined into white.

Chaves, Julio C.; Falicoff, Waqidi; Minano, Juan C.; Benitez, Pablo; Parkyn Jr., William A.; Alvarez, Roberto; Dross, Oliver

2008-06-03T23:59:59.000Z

133

Advanced method for increasing the efficiency of white light quantum dot LEDs  

SciTech Connect (OSTI)

Covering a light-emitting diode (LED) with quantum dots (QDs) can produce a broad spectrum of white light. However, current techniques for applying QDs to LEDs suffer from a high density of defects and a non-uniform distribution of QDs, which, respectively, diminish the efficiency and quality of emitted light. Oak Ridge National Laboratory (ORNL) has the unique capability to thermally anneal QD structures at extremely high power densities for very short durations. This process, called pulse thermal processing (PTP), reduces the number of point defects while maintaining the size and shape of the original QD nanostructure. Therefore, the efficiency of the QD wavelength conversion layer is improved without altering the emission spectrum defined by the size distribution of theQD nanoparticles. The current research uses a thermal model to predict annealing temperatures during PTP and demonstrates up to a 300% increase in photoluminescence for QDs on passive substrates.

Duty, Chad E [ORNL; Bennett, Charlee J C [ORNL; Sabau, Adrian S [ORNL; Jellison Jr, Gerald Earle [ORNL; Boudreaux, Philip R [ORNL; Walker, Steven C [ORNL; Ott, Ronald D [ORNL

2011-01-01T23:59:59.000Z

134

An Integrated Solid-State LED Luminaire for General Lighting  

SciTech Connect (OSTI)

A strong systems approach to designing and building practical LED-based replacement lamps is lacking. The general method of taking high-performance LEDs and marrying them to standard printed circuit boards, drivers and a heat sink has fallen short of the promise of LED lighting. In this program, a top-down assessment of requirements and a bottom-up reinvention of LED sources, electronics, optics and mechanics have resulted in the highest performance lamp possible. The team, comprised of Color Kinetics, the leaders in LED lighting and Cree, the leaders in LED devices took an approach to reinvent the package, the driver and the overall form and aesthetic of a replacement source. The challenge was to create a new benchmark in LED lighting - the resultant lamp, a PAR38 equivalent, met the light output, color, color quality and efficacy marks set out in the program as well as being dimmable, which is important for market acceptance. The approach combined the use of multiple source die, a chip-on-board approach, a very efficient driver topology, the use of both direct emission and phosphor conversion, and a unique faceted optic to avoid the losses, artifacts and hotspots of lensed approaches. The integral heat sink provided a mechanical base and airflow using a chimney-effect for use in a wide variety of locations and orientations. These research results led to a much better understanding of the system effects of component level technologies. It was clear that best-of-breed sub-system results do not necessarily result in the best end result for the complete system. In doing this work, we did not neglect the practical aspects of these systems. These were not rarified results and commercially impractical but lent themselves to eventual commercial products in the marketplace. The end result - a high performance replacement lamp - will save significant energy while providing a high-quality light source.

Kevin Dowling; Fritz Morgan Ihor Lys; Mike Datta; Bernd Keller; Thomas Yuan

2009-03-31T23:59:59.000Z

135

White organic light-emitting diodes: Status and perspective  

E-Print Network [OSTI]

White organic light-emitting diodes (OLEDs) are ultrathin, large-area light sources made from organic semiconductor materials. Over the past decades, much research has been spent on finding suitable materials to realize ...

Reineke, Sebastian

136

Department of Mechanical Engineering Spring 2013 Lumax Lighting 2: LED Industrial High Bay Light Fixture  

E-Print Network [OSTI]

PENNSTATE Department of Mechanical Engineering Spring 2013 Lumax Lighting 2: LED Industrial High Bay Light Fixture Overview The problem that our sponsor, Rich Taylor, presented to the team was to design a light fixture for an industrial setting using high power LED lights. The challenge

Demirel, Melik C.

137

Arnold Schwarzenegger LIGHTING RESEARCH PROGRAM  

E-Print Network [OSTI]

Project Summaries ELEMENT 2: ADVANCE LIGHTING TECHNOLOGIES PROJECT 2.1 LIGHT EMITTING DIODE (LED light emitting diodes (LED) technology for general lighting applications by developing a task lamp

138

Amber light-emitting diode comprising a group III-nitride nanowire active region  

DOE Patents [OSTI]

A temperature stable (color and efficiency) III-nitride based amber (585 nm) light-emitting diode is based on a novel hybrid nanowire-planar structure. The arrays of GaN nanowires enable radial InGaN/GaN quantum well LED structures with high indium content and high material quality. The high efficiency and temperature stable direct yellow and red phosphor-free emitters enable high efficiency white LEDs based on the RGYB color-mixing approach.

Wang, George T.; Li, Qiming; Wierer, Jr., Jonathan J.; Koleske, Daniel

2014-07-22T23:59:59.000Z

139

Metameric Modulation for Diffuse Visible Light Communications with Constant Ambient Lighting  

E-Print Network [OSTI]

untapped for wireless communications. Advancements in light emitting diode (LED) technology are making

Little, Thomas

140

High power light emitting diode based setup for photobleaching fluorescent impurities  

E-Print Network [OSTI]

High power light emitting diode based setup for photobleaching fluorescent impurities Tobias K be photobleached before final sample preparation. The instrument consists of high power light emitting diodes

Kaufman, Laura

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Enhancement in light emission and electrical efficiencies of a silicon nanocrystal light-emitting diode by indium tin oxide nanowires  

SciTech Connect (OSTI)

We report an enhancement in light emission and electrical efficiencies of a Si nanocrystal (NC) light-emitting diode (LED) by employing indium tin oxide (ITO) nanowires (NWs). The formed ITO NWs (diameter?LED were significantly improved, which was attributed to an enhancement in the current spreading property due to densely interconnecting ITO NWs. In addition, light output power and wall-plug efficiency from the Si NC LED were enhanced by 45% and 38%, respectively. This was originated from an enhancement in the escape probability of the photons generated in the Si NCs due to multiple scatterings at the surface of ITO NWs acting as a light waveguide. We show here that the use of the ITO NWs can be very useful for realizing a highly efficient Si NC LED.

Huh, Chul, E-mail: chuh@etri.re.kr; Kim, Bong Kyu; Ahn, Chang-Geun; Kim, Sang-Hyeob [IT Convergence Technology Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 305-350 (Korea, Republic of); Choi, Chel-Jong [Department of BIN Fusion Technology, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

2014-07-21T23:59:59.000Z

142

Proposal -Interactive City Lighting LED based lighting systems have enabled radically new  

E-Print Network [OSTI]

Proposal - Interactive City Lighting Abstract LED based lighting systems have also be integrated with sensors and smart environments. This has opened up a new world. The use of the LED as a potential means for providing interactive city lighting for social

143

Development of Advanced LED Phosphors by Spray-based Processes for Solid State Lighting  

SciTech Connect (OSTI)

The overarching goal of the project was to develop luminescent materials using aerosol processes for making improved LED devices for solid state lighting. In essence this means improving white light emitting phosphor based LEDs by improvement of the phosphor and phosphor layer. The structure of these types of light sources, displayed in Figure 1, comprises of a blue or UV LED under a phosphor layer that converts the blue or UV light to a broad visible (white) light. Traditionally, this is done with a blue emitting diode combined with a blue absorbing, broadly yellow emitting phosphor such as Y{sub 3}Al{sub 5}O{sub 12}:Ce (YAG). A similar result may be achieved by combining a UV emitting diode and at least three different UV absorbing phosphors: red, green, and blue emitting. These emitted colors mix to make white light. The efficiency of these LEDs is based on the combined efficiency of the LED, phosphor, and the interaction between the two. The Cabot SSL project attempted to improve the over all efficiency of the LED light source be improving the efficiency of the phosphor and the interaction between the LED light and the phosphor. Cabot's spray based process for producing phosphor powders is able to improve the brightness of the powder itself by increasing the activator (the species that emits the light) concentration without adverse quenching effects compared to conventional synthesis. This will allow less phosphor powder to be used, and will decrease the cost of the light source; thus lowering the barrier of entry to the lighting market. Cabot's process also allows for chemical flexibility of the phosphor particles, which may result in tunable emission spectra and so light sources with improved color rendering. Another benefit of Cabot's process is the resulting spherical morphology of the particles. Less light scattering results when spherical particles are used in the phosphor layer (Figure 1) compared to when conventional, irregular shaped phosphor particles are used. This spherical morphology will result in better light extraction and so an improvement of efficiency in the overall device. Cabot is a 2.5 billion dollar company that makes specialized materials using propriety spray based technologies. It is a core competency of Cabot's to exploit the spray based technology and resulting material/morphology advantages. Once a business opportunity is clearly identified, Cabot is positioned to increase the scale of the production to meet opportunity's need. Cabot has demonstrated the capability to make spherical morphology micron-sized phosphor powders by spray based routes for PDP and CRT applications, but the value proposition is still unproven for LED applications. Cabot believes that the improvements in phosphor powders yielded by their process will result in a commercial advantage over existing technologies. Through the SSL project, Cabot has produced a number of different compositions in a spherical morphology that may be useful for solid state lights, as well as demonstrated processes that are able to produce particles from 10 nanometers to 3 micrometers. Towards the end of the project we demonstrated that our process produces YAG:Ce powder that has both higher internal quantum efficiency (0.6 compared to 0.45) and external quantum efficiency (0.85 compared to 0.6) than the commercial standard (see section 3.4.4.3). We, however, only produced these highly bright materials in research and development quantities, and were never able to produce high quantum efficiency materials in a reproducible manner at a commercial scale.

Cabot Corporation

2007-09-30T23:59:59.000Z

144

LIGHT EMITTING DIODE (LED) TRAFFIC SIGNAL SURVEY RESULTS  

E-Print Network [OSTI]

Bernardino County Roseville Sebastopol West Covina San Diego County Ross Shasta Lake West Hollywood San

145

Demonstration Assessment of Light-Emitting Diode (LED) Freezer Case  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in Review: TopEnergy DOEDealing With the Issues of NuclearHighStatement| Department

146

An Brief Overview Of Using LEDs In Lab  

E-Print Network [OSTI]

Diodes · A Light-Emitting Diode (LED) is a special type of diode that emits photons (light) when current ­ Forward biased Diode Operation 0 V 5 V Current ~0 high (too high)5 V 0 V I anode cathode #12;3 Light-Emitting

Baas, Bevan

147

Light emitting diode package element with internal meniscus for bubble free lens placement  

DOE Patents [OSTI]

A method for fabricating a light emitting diode (LED) package comprising providing an LED chip and covering at least part of the LED chip with a liquid encapsulant having a radius of curvature. An optical element is provided having a bottom surface with at least a portion having a radius of curvature larger than the liquid encapsulant. The larger radius of curvature portion of the optical element is brought into contact with the liquid encapsulant. The optical element is then moved closer to the LED chip, growing the contact area between said optical element and said liquid encapsulant. The liquid encapsulant is then cured. A light emitting diode comprising a substrate with an LED chip mounted to it. A meniscus ring is on the substrate around the LED chip with the meniscus ring having a meniscus holding feature. An inner encapsulant is provided over the LED chip with the inner encapsulant having a contacting surface on the substrate, with the meniscus holding feature which defines the edge of the contacting surface. An optical element is included having a bottom surface with at least a portion that is concave. The optical element is arranged on the substrate with the concave portion over the LED chip. A contacting encapsulant is included between the inner encapsulant and optical element.

Tarsa, Eric; Yuan, Thomas C.; Becerra, Maryanne; Yadev, Praveen

2010-09-28T23:59:59.000Z

148

LED Update  

SciTech Connect (OSTI)

This article, which will appear in RESIDENTIAL LIGHTING MAGAZINE, interviews PNNL's Kelly Gordon and presents the interview in question and answer format. The topic is a light emitting diode (LED) lighting also known as solid state lighting. Solid state lighting will be a new category in an energy efficient lighting fixture design competition called Lighting for Tomorrow sponsored by the US Department of Energy Emerging Technologies Office, the American Institute for Lighting, and the Consortium for Energy Efficiency. LED technology has been around since the ’60s, but it has been used mostly for indicator lights on electronics equipment. The big breakthrough was the development in the 1990s of blue LEDs which can be combined with the red and green LEDs that already existed to make white light. LEDs produce 25 to 40 lumens of light per watt of energy used, almost as much as a CFL (50 lumens per watt) and much more efficient than incandescent sources, which are around 15 lumens per watt. They are much longer lived and practical in harsh environments unsuitable for incandescent lighting. They are ready for niche applications now, like under-counter lighting and may be practical for additional applications as technological challenges are worked out and the technology is advancing in leaps and bounds.

Johnson, Mark L.; Gordon, Kelly L.

2006-09-01T23:59:59.000Z

149

Investigation on Operating Characteristics of RGB LEDs.  

E-Print Network [OSTI]

??This thesis seeks to gain a better understanding on operating characteristics of the three primary color light emitting diode (LED). By applying direct, pulse and… (more)

Liao, Chi-nan

2007-01-01T23:59:59.000Z

150

Power control architectures for cold cathode fluorescent lamp and light emitting diode based light sources.  

E-Print Network [OSTI]

?? In this dissertation, two different energy efficient power supply topologies are introduced for controlling cold cathode fluorescent lamp (CCFL) and high-brightness light emitting diode… (more)

Doshi, Montu V.

2010-01-01T23:59:59.000Z

151

E-Print Network 3.0 - af led lyskilder Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Birgitte Thestrup... Roskilde, Denmark Abstract Research and development within Light Emitting Diode or LED Source: Ris National Laboratory Collection: Multidisciplinary...

152

Apply: Solid-State Lighting Advanced Technology R&D - 2014(DE...  

Energy Savers [EERE]

Through research and development of solid-state lighting (SSL),including both light-emitting diode (LED) and organic light emitting diode (OLED) technologies, the objectives of...

153

LED Surgical Task Lighting Scoping Study: A Hospital Energy Alliance Project  

SciTech Connect (OSTI)

Tungsten-halogen (halogen) lamps have traditionally been used to light surgical tasks in hospitals, even though they are in many respects ill-suited to the application due to the large percentage of radiant energy outside the visible spectrum and issues with color rendering/quality. Light-emitting diode (LED) technology offers potential for adjustable color and improved color rendition/quality, while simultaneously reducing side-effects from non-visible radiant energy. It also has the potential for significant energy savings, although this is a fairly narrow application in the larger commercial building energy use sector. Based on analysis of available products and Hospital Energy Alliance member interest, it is recommended that a product specification and field measurement procedure be developed for implementation in demonstration projects.

Tuenge, Jason R.

2011-01-17T23:59:59.000Z

154

TESLA-FEL 2007-03 Application of low cost GaAs LED as neutron  

E-Print Network [OSTI]

neutrons in unbiased Gallium Arsenide (GaAs) Light Emitting Diodes (LED) resulted in a reduction Keywords: COTS components, Displacement damage, Electron Linear Accelerator, GaAs Light emitting diode (LED) Gallium Arsenide (GaAs) light emitting diode (LED) for the assessment of integrated neutron fluence

155

Tunnel junction multiple wavelength light-emitting diodes  

DOE Patents [OSTI]

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect. 5 figs.

Olson, J.M.; Kurtz, S.R.

1992-11-24T23:59:59.000Z

156

Tunnel junction multiple wavelength light-emitting diodes  

DOE Patents [OSTI]

A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.

Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

1992-01-01T23:59:59.000Z

157

Thermal And Mechanical Analysis of High-power Light-emitting Diodes with Ceramic Packages  

E-Print Network [OSTI]

In this paper we present the thermal and mechanical analysis of high-power light-emitting diodes (LEDs) with ceramic packages. Transient thermal measurements and thermo-mechanical simulation were performed to study the thermal and mechanical characteristics of ceramic packages. Thermal resistance from the junction to the ambient was decreased from 76.1 oC/W to 45.3 oC/W by replacing plastic mould to ceramic mould for LED packages. Higher level of thermo-mechanical stresses in the chip were found for LEDs with ceramic packages despite of less mismatching coefficients of thermal expansion comparing with plastic packages. The results suggest that the thermal performance of LEDs can be improved by using ceramic packages, but the mounting process of the high power LEDs with ceramic packages is critically important and should be in charge of delaminating interface layers in the packages.

J. Hu; L. Yang; M. -W. Shin

2008-01-07T23:59:59.000Z

158

LED Site Lighting in the Commercial Building Sector: Opportunities, Challenges, and the CBEA Performance Specification  

Broader source: Energy.gov [DOE]

This March 26, 2009 webcast presented information about the Commercial Building Energy Alliances' (CBEA) efforts to explore the viability of LED site lighting in commercial parking lots. LED...

159

Revolutionary Method for Increasing the Efficiency of White Light Quantum Dot LEDs  

SciTech Connect (OSTI)

Covering a light-emitting diode (LED) with quantum dots (QDs) can produce a broad spectrum of white light. However, current techniques for applying QDs to LEDs suffer from a high density of defects and a non-uniform distribution of QDs, which respec-tively diminish the efficiency and quality of emitted light. Oak Ridge National Laboratory (ORNL) has the unique capability to thermally anneal QD structures at extremely high power densities for very short durations. This process, called pulse thermal proc-essing (PTP), reduces the number of point defects while main-taining the size and shape of the original QD nanostructure. Therefore, the efficiency of the QD wavelength conversion layer is improved without altering the emission spectrum defined by the size distribution of the quantum dot nanoparticles. The cur-rent research uses a thermal model to predict annealing tempera-tures during PTP and demonstrates up to a 300% increase in pho-toluminescence for QDs on passive substrates

Duty, Chad E [ORNL; Bennett, Charlee J C [ORNL; Sabau, Adrian S [ORNL; Jellison Jr, Gerald Earle [ORNL; Boudreaux, Philip R [ORNL; Walker, Steven C [ORNL; Ott, Ronald D [ORNL

2011-01-01T23:59:59.000Z

160

Sliding Mode Pulsed Averaging IC Drivers for High Brightness Light Emitting Diodes  

SciTech Connect (OSTI)

This project developed new Light Emitting Diode (LED) driver ICs associated with specific (uniquely operated) switching power supplies that optimize performance for High Brightness LEDs (HB-LEDs). The drivers utilize a digital control core with a newly developed nonlinear, hysteretic/sliding mode controller with mixed-signal processing. The drivers are flexible enough to allow both traditional microprocessor interface as well as other options such as “on the fly” adjustment of color and brightness. Some other unique features of the newly developed drivers include • AC Power Factor Correction; • High power efficiency; • Substantially fewer external components should be required, leading to substantial reduction of Bill of Materials (BOM). Thus, the LED drivers developed in this research : optimize LED performance by increasing power efficiency and power factor. Perhaps more remarkably, the LED drivers provide this improved performance at substantially reduced costs compared to the present LED power electronic driver circuits. Since one of the barriers to market penetration for HB-LEDs (in particular “white” light LEDs) is cost/lumen, this research makes important contributions in helping the advancement of SSL consumer acceptance and usage.

Dr. Anatoly Shteynberg, PhD

2006-08-17T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Commercialization of Quantum Dot White Light Emitting Diode technology  

E-Print Network [OSTI]

It is well known that the use of high-brightness LEDs for illumination has the potential to substitute conventional lighting and revolutionize the lighting industry over the next 10 to 20 years. However, successful penetration ...

Zhao, Xinyue, M. Eng. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

162

Vision Research 41 (2001) 427439 Characterization and use of a digital light projector for vision  

E-Print Network [OSTI]

. For example, a light emitting diode (LED)-based stimulator has many ideal characteristics. LEDs have high

Brainard, David H.

163

Internal efficiency of InGaN light-emitting diodes: Beyond a quasiequilibrium model  

SciTech Connect (OSTI)

We propose a model to better investigate InGaN light-emitting diode (LED) internal efficiency by extending beyond the usual total carrier density rate equation approach. To illustrate its capability, the model is applied to study intrinsic performance differences between violet and green LEDs. The simulations show performance differences, at different current densities and temperatures, arising from variations in spontaneous emission and heat loss rates. By tracking the momentum-resolved carrier populations, these rate changes are, in turn, traced to differences in bandstructure and plasma heating. The latter leads to carrier distributions that deviate from the quasiequilibrium ones at lattice temperature.

Chow, Weng W.; Crawford, Mary H.; Tsao, Jeffrey Y.; Kneissl, Michael

2010-01-01T23:59:59.000Z

164

Nanocrystalline Silicon Quantum Dot Light Emitting Diodes Using Metal Oxide Charge Transport Layers.  

E-Print Network [OSTI]

??Silicon-based lighting show promise for display and solid state lighting use. Here we demonstrate a novel thin film light emitting diode device using nanocrystalline silicon… (more)

Zhu, Jiayuan

2013-01-01T23:59:59.000Z

165

Designing Interactive Lighting Dzmitry Aliakseyeu, Bernt Meerbeek, Jon  

E-Print Network [OSTI]

The Light Emitting Diode (LED) has caused a profound change within the lighting industry. This is due

166

Point defect engineered Si sub-bandgap light-emitting diode  

E-Print Network [OSTI]

Point defect engineered Si sub-bandgap light-emitting diode Jiming Bao1 , Malek Tabbal1,2 , Taegon light emission in Si and demonstrate a sub-bandgap light emitting diode based on the introduction OCIS codes: (230.3670) Light-emitting diodes; (160.6000) Semiconductors; (130-0250) Optoelectronics

Bao, Jiming

167

Interplay between multiple scattering, emission, and absorption of light in the phosphor of a white light-emitting diode  

E-Print Network [OSTI]

We study light transport in phosphor plates of white light-emitting diodes (LEDs). We measure the broadband diffuse transmission through phosphor plates of varying YAG:Ce$^{3+}$ density. We distinguish the spectral ranges where absorption, scattering, and re-emission dominate. Using diffusion theory, we derive the transport and absorption mean free paths from first principles. We find that both transport and absorption mean free paths are on the order of the plate thickness. This means that phosphors in commercial LEDs operate well within an intriguing albedo range around 0.7. We discuss how salient parameters that can be derived from first principles control the optical properties of a white LED.

Leung, V Y F; Tukker, T W; Mosk, A P; IJzerman, W L; Vos, W L

2013-01-01T23:59:59.000Z

168

Amorphous silicon as electron transport layer for colloidal semiconductor nanocrystals light emitting diode  

SciTech Connect (OSTI)

We demonstrate the fabrication of light-emitting diodes (LEDs) made from all-inorganic colloidal semiconducting nanocrystals (NCs). The diode utilizes a sandwich structure formed by placing CdSe/CdS NCs between two layers of Si and Ag{sub x}O, which act as electron- and hole-transporting materials, respectively. The photoluminescence properties of NCs are rendered less dependent upon surface chemistry and chemical environment by growing a thick CdS shell. It also enhances stability of the NCs during the process of magnetron sputtering for silicon deposition. The resulting LED device exhibits a low turn-on voltage of 2.5 V and the maximum external quantum efficiency of nearly 0.08%.

Song Tao; Shen Xiaojuan; Sun Baoquan [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Functional Nano and Soft Materials Laboratory (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou 215123 (China); Zhang Fute [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Functional Nano and Soft Materials Laboratory (FUNSOM), Soochow University, 199 Ren'ai Road, Suzhou 215123 (China); Key Laboratory of Organic Synthesis of Jiangsu Province, School of Chemistry and Chemical Engineering, Soochow University, Suzhou 215123 (China); Zhang Xiaohong [Nano-Organic Photoelectronic Laboratory and Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Zhu Xiulin [Key Laboratory of Organic Synthesis of Jiangsu Province, School of Chemistry and Chemical Engineering, Soochow University, Suzhou 215123 (China)

2009-12-07T23:59:59.000Z

169

A spin light emitting diode incorporating ability of electrical helicity switching  

SciTech Connect (OSTI)

Fabrication and optical characteristics of a spin light-emitting-diode (spin-LED) having dual spin-injection electrodes with anti-parallel magnetization configuration are reported. Alternating a current between the two electrodes using a computer-driven current source has led us to the observation of helicity switching of circular polarization at the frequency of 1 kHz. Neither external magnetic fields nor optical delay modulators were used. Sending dc-currents to both electrodes with appropriate ratio has resulted in continuous variation of circular polarization between the two opposite helicity, including the null polarization. These results suggest that the tested spin-LED has the feasibility of a monolithic light source whose circular polarization can be switched or continuously tuned all electrically.

Nishizawa, N., E-mail: nishizawa@isl.titech.ac.jp; Nishibayashi, K.; Munekata, H. [Imaging Science and Engineering Laboratory, Tokyo Institute of Technology, 4259-J3-15 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)

2014-03-17T23:59:59.000Z

170

NANOSTRUCTURED HIGH PERFORMANCE ULTRAVIOLET AND BLUE LIGHT EMITTING DIODES FOR SOLID STATE LIGHTING  

SciTech Connect (OSTI)

We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and near ultraviolet for Solid State Lighting applications. Accomplishments in the first 12 month contract period include (1) new means of synthesizing zero- and one-dimensional GaN nanostructures, (2) establishment of the building blocks for making GaN-based microcavity devices, and (3) demonstration of top-down approach to nano-scale photonic devices for enhanced spontaneous emission and light extraction. These include a demonstration of eight-fold enhancement of the external emission efficiency in new InGaN QW photonic crystal structures. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

Arto V. Nurmikko; Jung Han

2004-10-01T23:59:59.000Z

171

Sidewall passivation for InGaN/GaN nanopillar light emitting diodes  

SciTech Connect (OSTI)

We studied the effect of sidewall passivation on InGaN/GaN multiquantum well-based nanopillar light emitting diode (LED) performance. In this research, the effects of varying etch rate, KOH treatment, and sulfur passivation were studied for reducing nanopillar sidewall damage and improving device efficiency. Nanopillars prepared under optimal etching conditions showed higher photoluminescence intensity compared with starting planar epilayers. Furthermore, nanopillar LEDs with and without sulfur passivation were compared through electrical and optical characterization. Suppressed leakage current under reverse bias and four times higher electroluminescence (EL) intensity were observed for passivated nanopillar LEDs compared with unpassivated nanopillar LEDs. The suppressed leakage current and EL intensity enhancement reflect the reduction of non-radiative recombination at the nanopillar sidewalls. In addition, the effect of sulfur passivation was found to be very stable, and further insight into its mechanism was gained through transmission electron microscopy.

Choi, Won Hyuck; Abraham, Michael; Yu, Shih-Ying [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); You, Guanjun; Liu, Jie; Wang, Li; Xu, Jian, E-mail: jianxu@engr.psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Mohney, Suzanne E., E-mail: mohney@ems.psu.edu [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2014-07-07T23:59:59.000Z

172

Injection and transport processes in organic light emitting diodes based on N. Huby a,b  

E-Print Network [OSTI]

1 Injection and transport processes in organic light emitting diodes based on a silole. N. Huby a- conductors in light emitting diodes1 . The different fields of research around the organic electronic allowed

Boyer, Edmond

173

High-Efficiency and Stable White Organic Light-Emitting Diode...  

Broader source: Energy.gov (indexed) [DOE]

Efficiency and Stable White Organic Light-Emitting Diode Using a Single Emitter High-Efficiency and Stable White Organic Light-Emitting Diode Using a Single Emitter Presenter: Jian...

174

Sandia National Laboratories: light-emitting diode  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted for USMaterialsthe Goal ofco-locatinglight-emitting diode Sandian

175

Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes: a promising molecular design  

E-Print Network [OSTI]

Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes Light Emitting Diode (OLED), intermolecular p­p interactions should be usually suppressed to avoid any Emitting Diodes (SMOLEDs) is almost absent from the literature. In this work, three aryl-substituted Di

Boyer, Edmond

176

Note: A portable, light-emitting diode-based ruby fluorescence spectrometer for high-pressure calibration  

SciTech Connect (OSTI)

Ruby (Al{sub 2}O{sub 3}, with {approx}0.5 wt. % Cr doping) is one of the most widely used manometers at the giga-Pascal scale. Traditionally, its fluorescence is excited with intense laser sources. Here, I present a simple, robust, and portable design that employs light-emitting diodes (LEDs) instead. This LED-based system is safer in comparison with laser-based ones.

Feng Yejun [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2011-04-15T23:59:59.000Z

177

Thermoelectrically Pumped Light-Emitting Diodes Operating above Unity Efficiency  

E-Print Network [OSTI]

A heated semiconductor light-emitting diode at low forward bias voltage V

Santhanam, Parthiban

178

P-66: Personal Communication System Hand-set with Organic Light Emitting Diode Display  

E-Print Network [OSTI]

Light Emitting Diodes (OLED) display panel. As a result, OLEDs technology was applied to a display for a

Seungeun Lee; Wonseok Oh; Sungchul Lee; Jongchan Choi

179

THE FABRICATION AND ANALYSIS OF QUANTUM-DOT THIN FILM LIGHT EMITTING DIODES FOR USE IN DISPLAYS TECHNOLOGIES.  

E-Print Network [OSTI]

??The quantum dot has many applications, one of which is the light emitting diode. Quantum dot light emitting diodes were fabricated for their use in… (more)

Pickering, Shawn

2011-01-01T23:59:59.000Z

180

LED Manufacturing Process Modifications Will Boost Quality and  

E-Print Network [OSTI]

2012 The Issue Highly energyefficient LightEmitting Diode (LED) lighting products have made great process that will enable LED manufacturers to produce higher quality, energyefficient products at lower

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Correlation between the Indium Tin Oxide morphology and the performances of polymer light-emitting diodes  

E-Print Network [OSTI]

: This paper reports on performance enhancement of polymer light-emitting diodes (PLEDs) based on poly(2,5-bis. Keywords : Polymer light emitting diode; Indium tin oxide; Atomic force microscopy; Rutherford backscattering spectroscopy 1. Introduction Polymer light-emitting diodes (PLEDs) have received worldwide

Paris-Sud XI, Université de

182

High efficiency light emitting diode with anisotropically etched GaN-sapphire interface  

E-Print Network [OSTI]

High efficiency light emitting diode with anisotropically etched GaN- sapphire interface M. H. Lo and optimization of a light-emitting diode projection micro-stereolithography three-dimensional manufacturingGaN micro-light emitting diodes Appl. Phys. Lett. 101, 231110 (2012) A bright cadmium-free, hybrid organic

183

Enhancement of Barrier Properties Using Ultrathin Hybrid Passivation Layer for Organic Light Emitting Diodes  

E-Print Network [OSTI]

acrylate layer and MS-31 (MgO : SiO2 ¼ 3 : 1 wt %) layer was adopted in organic light emitting diode (OLED the penetrations of oxygen and moisture. [DOI: 10.1143/JJAP.45.5970] KEYWORDS: organic light emitting diode (OLED. Introduction As a next generation display, the organic light emitting diode (OLED) has to great performances

Hwang, Sung Woo

184

Poly(p-phenylene vinylene)/tris(8-hydroxy) quinoline aluminum heterostructure light emitting diode  

E-Print Network [OSTI]

Poly(p-phenylene vinylene)/tris(8-hydroxy) quinoline aluminum heterostructure light emitting diode are presented from polymer/molecular organic heterostructure light emitting diodes composed of a layer,2 organic light emitting diodes OLEDs utilizing fluorescent molecules have attracted considerable interest

185

Room temperature 1.6 m electroluminescence from Ge light emitting diode on Si substrate  

E-Print Network [OSTI]

Room temperature 1.6 µm electroluminescence from Ge light emitting diode on Si substrate Szu n+/p light emitting diode on a Si substrate. Unlike normal electrically pumped devices, this device.4670) Optical materials; (230.3670) Light-emitting diodes. References and links 1. L. C. Kimerling, "Silicon

Vuckovic, Jelena

186

Demonstration Assessment of Light-Emitting Diode Roadway Lighting on the FDR Drive in New York, New York  

SciTech Connect (OSTI)

This a report about a field study of light-emitting diodes street lights by four different manufacturers installed on the FDR Drive in New York City, NY.

Myer, Michael; Hazra, Oindrila; Kinzey, Bruce R.

2011-12-01T23:59:59.000Z

187

Nanostructured High Performance Ultraviolet and Blue Light Emitting Diodes for Solid State Lighting  

SciTech Connect (OSTI)

We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and near ultraviolet for Solid State Lighting applications. Accomplishments in the second 12 month contract period include (i) new means of synthesizing AlGaN and InN quantum dots by droplet heteroepitaxy, (ii) synthesis of AlGaInN nanowires as building blocks for GaN-based microcavity devices, (iii) progress towards direct epitaxial alignment of the dense arrays of nanowires, (iv) observation and measurements of stimulated emission in dense InGaN nanopost arrays, (v) design and fabrication of InGaN photonic crystal emitters, and (vi) observation and measurements of enhanced fluorescence from coupled quantum dot and plasmonic nanostructures. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

Arto V. Nurmikko; Jung Han

2005-09-30T23:59:59.000Z

188

LED- ja loisteputkivalon vaikutus maitotaloustuotteiden ja perunan laatuun.  

E-Print Network [OSTI]

??Tutkielman kirjallisuuskatsauksessa tarkasteltiin valoa, erilaisia valonlähteitä ja niiden ominaisuuksia. Erityisesti keskityttiin LED (Light Emitting Diode) valoon ja sen ominaisuuksiin, koska sen käyttö myös yleisessä valaistuksessa… (more)

Solala, Kari

2009-01-01T23:59:59.000Z

189

Driver Circuit for White LED Lamps with TRIAC Dimming Control.  

E-Print Network [OSTI]

??An efficient Light Emitting Diode (LED) lamp driver circuit is proposed for retrofitting the conventionally used incandescent lamps with existing TRIAC dimmer. The dimming feature… (more)

Weng, Szu-Jung

2012-01-01T23:59:59.000Z

190

DARPA Soldier Self Care: Rapid Healing of Laser Eye Injuries with Light Emitting Diode Technology  

E-Print Network [OSTI]

RGC, retinal ganglion cell; TTX, tetrodotoxin. Photobiomodulation by light in the red to near infrared range (630-1000 nm) using low energy lasers or lightemitting diode (LED) arrays has been shown to accelerate wound healing, improve recovery from ischemic injury and attenuate degeneration in the injured optic nerve. At the cellular level, photoirradiation at low fluences can generate significant biological effects including cellular proliferation and the release of growth factors from cells. Mitochondrial cytochromes have been postulated as photoacceptors for red to near-infrared (NIR) light energy and reactive oxygen species or mitochondrial redox changes have been advanced as potential mediators of the biological effects of this light. We hypothesize that the therapeutic effects of red to near infrared light result, in part, from intracellular signaling mechanisms triggered by the interaction of NIR light with the mitochondrial photoacceptor

Harry T. Whelan; Margaret T. T. Wong-riley, Ph.D.; Janis T. Eells, Ph.D.; James N. Verhoeve, Ph.D.; Rina Das, Ph.D.; Marti Jett, Ph.D.

191

Synthesis and optical properties of cadmium selenide quantum dots for white light-emitting diode application  

SciTech Connect (OSTI)

Highlights: ? Stable CdSe QDs were synthesized by the one-step and two-level process respectively. ? The fabricated white LEDs show good white balance. ? CdSe QDs present well green to yellow band luminescence. ? CdSe QDs displayed a broad excitation band. - Abstract: Yellow light-emitting cadmium selenide quantum dots were synthesized using one-step and two-step methods in an aqueous medium. The structural luminescent properties of these quantum dots were investigated. The obtained cadmium selenide quantum dots displayed a broad excitation band suitable for blue or near-ultraviolet light-emitting diode applications. White light-emitting diodes were fabricated by coating the cadmium selenide samples onto a 460 nm-emitting indium gallium nitrite chip. Both samples exhibited good white balance. Under a 20 mA working current, the white light-emitting diode fabricated via the one-step and two-step methods showed Commission Internationale de l’Éclairage coordinates at (0.27, 0.23) and (0.27, 0.33), respectively, and a color rendering index equal to 41 and 37, respectively. The one-step approach was simpler, greener, and more effective than the two-step approach. The one-step approach can be enhanced by combining cadmium selenide quantum dots with proper phosphors.

Xu, Xianmei; Wang, Yilin; Gule, Teri; Luo, Qiang [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China); Zhou, Liya, E-mail: zhouliyatf@163.com [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China); Gong, Fuzhong [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 53000 (China)

2013-03-15T23:59:59.000Z

192

Amber-green light-emitting diodes using order-disorder Al[subscript x]In[subscript 1?x]P heterostructures  

E-Print Network [OSTI]

We demonstrate amber-green emission from Al[subscript x]In[subscript 1– x]P light-emitting diodes (LEDs) with luminescence peaked at 566?nm and 600?nm. The LEDs are metamorphically grown on GaAs substrates via a graded ...

Christian, Theresa M.

193

Angular distribution of polarized spontaneous emissions and its effect on light extraction behavior in InGaN-based light emitting diodes  

SciTech Connect (OSTI)

Angular intensity distributions of differently polarized light sources in multiple quantum wells (MQWs) and their effects on extraction behavior of spontaneous emission from light emitting diode (LED) chips have been studied. Theoretical calculation based on k·p approximation, ray tracing simulation and angular electroluminescence measurement were applied in this work. It is found that the electron-hole recombination in the InGaN MQWs produces a spherical distribution of an s-polarized source and a dumbbell-shaped p-polarized source. Light rays from different polarized sources experience different extraction processes, determining the polarization degree of electro-luminescence and extraction efficiency of LEDs.

Yuan, Gangcheng; Chen, Xinjuan; Yu, Tongjun, E-mail: tongjun@pku.edu.cn; Lu, Huimin; Chen, Zhizhong; Kang, Xiangning; Wu, Jiejun; Zhang, Guoyi [State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)

2014-03-07T23:59:59.000Z

194

A low-cost optical sensing device based on paired emitter-detector light emitting diodes. Analytica Chimica Acta 2006  

E-Print Network [OSTI]

A low power, high sensitivity, very low cost light emitting diode (LED) based device for intensity based light measurements is described. In this approach, a reverse-biased LED functioning as a photodiode, is coupled with a second LED configured in conventional emission mode. A simple timer circuit measures how long (in us) it takes for the photocurrent generated on the detector LED to discharge its capacitance from logic 1(+5 V) to logic 0 (+1.7 V). The entire instrument provides an inherently digital output of light intensity measurements for a few cents. this light intensity dependent discharge process has been applied to measuring concentrations of coloured solutions and a mathematical model developed based on the Beer-Lambert Law.

King-tong Lau; Susan Baldwin; Roderick Shepherd; William J. Yerazunis; Shinichi Izuo; Satoshi Ueyama; Dermont Diamond; Emitter-detector Leds; King-tong Lau; Susan Baldwin; Roderick Shepherd; William J; Shinichi Izuo; Satoshi Ueyama; Dermot Diamond

195

Enhancing the Field of View Limitation of Visible Light Communication-based Platoon  

E-Print Network [OSTI]

. In the mean time, Light Emitting Diode (LED) has become very common in automotive lighting due to its long

Boyer, Edmond

196

Article Published on LED Lumen Maintenance and Light Loss Factors...  

Broader source: Energy.gov (indexed) [DOE]

of a comprehensive lifetime rating - as well as the problematic relationship between SSL lifetime and lumen maintenance - determining an appropriate LLD factor for LED products...

197

Sixth International Conference on Solid State Lighting, edited by Ian T. Ferguson, Nadarajah Narendran, Tsunemasa Taguchi, Ian E. Ashdown,  

E-Print Network [OSTI]

commercial white light emitting diodes (LEDs) rely on complicated fabrication methods to produce white light: Cadmium Selenide, Nanocrystal, Photoluminescence, Phosphor, White Light, Light Emitting Diode, LED 1. INTRODUCTION 1.1 Solid state lighting Solid state lighting, in the form of white light emitting diodes (LEDs

Weiss, Sharon

198

Measured Off-Grid LED Lighting System Performance  

E-Print Network [OSTI]

The Specter of Fuel-Based Lighting," Science 308:1263-1264.Mills. 2008. "Solid-State Lighting on a Shoestring Budget:The Economics of Off-Grid Lighting for Small Businesses in

Granderson, Jessica

2009-01-01T23:59:59.000Z

199

Semiconductor Nanocrystals-Based White Light Emitting Diodes  

SciTech Connect (OSTI)

In response to the demands for energy and the concerns of global warming and climate change, energy efficient and environmentally friendly solid state lighting, such as white light emitting diodes (WLEDs), is considered to be the most promising and suitable light source. Because of their small size, high efficiency, and long lifetime, WLEDs based on colloidal semiconductor nanocrystals (or quantum dots) are emerging as a completely new technology platform for the development of flat-panel displays and solid state lighting, exhibiting the potential to replace the conventionally used incandescent and fluorescent lamps. This replacement could cut the ever-increasing energy consumption, solve the problem of rapidly depleting fossil fuel reserves, and improve the quality of the global environment. In this review, we highlight the recent progress in semiconductor nanocrystals-based WLEDs, compare different approaches for generating white light, and discuss the benefits and challenges of the solid state lighting technology.

Dai, Quanqin [ORNL; Hu, Michael Z. [ORNL; Duty, Chad E [ORNL

2010-01-01T23:59:59.000Z

200

Organic light-emitting diodes from homoleptic square planar complexes  

DOE Patents [OSTI]

Homoleptic square planar complexes [M(N.LAMBDA.N).sub.2], wherein two identical N.LAMBDA.N bidentate anionic ligands are coordinated to the M(II) metal center, including bidentate square planar complexes of triazolates, possess optical and electrical properties that make them useful for a wide variety of optical and electrical devices and applications. In particular, the complexes are useful for obtaining white or monochromatic organic light-emitting diodes ("OLEDs"). Improved white organic light emitting diode ("WOLED") designs have improved efficacy and/or color stability at high brightness in single- or two-emitter white or monochrome OLEDs that utilize homoleptic square planar complexes, including bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II) ("Pt(ptp).sub.2").

Omary, Mohammad A

2013-11-12T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Fabrication of InGaP LEDs on a graded buffer substrate  

E-Print Network [OSTI]

Introduction: Computer display panels create a vast color palette by combining color from three light emitting diodes (LEDs), each producing red, green, or blue light. The light from these three LEDs is chosen so that the ...

Martínez, Josué F

2007-01-01T23:59:59.000Z

202

Semiconductor-Nanocrystals-Based White Light-Emitting Diodes  

SciTech Connect (OSTI)

In response to the demands for energy and the concerns of global warming and climate change, energy efficient and environmentally friendly solid-state lighting, such as white lightemitting diodes (WLEDs), is considered to be the most promising and suitable light source. Because of their small size, high efficiency, and long lifetime, WLEDs based on colloidal semiconductor nanocrystals (or quantum dots) are emerging as a completely new technology platform for the development of flat-panel displays and solid-state lighting, exhibiting the potential to replace the conventionally used incandescent and fluorescent lamps. This replacement can cut the ever-increasing level of energy consumption, solve the problem of rapidly depleting fossil fuel reserves, and improve the quality of the global environment. In this review, the recent progress in semiconductor-nanocrystals-based WLEDs is highlighted, the different approaches for generating white light are compared, and the benefits and challenges of the solid-state lighting technology are discussed.

Dai, Quanqin [ORNL; Duty, Chad E [ORNL; Hu, Michael Z. [ORNL

2010-01-01T23:59:59.000Z

203

Fundamental Studies and Development of III-N Visible LEDs for High-Power Solid-State Lighting Applications  

SciTech Connect (OSTI)

The goal of this program is to understand in a fundamental way the impact of strain, defects, polarization, and Stokes loss in relation to unique device structures upon the internal quantum efficiency (IQE) and efficiency droop (ED) of III-nitride (III-N) light-emitting diodes (LEDs) and to employ this understanding in the design and growth of high-efficiency LEDs capable of highly-reliable, high-current, high-power operation. This knowledge will be the basis for our advanced device epitaxial designs that lead to improved device performance. The primary approach we will employ is to exploit new scientific and engineering knowledge generated through the application of a set of unique advanced growth and characterization tools to develop new concepts in strain-, polarization-, and carrier dynamics-engineered and low-defect materials and device designs having reduced dislocations and improved carrier collection followed by efficient photon generation. We studied the effects of crystalline defect, polarizations, hole transport, electron-spillover, electron blocking layer, underlying layer below the multiplequantum- well active region, and developed high-efficiency and efficiency-droop-mitigated blue LEDs with a new LED epitaxial structures. We believe new LEDs developed in this program will make a breakthrough in the development of high-efficiency high-power visible III-N LEDs from violet to green spectral region.

Dupuis, Russell

2012-02-29T23:59:59.000Z

204

Text-Alternative Version: MSSLC Member Case Studies- LED Street Lighting Programs Webinar  

Broader source: Energy.gov [DOE]

Below is the text-alternative version of the "MSSLC Member Case Studies - LED Street Lighting Programs" webcast, held May 8, 2013.

205

Text Alternative Version: Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products  

Broader source: Energy.gov [DOE]

Below is the text-alternative version of the "Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products" webcast, held March 28, 2013.

206

LED Linear Lamps and Troffer Lighting: CALiPER Report Series 21  

ScienceCinema (OSTI)

Video about CALiPER Report Series 21 on LED Linear Lamps and Troffer Lighting, featuring interviews with Tracy Beeson and Naomi Miller of Pacific Northwest National Laboratory.

Beeson, Tracy; Miller, Naomi

2014-06-23T23:59:59.000Z

207

LED Linear Lamps and Troffer Lighting: CALiPER Report Series 21  

SciTech Connect (OSTI)

Video about CALiPER Report Series 21 on LED Linear Lamps and Troffer Lighting, featuring interviews with Tracy Beeson and Naomi Miller of Pacific Northwest National Laboratory.

Beeson, Tracy; Miller, Naomi

2014-06-17T23:59:59.000Z

208

Text-Alternative Version: CALiPER Series 21 on LED Linear Lamps and Troffer Lighting  

Broader source: Energy.gov [DOE]

Following is a text version of a video about CALiPER Application Report Series 21 on LED Linear Lamps and Troffer Lighting.

209

White organic light-emitting diodes: Status and perspective  

E-Print Network [OSTI]

White organic light-emitting diodes (OLEDs) are ultra-thin, large-area light sources made from organic semiconductor materials. Over the last decades, much research has been spent on finding the suitable materials to realize highly efficient monochrome and white OLEDs. With their high efficiency, color-tunability, and color-quality, white OLEDs are emerging to become one of the next generation light sources. In this review, we discuss the physics of a variety of device concepts that are introduced to realize white OLEDs based on both polymer and small molecule organic materi als. Owing to the fact that about 80 % of the internally generated photons are trapped within the thin-film layer structure, we put a second focus on reviewing promising concepts for improved light outcoupling.

Reineke, Sebastian; Lüssem, Björn; Leo, Karl

2013-01-01T23:59:59.000Z

210

Energy Savings Estimates of Light Emitting Diodes in Niche Lighting...  

Office of Environmental Management (EM)

in Niche Lighting Applications Prepared for: Building Technologies Program Office of Energy Efficiency and Renewable Energy U.S. Department of Energy Prepared by: Navigant...

211

Member Case Studies: LED Street Lighting Programs in Algona (IA), Asheville (NC), and Boston (MA)  

Broader source: Energy.gov [DOE]

This May 8, 2013 webcast featured presentations from DOE Municipal Solid-State Street Lighting Consortium member cities about their experiences with LED street lighting. Presenters John Bilsten of...

212

A micrometer-size movable light emitting area in a resonant tunneling light emitting diode  

SciTech Connect (OSTI)

We report on the fabrication of a micrometer-size movable light emitting area in a GaAs/AlAs quantum well resonant tunneling p-i-n diode. The spatial position of the micrometer-size light emitting area shifts linearly with increasing applied bias, up to 30??m for a bias increment of 0.2?V. Also, the simultaneous resonant tunneling injection of both electrons and holes into the quantum well states is achieved at specific positions of the diode, thus resulting in a tenfold increase of the electroluminescence intensity.

Pettinari, G., E-mail: giorgio.pettinari@cnr.it [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); National Research Council (CNR), Institute for Photonics and Nanotechnologies (IFN-CNR), Via Cineto Romano 42, 00156 Roma (Italy); Balakrishnan, N.; Makarovsky, O.; Campion, R. P.; Patanè, A. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)] [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Polimeni, A.; Capizzi, M. [CNISM-Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185 Roma (Italy)] [CNISM-Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185 Roma (Italy)

2013-12-09T23:59:59.000Z

213

LED Traffic Lights Get Buy American Stamp | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10 DOEWashington, DCKickoffLDV HVAC ModelLEDLightsLED

214

78.1: Ultra Compact Polarization Recycling System for White Light LED based Pico-Projection System  

E-Print Network [OSTI]

78.1: Ultra Compact Polarization Recycling System for White Light LED based Pico-Projection System polarization recycling system, for white light LED based projectors, is proposed. White light LED is applied. In this paper, we propose an ultra compact polarization recycling system for white light LED based projection

215

Luminescence and Squeezing of a Superconducting Light Emitting Diode  

E-Print Network [OSTI]

We investigate a semiconductor $p$-$n$ junction in contact with superconducting leads that is operated under forward bias as a light-emitting diode. The presence of superconductivity results in a significant increase of the electroluminescence in a certain frequency window. We demonstrate that the tunneling of Cooper pairs induces an additional luminescence peak on resonance. There is a transfer of superconducting to photonic coherence which results in the emission of entangled photon pairs and squeezing of the fluctuations in the quadrature amplitudes of the emitted light. The squeezing angle can be electrically manipulated by changing the relative phase of the order parameters in the superconductors. We finally derive the conditions for lasing in the system and show that the laser threshold is reduced due to superconductivity. This shows how macroscopic coherence of a superconductor can be used to control the properties of light.

Patrik Hlobil; Peter P. Orth

2015-02-17T23:59:59.000Z

216

Luminescence and Squeezing of a Superconducting Light Emitting Diode  

E-Print Network [OSTI]

We investigate a semiconductor $p$-$n$ junction in contact with superconducting leads that is operated under forward bias as a light-emitting diode. The presence of superconductivity results in a significant increase of the electroluminescence in a certain frequency window. We demonstrate that the tunneling of Cooper pairs induces an additional luminescence peak on resonance. There is a transfer of superconducting to photonic coherence which results in the emission of entangled photon pairs and squeezing of the fluctuations in the quadrature amplitudes of the emitted light. The squeezing angle can be electrically manipulated by changing the relative phase of the order parameters in the superconductors. We finally derive the conditions for lasing in the system and show that the laser threshold is reduced due to superconductivity. This shows how macroscopic coherence of a superconductor can be used to control the properties of light.

Hlobil, Patrik

2015-01-01T23:59:59.000Z

217

Largest-area Photonic Crystal LED Fabricated Demonstrates Uniform Light Emission  

Broader source: Energy.gov [DOE]

Lumileds Lighting, the University of New Mexico, and Sandia National Laboratories teamed to demonstrate uniform light emission from the largest-area III-Nitride photonic crystal LED (1 x 1 mm2) ever fabricated. Most previous photonic crystal LED research has relied on small-area patterns written by slow, serial-writing electron-beam lithography.

218

Efficient narrow-band light emission from a single carbon nanotube pn diode  

E-Print Network [OSTI]

Efficient narrow-band light emission from a single carbon nanotube p­n diode Thomas Mueller1 and Phaedon Avouris1 * Electrically driven light emission from carbon nanotubes1­8 could be used in nanoscale. Here, we report electrically induced light emission from individual carbon nanotube p­n diodes. A new

Perebeinos, Vasili

219

Illuminating Solar Decathlon Homes: Exploring Next Generation Lighting Technology - Light Emitting Diodes  

SciTech Connect (OSTI)

This report was prepared by PNNL for the US Department of Energy Building Technologies Program, Solid-State Lighting Program. The report will be provided to teams of university students who are building houses for the 2009 Solar Decathlon, a home design competition sponsored in part by DOE, to encourage teams to build totally solar powered homes. One aspect of the competition is lighting. This report provides the teams with information about LED lighting that can help them determine how they incorporate LED lighting into their homes. The report provides an overview of LED technology, a status of where LED technology is today, questions and answers about lighting quality, efficiency, lifetime etc.; numerous examples of LED products; and several weblinks for further research.

Gordon, Kelly L.; Gilbride, Theresa L.

2008-05-22T23:59:59.000Z

220

COLLOIDAL ELECTROLUMINESCENCE: NOVEL ROUTES TO CONTROLLED EMISSION OF ORGANIC LIGHT EMITTING DIODE DEVICES.  

E-Print Network [OSTI]

??In recent years the importance of the organic light emitting diode (OLED) has grown immensely, and the past two decades have seen ongoing and exhaustive… (more)

Huebner, Christopher

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Low-Cost Light-Emitting Diode Luminaire for General Illumination...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Santa Barbara Technology Center This project is demonstrating an efficient and stable white organic light-emitting diode (WOLED) using a single emitter on a planar glass...

222

Chip-Scale Power Conversion for LED Lighting: Integrated Power Chip Converter for Solid-State Lighting  

SciTech Connect (OSTI)

ADEPT Project: Teledyne is developing cost-effective power drivers for energy-efficient LED lights that fit on a compact chip. These power drivers are important because they transmit power throughout the LED device. Traditional LED driver components waste energy and don't last as long as the LED itself. They are also large and bulky, so they must be assembled onto a circuit board separately which increases the overall manufacturing cost of the LED light. Teledyne is shrinking the size and improving the efficiency of its LED driver components by using thin layers of an iron magnetic alloy and new gallium nitride on silicon devices. Smaller, more efficient components will enable the drivers to be integrated on a single chip, reducing costs. The new semiconductors in Teledyne's drivers can also handle higher levels of power and last longer without sacrificing efficiency. Initial applications for Teledyne's LED power drivers include refrigerated grocery display cases and retail lighting.

None

2010-10-01T23:59:59.000Z

223

LED Lights for All Occasions | Department of Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample Environment: Magnet and6 th7525T3Scoringimpacts®LED

224

LEDs: The Future of Lighting is Here | Department of Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample Environment: Magnet and6ledp/ The listing of newLEDs:

225

LED Holiday Lights: Festive, Safe, and Efficient! | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10 DOEWashington, DCKickoffLDV HVAC Model DevelopmentHolidayLED

226

Energy - LEDs to light UT arena | ornl.gov  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia Nanoparticles asSecond stage ofDefects on . Grade K-3U.S.Energy - LEDs

227

Direct periodic patterning of GaN-based light-emitting diodes by three-beam interference laser ablation  

SciTech Connect (OSTI)

We report on the direct patterning of two-dimensional periodic structures in GaN-based light-emitting diodes (LEDs) through laser interference ablation for the fast and reliable fabrication of periodic micro- and nano-structures aimed at enhancing light output. Holes arranged in a two-dimensional hexagonal lattice array having an opening size of 500?nm, depth of 50?nm, and a periodicity of 1??m were directly formed by three-beam laser interference without photolithography or electron-beam lithography processes. The laser-patterned LEDs exhibit an enhancement in light output power of 20% compared to conventional LEDs having a flat top surface without degradation of electrical and optical properties of the top p-GaN layer and the active region, respectively.

Kim, Jeomoh; Ji, Mi-Hee; Detchprohm, Theeradetch [Center for Compound Semiconductors and School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Dr. NW, Atlanta, Georgia 30332-0250 (United States); Yuan, Dajun; Guo, Rui [Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States); Liu, Jianping [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215125 (China); Asadirad, Mojtaba [Materials Engineering Program, University of Houston, Houston, Texas 77204-4005 (United States); Kwon, Min-Ki [Department of Photonic Engineering, Chosun University, Seosuk-dong, Gwangju 501-759 (Korea, Republic of); Dupuis, Russell D. [Center for Compound Semiconductors and School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Dr. NW, Atlanta, Georgia 30332-0250 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245 (United States); Das, Suman [Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245 (United States); Ryou, Jae-Hyun, E-mail: jryou@uh.edu [Materials Engineering Program, University of Houston, Houston, Texas 77204-4005 (United States); Department of Mechanical Engineering and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, Texas 77204-4006 (United States)

2014-04-07T23:59:59.000Z

228

Light-extraction enhancement in GaN-based light-emitting diodes using grade-refractive-index amorphous titanium oxide films with porous structures  

SciTech Connect (OSTI)

Amorphous titanium oxide (a-TiO{sub x}:OH) films prepared by plasma-enhanced chemical-vapor deposition at 200 and 25 deg. C are in turn deposited onto the GaN-based light-emitting diode (LED) to enhance the associated light extraction efficiency. The refractive index, porosity, and photocatalytic effect of the deposited films are correlated strongly with the deposition temperatures. The efficiency is enhanced by a factor of {approx}1.31 over that of the uncoated LEDs and exhibited an excellent photocatalytic property after an external UV light irradiation. The increase in the light extraction is related to the reduction in the Fresnel transmission loss and the enhancement of the light scattering into the escape cone by using the graded-refractive-index a-TiO{sub x}:OH film with porous structures.

Liu, D.-S.; Lin, T.-W.; Huang, B.-W.; Juang, F.-S.; Lei, P.-H. [Institute of Electro-Optical and Materials Science, National Formosa University, Huwei 63201, Taiwan (China); Hu, C.-Z. [Chilin Technology Co. Ltd., Tainan County 71758, Taiwan (China)

2009-04-06T23:59:59.000Z

229

Seventh International Conference on Solid State Lighting, Edited by Ian T. Ferguson, Nadarajah Narendran, Tsunemasa Taguchi, Ian E. Ashdown,  

E-Print Network [OSTI]

Selenide, Nanocrystal, Photoluminescence, Phosphor, White Light, Light Emitting Diode, LED 1. INTRODUCTION 1.1 Solid state lighting and white-light LEDs The use of white light emitting diodes (LEDs emitting diodes[11] , though they are a less mature technology as compared to inorganic semiconductor

Weiss, Sharon

230

Electrical spin injection using GaCrN in a GaN based spin light emitting diode  

SciTech Connect (OSTI)

We have demonstrated electrical spin-injection from GaCrN dilute magnetic semiconductor (DMS) in a GaN-based spin light emitting diode (spin-LED). The remanent in-plane magnetization of the thin-film semiconducting ferromagnet has been used for introducing the spin polarized electrons into the non-magnetic InGaN quantum well. The output circular polarization obtained from the spin-LED closely follows the normalized in-plane magnetization curve of the DMS. A saturation circular polarization of ?2.5% is obtained at 200?K.

Banerjee, D.; Ganguly, S.; Saha, D., E-mail: dipankarsaha@iitb.ac.in [Centre of Excellence in Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India); IITB-Monash Research Academy, Indian Institute of Technology Bombay, Mumbai 400076 (India); Adari, R.; Sankaranarayan, S.; Kumar, A. [Centre of Excellence in Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India)] [Centre of Excellence in Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India); Aldhaheri, R. W.; Hussain, M. A.; Balamesh, A. S. [Department of Electrical and Computer Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)] [Department of Electrical and Computer Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2013-12-09T23:59:59.000Z

231

An Efficient LED System-in-Module for General Lighting Applications  

SciTech Connect (OSTI)

The objective of the project was to realize an LED-based lighting technology platform for general illumination, starting with LED chips, and integrating the necessary technologies to make compact, user-friendly, high-efficiency, energy-saving sources of controlled white (or variable-colored) light. The project is to build the system around the LEDs, and not to work on the LEDs themselves, in order that working products can be introduced soon after the LEDs reach suitable efficiency for mass-production of high-power light sources for general illumination. Because the light sources are intended for general illumination, color must be accurately maintained, requiring feedback control in the electronics. The project objective has been realized and screw base demonstrators, based on the technology developed in the project, have been built.

None

2008-09-14T23:59:59.000Z

232

Electroluminescence property of organic light emitting diode (OLED)  

SciTech Connect (OSTI)

Transport properties of electrons and holes were investigated not only in a anthracene-containing poly(p-phenylene-ethynylene)- alt - poly(p-phenylene-vinylene) (PPE-PPV) polymer (AnE-PVstat) light emitting diodes (OLED) but also in an ITO/Ag/polymer/Ag electron and ITO/PEDOT:PSS/polymer/Au hole only devices. Mobility of injected carriers followed the Poole-Frenkel type conduction mechanism and distinguished in the frequency range due to the difference of transit times in admittance measurement. Beginning of light output took place at the turn-on voltage (or flat band voltage), 1.8 V, which was the difference of energy band gap of polymer and two barrier offsets between metals and polymer.

Özdemir, Orhan; Kavak, Pelin; Saatci, A. Evrim; Gökdemir, F. P?nar; Menda, U. Deneb; Can, Nursel; Kutlu, Kubilay [Y?ld?z Technical University, Department of Physics, Esenler, Istanbul (Turkey); Tekin, Emine; Pravadal?, Selin [National Metrology Inst?tute of Turkey (TUB?TAK-UME), Kocaeli (Turkey)

2013-12-16T23:59:59.000Z

233

Chapter 6, Residential Lighting Evaluation Protocol: The Uniform...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

STAR lighting fixtures. More recently, programs are introducing solid-state light-emitting diode (LED) lamps. The future of savings claims from residential lighting programs is...

234

Energy Department Announces Indoor Lighting Winners of Next Generation...  

Broader source: Energy.gov (indexed) [DOE]

was launched in 2008 to promote excellence in the design of energy-efficient light-emitting diode (LED) commercial lighting fixtures or "luminaires." Solid-state lighting...

235

Shedding new light on LEDs | Argonne National Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2)Sharing Smart Grid ExperiencesNational Laboratory light

236

Wavelength-resolved low-frequency noise of GaInN/GaN green light emitting diodes  

E-Print Network [OSTI]

Wavelength-resolved low-frequency noise of GaInN/GaN green light emitting diodes S. L. Rumyantseva well light emitting diodes. The light intensity noise was measured as a function of wavelength within the light emitting diode spectral emission line. The spectral noise density is found to increase

Wetzel, Christian M.

237

Measured Off-Grid LED Lighting System Performance  

SciTech Connect (OSTI)

This report is a product of our ongoing effort to support the development of high-quality yet affordable products for off-grid lighting in the developing world that have good potential to succeed in the market. The effort includes work to develop low-cost testing procedures, to identify useful performance metrics, and to facilitate the development of industry standards and product rating protocols. We conducted laboratory testing of nine distinct product lines. In some cases we also tested multiple generations of a single product line and/or operating modes for a product. The resultsare summarized in Table 1. We found that power consumption and light output varied by nearly a factor of 12, with efficacy varying by a factor of more than six. Of particular note, overall luminous efficacy varied from 8.2 to 53.1 lumens per watt. Color quality indices variedmaterially, especially for correlated color temperature. Maximum illuminance, beamcandlepower, and luminance varied by 8x, 32x, and 61x respectively, suggesting considerable differences among products in terms of service levels and visual comfort. Glare varied by1.4x, and was above acceptable thresholds in most cases. Optical losses play a role in overall performance, varying by a factor of 3.2 and ranging as high as 24percent. These findings collectively indicate considerable potential for improved product design.

Granderson, Jessica; Galvin, James; Bolotov, Dmitriy; Clear, Robert; Jacobson, Arne; Mills, Evan

2008-12-18T23:59:59.000Z

238

Ruofan Wu, Hieu Pham Trung Nguyen and Zetian Mi INTRODUCTION TO LEDs  

E-Print Network [OSTI]

-in-a-Wire Light Emitting Diodes and Prevention Method Nano-electronic Devices and Materials, Electrical Computer., Efficiency droop in nitride-based light-emitting diodes. Physica Status Solidi a-Applications and Materials history. Nature Photonics 2007, 1 (4), 189-192. [4] Holonyak, N., Is the light emitting diode (LED

Barthelat, Francois

239

Coupled optical and electronic simulations of electrically pumped photonic-crystal-based LEDs  

E-Print Network [OSTI]

to investigate design tradeoffs in electrically pumped photonic crystal light emitting diodes. A finite. Keywords: Photonic crystal light emitting diode, electrically pumped device 1. INTRODUCTION Recently optoelectronic devices, such as light emitting diodes (LEDs) and lasers. It has been suggested that a thin slab

Dutton, Robert W.

240

Stress-induced piezoelectric field in GaN-based 450-nm light-emitting diodes  

SciTech Connect (OSTI)

We investigated the influence of the built-in piezoelectric field induced by compressive stress on the characteristics of GaN-based 450-nm light-emitting diodes (LEDs) prepared on sapphire substrates of different thicknesses. As the sapphire substrate thickness was reduced, the compressive stress in the GaN layer was released, resulting in wafer bowing. The wafer bowing-induced mechanical stress altered the piezoelectric field, which in turn reduced the quantum confined Stark effect in the InGaN/GaN active region of the LED. The flat-band voltage was estimated by measuring the applied bias voltage that induced a 180° phase shift in the electro-reflectance (ER) spectrum. The piezoelectric field estimated by the ER spectra changed by ?110?kV/cm. The electroluminescence spectral peak wavelength was blue-shifted, and the internal quantum efficiency was improved by about 22% at a high injection current of 100?mA. The LED on the 60-?m-thick sapphire substrate exhibited the highest light output power of ?59?mW at an injection current of 100?mA, with the operating voltage unchanged.

Tawfik, Wael Z. [Department of Materials Science and Engineering, Chonnam National University, Yongbong 300 Gwangju 500-757 (Korea, Republic of); Department of Physics, Faculty of Science, Beni-Suef University, Beni-Suef 62511 (Egypt); Hyeon, Gil Yong; Lee, June Key, E-mail: junekey@chonnam.ac.kr [Department of Materials Science and Engineering, Chonnam National University, Yongbong 300 Gwangju 500-757 (Korea, Republic of)

2014-10-28T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Red-emitting fluorescent Organic Light emitting Diodes with low sensitivity to self-quenching  

E-Print Network [OSTI]

Red-emitting fluorescent Organic Light emitting Diodes with low sensitivity to self-quenching S, France *E-mail : sebastien.forget@univ-paris13.fr Keywords: OLED, quenching, doping, red-emitting organic. We herein report on Organic Light-Emitting Diodes (OLEDs) based on a fluorescent amorphous red

Paris-Sud XI, Université de

242

White Organic Light-Emitting Diodes with fine chromaticity tuning via ultrathin layer position shifting  

E-Print Network [OSTI]

White Organic Light-Emitting Diodes with fine chromaticity tuning via ultrathin layer position : Non-doped white organic light-emitting diodes using an ultrathin yellow-emitting layer of rubrene (5 via a bright white (WOLED) with CIE coordinates (x= 0.33, y= 0.32), a ext of 1.9%, and a color

Paris-Sud XI, Université de

243

Broadband visible light source based on AllnGaN light emitting diodes  

DOE Patents [OSTI]

A visible light source device is described based on a light emitting diode and a nanocluster-based film. The light emitting diode utilizes a semiconductor quantum well structure between n-type and p-type semiconductor materials on the top surface a substrate such as sapphire. The nanocluster-based film is deposited on the bottom surface of the substrate and can be derived from a solution of MoS.sub.2, MoSe.sub.2, WS.sub.2, and WSe.sub.2 particles of size greater than approximately 2 nm in diameter and less than approximately 15 nm in diameter, having an absorption wavelength greater than approximately 300 nm and less than approximately 650 nm.

Crawford, Mary H.; Nelson, Jeffrey S.

2003-12-16T23:59:59.000Z

244

MOF Coating a Promising Path to White LEDs  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(MOF); the structure was determined at Beamline 11.3.1. Coating a blue light-emitting diode (LED) with this compound readily generates white light with high luminous...

245

Ultraviolet emission from a multi-layer graphene/MgZnO/ZnO light-emitting diode  

SciTech Connect (OSTI)

We report on ultraviolet emission from a multi-layer graphene (MLG)/MgZnO/ZnO light-emitting diodes (LED). The p-type MLG and MgZnO in the MLG/MgZnO/ZnO LED are used as transparent hole injection and electron blocking layers, respectively. The current-voltage characteristics of the MLG/MgZnO/ZnO LED show that current transport is dominated by tunneling processes in the MgZnO barrier layer under forward bias conditions. The holes injected from p-type MLG recombine efficiently with the electrons accumulated in ZnO, and the MLG/MgZnO/ZnO LED shows strong ultraviolet emission from the band edge of ZnO and weak red-orange emission from the deep levels of ZnO.

Kang, Jang-Won; Choi, Yong-Seok; Goo Kang, Chang; Hun Lee, Byoung [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Kim, Byeong-Hyeok [Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Tu, C. W. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093-0407 (United States); Park, Seong-Ju, E-mail: sjpark@gist.ac.kr [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

2014-02-03T23:59:59.000Z

246

LED Linear Lamps and Troffer Lighting: CALiPER Report Series 21  

Broader source: Energy.gov [DOE]

View the video about CALiPER Report Series 21 on LED Linear Lamps and Troffer Lighting, featuring interviews with Tracy Beeson and Naomi Miller of Pacific Northwest National Laboratory.

247

Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products  

Broader source: Energy.gov [DOE]

This March 28, 2013 webcast reviewed DOE's recently completed three-part study of the life-cycle energy and environmental impacts of LED lighting products relative to incandescent and CFL...

248

A LIGHT READ: A flexible array of LEDs on a folded sheet of paper.  

E-Print Network [OSTI]

electrically conductive polymers and deposited on bendable plastic substrates. Conventional, inorganic LEDs and inorganic LEDs by harnessing the light of conventional electronics in an elastic system with biomedical potential. "The applications we're interested in mostly include interfaces with the human body," says John

Rogers, John A.

249

Electrical, optical, and material characterizations of blue InGaN light emitting diodes submitted to reverse-bias stress in water vapor condition  

SciTech Connect (OSTI)

In this paper, we investigate degradation of InGaN/GaN light emitting diodes (LEDs) under reverse-bias operations in water vapor and dry air. To examine failure origins, electrical characterizations including current-voltage, breakdown current profiles, optical measurement, and multiple material analyses were performed. Our findings indicate that the diffusion of indium atoms in water vapor can expedite degradation. Investigation of reverse-bias stress can help provide insight into the effects of water vapor on LEDs.

Chen, Hsiang, E-mail: hchen@ncnu.edu.tw; Chu, Yu-Cheng; Chen, Yun-Ti; Chen, Chian-You [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, No. 1, University Road, Puli, Nantou County 54561, Taiwan (China); Shei, Shih-Chang [Department of Electrical Engineering, National University of Tainan, No.33, Sec. 2, Shulin St., West Central Dist., Tainan City 70005, Taiwan (China)

2014-09-07T23:59:59.000Z

250

Model for Triplet State Engineering in Organic Light Emitting Diodes  

E-Print Network [OSTI]

Engineering the position of the lowest triplet state (T1) relative to the first excited singlet state (S1) is of great importance in improving the efficiencies of organic light emitting diodes and organic photovoltaic cells. We have carried out model exact calculations of substituted polyene chains to understand the factors that affect the energy gap between S1 and T1. The factors studied are backbone dimerisation, different donor-acceptor substitutions and twisted geometry. The largest system studied is an eighteen carbon polyene which spans a Hilbert space of about 991 million. We show that for reverse intersystem crossing (RISC) process, the best system involves substituting all carbon sites on one half of the polyene with donors and the other half with acceptors.

Prodhan, Suryoday; Ramasesha, S

2014-01-01T23:59:59.000Z

251

Replacement of Lighting Fixtures with LED Energy Efficient Lights at the Parking Facility, Milwaukee, Wisconsin  

SciTech Connect (OSTI)

The Forest County Potawatomi Community (FCPC or Tribe) owns a six-story parking facility adjacent to its Potawatomi Bingo Casino (the Casino) in Milwaukee, Wisconsin, as well as a valet parking facility under the Casino (collectively, the Parking Facility). The Parking Facility contained 205-watt metal halide-type lights that, for security reasons, operated 24 hours per day, 7 days per week. Starting on August 30, 2010, the Tribe replaced these fixtures with 1,760 state-of-the-art, energy efficient 55-Watt LED lights. This project resulted in an immediate average reduction in monthly peak demand of 238 kW over the fourth quarter of 2010. The average reduction in monthly peak demand from October 1 through December 31, 2010 translates into a forecast annual electrical energy reduction of approximately 1,995,000 kWh or 47.3% of the pre-project demand. This project was technically effective, economically feasible, and beneficial to the public not only in terms of long term energy efficiency and associated emissions reductions, but also in the short-term jobs provided for the S.E. Wisconsin region. The project was implemented, from approval by U.S. Department of Energy (DOE) to completion, in less than 6 months. The project utilized off-the-shelf proven technologies that were fabricated locally and installed by local trade contractors.

David Brien

2012-06-21T23:59:59.000Z

252

Interface electronic structures of organic light-emitting diodes with WO3 interlayer: A study by photoelectron spectroscopy  

E-Print Network [OSTI]

Interface electronic structures of organic light-emitting diodes with WO3 interlayer: A study injec- tion and transport layers in an organic light-emitting diode (OLED) structure has been studied B.V. All rights reserved. 1. Introduction OLEDs (organic light-emitting diodes) are display de

Kim, Sehun

253

4.2: Design of an Improved Pixel for a Polysilicon Active Matrix Organic Light Emitting Diode Display  

E-Print Network [OSTI]

4.2: Design of an Improved Pixel for a Polysilicon Active Matrix Organic Light Emitting Diode active matrix organic light emitting diode (AMOLED) pixel with high pixel to pixel luminance uniformity such as organic light emitting diodes (OLEDs) are presently of great interest due to their potential application

254

Polarization engineering via staggered InGaN quantum wells for radiative efficiency enhancement of light emitting diodes  

E-Print Network [OSTI]

of light emitting diodes Ronald A. Arif, Yik-Khoon Ee, and Nelson Tansu Citation: Appl. Phys. Lett. 91 extraction in GaN-based light emitting diodes Appl. Phys. Lett. 100, 061107 (2012) Electrically driven nanopyramid green light emitting diode Appl. Phys. Lett. 100, 061106 (2012) Ultraviolet electroluminescence

Gilchrist, James F.

255

High-density organic light emitting diodes by nanoimprint technology Krutarth Trivedi, Caleb Nelson, Li Tao, Mathew Goeckner, Walter Hua)  

E-Print Network [OSTI]

High-density organic light emitting diodes by nanoimprint technology Krutarth Trivedi, Caleb Nelson sources. Despite the considerable development of inorganic semiconductor based light emitting diodes of miniaturization to nanoscale. Organic light emitting diode (OLED) technology is immune to quantum confinement

Hu, Wenchuang "Walter"

256

DOE Science Showcase - Light-emitting Diode (LED) Lighting Research | OSTI,  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct: CrudeOffice of Scientific and Technical InformationUS

257

Dislocation-related trap levels in nitride-based light emitting diodes  

SciTech Connect (OSTI)

Deep level transient spectroscopy was performed on InGaN/GaN multiple quantum well light emitting diodes (LEDs) in order to determine the effect of the dislocation density on the deep intragap electronic levels. The LEDs were grown by metalorganic vapor phase epitaxy on GaN templates with a high dislocation density of 8 × 10{sup 9} cm{sup ?2} and a low dislocation density of 3 × 10{sup 8} cm{sup ?2}. Three trapping levels for electrons were revealed, named A, A1, and B, with energies E{sub A}???0.04?eV, E{sub A1}???0.13?eV, and E{sub B}???0.54?eV, respectively. The trapping level A has a much higher concentration in the LEDs grown on the template with a high density of dislocations. The logarithmic dependence of the peak amplitude on the bias pulse width for traps A and A1 identifies the defects responsible for these traps as associated with linearly arranged defects. We conclude that traps A and A1 are dislocation-related intragap energy levels.

Venturi, Giulia; Castaldini, Antonio; Cavallini, Anna [Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, Bologna 40127 (Italy); Meneghini, Matteo; Zanoni, Enrico [Department of Information Engineering, University of Padova, via Gradenigo 6/B, Padova 35131 (Italy); Zhu, Dandan; Humphreys, Colin [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2014-05-26T23:59:59.000Z

258

Patterned three-color ZnCdSeZnCdMgSe quantum-well structures for integrated full-color and white light emitters  

E-Print Network [OSTI]

. This result demonstrates the feasibility of fabricating integrated full-color light emitting diode and laser American Institute of Physics. S0003-6951 00 04149-8 Light emitting diodes LEDs and laser diodes LDs having

259

An optimal light-extracting overlayer, inspired by the lantern of a Photuris firefly, to improve the external efficiency of existing light-emitting diodes  

E-Print Network [OSTI]

Actual light emission diodes (LED) have most often good internal efficiencies but poor external efficiencies due to total internal reflection at the air interface. In this paper the design, fabrication and characterization of a bioinspired overlayer deposited on a GaN LED is investigated. The purpose of this overlayer is to improve light extraction into air, after the photons have been generated in the diode's high refractive-index active material. The layer design is inspired by the microstructure found in the firefly Photuris sp., described by Bay et al. : a surface with an asymmetrical triangular profile (a "factory-roof" shape), developed on the scale of a few micrometers, thus somewhat larger than usually suggested in the related literature. The profile of the overlayer corrugated surface of the coating film was copied from the natural model. Yet, the actual dimensions and material composition have been optimized to take into account the high refractive index of the GaN diode stack. The optimization proc...

Bay, Annick; Sarrazin, Michael; Belarouci, Ali; Aimez, Vincent; Francis, Laurent A; Vigneron, Jean Pol

2012-01-01T23:59:59.000Z

260

Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LED's  

SciTech Connect (OSTI)

Synopsis: Light loss factors are used to help lighting systems meet quantitative design criteria throughout the life of the installation, but they also influence energy use. As the light sources currently being specified continue to evolve, it is necessary to reevaluate the methods used in calculating light loss factors, as well as carefully consider the consequences of different product performance attributes. Because of the unique operating characteristics of LEDs and lack of a comprehensive lifetime rating—as well as the problematic relationship between lifetime and lumen maintenance—determining an appropriate lamp lumen depreciation (LLD) factor for LED products is difficult. As a result, a unique solution has been advocated: when quantity of light is an important design consideration, the IES recommends using an LLD of not greater than 0.70. This method deviates from the typical practice for conventional sources of using the ratio of mean to initial lumen output, and can misrepresent actual performance, increase energy use, and inhibit comparisons between products. This paper discusses the complications related to LLD and LEDs, compares the performance of conventional and LED products, and examines alternatives to a maximum LLD of 0.70 for LEDs.

Royer, Michael P.

2013-09-17T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Differential spectral responsivity measurement of photovoltaic detectors with a light-emitting-diode-based integrating sphere source  

SciTech Connect (OSTI)

We present an experimental realization of differential spectral responsivity measurement by using a light-emitting diode (LED)-based integrating sphere source. The spectral irradiance responsivity is measured by a Lambertian-like radiation field with a diameter of 40mm at the peak wavelengths of the 35 selectable LEDs covering a range from 280 to 1550nm. The systematic errors and uncertainties due to lock-in detection, spatial irradiance distribution, and reflection from the test detector are experimentally corrected or considered. In addition, we implemented a numerical procedure to correct the error due to the broad spectral bandwidth of the LEDs. The overall uncertainty of the DSR measurement is evaluated to be 2.2% (k=2) for Si detectors. To demonstrate its application, we present the measurement results of two Si photovoltaic detectors at different bias irradiance levels up to 120mW/cm{sup 2}.

Zaid, Ghufron; Park, Seung-Nam; Park, Seongchong; Lee, Dong-Hoon

2010-12-10T23:59:59.000Z

262

Observation of enhanced visible and infrared emissions in photonic crystal thin-film light-emitting diodes  

SciTech Connect (OSTI)

Photonic crystals, in the form of closed-packed nano-pillar arrays patterned by nanosphere lithography, have been formed on the n-faces of InGaN thin-film vertical light-emitting diodes (LEDs). Through laser lift-off of the sapphire substrate, the thin-film LEDs conduct vertically with reduced dynamic resistances, as well as reduced thermal resistances. The photonic crystal plays a role in enhancing light extraction, not only at visible wavelengths but also at infrared wavelengths boosting heat radiation at high currents, so that heat-induced effects on internal quantum efficiencies are minimized. The observations are consistent with predictions from finite-difference time-domain simulations.

Cheung, Y. F.; Li, K. H.; Hui, R. S. Y.; Choi, H. W., E-mail: hwchoi@hku.hk [Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road (Hong Kong)

2014-08-18T23:59:59.000Z

263

Two-color photoionization of calcium using SHG and LED light  

E-Print Network [OSTI]

We present a photoionization method to load single 40Ca ions in a linear Paul trap from an atomic beam. Neutral Ca I atoms are resonantly excited from the ground state to the intermediate 4s4p 1P_1-level using coherent 423nm radiation produced by single-pass second harmonic generation in a periodically poled KTiOPO_4 crystal pumped with an 120mW extended cavity diode laser. Ionization is then attained with a high-power light emitting diode imaged to the trap center, using an appropriately designed optical system composed of standard achromatic doublet lenses. The setup simplifies previous implementations at similar efficiency, and it hardly requires any maintenance at all.

C. Schuck; F. Rohde; M. Almendros; M. Hennrich; J. Eschner

2009-11-19T23:59:59.000Z

264

Components, production processes, and recommendations for future research in organic light emitting diodes  

E-Print Network [OSTI]

Organic Light Emitting Diodes (OLEDs) are small, optoelectronic devices that can be used in the production of energy-efficient, high definition displays in cell phones, computers, and televisions. These devices have great ...

Hunting, Lindsay (Lindsay E.)

2009-01-01T23:59:59.000Z

265

Storage of charge carriers on emitter molecules in organic light-emitting diodes  

E-Print Network [OSTI]

Organic light-emitting diodes (OLEDs) using the red phosphorescent emitter iridium(III)bis(2-methyldibenzo[f,h]quinoxaline) (acetylacetonate) [Ir(MDQ)[subscript 2](acac)] are studied by time-resolved electroluminescence ...

Reineke, Sebastian

266

Consumer Light Bulb Changes: Briefing and Resources for Media...  

Broader source: Energy.gov (indexed) [DOE]

flux") - CFL: Compact Fluorescent Lamp: The curly fluorescent bulbs - LED: Light Emitting Diode: more recently emerging technology, also called "solid state lighting" as it is...

267

Ultrastrong light-matter coupling in electrically doped microcavity organic light emitting diodes  

SciTech Connect (OSTI)

The coupling of the electromagnetic field with an electronic transition gives rise, for strong enough light-matter interactions, to hybrid states called exciton-polaritons. When the energy exchanged between light and matter becomes a significant fraction of the material transition energy an extreme optical regime called ultrastrong coupling (USC) is achieved. We report a microcavity embedded p-i-n monolithic organic light emitting diode working in USC, employing a thin film of squaraine dye as active layer. A normalized coupling ratio of 30% has been achieved at room temperature. These USC devices exhibit a dispersion-less angle-resolved electroluminescence that can be exploited for the realization of innovative optoelectronic devices. Our results may open the way towards electrically pumped polariton lasers.

Mazzeo, M., E-mail: marco.mazzeo@unisalento.it [Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento, Via Monteroni, 73100 Lecce (Italy); NNL, Istituto Nanoscienze - CNR, Via Arnesano, 73100 Lecce (Italy); Genco, A. [Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento, Via Monteroni, 73100 Lecce (Italy); Gambino, S. [NNL, Istituto Nanoscienze - CNR, Via Arnesano, 73100 Lecce (Italy); CBN, Istituto Italiano Tecnologia, Via Barsanti 1, 73010 Lecce (Italy); Ballarini, D.; Mangione, F.; Sanvitto, D. [NNL, Istituto Nanoscienze - CNR, Via Arnesano, 73100 Lecce (Italy); Di Stefano, O.; Patanè, S.; Savasta, S. [Dipartimento di Fisica e Scienze della Terra, Università di Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina (Italy); Gigli, G. [Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento, Via Monteroni, 73100 Lecce (Italy); NNL, Istituto Nanoscienze - CNR, Via Arnesano, 73100 Lecce (Italy); CBN, Istituto Italiano Tecnologia, Via Barsanti 1, 73010 Lecce (Italy)

2014-06-09T23:59:59.000Z

268

E-Print Network 3.0 - advanced uv light Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

vapour lamp. We propose and demonstrate charge management using a deep UV light emitting diode (LED... sufficient for LISA applications. We have directly observed the LED ......

269

Understanding Drooping Light Emitting Diodes CEEM | U.S. DOE...  

Office of Science (SC) Website

Impact Understanding "droop" may result in cheaper, more efficient LEDs; LEDs are more energy efficient, smaller, and longer-lived than incandescent lamps or fluorescent...

270

Surface plasmon enhanced InGaN light emitter Koichi Okamoto*a  

E-Print Network [OSTI]

is a very promising method for developing the super bright light emitting diodes (LEDs). Moreover, we foundGaN/GaN, light emitting diode, quantum well, internal quantum efficiency, solid-state light source 1. INTRODUCTION Since 1993, InGaN quantum wells (QW)-based light emitting diodes (LEDs) have been continuously

Okamoto, Koichi

271

An Investigation into the Perception of Color under LED White Composite Spectra with Modulated Color Rendering  

E-Print Network [OSTI]

emitting diodes, LEDs. We examined seven LED white composite spectra with different color rendering of a pilot study that evaluates the perceptual impact of modulation of color rendering using multi-chip light

O'Reilly, Una-May

272

LED Lighting Flicker and Potential Health Concerns: IEEE Standard PAR1789 Update  

E-Print Network [OSTI]

for mitigating health risks to viewers" has been formed to advise the lighting industry, ANSI/NEMA, IEC, Energy. The effects of flicker can range from decreased visual performance to non-specific malaise to the onset and decisions to be made on development of future LED lamps as the market continues to have explosive growth

Lehman, Brad

273

Space charge spectroscopy of integrated quantum well infrared photodetectorlight emitting diode  

E-Print Network [OSTI]

Space charge spectroscopy of integrated quantum well infrared photodetector±light emitting diode M ± light emitting diode (QWIP-LED). Quasistatic capacitance±voltage (C±V ) characteristics under reverse.V. All rights reserved. Keywords: Quantum-well infrared photodetector; Light-emitting diode; Space charge

Perera, A. G. Unil

274

Electro-luminescent cooling: light emitting diodes above unity efficiency  

E-Print Network [OSTI]

Experimental demonstration of net electro-luminescent cooling in a diode, or equivalently electroluminescence with wall-plug efficiency greater than unity, had eluded direct observation for more than five decades. We review ...

Santhanam, Parthiban

275

Fabrication and Characterization of New Hybrid Organic Light Emitting Diode (OLED): Europium-picrate-triethylene oxide Complex  

SciTech Connect (OSTI)

Thin-film light emitting devices based on organic materials have attracted vast interest in applications such as light emitting diode (LED) and flat-panel display. The organic material can be attached with inorganic material to enhance the performance of the light emitting device. A hybrid OLED based on a new complex of europium picrate (Eu-pic) with triethylene oxide (EO3) ligand is fabricated. The OLED is fabricated by using spin coating technique with acetone as the solvent and aluminum as the top electrode. The optical, photoluminescence (PL) and electrical properties of the sample are carried out by UV-Vis spectroscopy (Jasco V-750), luminescence spectroscopy (Perkin Elmer LS-500) and source measure unit (SMU)(Keithly), respectively.

Sarjidan, M. A. Mohd; Abu Zakaria, N. Z. A.; Abd. Majid, W. H. [Solid State Research Laboratory, Department of Physics, University of Malaya, 50603, Kuala Lumpur (Malaysia); Kusrini, Eny; Saleh, M. I. [School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia)

2009-07-07T23:59:59.000Z

276

Energy Department Offers $10 Million for Energy-Saving Lighting...  

Broader source: Energy.gov (indexed) [DOE]

technologies. This funding will help accelerate the development of high-quality light-emitting diode (LED) and organic light-emitting diode (OLED) products with the potential to...

277

Phosphors for near UV-Emitting LED's for Efficacious Generation of White Light  

SciTech Connect (OSTI)

1) We studied phosphors for near-UV (nUV) LED application as an alternative to blue LEDs currently being used in SSL systems. We have shown that nUV light sources could be very efficient at high current and will have significantly less binning at both the chip and phosphor levels. We identified phosphor blends that could yield 4100K lamps with a CRI of approximately 80 and LPWnUV,opt equal to 179 for the best performing phosphor blend. Considering the fact that the lamps were not optimized for light coupling, the results are quite impressive. The main bottleneck is an optimum blue phosphor with a peak near 440 nm with a full width half maximum of about 25 nm and a quantum efficiency of >95%. Unfortunately, that may be a very difficult task when we want to excite a phosphor at ~400 nm with a very small margin for Stokes shift. Another way is to have all the phosphors in the blend having the excitation peak at 400 nm or slightly shorter wavelength. This could lead to a white light source with no body color and optimum efficacy due to no self-absorption effects by phosphors in the blend. This is even harder than finding an ideal blue phosphor, but not necessarily impossible. 2) With the phosphor blends identified, light sources using nUV LEDs at high current could be designed with comparable efficacy to those using blue LEDs. It will allow us to design light sources with multiple wattages using the same chips and phosphor blends simply by varying the input current. In the case of blue LEDs, this is not currently possible because varying the current will lower the efficacy at high current and alter the color point. With improvement of phosphor blends, control over CRI could improve. Less binning at the chip level and also at the phosphor blend level could reduce the cost of SSL light sources. 3) This study provided a deeper understanding of phosphor characteristics needed for LEDs in general and nUV LEDs in particular. Two students received Ph.D. degrees and three undergraduates participated in this work. Two of the undergraduate students are now in graduate school. The results were widely disseminated – 20 archival journal publications (published, accepted or in preparation) and three conference proceedings resulted. The students presented their work at 11 different national/international conferences (32 oral or poster presentations) and the PI’s delivered 12 invited, keynote or plenary lectures.

McKittrick, Joanna

2013-09-30T23:59:59.000Z

278

Self-reported Impacts of LED Lighting Technology Compared to Fuel-based Lighting on Night Market Business Prosperity in Kenya  

E-Print Network [OSTI]

Time period Pre 07/2008 Lighting Technology (Nightly Cost,2 Self-reported Impacts of LED Lighting Technology Comparedto Fuel-based Lighting on Night Market Business Prosperity

Johnstone, Peter

2009-01-01T23:59:59.000Z

279

LED Lamp Project Lights the Way to Flicker-Free Replacement Jade Sky Technologies and UC Davis's California Lighting Technology Center demonstrate the  

E-Print Network [OSTI]

, 2014 ­ Jade Sky Technologies ("JST"), a clean-tech start-up manufacturer of LED Technologies and UC Davis's California Lighting Technology Center demonstrate the lighting Specification. JST collaborated with UC Davis's California Lighting Technology Center

California at Davis, University of

280

Text-Alternative Version: LED Site Lighting in the Commercial Building Sector: Opportunities, Challenges, and the CBEA Performance Specification  

Broader source: Energy.gov [DOE]

Below is the text-alternative version of the LED Site Lighting in the Commercial Building Sector: Opportunities, Challenges, and the CBEA Performance Specification webcast.

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Vacuum-free lamination of low work function cathode for efficient solution-processed organic light-emitting diodes  

E-Print Network [OSTI]

-coated organic light-emitting diode is transferred from a soft polydimethylsiloxane (PDMS) mold by lamination, or blade coating [1,2] for organic light emitting diode (OLED) as well as solar cell. The top electrodeVacuum-free lamination of low work function cathode for efficient solution-processed organic light-emitting

Meng, Hsin-Fei

282

Method and apparatus for improving the performance of light emitting diodes  

DOE Patents [OSTI]

A method for increasing the resistance of a light emitting diode and other semiconductor devices to extremes of temperature is disclosed. During the manufacture of the light emitting diode, a liquid coating is applied to the light emitting die after the die has been placed in its lead frame. After the liquid coating has been placed on the die and its lead frames, a thermosetting encapsulant material is placed over the coating. The operation that cures the thermosetting material leaves the coating liquid intact. As the die and the encapsulant expand and contract at different rates with respect to changes in temperature, and as in known light emitting diodes the encapsulating material adheres to the die and lead frames, this liquid coating reduces the stresses that these different rates of expansion and contraction normally cause by eliminating the adherence of the encapsulating material to the die and frame.

Lowery, Christopher H. (Fremont, CA); McElfresh, David K. (Union City, CA); Burchet, Steve (Cedar Crest, NM); Adolf, Douglas B. (Albuquerque, NM); Martin, James (Tijeras, NM)

1996-01-01T23:59:59.000Z

283

Printed assemblies of ultrathin, microscale inorganic light emitting diodes for deformable and semitransparent displays  

DOE Patents [OSTI]

Described herein are printable structures and methods for making, assembling and arranging electronic devices. A number of the methods described herein are useful for assembling electronic devices where one or more device components are embedded in a polymer which is patterned during the embedding process with trenches for electrical interconnects between device components. Some methods described herein are useful for assembling electronic devices by printing methods, such as by dry transfer contact printing methods. Also described herein are GaN light emitting diodes and methods for making and arranging GaN light emitting diodes, for example for display or lighting systems.

Rogers, John A; Nuzzo, Ralph; Kim, Hoon-sik; Brueckner, Eric; Park, Sang Il; Kim, Rak Hwan

2014-10-21T23:59:59.000Z

284

New red phosphor for near-ultraviolet light-emitting diodes with high color-purity  

SciTech Connect (OSTI)

New red phosphors, Na{sub 5}Eu(MoO{sub 4}){sub 4} doped with boron oxide were prepared by the solid-state reaction. Their structure and photo-luminescent properties were investigated. With the introduction of boron oxide, the red emission intensity of the phosphors under 395 nm excitation is strengthened, with high color-purity (x = 0.673, y = 0.327). The single red light-emitting diode was obtained by combining InGaN chip with the red phosphor, bright red light can be observed by naked eyes from the red light-emitting diodes under a forward bias of 20 mA.

Wang, Zhengliang, E-mail: wzhl_ww@yahoo.com.cn [School of Chemistry and Biotechnology, Yunnan Nationalities University, Kunming, Yunnan 650031 (China)] [School of Chemistry and Biotechnology, Yunnan Nationalities University, Kunming, Yunnan 650031 (China); He, Pei; Wang, Rui [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China)] [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China); Zhao, Jishou [School of Chemistry and Biotechnology, Yunnan Nationalities University, Kunming, Yunnan 650031 (China)] [School of Chemistry and Biotechnology, Yunnan Nationalities University, Kunming, Yunnan 650031 (China); Gong, Menglian [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China)] [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China)

2010-02-15T23:59:59.000Z

285

Development of Advanced Manufacturing Methods for Warm White LEDs for General Lighting  

SciTech Connect (OSTI)

GE Lighting Solutions will develop precise and efficient manufacturing techniques for the “remote phosphor” platform of warm-white LED products. In volume, this will be demonstrated to drive significant materials, labor and capital productivity to achieve a maximum possible 53% reduction in overall cost. In addition, the typical total color variation for these white LEDs in production will be well within the ANSI bins and as low as a 4-step MacAdam ellipse centered on the black body curve. Achievement of both of these objectives will be demonstrated while meeting a performance target of > 75 lm/W for a warm-white LED and a reliability target of <30% lumen drop / <2-step MacAdam ellipse shift, estimated over 50,000 hrs.

Deshpande, Anirudha; Kolodin, Boris; Jacob, Cherian; Chowdhury, Ashfaqul; Kuenzler, Glenn; Sater, Karen; Aesram, Danny; Glaettli, Steven; Gallagher, Brian; Langer, Paul; Setlur, Anant; Beers, Bill

2012-03-31T23:59:59.000Z

286

Surface Plasmon Enhanced Phosphorescent Organic Light Emitting Diodes  

SciTech Connect (OSTI)

The objective of the proposed work was to develop the fundamental understanding and practical techniques for enhancement of Phosphorescent Organic Light Emitting Diodes (PhOLEDs) performance by utilizing radiative decay control technology. Briefly, the main technical goal is the acceleration of radiative recombination rate in organometallic triplet emitters by using the interaction with surface plasmon resonances in noble metal nanostructures. Increased photonic output will enable one to eliminate constraints imposed on PhOLED efficiency by triplet-triplet annihilation, triplet-polaron annihilation, and saturation of chromophores with long radiative decay times. Surface plasmon enhanced (SPE) PhOLEDs will operate more efficiently at high injection current densities and will be less prone to degradation mechanisms. Additionally, introduction of metal nanostructures into PhOLEDs may improve their performance due to the improvement of the charge transport through organic layers via multiple possible mechanisms ('electrical bridging' effects, doping-like phenomena, etc.). SPE PhOLED technology is particularly beneficial for solution-fabricated electrophosphorescent devices. Small transition moment of triplet emitters allows achieving a significant enhancement of the emission rate while keeping undesirable quenching processes introduced by the metal nanostructures at a reasonably low level. Plasmonic structures can be introduced easily into solution-fabricated PhOLEDs by blending and spin coating techniques and can be used for enhancement of performance in existing device architectures. This constitutes a significant benefit for a large scale fabrication of PhOLEDs, e.g. by roll-to-roll fabrication techniques. Besides multieexciton annihilation, the power efficacy of PhOLEDs is often limited by high operational bias voltages required for overcoming built-in potential barriers to injection and transport of electrical charges through a device. This problem is especially pronounced in solution processed OLEDs lacking the accuracy and precision of fabrication found in their small molecule counterparts. From this point of view, it seems beneficial to develop materials allowing reduction of the operation bias voltage via improvement of the charge injection. The materials sought have to be compatible with solution-based fabrication process and allow easy incorporation of metal nanostructures.

Guillermo Bazan; Alexander Mikhailovsky

2008-08-01T23:59:59.000Z

287

DUAL USE OF LEDS: SIGNALING AND COMMUNICATIONS IN ITS Grantham Pang, Chi-ho Chan, Hugh Liu, Thomas Kwan  

E-Print Network [OSTI]

of light-emitting diodes (LEDs) over incandescent lights is well-supported. This is due to their high shown that the high brightness LEDs are significantly brighter than the incandescent lights lights with LEDs is a reduction in power consumption [7]. In addition, incandescent traffic signals burn

Pang, Grantham

288

Layering Mismatched Lattices Creates Long-Sought-After Green Light-Emitting Diode (Fact Sheet)  

SciTech Connect (OSTI)

Scientists at the National Renewable Energy Laboratory (NREL) invent a deep green LED that can lead to higher-efficiency white light, lower electric bills.

Not Available

2011-02-01T23:59:59.000Z

289

Advanced Epi Tools for Gallium Nitride Light Emitting Diode Devices  

SciTech Connect (OSTI)

Over the course of this program, Applied Materials, Inc., with generous support from the United States Department of Energy, developed a world-class three chamber III-Nitride epi cluster tool for low-cost, high volume GaN growth for the solid state lighting industry. One of the major achievements of the program was to design, build, and demonstrate the world’s largest wafer capacity HVPE chamber suitable for repeatable high volume III-Nitride template and device manufacturing. Applied Materials’ experience in developing deposition chambers for the silicon chip industry over many decades resulted in many orders of magnitude reductions in the price of transistors. That experience and understanding was used in developing this GaN epi deposition tool. The multi-chamber approach, which continues to be unique in the ability of the each chamber to deposit a section of the full device structure, unlike other cluster tools, allows for extreme flexibility in the manufacturing process. This robust architecture is suitable for not just the LED industry, but GaN power devices as well, both horizontal and vertical designs. The new HVPE technology developed allows GaN to be grown at a rate unheard of with MOCVD, up to 20x the typical MOCVD rates of 3{micro}m per hour, with bulk crystal quality better than the highest-quality commercial GaN films grown by MOCVD at a much cheaper overall cost. This is a unique development as the HVPE process has been known for decades, but never successfully commercially developed for high volume manufacturing. This research shows the potential of the first commercial-grade HVPE chamber, an elusive goal for III-V researchers and those wanting to capitalize on the promise of HVPE. Additionally, in the course of this program, Applied Materials built two MOCVD chambers, in addition to the HVPE chamber, and a robot that moves wafers between them. The MOCVD chambers demonstrated industry-leading wavelength yield for GaN based LED wafers and industry-leading uptime enabled in part by a novel in-situ cleaning process developed in this program.

Patibandla, Nag; Agrawal, Vivek

2012-12-01T23:59:59.000Z

290

Effect of mechanical vibrations on light emitting diode luminaires.  

E-Print Network [OSTI]

??In this work, a LED and two types of Compact fluorescent lamps were investigated for the intensity variation due to mechanical vibrations in the range… (more)

Paladugu, Jayalakshmi

2009-01-01T23:59:59.000Z

291

Origin of InGaN/GaN light-emitting diode efficiency improvements using tunnel-junction-cascaded active regions  

SciTech Connect (OSTI)

This Letter investigates the efficiency enhancement achieved by tunnel junction insertion into the InGaN/GaN multi-quantum well (MQW) active region of blue light emitting diodes (LEDs). The peak quantum efficiency of such LED exceeds 100%, but the maximum wall-plug efficiency (WPE) hardly changes. However, due to the increased bias, the WPE peaks at much higher input power, i.e., the WPE droop is significantly delayed, and the output power is strongly enhanced. The main physical reason for this improvement lies in the non-uniform vertical carrier distribution typically observed within InGaN MQWs.

Piprek, Joachim, E-mail: piprek@nusod.org [NUSOD Institute LLC, P.O. Box 7204, Newark, Delaware 19714 (United States)

2014-02-03T23:59:59.000Z

292

Zinc Oxide and Nitride Nanowire Based Light Emitting Diodes  

E-Print Network [OSTI]

of incandescent light bulb, fluorescent lamp, and blue lightof incandescent light bulb, fluorescent lamp, and blue lightincandescent bulb and is on the same order as fluorescent

Lai, Elaine Michelle

2009-01-01T23:59:59.000Z

293

Zinc Oxide and Nitride Nanowire Based Light Emitting Diodes  

E-Print Network [OSTI]

only be able to find incandescent lightbulbs and fluorescent10: Output spectra of incandescent light bulb, fluorescentemission spectra. The incandescent light bulb for example

Lai, Elaine Michelle

2009-01-01T23:59:59.000Z

294

Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming  

DOE Patents [OSTI]

The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

Li, Ting (Ventura, CA)

2011-04-26T23:59:59.000Z

295

Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming  

DOE Patents [OSTI]

The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

Li, Ting

2013-08-13T23:59:59.000Z

296

Growths of staggered InGaN quantum wells light-emitting diodes emitting at 520525 nm employing graded growth-temperature profile  

E-Print Network [OSTI]

Growths of staggered InGaN quantum wells light-emitting diodes emitting at 520­525 nm employing current spreading and light extraction in GaN-based light emitting diodes Appl. Phys. Lett. 100, 061107 (2012) Electrically driven nanopyramid green light emitting diode Appl. Phys. Lett. 100, 061106 (2012

Gilchrist, James F.

297

Evaluation of potential applications for templated arrays of heterostructural semiconductor nanowires as light emitting devices  

E-Print Network [OSTI]

While light emitting devices, such as laser diodes (LDs) and light emitting diodes (LEDs), were first introduced decades ago, they have been the subject of continuing research and improvements due to their relatively poor ...

Zou, Ting, M. Eng. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

298

Multi-Wavelength Visible Light Communication System Design Pankil Butala 1a  

E-Print Network [OSTI]

-converted light emitting diodes, or by filtering to iso- late the blue component from these sources. Multi efficient illumination devices called light emitting diodes (LED). The intensity of radiant flux emitted

Little, Thomas

299

Soft holographic interference lithography microlens for enhanced organic light emitting diode light extraction  

SciTech Connect (OSTI)

Very uniform 2 {micro}m-pitch square microlens arrays ({micro}LAs), embossed on the blank glass side of an indium-tin-oxide (ITO)-coated 1.1 mm-thick glass, are used to enhance light extraction from organic light-emitting diodes (OLEDs) by {approx}100%, significantly higher than enhancements reported previously. The array design and size relative to the OLED pixel size appear to be responsible for this enhancement. The arrays are fabricated by very economical soft lithography imprinting of a polydimethylsiloxane (PDMS) mold (itself obtained from a Ni master stamp that is generated from holographic interference lithography of a photoresist) on a UV-curable polyurethane drop placed on the glass. Green and blue OLEDs are then fabricated on the ITO to complete the device. When the {mu}LA is {approx}15 x 15 mm{sup 2}, i.e., much larger than the {approx}3 x 3 mm{sup 2} OLED pixel, the electroluminescence (EL) in the forward direction is enhanced by {approx}100%. Similarly, a 19 x 25 mm{sup 2} {mu}LA enhances the EL extracted from a 3 x 3 array of 2 x 2 mm{sup 2} OLED pixels by 96%. Simulations that include the effects of absorption in the organic and ITO layers are in accordance with the experimental results and indicate that a thinner 0.7 mm thick glass would yield a {approx}140% enhancement.

Park, Joong-Mok; Gan, Zhengqing; Leung, Wai Y.; Liu, Rui; Ye, Zhuo; Constant, Kristen; Shinar, Joseph; Shinar, Ruth; Ho, Kai-Ming

2011-06-06T23:59:59.000Z

300

Philips Light Sources & Electronics is Developing an Efficient, Smaller, Cost-Effective Family of LED Drivers  

Broader source: Energy.gov [DOE]

With the help of DOE funding, Philips Light Sources & Electronics is developing a new family of LED drivers that are more efficient and cost-effective as well as smaller in size than currently available drivers. The new drivers are switch-mode power supplies that are similar to today's drivers, but with an improved design. In addition, they have a different topology—boost plus LLC—for wattages of 40W and above, but they retain the commonly used flyback topology at lower wattages.

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

SciTech Connect: Demonstration Assessment of Light-Emitting Diode (LED)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systems controllerAdditiveBetatronAerogel Deep Bed AdsorptionPost-Top

302

LED Lighting in a Performing Arts Building at the University of Florida  

SciTech Connect (OSTI)

The U.S. DOE GATEWAY Demonstration Program supports demonstrations of high-performance solid-state lighting (SSL) products in order to develop empirical data and experience with the in-the-field applications of this advanced lighting technology. This report describes the process and results of the 2013 - 2014 GATEWAY demonstration of SSL technology in the Nadine McGuire Theatre and Dance Pavilion at the University of Florida, Gainesville, FL. The LED solutions combined with dimming controls utilized in four interior spaces - the Acting Studio, Dance Studio, Scene Shop, and Dressing Room - received high marks from instructors, students/performers, and reduced energy use in all cases. The report discusses in depth and detail of each project area including specifications, energy savings, and user observations. The report concludes with lessons learned during the demonstration.

Miller, Naomi J.; Kaye, Stan; Coleman, Patricia; Wilkerson, Andrea M.; Perrin, Tess E.; Sullivan, Gregory P.

2014-07-01T23:59:59.000Z

303

Local tuning of organic light-emitting diode color by dye droplet application  

E-Print Network [OSTI]

Local tuning of organic light-emitting diode color by dye droplet application T. R. Hebner and J. C 1998 We have demonstrated that fluorescent dyes may be introduced into previously fabricated polymer thin films by local application of a dye-containing droplet. The UV fluorescence spectra of the films

304

Solvent-enhanced dye diffusion in polymer thin films for polymer light-emitting diode application  

E-Print Network [OSTI]

Solvent-enhanced dye diffusion in polymer thin films for polymer light-emitting diode application 2004; accepted 24 August 2004) The method of solvent-enhanced dye diffusion for patterning full dry transfer of dye onto a device polymer film, the dye remains on the surface of the polymer layer

305

InP-Based Oxide-Confined 16 p.m Microcavity Light Emitting Diodes Weidong Zhou, Omar Qasaimeh, and Pallab Bhattacharya  

E-Print Network [OSTI]

InP-Based Oxide-Confined 16 p.m Microcavity Light Emitting Diodes Weidong Zhou, Omar Qasaimeh light emitting diodes (MCLEDs) have been designed, fabricated and characterized. Oxide- confined MCLEDs region emission peak and cavity resonance peak. Key words: Microcavity light emitting diode (MCLED), wet

Zhou, Weidong

306

Confocal microphotoluminescence of InGaN-based light-emitting diodes Koichi Okamoto,a  

E-Print Network [OSTI]

for conventional incandescent and fluorescent light bulbs.5 However, luminous efficacies of commercial white LEDs spectrum region, the external quantum efficiency ext of the LED has achieved 20% at room temperature 25 lm/W have been still lower than that of fluorescent tubes 75 lm/W . Thus, the most important re

Okamoto, Koichi

307

High Performance Green LEDs by Homoepitaxial  

SciTech Connect (OSTI)

This work's objective was the development of processes to double or triple the light output power from green and deep green (525 - 555 nm) AlGaInN light emitting diode (LED) dies within 3 years in reference to the Lumileds Luxeon II. The project paid particular effort to all aspects of the internal generation efficiency of light. LEDs in this spectral region show the highest potential for significant performance boosts and enable the realization of phosphor-free white LEDs comprised by red-green-blue LED modules. Such modules will perform at and outperform the efficacy target projections for white-light LED systems in the Department of Energy's accelerated roadmap of the SSL initiative.

Wetzel, Christian; Schubert, E Fred

2009-11-22T23:59:59.000Z

308

Enhanced optical power of GaN-based light-emitting diode with compound photonic crystals by multiple-exposure nanosphere-lens lithography  

SciTech Connect (OSTI)

The light-emitting diodes (LEDs) with single, twin, triple, and quadruple photonic crystals (PCs) on p-GaN are fabricated by multiple-exposure nanosphere-lens lithography (MENLL) process utilizing the focusing behavior of polystyrene spheres. Such a technique is easy and economical for use in fabricating compound nano-patterns. The optimized tilted angle is decided to be 26.6° through mathematic calculation to try to avoid the overlay of patterns. The results of scanning electron microscopy and simulations reveal that the pattern produced by MENLL is a combination of multiple ovals. Compared to planar-LED, the light output power of LEDs with single, twin, triple, and quadruple PCs is increased by 14.78%, 36.03%, 53.68%, and 44.85% under a drive current 350?mA, respectively. Furthermore, all PC-structures result in no degradation of the electrical properties. The stimulated results indicate that the highest light extraction efficiency of LED with the clover-shape triple PC is due to the largest scattering effect on propagation of light from GaN into air.

Zhang, Yonghui; Wei, Tongbo, E-mail: tbwei@semi.ac.cn; Xiong, Zhuo; Shang, Liang; Tian, Yingdong; Zhao, Yun; Zhou, Pengyu; Wang, Junxi; Li, Jinmin [Semiconductor Lighting Technology Research and Development Center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

2014-07-07T23:59:59.000Z

309

Photodegradation and wavelength dependency of blue polymer light-emitting diode devices  

SciTech Connect (OSTI)

A systematic study of the wavelength dependency of the photodegradation of blue polymer light-emitting diodes is reported. Clearly two different regions can be distinguished, inside the absorption band, where the strongest and permanent photodegradation is found, and at wavelengths above the edge of absorption, where at least partially reversible photodegradation is observed. Irradiation experiments on samples with and without a cathode show the effect of the cathode-polymer interface and its contribution to the degradation mechanisms involved.

Colditz, H.J.O.; Kurt, R.; Buechel, M. [Royal Philips Electronics, Philips Research Laboratories Eindhoven, High Tech Campus 4 (WAG11), 5656 AE Eindhoven (Netherlands)

2005-12-19T23:59:59.000Z

310

Digital Architecture for Driving Large LED Arrays with Dynamic Bus Voltage Regulation and Phase Shifted PWM  

E-Print Network [OSTI]

Emitting Diodes (HB-LEDs) with improved system efficiency and reduced EMI. Key advantages are achieved - This paper introduces a digital architecture suitable for driving a large number of High Brightness Light

311

Transcranial LED therapy for cognitive dysfunction in chronic, mild traumatic brain injury: Two case reports  

E-Print Network [OSTI]

Two chronic, traumatic brain injury (TBI) cases are presented, where cognitive function improved following treatment with transcranial light emitting diodes (LEDs). At age 59, P1 had closed-head injury from a motor vehicle ...

Hamblin, Michael R.

312

Deposition of colloidal quantum dots by microcontact printing for LED display technology  

E-Print Network [OSTI]

This thesis demonstrates a new deposition method of colloidal quantum dots within a quantum dot organic light-emitting diode (QD-LED). A monolayer of quantum dots is microcontact printed as small as 20 ,Lm lines as well ...

Kim, LeeAnn

2006-01-01T23:59:59.000Z

313

The Spectrum of Clean Energy Innovationinnovati nGreen Light-Emitting Diode Makes  

E-Print Network [OSTI]

- ing as an efficient solid-state light source, able to replace incandescent and compact fluorescent light bulbs in many applications. A new green LED from NREL may yield more efficient solid to accelerating market deployment, NREL works in partnership with private industry to drive the transformation

314

Growth and characterizations of GaN micro-rods on graphene films for flexible light emitting diodes  

SciTech Connect (OSTI)

We report the growth of GaN micro-rods and coaxial quantum-well heterostructures on graphene films, together with structural and optical characterization, for applications in flexible optical devices. Graphene films were grown on Cu foil by means of chemical vapor deposition, and used as the substrates for the growth of the GaN micro-rods, which were subsequently transferred onto SiO{sub 2}/Si substrates. Highly Si-doped, n-type GaN micro-rods were grown on the graphene films using metal–organic chemical vapor deposition. The growth and vertical alignment of the GaN micro-rods, which is a critical factor for the fabrication of high-performance light-emitting diodes (LEDs), were characterized using electron microscopy and X-ray diffraction. The GaN micro-rods exhibited promising photoluminescence characteristics for optoelectronic device applications, including room-temperature stimulated emission. To fabricate flexible LEDs, In{sub x}Ga{sub 1–x}N/GaN multiple quantum wells and a p-type GaN layer were deposited coaxially on the GaN micro-rods, and transferred onto Ag-coated polymer substrates using lift-off. Ti/Au and Ni/Au metal layers were formed to provide electrical contacts to the n-type and p-type GaN regions, respectively. The micro-rod LEDs exhibited intense emission of visible light, even after transfer onto the flexible polymer substrate, and reliable operation was achieved following numerous cycles of mechanical deformation.

Chung, Kunook; Beak, Hyeonjun; Tchoe, Youngbin; Oh, Hongseok; Yi, Gyu-Chul, E-mail: gcyi@snu.ac.kr [Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Yoo, Hyobin; Kim, Miyoung [Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2014-09-01T23:59:59.000Z

315

All-small-molecule efficient white organic light-emitting diodes by multi-layer blade coating  

E-Print Network [OSTI]

Letter All-small-molecule efficient white organic light-emitting diodes by multi-layer blade-molecule organic light-emitting diodes are fabricated by multi-layer blade coating on hot plate at 80 °C with hot.3 lm/W). Orange emitter iridium(III)bis (4-(4-t-butylphenyl) thie- no[3,2-c]pyridinato-N,C20

Meng, Hsin-Fei

316

Light extraction enhanced white light-emitting diodes with multi-layered phosphor configuration  

E-Print Network [OSTI]

The phosphor conversion efficiency ( ? PCE ) can becalculated by ? PCE = ? q × ? p = P Y + P R P B o ? P Bconversion efficiency (PCE) of BL-R/Y LEDs and mixed-RY LEDs

You, Jiun Pyng; Tran, Nguyen T.; Shi, Frank G.

2010-01-01T23:59:59.000Z

317

DOE Publishes Technical Brief Clarifying Misconceptions about Safety of LED Lighting  

Broader source: Energy.gov [DOE]

The spectral emission of LEDs is a frequent subject of concern, so to set the record straight, the U.S. Department of Energy has published a technical brief entitled True Colors: LEDs and the...

318

Organic Light Emitting Diodes Using a Ga:ZnO Anode  

SciTech Connect (OSTI)

We report the application of gallium doped zinc oxide (GZO) films as anodes in organic light emitting diodes (OLEDs). Pulsed laser deposited GZO films of differing Ga composition are examined. Bilayer OLEDs using GZO and indium tin oxide (ITO) anodes are then compared. Relative to ITO, the GZO anodes have slightly better sheet resistance and transparency in the visible spectral region. Device data suggest GZO results in more effective hole injection into an aromatic triamine hole transporting layer. Indium free anodes are expected toimprove OLED stability while lowering the cost per unit area, crucial for OLED based lighting applications.

Berry, J. J.; Ginley, D. S.; Burrows, Paul E.

2008-05-12T23:59:59.000Z

319

Over the past decade, lighting became more efficient across all...  

Broader source: Energy.gov (indexed) [DOE]

of light output (in lumen-hours) provided by each lamp type. "Other" includes light-emitting diode (LED) lamps as well as other lamps such as fiber optic lights, induction lamps,...

320

Nanospherical-lens lithographical Ag nanodisk arrays embedded in p-GaN for localized surface plasmon-enhanced blue light emitting diodes  

SciTech Connect (OSTI)

Large-scale Ag nanodisks (NDs) arrays fabricated using nanospherical-lens lithography (NLL) are embedded in p-GaN layer of an InGaN/GaN light-emitting diode (LED) for generating localized surface plasmon (LSP) coupling with the radiating dipoles in the quantum-well (QWs). Based on the Ag NDs with the controlled surface coverage, LSP leads to the improved crystalline quality of regrowth p-GaN, increased photoluminescence (PL) intensity, reduced PL decay time, and enhanced output power of LED. Compared with the LED without Ag NDs, the optical output power at a current of 350 mA of the LSP-enhanced LEDs with Ag NDs having a distance of 20 and 35 nm to QWs is increased by 26.7% and 31.1%, respectively. The electrical characteristics and optical properties of LEDs with embedded Ag NPs are dependent on the distance of between Ag NPs and QWs region. The LED with Ag NDs array structure is also found to exhibit reduced emission divergence, compared to that without Ag NDs.

Wei, Tongbo, E-mail: tbwei@semi.ac.cn; Wu, Kui; Sun, Bo; Zhang, Yonghui; Chen, Yu; Huo, Ziqiang; Hu, Qiang; Wang, Junxi; Zeng, Yiping; Li, Jinmin [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 (China); Lan, Ding [National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100080 (China)

2014-06-15T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Illuminating the Pecking Order in Off-Grid Lighting: A Demonstration of LED Lighting for Saving Energy in the Poultry Sector  

SciTech Connect (OSTI)

The Lumina Project and Lighting Africa conducted a full-scale field test involving a switch from kerosene to solar-LED lighting for commercial broiler chicken production at an off-grid farm in Kenya. The test achieved lower operating costs, produced substantially more light, improved the working environment, and had no adverse effect on yields. A strategy using conventional solar-fluorescent lighting also achieved comparable yields, but entailed a six-fold higher capital cost and significantly higher recurring battery replacement costs. Thanks to higher energy and optical efficiencies, the LED system provided approximately twice the illumination to the chicken-production area and yet drew less than half the power.At the study farm, 3000 chickens were grown in each of three identical houses under kerosene, fluorescent, and LED lighting configurations. Under baseline conditions, a yearly expenditure of 1,200 USD is required to illuminate the three houses with kerosene. The LED system eliminates this fuel use and expense with a corresponding simple payback time of 1.5 years, while the solar-fluorescent system has a payback time of 9.3 years. The corresponding reduction in fuel expenditure in both cases represents a 15percent increase in after-tax net income (revenues minus expenses) across the entire business operation. The differential cost-effectiveness between the LED and fluorescent systems would be substantially greater if the fluorescent system were upsized to provide the same light as the LED system. Providing light with the fluorescent or LED systems is also far more economical than connecting to the grid in this case. The estimated grid-connection cost at this facility is 1.7 million Kenya Schillings (approximately 21,250 USD), which is nearly six-times the cost of the fluorescent system and 35-times the cost of the LED system.The LED system also confers various non-energy benefits. The relative uniformity of LED lighting, compared to the fluorescent or kerosene lighting, reduced crowding which in turn created a less stressful environment for the chickens. The far higher levels of illumination also created a better environment for the workers, while eliminating the time required for obtaining fuel and maintaining kerosene lanterns. An additional advantage of the LED system relative to the solar fluorescent system was that the former does not require a skilled technician to carry out the installation. The portable LED system lighting layout is also more easily adjusted than that of the hardwired fluorescent systems. Furthermore, switching to the LED system avoids over one metric ton of carbon dioxide emissions per house on an annual basis compared to kerosene. There is high potential for replication of this particular LED lighting strategy in the developing world. In order to estimate the scale of kerosene use and the potential for savings, more information is needed on the numbers of chickens produced off-grid, as well as lighting uses for other categories of poultry production (egg layers, indigenous broilers ). Our discovery that weight gain did not slow in the solar-fluorescent house after it experienced extended lighting outages beginning on day 14 of the 35-day study suggests that conventional farming practices in Kenyan broiler operations may call for more hours of lighting than is needed to achieve least-cost production.

Tracy, Jennifer; Mills, Evan

2010-11-06T23:59:59.000Z

322

2012 Solid-State Lighting Manufacturing R&D Workshop Presentations...  

Broader source: Energy.gov (indexed) [DOE]

Frank Cerio, Veeco Instruments Advanced Epi Tools for Gallium Nitride Light Emitting Diode Devices Vivek Agrawal, Applied Materials Driving Down HB-LED Costs:...

323

DOE Publishes GATEWAY Report on High-Luminous-Flux LED Lighting...  

Office of Environmental Management (EM)

LED technology performs well in a region with high ambient temperature and solar radiation, it can perform well in most outdoor environments. The full report and a report...

324

Demonstration Assessment of LED Roadway Lighting: NE Cully Boulevard Portland, OR  

SciTech Connect (OSTI)

A new roadway lighting demonstration project was initiated in late 2010, which was planned in conjunction with other upgrades to NE Cully Boulevard, a residential collector road in the northeast area of Portland, OR. With the NE Cully Boulevard project, the Portland Bureau of Transportation hoped to demonstrate different light source technologies and different luminaires side-by-side. This report documents the initial performance of six different newly installed luminaires, including three LED products, one induction product, one ceramic metal halide product, and one high-pressure sodium (HPS) product that represented the baseline solution. It includes reported, calculated, and measured performance; evaluates the economic feasibility of each of the alternative luminaires; and documents user feedback collected from a group of local Illuminating Engineering Society (IES) members that toured the site. This report does not contain any long-term performance evaluations or laboratory measurements of luminaire performance. Although not all of the installed products performed equally, the alternative luminaires generally offered higher efficacy, more appropriate luminous intensity distributions, and favorable color quality when compared to the baseline HPS luminaire. However, some products did not provide sufficient illumination to all areas—vehicular drive lanes, bicycle lanes, and sidewalks—or would likely fail to meet design criteria over the life of the installation due to expected depreciation in lumen output. While the overall performance of the alternative luminaires was generally better than the baseline HPS luminaire, cost remains a significant barrier to widespread adoption. Based on the cost of the small quantity of luminaires purchased for this demonstration, the shortest calculated payback period for one of the alternative luminaire types was 17.3 years. The luminaire prices were notably higher than typical prices for currently available luminaires purchased in larger quantities. At prices that are more typical, the payback would be less than 10 years. In addition to the demonstration luminaires, a networked control system was installed for additional evaluation and demonstration purposes. The capability of control system to measure luminaire input power was explored in this study. A more exhaustive demonstration and evaluation of the control system will be the subject of future GATEWAY report(s).

Royer, Michael P.; Poplawski, Michael E.; Tuenge, Jason R.

2012-06-29T23:59:59.000Z

325

Energy 101: Lighting Choices | Department of Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in your home to energy-saving incandescent, compact fluorescent lamp (CFL), or light emitting diode (LED) bulbs could save you about 50 per year. For more information on lighting...

326

Analysis of the causes of the decrease in the electroluminescence efficiency of AlGaInN light-emitting-diode heterostructures at high pumping density  

SciTech Connect (OSTI)

The study is devoted to theoretical explanation of a decrease in the electroluminescence efficiency as the pump current increases, which is characteristic of light-emitting-diode (LED) heterostructures based on AlInGaN. Numerical simulation shows that the increase in the external quantum efficiency at low current densities J {approx} 1 A/cm{sup 2} is caused by the competition between radiative and nonradiative recombination. The decrease in the quantum efficiency at current densities J > 1 A/cm{sup 2} is caused by a decrease in the efficiency of hole injection into the active region. It is shown that the depth of the acceptor energy level in the AlGaN emitter, as well as low electron and hole mobilities in the p-type region, plays an important role in this effect. A modified LED heterostructure is suggested in which the efficiency decrease with the pump current should not occur.

Rozhansky, I. V., E-mail: igor@quantum.ioffe.ru; Zakheim, D. A. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

2006-07-15T23:59:59.000Z

327

p-doping-free InGaN/GaN light-emitting diode driven by three-dimensional hole gas  

SciTech Connect (OSTI)

Here, GaN/Al{sub x}Ga{sub 1-x}N heterostructures with a graded AlN composition, completely lacking external p-doping, are designed and grown using metal-organic-chemical-vapour deposition (MOCVD) system to realize three-dimensional hole gas (3DHG). The existence of the 3DHG is confirmed by capacitance-voltage measurements. Based on this design, a p-doping-free InGaN/GaN light-emitting diode (LED) driven by the 3DHG is proposed and grown using MOCVD. The electroluminescence, which is attributed to the radiative recombination of injected electrons and holes in InGaN/GaN quantum wells, is observed from the fabricated p-doping-free devices. These results suggest that the 3DHG can be an alternative hole source for InGaN/GaN LEDs besides common Mg dopants.

Zhang, Zi-Hui; Tiam Tan, Swee; Kyaw, Zabu; Liu, Wei; Ji, Yun; Ju, Zhengang; Zhang, Xueliang [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore) [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Wei Sun, Xiao, E-mail: EXWSUN@ntu.edu.sg [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Department of Electronics and Electrical Engineering, South University of Science and Technology of China, Shenzhen, Guangdong 518055 (China); Volkan Demir, Hilmi, E-mail: VOLKAN@stanfordalumni.org [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Department of Electrical and Electronics, UNAM-Institute of Material Science and Nanotechnology, Bilkent University, Ankara TR-06800 (Turkey); Department of Physics, UNAM-Institute of Material Science and Nanotechnology, Bilkent University, Ankara TR-06800 (Turkey)

2013-12-23T23:59:59.000Z

328

Further reduction of efficiency droop effect by adding a lower-index dielectric interlayer in a surface plasmon coupled blue light-emitting diode with surface metal nanoparticles  

SciTech Connect (OSTI)

Further reduction of the efficiency droop effect and further enhancements of internal quantum efficiency (IQE) and output intensity of a surface plasmon coupled, blue-emitting light-emitting diode (LED) by inserting a dielectric interlayer (DI) of a lower refractive index between p-GaN and surface Ag nanoparticles are demonstrated. The insertion of a DI leads to a blue shift of the localized surface plasmon (LSP) resonance spectrum and increases the LSP coupling strength at the quantum well emitting wavelength in the blue range. With SiO{sub 2} as the DI, a thinner DI leads to a stronger LSP coupling effect, when compared with the case of a thicker DI. By using GaZnO, which is a dielectric in the optical range and a good conductor under direct-current operation, as the DI, the LSP coupling results in the highest IQE, highest LED output intensity, and weakest droop effect.

Lin, Chun-Han; Su, Chia-Ying; Chen, Chung-Hui; Yao, Yu-Feng; Shih, Pei-Ying; Chen, Horng-Shyang; Hsieh, Chieh; Kiang, Yean-Woei, E-mail: ywkiang@ntu.edu.tw; Yang, C. C., E-mail: ccycc@ntu.edu.tw [Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan (China); Kuo, Yang [Department of Energy and Refrigerating Air-Conditioning Engineering, Tung Nan University, 152 Beishen Road, Section 3, New Taipei City, 22202 Taiwan (China)

2014-09-08T23:59:59.000Z

329

Journal of Light Emitting Diodes Vol 2 N0 1, April 2010 1 Abstract--In metal organic vapor phase epitaxy we developed  

E-Print Network [OSTI]

Journal of Light Emitting Diodes Vol 2 N0 1, April 2010 1 Abstract-- In metal organic vapor phase epitaxy we developed GaInN/GaN quantum well material suitable for 500 ­ 580 nm light emitting diodes at longer wavelengths. Index Terms-- a-plane GaN, GaInN, Green light emitting diode, m-plane GaN I

Wetzel, Christian M.

330

Assessing the Performance of 5mm White LED Light Sources for Developing-Country Applications  

E-Print Network [OSTI]

performance variations. Incandescent and fluorescent lightbetter than the common incandescent lamp. Off-grid lighting

Mills, Evan

2007-01-01T23:59:59.000Z

331

Journal of Crystal Growth 298 (2007) 272275 Dislocation analysis in homoepitaxial GaInN/GaN light emitting  

E-Print Network [OSTI]

of GaInN/GaN-based light emitting diodes (LED) on quasi-bulk GaN with an atomically flat polished were much improved. The optical output power of the light emitting diode increased by more than one. Cathodoluminescence; A1. Threading dislocation density; A2. Homoepitaxial growth; B1. GaInN; B3. Light emitting diode

Wetzel, Christian M.

332

Room temperature midinfrared electroluminescence from InSb/InAs quantum dot light emitting diodes  

SciTech Connect (OSTI)

Self-assembled InSb submonolayer quantum dots (QDs) in an InAs matrix have been grown by molecular beam epitaxy using Sb{sub 2} and As{sub 2} fluxes. The structures exhibit bright midinfrared photoluminescence up to room temperature. Intense room temperature electroluminescence with a peak at wavelength near 3.8 {mu}m was observed from p-i-n light emitting diode structures containing ten InSb submonolayer QD sheets inserted within the InAs active region.

Carrington, P. J.; Solov'ev, V. A.; Zhuang, Q.; Krier, A. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom); Ivanov, S. V. [Ioffe Physico-Technical Institute, Polytekhnicheskaya 26, St. Petersburg 194021 (Russian Federation)

2008-09-01T23:59:59.000Z

333

Temperature-dependent efficiency droop of blue InGaN micro-light emitting diodes  

SciTech Connect (OSTI)

Temperature-dependent trends in radiative and Auger recombination coefficients have been determined at different injection carrier concentrations using InGaN micro-light emitting diodes 40 ?m in diameter. The differential lifetime was obtained first from the measured modulation bandwidth and was then employed to calculate the carrier concentration in the quantum well active region. When the temperature increases, the carrier concentration increases, but both the radiative and Auger recombination coefficients decrease. In addition, the temperature dependence of radiative and Auger recombination coefficients is weaker at a higher injection carrier concentration, which is strongly related to phase space filling.

Tian, Pengfei; McKendry, Jonathan J. D.; Herrnsdorf, Johannes; Ferreira, Ricardo; Watson, Ian M.; Gu, Erdan, E-mail: erdan.gu@strath.ac.uk; Dawson, Martin D. [Institute of Photonics, University of Strathclyde, 106 Rottenrow, Glasgow G4 0NW (United Kingdom); Watson, Scott; Kelly, Anthony E. [School of Engineering, University of Glasgow, James Watt South Building, Glasgow G12 8LT (United Kingdom)

2014-10-27T23:59:59.000Z

334

Effect of carbazoleoxadiazole excited-state complexes on the efficiency of dye-doped light-emitting diodes  

E-Print Network [OSTI]

Effect of carbazole­oxadiazole excited-state complexes on the efficiency of dye-doped light a profound effect on the external quantum efficiency of dye-doped organic light-emitting diodes employing the matrix to the dye. Single-layer devices doped with either coumarin 47 C47 , coumarin 6 C6 , or nile red

335

Solvent-enhanced dye diffusion in polymer thin films for color tuning of organic light-emitting diodes  

E-Print Network [OSTI]

Solvent-enhanced dye diffusion in polymer thin films for color tuning of organic light; accepted for publication 27 February 2001 A method of solvent-enhanced dye diffusion in polymer films for organic light-emitting diode OLED application is introduced. After an initial dye transfer from a dye

336

Jade Sky Technologies Partners with CLTC on LED Replacement Lamp Upgrade Project UC Davis' California Lighting Technology Center will utilize Jade Sky Technologies' driver ICs to help spur  

E-Print Network [OSTI]

' California Lighting Technology Center will utilize Jade Sky Technologies' driver ICs to help spur adoption of cost-effective, easy-to-use LED lighting solutions Milpitas, Calif. ­ October 15, 2013 ­ Jade Sky Technologies (JST), a clean-tech start-up manufacturer of driver ICs for LED lighting applications, announces

California at Davis, University of

337

GaN-based light-emitting diode with textured indium tin oxide transparent layer coated with Al{sub 2}O{sub 3} powder  

SciTech Connect (OSTI)

Surface-textured InGaN/GaN light-emitting diodes (LEDs) coated with transparent Al{sub 2}O{sub 3} powder were fabricated by natural lithography combined with inductively coupled plasma etching. For surface texturing, 300 nm size Al{sub 2}O{sub 3} powder is used as an etching mask by simply coating the surface using a spin-coating process. Also, the powders are left on the surface after surface texturing to further increase extraction efficiency. At 20 mA, the light output power of the textured indium tin oxide (ITO) InGaN/GaN LEDs coated with the Al{sub 2}O{sub 3} powder is enhanced by {approx}112% compared with the conventional nontextured ITO LED. The enhanced light output power is attributed to the improved extraction efficiency resulting from an overall decrease in the total internal reflection due to the textured surface and the Al{sub 2}O{sub 3} powder coating.

Kim, T. K.; Kim, S. H.; Yang, S. S.; Son, J. K.; Lee, K. H.; Hong, Y. G.; Shim, K. H.; Yang, J. W.; Lim, K. Y.; Yang, G. M. [Department of Semiconductor and Chemical Engineering and Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Bae, S. J. [Optowell Co., Ltd., 308, Semiconductor Physics Research Center, 664-14, Dukjin-Dong, Dukjin-Gu, Jeonju 561-756 (Korea, Republic of)

2009-04-20T23:59:59.000Z

338

Text-Alternative Version: LED Lighting in a Performing Arts Building Webinar  

Broader source: Energy.gov [DOE]

 Welcome ladies and gentlemen. I'm Bob Davis with the Pacific Northwest National Laboratory, and I'd like to welcome you to today's webcast titled, LEDs, Can They Perform in a Performing Arts...

339

Enhanced light emission from top-emitting organic light-emitting diodes by optimizing surface plasmon polariton losses  

E-Print Network [OSTI]

We demonstrate enhanced light extraction for monochrome top-emitting organic light-emitting diodes (OLEDs). The enhancement by a factor of 1.2 compared to a reference sample is caused by the use of a hole transport layer (HTL) material possessing a low refractive index (1.52). The low refractive index reduces the in-plane wave vector of the surface plasmon polariton (SPP) excited at the interface between the bottom opaque metallic electrode (anode) and the HTL. The shift of the SPP dispersion relation decreases the power dissipated into lost evanescent excitations and thus increases the outcoupling efficiency, although the SPP remains constant in intensity. The proposed method is suitable for emitter materials owning isotropic orientation of the transition dipole moments as well as anisotropic, preferentially horizontal orientation, resulting in comparable enhancement factors. Furthermore, for sufficiently low refractive indices of the HTL material, the SPP can be modeled as a propagating plane wave within ot...

Fuchs, Cornelius; Wieczorek, Martin; Gather, Malte C; Hofmann, Simone; Reineke, Sebastian; Leo, Karl; Scholz, Reinhard

2015-01-01T23:59:59.000Z

340

Light extraction in individual GaN nanowires on Si for LEDs  

E-Print Network [OSTI]

GaN-based nanowires hold great promise for solid state lighting applications because of their waveguiding properties and the ability to grow nonpolar GaN nanowire-based heterostructures, which could lead to increased light ...

Zhou, Xiang

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

GREEN LIVING Replace incandencent and halogen light bulbs with LED and CLFs  

E-Print Network [OSTI]

GREEN LIVING GUIDE ENERGY TRAVEL FOOD sustain yosef WATER Replace incandencent and halogen light for your laundry RESIST THAT SWITCH! Use natural light during the day, and no lights when you are gone USE MORE THAN YOU CAN EAT, reduce your waste stream DRINK FAIR TRADE COFFEE - Check out Conrad

Thaxton, Christopher S.

342

Green cubic GaInN/GaN light-emitting diode on microstructured silicon (100)  

SciTech Connect (OSTI)

GaInN/GaN light-emitting diodes free of piezoelectric polarization were prepared on standard electronic-grade Si(100) substrates. Micro-stripes of GaN and GaInN/GaN quantum wells in the cubic crystal structure were grown on intersecting (111) planes of microscale V-grooved Si in metal-organic vapor phase epitaxy, covering over 50% of the wafer surface area. Crystal phases were identified in electron back-scattering diffraction. A cross-sectional analysis reveals a cubic structure virtually free of line defects. Electroluminescence over 20 to 100??A is found fixed at 487?nm (peak), 516?nm (dominant). Such structures therefore should allow higher efficiency, wavelength-stable light emitters throughout the visible spectrum.

Stark, Christoph J. M.; Detchprohm, Theeradetch; Wetzel, Christian, E-mail: wetzel@ieee.org [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States) [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Future Chips Constellation, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States); Lee, S. C.; Brueck, S. R. J. [Department of Electrical and Computer Engineering and Center for High Technology Materials, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico 87106 (United States)] [Department of Electrical and Computer Engineering and Center for High Technology Materials, University of New Mexico, 1313 Goddard SE, Albuquerque, New Mexico 87106 (United States); Jiang, Y.-B. [Department of Earth and Planetary Science, University of New Mexico, Albuquerque, New Mexico 87131 (United States)] [Department of Earth and Planetary Science, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

2013-12-02T23:59:59.000Z

343

Highly efficient greenish-blue platinum-based phosphorescent organic light-emitting diodes on a high triplet energy platform  

SciTech Connect (OSTI)

We have demonstrated high-efficiency greenish-blue phosphorescent organic light-emitting diodes (PHOLEDs) based on a dimesitylboryl-functionalized C^N chelate Pt(II) phosphor, Pt(m-Bptrz)(t-Bu-pytrz-Me). Using a high triplet energy platform and optimized double emissive zone device architecture results in greenish-blue PHOLEDs that exhibit an external quantum efficiency of 24.0% and a power efficiency of 55.8?lm/W. This record high performance is comparable with that of the state-of-the-art Ir-based sky-blue organic light-emitting diodes.

Chang, Y. L., E-mail: yilu.chang@mail.utoronto.ca; Gong, S., E-mail: sgong@chem.utoronto.ca; White, R.; Lu, Z. H., E-mail: zhenghong.lu@utoronto.ca [Department of Materials Science and Engineering, University of Toronto, 184 College St., Toronto, Ontario M5S 3E4 (Canada); Wang, X.; Wang, S., E-mail: wangs@chem.queensu.ca [Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6 (Canada); Yang, C. [Department of Chemistry, Wuhan University, Wuhan 430072 (China)

2014-04-28T23:59:59.000Z

344

Municipal Consortium LED Street Lighting Workshop: April 19–20, Los Angeles, CA  

Broader source: Energy.gov [DOE]

Workshop Location: The Sheraton Los Angeles Downtown Hotel, 711 Hope Street, Los Angeles, CA 90017City Partner: City of Los Angeles Bureau of Street LightingCost: $175

345

Multicolor, High Efficiency, Nanotextured LEDs  

SciTech Connect (OSTI)

We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and green for Solid State Lighting applications. Accomplishments in the duration of the contract period include (i) heteroepitaxy of nitrogen-polar LEDs on sapphire, (ii) heteroepitaxy of semipolar (11{bar 2}2) green LEDs on sapphire, (iii) synthesis of quantum-dot loaded nanoporous GaN that emits white light without phosphor conversion, (iv) demonstration of the highest quality semipolar (11{bar 2}2) GaN on sapphire using orientation-controlled epitaxy, (v) synthesis of nanoscale GaN and InGaN medium, and (vi) development of a novel liftoff process for manufacturing GaN thin-film vertical LEDs. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

Jung Han; Arto Nurmikko

2011-09-30T23:59:59.000Z

346

E-Print Network 3.0 - alters high light Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

One of the key... Light Communication What is the problem? The white light-emitting diode (LED) stands at the threshold... of a new era of energy-efficient lighting...

347

E-Print Network 3.0 - alingap light emitting Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: :http:www.eee.hku.hkgpang Abstract The visible light from an LED (light emitting diode) traffic light can be modulated and encoded... on the description of an audio...

348

E-Print Network 3.0 - advanced pressurized light Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in the use of light... Light Communication What is the problem? The white light-emitting diode (LED) stands at the threshold... the need to develop low-power, integrated...

349

Optical remote monitoring of CH/sub 4/ gas using low-loss optical fiber link and InGaAsP light-emitting diode in 1. 33-. mu. m region  

SciTech Connect (OSTI)

Purely optical remote monitoring of low-level CH/sub 4/ gas is realized for the first time by the method employing a 2-km long-distance, low-loss silica optical fiber link and a compact absorption cell in conjunction with a high radiant InGaAsP light-emitting diode (LED) at 1.33 ..mu..m. Based on the present experiment, the detection limit of CH/sub 4/ in air was confirmed to be approximately 2000 ppm, i.e., 4% of the lower explosion limit of CH/sub 4/. This result supports the conclusion that the fully optical remote sensing system incorporating ultralow loss optical fiber networks and near infrared LEDs or laser diodes can be extensively used for the detection and surveillance of various inflammable and/or explosive gases in industrial and mining complexes as well as in residential areas.

Chan, K.; Ito, H.; Inaba, H.

1983-10-01T23:59:59.000Z

350

3.2: Invited Paper: Biopolymers in Light Emitting Devices Andrew J. Steckl , Joshua A. Hagen, Zhou Yu, Robert A. Jones,  

E-Print Network [OSTI]

and as an integral element of biopolymeric organic light emitting diodes. We have shown [1] that these BioLEDs have

Steckl, Andrew J.

351

WHITE ORGANIC LIGHT-EMITTING DIODES USING 1,1,2,3,4,5-HEXAPHENYLSILOLE (HPS) AS GREENISH-BLUE EMITTER  

E-Print Network [OSTI]

WHITE ORGANIC LIGHT-EMITTING DIODES USING 1,1,2,3,4,5- HEXAPHENYLSILOLE (HPS) AS GREENISH, Hong Kong, P. R. China Abstract White organic light-emitting diodes (WOLEDs) with the structure of ITO emitter and the 1,1,2,3,4,5- hexaphenylsilole (HPS) layer was used as the greenish- blue emitter. White

352

ZnO PN Junctions for Highly-Efficient, Low-Cost Light Emitting Diodes  

SciTech Connect (OSTI)

By 2015, the US Department of Energy has set as a goal the development of advanced solid state lighting technologies that are more energy efficient, longer lasting, and more cost-effective than current technology. One approach that is most attractive is to utilize light-emitting diode technologies. Although III-V compound semiconductors have been the primary focus in pursuing this objective, ZnO-based materials present some distinct advantages that could yield success in meeting this objective. As with the nitrides, ZnO is a direct bandgap semiconductor whose gap energy (3.2 eV) can be tuned from 3.0 to 4 eV with substitution of Mg for higher bandgap, Cd for lower bandgap. ZnO has an exciton binding energy of 60 meV, which is larger than that for the nitrides, indicating that it should be a superior light emitting semiconductor. Furthermore, ZnO thin films can be deposited at temperatures on the order of 400-600 C, which is significantly lower than that for the nitrides and should lead to lower manufacturing costs. It has also been demonstrated that functional ZnO electronic devices can be fabricated on inexpensive substrates, such as glass. Therefore, for the large-area photonic application of solid state lighting, ZnO holds unique potential. A significant impediment to exploiting ZnO in light-emitting applications has been the absence of effective p-type carrier doping. However, the recent realization of acceptor-doped ZnO material overcomes this impediment, opening the door to ZnO light emitting diode development In this project, the synthesis and properties of ZnO-based pn junctions for light emitting diodes was investigated. The focus was on three issues most pertinent to realizing a ZnO-based solid state lighting technology, namely (1) achieving high p-type carrier concentrations in epitaxial and polycrystalline films, (2) realizing band edge emission from pn homojunctions, and (3) investigating pn heterojunction constructs that should yield efficient light emission. The project engaged established expertise at the University of Florida in ZnO film growth (D. Norton), device fabrication (F. Ren) and wide bandgap photonics (S. Pearton). It addressed p-type doping and junction formation in (Zn,Mg)O alloy thin films. The project employed pulsed laser deposition for film growth. The p-type dopant of interest was primarily phosphorus, given the recent results in our laboratory and elsewhere that this anions can yield p-type ZnO-based materials. The role of Zn interstitials, oxygen vacancies, and/or hydrogen complexes in forming compensating shallow donor levels imposes the need to simultaneously consider the role of in situ and post-growth processing conditions. Temperature-dependent Hall, Seebeck, C-V, and resistivity measurements was used to determine conduction mechanisms, carrier type, and doping. Temperature-dependent photoluminescence was used to determine the location of the acceptor level, injection efficiency, and optical properties of the structures. X-ray diffraction will used to characterize film crystallinity. Using these materials, the fabrication and characterization of (Zn,Mg)O pn homojunction and heterojunction devices was pursued. Electrical characterization of the junction capacitance and I-V behavior was used to extract junction profile and minority carrier lifetime. Electroluminescence from biased junctions was the primary property of interest.

David P. Norton; Stephen Pearton; Fan Ren

2007-09-30T23:59:59.000Z

353

Assessing the Performance of LED-Based Flashlights Available in the Kenyan Off-Grid Lighting Market  

SciTech Connect (OSTI)

Low cost rechargeable flashlights that use LED technology are increasingly available in African markets. While LED technology holds promise to provide affordable, high quality lighting services, the widespread dissemination of low quality products may make it difficult to realize this potential. This study includes performance results for three brands of commonly available LED flashlights that were purchased in Kenya in 2009. The performance of the flashlights was evaluated by testing five units for each of the three brands. The tests included measurements of battery capacity, time required to charge the battery, maximum illuminance at one meter, operation time and lux-hours from a fully charged battery, light distribution, and color rendering. All flashlights tested performed well below the manufacturers? rated specifications; the measured battery capacity was 30-50percent lower than the rated capacity and the time required to fully charge the battery was 6-25percent greater than the rated time requirement. Our analysis further shows that within each brand there is considerable variability in each performance indicator. The five samples within a single brand varied from each other by as much as 22percent for battery capacity measurements, 3.6percent for the number of hours required for a full charge, 23percent for maximum initial lux, 38percent for run time, 11percent for light distribution and by as much as 200percent for color rendering. Results obtained are useful for creating a framework for quality assurance of off-grid LED products and will be valuable for informing consumers, distributors and product manufacturers about product performance.

Tracy, Jennifer; Jacobson, Arne; Mills, Evan

2010-03-02T23:59:59.000Z

354

Choosing Energy-Saving Lighting Products Saves You Money | Department...  

Broader source: Energy.gov (indexed) [DOE]

about 1.50 to light the same space with a compact fluorescent lamp (CFL) or light emitting diode (LED). That's 4.50 in savings each year per bulb. Over their lifetime,...

355

The Laser DiodeThe Laser Diode Jason HillJason Hill  

E-Print Network [OSTI]

a Laser Diode Works Edge Emitting Laser Diode Operates similar to a Light Emitting DiodeOperates similar to a Light Emitting Diode Active medium is a semiconductor pActive medium is a semiconductor p--n junctionn Operates similar to a Light Emitting DiodeOperates similar to a Light Emitting Diode Active medium

La Rosa, Andres H.

356

SciTech Connect: Demonstration of LED Street Lighting in Kansas City, MO  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systems controllerAdditiveBetatronAerogel Deep BedDemonstration of LED

357

LED Provides Effective and Efficient Parking Area Lighting at the NAVFAC Engineering Service Center  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10 DOEWashington, DCKickoffLDV HVAC ModelLEDLightsLED parking

358

Room-temperature spin-polarized organic light-emitting diodes with a single ferromagnetic electrode  

SciTech Connect (OSTI)

In this paper, we demonstrate the concept of a room-temperature spin-polarized organic light-emitting diode (Spin-OLED) structure based on (i) the deposition of an ultra-thin p-type organic buffer layer on the surface of the ferromagnetic electrode of the Spin-OLED and (ii) the use of oxygen plasma treatment to modify the surface of that electrode. Experimental results demonstrate that the brightness of the developed Spin-OLED can be increased by 110% and that a magneto-electroluminescence of 12% can be attained for a 150?mT in-plane magnetic field, at room temperature. This is attributed to enhanced hole and room-temperature spin-polarized injection from the ferromagnetic electrode, respectively.

Ding, Baofu, E-mail: b.ding@ecu.edu.au; Alameh, Kamal, E-mail: k.alameh@ecu.edu.au [Electron Science Research Institute, Edith Cowan University, 270 Joondalup Drive, Joondalup WA 6027 Australia (Australia); Song, Qunliang [Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing 400715 (China)

2014-05-19T23:59:59.000Z

359

Top-emitting Organic Light-Emitting Diode with a Cap Layer Chengfeng Qiu, Huajun Peng, Haiying Chen, Zhilang Xie,  

E-Print Network [OSTI]

, Kowloon, Hong Kong, China ABSTRACT For top emitting Organic Light-Emitting Diodes (OLED), the study of top layer is very important aiming to acquire good device performance. In this report, Pt as anode for Cu coated on glass as anode, copper (II) phthalocyanine (CuPc) as organic buffer layer, N,N'- diphenyl

Kwok, Hoi S.

360

Solution Processed Tungsten Oxide Interfacial Layer for Efficient Hole-Injection in Quantum Dot Light-Emitting Diodes  

E-Print Network [OSTI]

2/2014 Solution Processed Tungsten Oxide Interfacial Layer for Efficient Hole-Injection in Quantum Layer for Efficient Hole-Injection in Quantum Dot Light- Emitting Diodes Xuyong Yang, Evren Mutlugun-based devices, the organic interfacial buffer layers have inferior thermal stability. Efforts to replace PEDOT

Demir, Hilmi Volkan

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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361

An LED pulser for measuring photomultiplier linearity  

E-Print Network [OSTI]

A light-emitting diode (LED) pulser for testing the low-rate response of a photomultiplier tube (PMT) to scintillator-like pulses has been designed, developed, and implemented. This pulser is intended to simulate 80 ns full width at half maximum photon pulses over the dynamic range of the PMT, in order to precisely determine PMT linearity. This particular design has the advantage that, unlike many LED test rigs, it does not require the use of multiple calibrated LEDs, making it insensitive to LED gain drifts. Instead, a finite-difference measurement is made using two LEDs which need not be calibrated with respect to one another. These measurements give a better than 1% mapping of the response function, allowing for the testing and development of particularly linear PMT bases.

Friend, M; Quinn, B

2011-01-01T23:59:59.000Z

362

Organic Light-Emitting Diodes (OLEDs) and Optically-Detected Magnetic Resonance (ODMR) studies on organic materials  

SciTech Connect (OSTI)

Organic semiconductors have evolved rapidly over the last decades and currently are considered as the next-generation technology for many applications, such as organic light-emitting diodes (OLEDs) in flat-panel displays (FPDs) and solid state lighting (SSL), and organic solar cells (OSCs) in clean renewable energy. This dissertation focuses mainly on OLEDs. Although the commercialization of the OLED technology in FPDs is growing and appears to be just around the corner for SSL, there are still several key issues that need to be addressed: (1) the cost of OLEDs is very high, largely due to the costly current manufacturing process; (2) the efficiency of OLEDs needs to be improved. This is vital to the success of OLEDs in the FPD and SSL industries; (3) the lifetime of OLEDs, especially blue OLEDs, is the biggest technical challenge. All these issues raise the demand for new organic materials, new device structures, and continued lower-cost fabrication methods. In an attempt to address these issues, we used solution-processing methods to fabricate highly efficient small molecule OLEDs (SMOLEDs); this approach is costeffective in comparison to the more common thermal vacuum evaporation. We also successfully made efficient indium tin oxide (ITO)-free SMOLEDs to further improve the efficiency of the OLEDs. We employed the spin-dependent optically-detected magnetic resonance (ODMR) technique to study the luminescence quenching processes in OLEDs and organic materials in order to understand the intrinsic degradation mechanisms. We also fabricated polymer LEDs (PLEDs) based on a new electron-accepting blue-emitting polymer and studied the effect of molecular weight on the efficiency of PLEDs. All these studies helped us to better understand the underlying relationship between the organic semiconductor materials and the OLEDs’ performance, and will subsequently assist in further enhancing the efficiency of OLEDs. With strongly improved device performance (in addition to other OLEDs' attributes such as mechanical flexibility and potential low cost), the OLED technology is promising to successfully compete with current technologies, such as LCDs and inorganic LEDs.

Cai, Min

2011-11-30T23:59:59.000Z

363

Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes  

SciTech Connect (OSTI)

We demonstrate a GaN quantum dot ultraviolet light-emitting diode that uses tunnel injection of carriers through AlN barriers into the active region. The quantum dot heterostructure is grown by molecular beam epitaxy on AlN templates. The large lattice mismatch between GaN and AlN favors the formation of GaN quantum dots in the Stranski-Krastanov growth mode. Carrier injection by tunneling can mitigate losses incurred in hot-carrier injection in light emitting heterostructures. To achieve tunnel injection, relatively low composition AlGaN is used for n- and p-type layers to simultaneously take advantage of effective band alignment and efficient doping. The small height of the quantum dots results in short-wavelength emission and are simultaneously an effective tool to fight the reduction of oscillator strength from quantum-confined Stark effect due to polarization fields. The strong quantum confinement results in room-temperature electroluminescence peaks at 261 and 340 nm, well above the 365 nm bandgap of bulk GaN. The demonstration opens the doorway to exploit many varied features of quantum dot physics to realize high-efficiency short-wavelength light sources.

Verma, Jai; Kandaswamy, Prem Kumar; Protasenko, Vladimir; Verma, Amit; Grace Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)] [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)

2013-01-28T23:59:59.000Z

364

A Polysilicon Active Matrix Organic Light Emitting Diode Display with Integrated Drivers R.M.A. Dawson, Z. Shen, D.A. Furst, S. Connor, J. Hsu, M.G. Kane, R.G. Stewart, A. Ipri  

E-Print Network [OSTI]

A Polysilicon Active Matrix Organic Light Emitting Diode Display with Integrated Drivers R.S.A. Abstract The design of an active matrix organic light emitting diode (AMOLED) display using a polysilicon. Introduction Organic light emitting diodes (OLEDs) are presently of great interest due to their potential

365

Optical Simulation of Top-emitting Organic Light Emitting Diodes H. J. Peng, C.F. Qiu, Z. L. Xie, H. Y. Chen, M. Wong and H. S. Kwok  

E-Print Network [OSTI]

8.3.3-89 Optical Simulation of Top-emitting Organic Light Emitting Diodes H. J. Peng, C.F. Qiu, Z the optical effects for the top-emitting organic light emitting diodes. The optical performance of the devices with experiments Keywords: Top-emitting organic light emitting diode, optical modeling, microcavity INTRODUCTION

Kwok, Hoi S.

366

Enhancement of hole injection using O{sub 2} plasma-treated Ag anode for top-emitting organic light-emitting diodes  

SciTech Connect (OSTI)

We report the enhancement of hole injection using AgO{sub x} layer between Ag anode and 4,4{sup '}-bis[N-(1-naphtyl)-N-phenyl-amino]biphenyl in top-emitting organic light-emitting diode (OLED). The turn-on voltage of OLEDs decreased from 17 to 7 V as Ag changed to AgO{sub x} by the surface treatment using O{sub 2} plasma. Synchrotron radiation photoelectron spectroscopy results showed that the work function increased about 0.4 eV by the O{sub 2} plasma treatment. This led to the decrease of the energy barrier for hole injection, reducing the turn-on voltage of OLEDs.

Ho, Won Choi; Soo, Young Kim; Kim, Ki-Beom; Tak, Yoon-Heung; Lee, Jong-Lam [Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Kyungbuk 790-784, Korea (Korea, Republic of); LG Electronics Inc., Kumi, Kyungbuk, 730-030 (Korea, Republic of); Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Kyungbuk 790-784 (Korea, Republic of)

2005-01-03T23:59:59.000Z

367

Self-reported Impacts of LED Lighting Technology Compared to Fuel-based Lighting on Night Market Business Prosperity in Kenya  

SciTech Connect (OSTI)

The notion of"productive use" is often invoked in discussions about whether new technologies improve productivity or otherwise enhance commerce in developing-country contexts. It an elusive concept,especially when quantitative measures are sought. Improved and more energy efficient illumination systems for off-gridapplication--the focus of the Lumina Project--provide a case in which a significant productivity benefit can be imagined, given the importance of light to the successful performance of many tasks, and the very low quality of baseline illumination provided by flame-based source. This Research Note summarizes self-reported quantitative and qualitative impacts of switching to LED lighting technology on the prosperity of night-market business owners and operators. The information was gathered in the context of our 2008 market testing field work in Kenya?s Rift Valley Province, which was performed in the towns of Maai Mahiu and Karagita by Arne Jacobson, Kristen Radecsky, Peter Johnstone, Maina Mumbi, and others. Maai Mahiu is a crossroads town; provision of services to travelers and freight carriers is a primary income source for the residents. In contrast, the primary income for Karagita's residents is from work in the large, factory style flower farms on the eastern shores of Lake Naivasha that specialize in producing cut flowers for export to the European market. According to residents, both towns had populations of 6,000 to 8,000 people in June 2008. We focused on quantifying the economics of fuel-based and LED lighting technology in the context of business use by night market vendors and shop keepers. Our research activities with the business owners and operators included baseline measurement of their fuel-based lighting use, an initial survey, offering for sale data logger equipped rechargeable LED lamps, monitoring the adoption of the LED lamps, and a follow-up survey.

Johnstone, Peter; Jacobson, Arne; Mills, Evan; Mumbi, Maina

2009-02-11T23:59:59.000Z

368

Remarkably reduced efficiency droop by using staircase thin InGaN quantum barriers in InGaN based blue light emitting diodes  

SciTech Connect (OSTI)

The efficiency droop of InGaN/GaN(InGaN) multiple quantum well (MQW) light emitting diodes (LEDs) with thin quantum barriers (QB) is studied. With thin GaN QB (3?nm–6?nm thickness), the efficiency droop is not improved, which indicates that hole transport cannot be significantly enhanced by the thin GaN QBs. On the contrary, the efficiency droop was remarkably reduced by using a InGaN staircase QB (InGaN SC-QB) MQWs structure where InGaN SC-QBs lower the transport energy barrier of holes. The efficiency droop ratio was as low as 3.3% up to 200?A/cm{sup 2} for the InGaN SC-QB LED. By using monitoring QW with longer wavelength we observe a much uniform carrier distribution in the InGaN SC-QB LEDs, which reveals the mechanism of improvement in the efficiency droop.

Zhou, Kun; Ikeda, Masao, E-mail: mikeda2013@sinano.ac.cn, E-mail: jpliu2010@sinano.ac.cn; Liu, Jianping, E-mail: mikeda2013@sinano.ac.cn, E-mail: jpliu2010@sinano.ac.cn; Zhang, Shuming; Li, Deyao; Zhang, Liqun; Yang, Hui [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou (China); Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou (China); Cai, Jin; Wang, Hui; Wang, H. B. [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou (China); Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou (China); Suzhou Nanojoin Photonics Co., Ltd., Suzhou (China)

2014-10-27T23:59:59.000Z

369

The impact of trench defects in InGaN/GaN light emitting diodes and implications for the “green gap” problem  

SciTech Connect (OSTI)

The impact of trench defects in blue InGaN/GaN light emitting diodes (LEDs) has been investigated. Two mechanisms responsible for the structural degradation of the multiple quantum well (MQW) active region were identified. It was found that during the growth of the p-type GaN capping layer, loss of part of the active region enclosed within a trench defect occurred, affecting the top-most QWs in the MQW stack. Indium platelets and voids were also found to form preferentially at the bottom of the MQW stack. The presence of high densities of trench defects in the LEDs was found to relate to a significant reduction in photoluminescence and electroluminescence emission efficiency, for a range of excitation power densities and drive currents. This reduction in emission efficiency was attributed to an increase in the density of non-radiative recombination centres within the MQW stack, believed to be associated with the stacking mismatch boundaries which form part of the sub-surface structure of the trench defects. Investigation of the surface of green-emitting QW structures found a two decade increase in the density of trench defects, compared to its blue-emitting counterpart, suggesting that the efficiency of green-emitting LEDs may be strongly affected by the presence of these defects. Our results are therefore consistent with a model that the “green gap” problem might relate to localized strain relaxation occurring through defects.

Massabuau, F. C.-P., E-mail: fm350@cam.ac.uk; Oehler, F.; Pamenter, S. K.; Thrush, E. J.; Kappers, M. J.; Humphreys, C. J.; Oliver, R. A. [Department of Materials Science and Metallurgy, University of Cambridge, 22 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Davies, M. J.; Dawson, P. [Photon Science Institute, School of Physics and Astronomy, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Kovács, A.; Dunin-Borkowski, R. E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Leo-Brandt- Straße, D-52425 Jülich (Germany); Williams, T.; Etheridge, J. [Monash Centre for Electron Microscopy, Monash University, Clayton Campus, VIC 3800 (Australia); Hopkins, M. A.; Allsopp, D. W. E. [Department of Electronic and Electrical Engineering, University of Bath, Bath BA2 7AY (United Kingdom)

2014-09-15T23:59:59.000Z

370

Comparison of the properties of AlGaInN light-emitting diode chips of vertical and flip-chip design using silicon as the a submount  

SciTech Connect (OSTI)

Vertical and flip-chip light-emitting diode (LED) chips are compared from the viewpoint of the behavior of current spreading in the active region and the distribution of local temperatures and thermal resistances of chips. AlGaInN LED chips of vertical design are fabricated using Si as a submount and LED flipchips were fabricated with the removal of a sapphire substrate. The latter are also mounted on a Si submount. The active regions of both chips are identical and are about 1 mm{sup 2} in size. It is shown that both the emittance of the crystal surface in the visible range and the distribution of local temperatures estimated from radiation in the infrared region are more uniform in crystals of vertical design. Heat removal from flip-chips is insufficient in regions of the n contact, which do not possess good thermal contact with the submount. As a result, the total thermal resistances between the p-n junction and the submount both for the vertical chips and for flip-chips are approximately 1 K/W. The total area of the flip-chips exceeds that of the vertical design chips by a factor of 1.4.

Markov, L. K., E-mail: l.markov@mail.ioffe.ru; Smirnova, I. P.; Pavlyuchenko, A. S. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Kukushkin, M. V.; Vasil'eva, E. D. [ZAO Innovation 'Tetis' (Russian Federation); Chernyakov, A. E. [Russian Academy of Sciences, Science-and-Technology Microelectronics Center (Russian Federation); Usikov, A. S. [De Core Nanosemiconductors Ltd. (India)

2013-03-15T23:59:59.000Z

371

LASER DIODE TECHNOLOGY AND APPLICATIONS Submitted to  

E-Print Network [OSTI]

and a normal diode and a light emitting diode. I will also define the terms homojunction and heterojunction, and is the main source of light in a light-emitting diode. Under suitable conditions, the electron and the hole

La Rosa, Andres H.

372

White LED with High Package Extraction Efficiency  

SciTech Connect (OSTI)

The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/W{sub e} using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat generated in the package may cause a deterioration of encapsulant materials, affecting the performance of both the LED die and phosphor, leading to a decrease in the luminous efficacy over lifetime. Recent studies from research groups at Rensselaer Polytechnic Institute found that, under the condition to obtain a white light, about 40% of the light is transmitted outward of the phosphor layer and 60% of the light is reflected inward.1,2 It is claimed that using scattered photon extraction (SPE) technique, luminous efficacy is increased by 60%. In this project, a transparent/translucent monolithic phosphor was used to replace the powdered phosphor layer. In the normal pcLED package, the powdered phosphor is mixed with silicone either to be deposited on the top of LED die forming a chip level conversion (CLC) white LED or to be casted in the package forming a volume conversion white LED. In the monolithic phosphors there are no phosphor powder/silicone interfaces so it can reduce the light scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is inserted in the white LED package between the blue LED die and phosphor layer. It will selectively transmit the blue light from the LED die and reflect the phosphor's yellow inward emission outward. The two technologies try to recover backward light to the outward direction in the pcLED package thereby improving the package extraction efficiency.

Yi Zheng; Matthew Stough

2008-09-30T23:59:59.000Z

373

Task lights, commonly used in offices, homes, and dormitories, often use  

E-Print Network [OSTI]

and posing difficulties in focusing the light. Light-emitting diode (LED) lighting, a fairly new solid-state Laboratory (LBNL) developed a high-performance prototype LED task light using state-of-the-art technology THE TWO LIGHT SOURCES HAVE SIMILAR ENERGY EFFICIENCY. IN ADDITION, THE FIXTURE USES A CONSUMER- FRIENDLY

374

LED ProspectsLED Prospects photometric units  

E-Print Network [OSTI]

/5/8 #12;16 Light bulb comparisonLight bulb comparison W lumens khours CRI $US Incandescent (long life) 75-life incandescent with LED. · 10 light fixtures/home, lights on for 6h/day, 333 days/yr. · Electricity 0.12 $/kWh. W khours $US Incandescent (long life) 100 10 2 LED (PAR38, warm, dimmable) 11 40 90 · What is the lifetime

Pulfrey, David L.

375

Chapter 21: Residential Lighting Evaluation Protocol. Uniform...  

Energy Savers [EERE]

of use HVAC heating, ventilation, and air conditioning ISR in-service rate LED light-emitting diode TRM Technical Reference Manual W Watt v This report is available at no cost...

376

Phys. Med. Biol. 43 (1998) 24072412. Printed in the UK PII: S0031-9155(98)90934-4 Effects of read-out light sources and ambient light on  

E-Print Network [OSTI]

laser, light emitting diode (LED) and incandescent read-out light sources produce an equivalent dose, fluorescent light and incandescent ambient light produce an equivalent dose coloration of 30 cGy h-1, 18 cGy h the optical density of Gafchromic films include, helium neon lasers, ultrabright diodes, incandescent

Yu, K.N.

377

GaInN light-emitting diodes using separate epitaxial growth for the p-type region to attain polarization-inverted electron-blocking layer, reduced electron leakage, and improved hole injection  

SciTech Connect (OSTI)

A GaInN light-emitting diode (LED) structure is analyzed that employs a separate epitaxial growth for the p-type region, i.e., the AlGaN electron-blocking layer (EBL) and p-type GaN cladding layer, followed by wafer or chip bonding. Such LED structure has a polarization-inverted EBL and allows for uncompromised epitaxial-growth optimization of the p-type region, i.e., without the need to consider degradation of the quantum-well active region during p-type region growth. Simulations show that such an LED structure reduces electron leakage, reduces the efficiency droop, improves hole injection, and has the potential to extend high efficiencies into the green spectral region.

Meyaard, David S., E-mail: meyaad@rpi.edu; Lin, Guan-Bo; Ma, Ming; Fred Schubert, E. [Future Chips Constellation, Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)] [Future Chips Constellation, Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Cho, Jaehee [Future Chips Constellation, Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States) [Future Chips Constellation, Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Semiconductor Physics Research Center, School of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Han, Sang-Heon; Kim, Min-Ho; Shim, HyunWook; Sun Kim, Young [LED Business, Samsung Electronics, Yongin 446-920 (Korea, Republic of)] [LED Business, Samsung Electronics, Yongin 446-920 (Korea, Republic of)

2013-11-11T23:59:59.000Z

378

Effects of Mg-doped AlN/AlGaN superlattices on properties of p-GaN contact layer and performance of deep ultraviolet light emitting diodes  

SciTech Connect (OSTI)

Mg-doped AlN/AlGaN superlattice (Mg-SL) and Mg-doped AlGaN epilayers have been investigated in the 284 nm deep ultraviolet (DUV) light emitting diodes (LEDs) as electron blocking layers. It was found that the use of Mg-SL improved the material quality of the p-GaN contact layer, as evidenced in the decreased density of surface pits and improved surface morphology and crystalline quality. The performance of the DUV LEDs fabricated using Mg-SL was significantly improved, as manifested by enhanced light intensity and output power, and reduced turn-on voltage. The improved performance is attributed to the enhanced blocking of electron overflow, and enhanced hole injection.

Al tahtamouni, T. M., E-mail: talal@yu.edu.jo [Department of Physics, Yarmouk University, Irbid 21163 (Jordan); Lin, J. Y.; Jiang, H. X. [Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)] [Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

2014-04-15T23:59:59.000Z

379

Voltage-induced electroluminescence characteristics of hybrid light-emitting diodes with CdSe/Cd/ZnS core-shell nanoparticles embedded in a conducting polymer on plastic substrates  

SciTech Connect (OSTI)

We investigate the electroluminescence (EL) characteristics of a hybrid light-emitting diode (HyLED) with an emissive layer comprised of CdSe/Cd/ZnS core-shell nanoparticles (NPs) embedded in poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) on a plastic substrate. The EL characteristics change dramatically with increasing of the biased voltage. At low voltages, recombination of electrons and holes occurs only in the PFO film because of poor charge transfer in the PFO-CdSe/Cd/ZnS NPs composite film, while the color of the light-emitting from the HyLED changes from blue to red as the biased voltage increases from 7.5 to 17.5?V. We examine and discuss the mechanism of this color tunability.

Kwak, Kiyeol; Cho, Kyoungah, E-mail: chochem@korea.ac.kr, E-mail: sangsig@korea.ac.kr; Kim, Sangsig, E-mail: chochem@korea.ac.kr, E-mail: sangsig@korea.ac.kr [Department of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of)] [Department of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

2014-03-10T23:59:59.000Z

380

Performance enhancement of organic light-emitting diodes by chlorine plasma treatment of indium tin oxide  

SciTech Connect (OSTI)

The characteristics of green phosphorescent organic light-emitting diodes (OLEDs) fabricated on ITO/glass substrates pretreated with low-energy O{sub 2} and Cl{sub 2} plasma were compared. At 20 mA/cm{sup 2}, the OLEDs with O{sub 2} and Cl{sub 2} plasma-treated indium tin oxide (ITO) had voltages of 9.6 and 7.6 eV, and brightness of 9580 and 12380 cd/m{sup 2}, respectively. At {approx}10{sup 4} cd/m{sup 2}, the latter had a 30% higher external quantum efficiency and a 74% higher power efficiency. Photoelectron spectroscopies revealed that Cl{sub 2} plasma treatment created stable In-Cl bonds and raised the work function of ITO by up to 0.9 eV. These results suggest that the better energy level alignment at the chlorinated ITO/organic interface enhances hole injection, leading to more efficient and more reliable operation of the OLEDs. The developed plasma chlorination process is very effective for surface modification of ITO and compatible with the fabrication of various organic electronics.

Cao, X. A.; Zhang, Y. Q. [Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, West Virginia 26506 (United States)

2012-04-30T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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to obtain the most current and comprehensive results.


381

White organic light-emitting diodes with an ultra-thin premixed emitting layer  

E-Print Network [OSTI]

We described an approach to achieve fine color control of fluorescent White Organic Light-Emitting Diodes (OLED), based on an Ultra-thin Premixed emitting Layer (UPL). The UPL consists of a mixture of two dyes (red-emitting 4-di(4'-tert-butylbiphenyl-4-yl)amino-4'-dicyanovinylbenzene or fvin and green-emitting 4-di(4'-tert-butylbiphenyl-4-yl)aminobenzaldehyde or fcho) premixed in a single evaporation cell: since these two molecules have comparable structures and similar melting temperatures, a blend can be evaporated, giving rise to thin films of identical and reproducible composition compared to those of the pre-mixture. The principle of fine color tuning is demonstrated by evaporating a 1-nm-thick layer of this blend within the hole-transport layer (4,4'-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (\\alpha-NPB)) of a standard fluorescent OLED structure. Upon playing on the position of the UPL inside the hole-transport layer, as well as on the premix composition, two independent parameters are available to finel...

Jeon, T; Tondelier, Denis; Bonnassieux, Yvan; Forget, Sebastien; Chenais, Sebastien; Ishow, Elena

2014-01-01T23:59:59.000Z

382

Milliwatt operation of AlGaN-based single-quantum-well light emitting diode in the ultraviolet region  

SciTech Connect (OSTI)

By introducing a single-quantum-well active layer and a high-Al-content carrier blocking layer, the output power of an AlGaN-based ultraviolet light-emitting diode has been improved by one order of magnitude. Optical output of 1 mW was achieved at the emission peak wavelength of 341{endash}343 nm. {copyright} 2001 American Institute of Physics.

Nishida, Toshio; Saito, Hisao; Kobayashi, Naoki

2001-06-18T23:59:59.000Z

383

Photovoltaic nanopillar radial junction diode architecture enhanced by integrating semiconductor quantum dot nanocrystals as light harvesters  

E-Print Network [OSTI]

Photovoltaic nanopillar radial junction diode architecture enhanced by integrating semiconductor hybridized, radial p-n junction based, nanopillar solar cells with photovoltaic performance enhanced. By furnishing Si based nanopillar photovoltaic diodes with CdSe quantum dots, we experimentally showed up

Demir, Hilmi Volkan

384

Assessing the Performance of LED-Based Flashlights Available in the Kenyan Off-Grid Lighting Market  

E-Print Network [OSTI]

30), 477-499. Efficient Lighting Initiative. 2004. Lighting Energy Bill, Internationalfor Energy-Efficient Lighting and Lawrence Berkeley National

Tracy, Jennifer

2010-01-01T23:59:59.000Z

385

GaN nanorod light emitting diodes with suspended graphene transparent electrodes grown by rapid chemical vapor deposition  

SciTech Connect (OSTI)

Ordered and dense GaN light emitting nanorods are studied with polycrystalline graphene grown by rapid chemical vapor deposition as suspended transparent electrodes. As the substitute of indium tin oxide, the graphene avoids complex processing to fill up the gaps between nanorods and subsequent surface flattening and offers high conductivity to improve the carrier injection. The as-fabricated devices have 32% improvement in light output power compared to conventional planar GaN-graphene diodes. The suspended graphene remains electrically stable up to 300?°C in air. The graphene can be obtained at low cost and high efficiency, indicating its high potential in future applications.

Xu, Kun; Xu, Chen, E-mail: xuchen58@bjut.edu.cn; Deng, Jun; Zhu, Yanxu; Guo, Weiling; Mao, Mingming; Xun, Meng; Chen, Maoxing; Zheng, Lei [Key Laboratory of Optoelectronics Technology, Beijing University of Technology, Ministry of Education, Beijing 100124 (China)] [Key Laboratory of Optoelectronics Technology, Beijing University of Technology, Ministry of Education, Beijing 100124 (China); Xie, Yiyang [State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductor, Chinese Academy of Sciences, Beijing 100083 (China)] [State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductor, Chinese Academy of Sciences, Beijing 100083 (China); Sun, Jie, E-mail: jie.sun@chalmers.se [Key Laboratory of Optoelectronics Technology, Beijing University of Technology, Ministry of Education, Beijing 100124 (China) [Key Laboratory of Optoelectronics Technology, Beijing University of Technology, Ministry of Education, Beijing 100124 (China); Mikroteknologi och Nanovetenskap, Chalmers Tekniska Högskola AB, Göteborg 41296 (Sweden)

2013-11-25T23:59:59.000Z

386

Development and Utilization of Host Materials for White Phosphorescent Organic Light-Emitting Diodes  

SciTech Connect (OSTI)

Our project was primarily focused on the MYPP 2015 goal for white phosphorescent organic devices (PhOLEDs or phosphorescent organic light-emitting diodes) for solid-state lighting with long lifetimes and high efficiencies. Our central activity was to synthesize and evaluate a new class of host materials for blue phosphors in the PhOLEDs, known to be a weak link in the device operating lifetime. The work was a collaborative effort between three groups, one primarily responsible for chemical design and characterization (Chen), one primarily responsible for device development (Tang) and one primarily responsible for mechanistic studies and degradation analysis (Rothberg). The host materials were designed with a novel architecture that chemically links groups with good ability to move electrons with those having good ability to move “holes” (positive charges), the main premise being that we could suppress the instability associated with physical separation and crystallization of the electron conducting and hole conducting materials that might cause the devices to fail. We found that these materials do prevent crystallization and that this will increase device lifetimes but that efficiencies were reduced substantially due to interactions between the materials creating new low energy “charge transfer” states that are non-luminescent. Therefore, while our proposed strategy could in principle improve device lifetimes, we were unable to find a materials combination where the efficiency was not substantially compromised. In the course of our project, we made several important contributions that are peripherally related to the main project goal. First, we were able to prepare the proposed new family of materials and develop synthetic routes to make them efficiently. These types of materials that can transport both electrons and holes may yet have important roles to play in organic device technology. Second we developed an important new method for controlling the deposition profile of material so that arbitrary concentration gradients can be implemented in layers with mixed composition. These concentration profiles are known to increase device efficiency and longevity and we confirmed that experimentally. Third, we investigated a new method for analyzing degradation in devices using mass spectrometry to look for degradation products. We showed that these methods are not simple to interpret unambiguously and need to be used with caution.

Tang, Ching; Chen, Shaw

2013-05-31T23:59:59.000Z

387

Determination of the emission zone in a single-layer polymer light-emitting diode through optical measurements  

SciTech Connect (OSTI)

We study the emission zone in a single-layer polymer light-emitting diode. The emission zone is found by studying the angular distribution of the electroluminescence. The emission is modeled by accounting for optical interference. We account for birefringence of the anode layer in our model. The active polymer was, however, found to be isotropic. The anode consists of a single-layer of the conducting polymer complex poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate) (PEDOT-PSS), with enhanced conductivity. As a cathode we use plain aluminum. By using only PEDOT-PSS we avoid having a thin metal layer or indium-tin-oxide as the anode in the path of the escaping light. The active material is a substituted polythiophene with excellent film forming properties. A comparison between the experimental and calculated angular distribution of light emission from a single-layered polymer light-emitting diode was shown to be in good agreement for the spectral region studied. By assuming a distribution of the emission zone, we deduce the position as well as the width of the zone. {copyright} 2001 American Institute of Physics.

Granlund, Thomas; Pettersson, Leif A. A.; Inganas, Olle

2001-06-01T23:59:59.000Z

388

Sandia National Laboratories: Brief History of Solid-State Lighting...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

389

Comparative study of field-dependent carrier dynamics and emission kinetics of InGaN/GaN light-emitting diodes grown on (11 2 2) semipolar versus (0001) polar  

E-Print Network [OSTI]

Articles you may be interested in Ultraviolet light-emitting diodes grown by plasma-assisted molecular beam light-emitting diodes prepared on ( 11 2 ¯ 2 ) -plane GaN J. Appl. Phys. 100, 113109 (2006); 10.1063/1.2382667 Demonstration of a semipolar ( 10 1 ¯ 3 ¯ ) In Ga N Ga N green light emitting diode Appl. Phys. Lett. 87, 231110

Demir, Hilmi Volkan

390

2014-06-18 Issuance: Test Procedure for Integrated Light-Emitting Diode Lamps; Supplemental Notice of Proposed Rulemaking  

Broader source: Energy.gov [DOE]

This document is a pre-publication Federal Register Supplemental Notice of Proposed Rulemaking regarding Test Procedures for Integrated Light-Emitting Diode Lamps, as issued by the Deputy Assistant Secretary for Energy Efficiency on June 18, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

391

Modeling of temperature and excitation dependences of efficiency in an InGaN light-emitting diode  

E-Print Network [OSTI]

The changes in excitation dependence of efficiency with temperature is modeled for a wurtzite InGaN light-emitting diode. The model incorporates bandstructure changes with carrier density arising from screening of quantum-confined Stark effect. Bandstructure is computed by solving Poisson and k.p equations in the envelop approximation. The information is used in a dynamical model for populations in momentum-resolved electron and hole states. Application of the approach shows the interplay of quantum-well and barrier emissions giving rise to shape changes in efficiency versus current density with changing temperature, as observed in some experiments.

Chow, Weng W

2013-01-01T23:59:59.000Z

392

Influences of excitation-dependent bandstructure changes on InGaN light-emitting diode efficiency  

E-Print Network [OSTI]

Bandstructure properties in wurtzite quantum wells can change appreciably with changing carrier density because of screening of quantum-confined Stark effect. An approach for incorporating these changes in an InGaN light-emitting-diode model is described. Bandstructure is computed for different carrier densities by solving Poisson and k\\cdotp equations in the envelop approximation. The information is used as input in a dynamical model for populations in momentum-resolved electron and hole states. Application of the approach is illustrated by modeling device internal quantum efficiency as a function of excitation.

Chow, Weng W

2011-01-01T23:59:59.000Z

393

Driving conditions dependence of magneto-electroluminescence in tri-(8-hydroxyquinoline)-aluminum based organic light emitting diodes  

E-Print Network [OSTI]

we investigated the magneto-electroluminescence (MEL) in tri-(8-hydroxyquinoline)-aluminum based organic light-emitting diodes (OLEDs) through the steady-state and transient method simultaneously. The MELs show the great different behaviors when we turn the driving condition from a constant voltage to a pulse voltage. For devices driven by the constant voltage, the MELs are similar with the literature data; for devices driven by the pulse voltage, the MELs are quite different, they firstly increase to a maximum then decrease as the magnetic field increases continuously. Negative MELs can be seen when both the magnetic field and driving voltage are high enough.

Peng, Qiming; Li, Xianjie; Li, Mingliang; Li, Feng

2011-01-01T23:59:59.000Z

394

MoO3 as combined hole injection layer and tapered spacer in combinatorial multicolor microcavity organic light emitting diodes  

SciTech Connect (OSTI)

Multicolor microcavity ({mu}C) organic light-emitting diode (OLED) arrays were fabricated simply by controlling the hole injection and spacer MoO{sub 3} layer thickness. The normal emission was tunable from {approx}490 to 640 nm and can be further expanded. A compact, integrated spectrometer with two-dimensional combinatorial arrays of {mu}C OLEDs was realized. The MoO{sub 3} yields more efficient and stable devices, revealing a new breakdown mechanism. The pixel current density reaches {approx}4 A/cm{sup 2} and a maximal normal brightness {approx}140 000 Cd/m{sup 2}, which improves photoluminescence-based sensing and absorption measurements.

Liu, R.; Xu, Chun; Biswas, Rana; Shinar, Joseph; Shinar, Ruth

2011-09-01T23:59:59.000Z

395

LED Chips and Packaging for 120 LPW SSL Component  

SciTech Connect (OSTI)

Cree has developed a new, high-efficiency, low-cost, light emitting diode (LED) lamp module that should be capable of replacing standard, halogen, fluorescent and metal halide lamps based on the total cost of ownership. White LEDs are produced by combining one or more saturated color LEDs with a phosphor or other light down-converting media to achieve white broad-band illumination. This two year project addressed LED chip and package efficiency improvements to establish a technology platform suitable for low-cost, high-efficiency commercial luminaires. Novel photonic-crystal LEDs were developed to improve the light extraction efficiency of blue GaN-based LEDs compared to the baseline technology. Improved packaging designs that reduced down-conversion and absorption related light losses, led to a higher overall LED efficiency. Specifically, blue LEDs were demonstrated with light output nearing 600 mW and an external quantum efficiency greater than 60 percent (using 1 mm2 chips at an operating current of 350 mA). The results were achieved using a novel, production capable photonic-crystal LED fabrication process. These LEDs formed the basis for a multi-chip white lamp module prototype, which provided 510 lumens light output at a correlated color temperature (CCT) of 3875 K and an operating current of 350 mA per 1mm2 chip. The overall conversion efficiency at 4100 K improved to ~ 65%. The resulting efficacy is 112 lumens per watt (LPW) â?? a 33% improvement over the start of the project. In addition, a proof-of-concept luminaire was demonstrated that provided a flux of 1700 lumens at a 3842 K CCT.

James Ibbetson

2009-09-30T23:59:59.000Z

396

Full phosphorescent white-light organic light-emitting diodes with improved color stability and efficiency by fine tuning primary emission contributions  

SciTech Connect (OSTI)

In this paper, a novel type of white-light organic light emitting diode (OLED) with high color stability was reported, in which the yellow-light emission layer of (4,4{sup ?}-N,N{sup ?}-dicarbazole)biphenyl (CBP) : tris(2-phenylquinoline-C2,N{sup ?})iridium(III) (Ir(2-phq){sub 3}) was sandwiched by double blue-light emission layers of 1,1-bis-[(di-4-tolylamino)pheny1]cyclohexane (TAPC) : bis[4,6-(di-fluorophenyl)-pyridinato-N,C2{sup ?}]picolinate (FIrpic) and tris[3-(3-pyridyl)mesityl]borane (3TPYMB):FIrpic. And, it exhibited the maximum current efficiency of 33.1 cd/A, the turn-on voltage at about 3 V and the maximum luminance in excess of 20000 cd/m{sup 2}. More important, it realized very stable white-light emission, and its CIE(x, y) coordinates only shift from (0.34, 0.37) to (0.33, 0.37) as applied voltage increased from 5 V to 12 V. It is believed that the new scheme in emission layer of white-light OLED can fine tune the contribution of primary emission with applied voltage changed, resulting in high quality white-light OLED.

Hua, Wang, E-mail: wmsu2008@sinano.ac.cn, E-mail: wanghua001@tyut.edu.cn; Du, Xiaogang [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China) [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China); Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Su, Wenming, E-mail: wmsu2008@sinano.ac.cn, E-mail: wanghua001@tyut.edu.cn; Zhang, Dongyu [Printable Electronics Research Centre, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, suzhou 215123 (China)] [Printable Electronics Research Centre, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, suzhou 215123 (China); Lin, Wenjing [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China) [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China); Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Printable Electronics Research Centre, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, suzhou 215123 (China)

2014-02-15T23:59:59.000Z

397

The use of short-period InGaN/GaN superlattices in blue-region light-emitting diodes  

SciTech Connect (OSTI)

Optical and light-emitting diode structures with an active InGaN region containing short-period InGaN/GaN superlattices are studied. It is shown that short-period superlattices are thin two-dimensional layers with a relatively low In content that contain inclusions with a high In content 1-3 nm thick. Inclusions manifest themselves from the point of view of optical properties as a nonuniform array of quantum dots involved in a residual quantum well. The use of short-period superlattices in light-emitting diode structures allows one to decrease the concentration of nonradiative centers, as well as to increase the injection of carriers in the active region due to an increase in the effective height of the AlGaN barrier, which in general leads to an increase in the quantum efficiency of light-emitting diodes.

Sizov, V. S., E-mail: vsizov@mail.ioffe.ru; Tsatsulnikov, A. F.; Sakharov, A. V.; Lundin, W. V.; Zavarin, E. E.; Cherkashin, N. A. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Hytch, M. J. [National Center for Scientific Research (CNRS), Center for Material Elaboration and Structural Studies (CEMES) (France); Nikolaev, A. E. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Mintairov, A. M.; He Yan; Merz, J. L. [University of Notre Dame, EE Department (United States)

2010-07-15T23:59:59.000Z

398

Phosphor-free nanopyramid white light-emitting diodes grown on (101{sup ¯}1) planes using nanospherical-lens photolithography  

SciTech Connect (OSTI)

We reported a high-efficiency and low-cost nano-pattern method, the nanospherical-lens photolithography technique, to fabricate a SiO{sub 2} mask for selective area growth. By controlling the selective growth, we got a highly ordered hexagonal nanopyramid light emitting diodes with InGaN/GaN quantum wells grown on nanofacets, demonstrating an electrically driven phosphor-free white light emission. We found that both the quantum well width and indium incorporation increased linearly along the (101{sup ¯}1) planes towards the substrate and the perpendicular direction to the (101{sup ¯}1) planes as well. Such spatial distribution was responsible for the broadband emission. Moreover, using cathodoluminescence techniques, it was found that the blue emission originated from nanopyramid top, resembling the quantum dots, green emission from the InGaN quantum wells layer at the middle of sidewalls, and yellow emission mainly from the bottom of nanopyramid ridges, similar to the quantum wires.

Wu, Kui [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China) [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Department of Electronic Engineering, Tsinghua National Laboratory for Information Science and Technology/State Key Lab on Integrated Optoelectronics, Tsinghua University, Beijing 100084 (China); Wei, Tongbo, E-mail: tbwei@semi.ac.cn; Wei, Xuecheng; Zheng, Haiyang; Chen, Yu; Lu, Hongxi; Wang, Junxi; Li, Jinmin [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)] [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Lan, Ding [National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080 (China)] [National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080 (China); Huang, Kai [Platform of Characterization and Test, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215000 (China)] [Platform of Characterization and Test, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215000 (China); Luo, Yi [Department of Electronic Engineering, Tsinghua National Laboratory for Information Science and Technology/State Key Lab on Integrated Optoelectronics, Tsinghua University, Beijing 100084 (China)] [Department of Electronic Engineering, Tsinghua National Laboratory for Information Science and Technology/State Key Lab on Integrated Optoelectronics, Tsinghua University, Beijing 100084 (China)

2013-12-09T23:59:59.000Z

399

Monolithic phosphor-free InGaN/GaN quantum dot wavelength converter white light emitting diodes  

SciTech Connect (OSTI)

We report the characteristics of phosphor-free self-organized InGaN/GaN quantum dot wavelength converter white light emitting diodes grown by plasma assisted molecular beam epitaxy. The exciting quantum dots, in which electrically injected carriers recombine, are blue-emitting and the converter dots are red-emitting. We have studied the effect of tuning the number of dot layers and the peak emission wavelength of the exciting and converter dots on the nature of the emitted white light, in terms of the chromaticity coordinates and correlated color temperature. Depending on the values of these wavelengths, color temperatures in the range of 4420–6700?K have been derived at a current density of 45?A/cm{sup 2} across multiple devices. The variation of the color temperature with change in injection current is found to be very small.

Jahangir, Shafat; Bhattacharya, Pallab, E-mail: pkb@eecs.umich.edu [Center for Photonics and Multiscale Nanomaterials, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States); Pietzonka, Ines; Strassburg, Martin [OSRAM Opto Semiconductors GmbH, Leibnizstrasse 4, Regensburg (Germany)

2014-09-15T23:59:59.000Z

400

How to upgrade your incandescent light bulbs Many people are choosing replacements for their standard incandescent light bulbs to save money or energy, because they've heard of new LED  

E-Print Network [OSTI]

How to upgrade your incandescent light bulbs Many people are choosing replacements for their standard incandescent light bulbs to save money or energy, because they've heard of new LED options, or in anticipation of the phase-out of standard incandescent bulbs in the U.S. starting in 2012. If you've shopped

Bystroff, Chris

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Illuminating the Pecking Order in Off-Grid Lighting: A Demonstration of LED Lighting for Saving Energy in the Poultry Sector  

E-Print Network [OSTI]

workers in comparison to the other lighting systems. Therelamps. 3. In comparison to the other lighting systems, the

Tracy, Jennifer

2012-01-01T23:59:59.000Z

402

Enhancement of Radiative Efficiency with Staggered InGaN Quantum Well Light Emitting Diodes  

SciTech Connect (OSTI)

The technology on the large overlap InGaN QWs developed in this program is currently implemented in commercial technology in enhancing the internal quantum efficiency in major LED industry in US and Asia. The scientific finding from this work supported by the DOE enabled the implementation of this step-like staggered quantum well in the commercial LEDs.

Tansu, Nelson; Dierolf, Volkmar; Huang, Gensheng; Penn, Samson; Zhao, Hongping; Liu, Guangyu; Li, Xiaohang; Poplawsky, Jonathan

2011-07-14T23:59:59.000Z

403

July 18, 2012 Using QECBs for Street Lighting Upgrades  

E-Print Network [OSTI]

lighting technologies (e.g. light-emitting diodes, induction lighting) can reduce street light energy

404

Fabrication of ZnO photonic crystals by nanosphere lithography using inductively coupled-plasma reactive ion etching with CH{sub 4}/H{sub 2}/Ar plasma on the ZnO/GaN heterojunction light emitting diodes  

SciTech Connect (OSTI)

This article reports fabrication of n-ZnO photonic crystal/p-GaN light emitting diode (LED) by nanosphere lithography to further booster the light efficiency. In this article, the fabrication of ZnO photonic crystals is carried out by nanosphere lithography using inductively coupled plasma reactive ion etching with CH{sub 4}/H{sub 2}/Ar plasma on the n-ZnO/p-GaN heterojunction LEDs. The CH{sub 4}/H{sub 2}/Ar mixed gas gives high etching rate of n-ZnO film, which yields a better surface morphology and results less plasma-induced damages of the n-ZnO film. Optimal ZnO lattice parameters of 200 nm and air fill factor from 0.35 to 0.65 were obtained from fitting the spectrum of n-ZnO/p-GaN LED using a MATLAB code. In this article, we will show our recent result that a ZnO photonic crystal cylinder has been fabricated using polystyrene nanosphere mask with lattice parameter of 200 nm and radius of hole around 70 nm. Surface morphology of ZnO photonic crystal was examined by scanning electron microscope.

Chen, Shr-Jia; Chang, Chun-Ming; Kao, Jiann-Shiun; Chen, Fu-Rong; Tsai, Chuen-Horng [Engineering and System Science, National Tsing Hua University, Hsinchu, 30013 Taiwan (China); Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, 300 Taiwan (China); Engineering and System Science, National Tsing Hua University, Hsinchu, 30013 Taiwan (China)

2010-07-15T23:59:59.000Z

405

Understanding the role of ultra-thin polymeric interlayers in improving efficiency of polymer light emitting diodes  

SciTech Connect (OSTI)

Insertion of ultra-thin polymeric interlayers (ILs) between the poly(3,4-ethylenedioxythiophene):polystyrene sulphonate hole injection and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) light emission layers of polymer light emitting diodes (PLEDs) can significantly increase their efficiency. In this paper, we investigate experimentally a broad range of probable causes of this enhancement with an eye to determining which IL parameters have the most significant effects. The importance of hole injection and electron blocking was studied through varying the IL material (and consequently its electronic energy levels) for both PLED and hole-only diode structures. The role of IL conductivity was examined by introducing a varying level of charge-transfer doping through blending the IL materials with a strong electron-accepting small molecule in concentrations from 1% to 7% by weight. Depositing ILs with thicknesses below the exciton diffusion length of ?15?nm allowed the role of the IL as a physical barrier to exciton quenching to be probed. IL containing PLEDs was also fabricated with Lumation Green Series 1300 (LG 1300) light emission layers. On the other hand, the PLEDs were modeled using a 3D multi-particle Kinetic Monte Carlo simulation coupled with an optical model describing how light is extracted from the PLED. The model describes charge carrier transport and interactions between electrons, holes, singlets, and triplets, with the current density, luminance, and recombination zone (RZ) locations calculated for each PLED. The model shows F8BT PLEDs have a narrow charge RZ adjacent to the anode, while LG 1300 PLEDs have a wide charge RZ that is evenly distributed across the light emitting layer. Varying the light emitting layer from F8BT to Lumation Green Series 1300, we therefore experimentally examine the dependence of the IL function, specifically in regard to anode-side exciton quenching, on the location of the RZ. We found an exponential dependence of F8BT PLED luminance on the difference, ?, in the highest occupied to lowest unoccupied molecular orbital energy gap between the light emitting polymer and a semiconducting polymeric IL, with ? consequently the most important parameter determining efficiency. Understanding the exponential effect that wider energy gap IL materials have on exciton quenching may allow ? to be used to better guide PLED structure design.

Bailey, Jim; Wang, Xuhua; Bradley, Donal D. C.; Kim, Ji-Seon, E-mail: ji-seon.kim@imperial.ac.uk [Department of Physics and Centre for Plastic Electronics, South Kensington Campus, Imperial College London, London SW7 2AZ (United Kingdom); Wright, Edward N.; Walker, Alison B. [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)

2014-05-28T23:59:59.000Z

406

An LED-based Flasher System for VERITAS  

E-Print Network [OSTI]

We describe a flasher system designed for use in monitoring the gains of the photomultiplier tubes used in the VERITAS gamma-ray telescopes. This system uses blue light-emitting diodes (LEDs) so it can be operated at much higher rates than a traditional laser-based system. Calibration information can be obtained with better statistical precision with reduced loss of observing time. The LEDs are also much less expensive than a laser. The design features of the new system are presented, along with measurements made with a prototype mounted on one of the VERITAS telescopes.

Hanna, D; McCutcheon, M; Nikkinen, L; 10.1016/j.nima.2009.10.107

2009-01-01T23:59:59.000Z

407

Colloidal quantum-dot light-emitting diodes with metal-oxide charge  

E-Print Network [OSTI]

across the pixel area, and fabrication required the specialized deposition technique of energy-neutral over previously reported structures8,10 . Previous efforts at building colloidal quantum-dot (QD) LEDs concentrations and energy-band

408

Laser Diode Setup and Operation Eric Lochbrunner  

E-Print Network [OSTI]

Laser Diode Setup and Operation Eric Lochbrunner Diodes are a very important electrical of current. Laser diodes are complex semiconductors similar to regular diodes that convert an electrical of the diode to create laser activity. Light emitters are a key element in any fiber optic system

La Rosa, Andres H.

409

Illuminating the Pecking Order in Off-Grid Lighting: A Demonstration of LED Lighting for Saving Energy in the Poultry Sector  

E-Print Network [OSTI]

each of the three systems. Lighting System Kerosene Solar-opened and all available lighting points in use—we measuredin comparison to the other lighting systems. There is

Tracy, Jennifer

2012-01-01T23:59:59.000Z

410

E-Print Network 3.0 - amplitude modulated light Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the phase shift in the modulation... in this experiment using a high speed light emitting diode (LED) modulated at 40 MHz as the source, and a PIN... PHYSICS 359 THE SPEED OF...

411

600 New Lights Bulbs to Improve Energy Efficiency at DOE | Department...  

Broader source: Energy.gov (indexed) [DOE]

our Washington, D.C., Forrestal North Building canopy with state of the art Light Emitting Diode (LED) fixtures. Every new bulb now uses just 23 watts instead of 205 watts....

412

An intentionally positioned (In,Ga)As quantum dot in a micron sized light emitting diode  

SciTech Connect (OSTI)

We have integrated individual (In,Ga)As quantum dots (QDs) using site-controlled molecular beam epitaxial growth into the intrinsic region of a p-i-n junction diode. This is achieved using an in situ combination of focused ion beam prepatterning, annealing, and overgrowth, resulting in arrays of individually electrically addressable (In,Ga)As QDs with full control on the lateral position. Using microelectroluminescence spectroscopy we demonstrate that these QDs have the same optical quality as optically pumped Stranski-Krastanov QDs with random nucleation located in proximity to a doped interface. The results suggest that this technique is scalable and highly interesting for different applications in quantum devices.

Mehta, M.; Michaelis de Vasconcellos, S.; Zrenner, A.; Meier, C. [Department of Physics and Center for Optoelectronics and Photonics Paderborn (CeOPP), University of Paderborn, Warburger Street 100, 33098 Paderborn (Germany); Reuter, D.; Wieck, A. D. [Applied Solid State Physics, Ruhr-University of Bochum, Universitaetsstr. 150, 44780 Bochum (Germany)

2010-10-04T23:59:59.000Z

413

Assessing the Performance of LED-Based Flashlights Available in the Kenyan Off-Grid Lighting Market  

E-Print Network [OSTI]

have largely displaced incandescent flashlights in retailinvolving the use of incandescent lighting, unless there areFluorescent Flashlight C Incandescent SPX 50 Fluorescent y x

Tracy, Jennifer

2010-01-01T23:59:59.000Z

414

Low-cost electrochemical treatment of indium tin oxide anodes for high-efficiency organic light-emitting diodes  

SciTech Connect (OSTI)

We demonstrate a simple low-cost approach as an alternative to conventional O{sub 2} plasma treatment to modify the surface of indium tin oxide (ITO) anodes for use in organic light-emitting diodes. ITO is functionalized with F{sup ?} ions by electrochemical treatment in dilute hydrofluoric acid. An electrode with a work function of 5.2?eV is achieved following fluorination. Using this electrode, a maximum external quantum efficiency of 26.0% (91?cd/A, 102?lm/W) is obtained, which is 12% higher than that of a device using the O{sub 2} plasma-treated ITO. Fluorination also increases the transparency in the near-infrared region.

Hui Cheng, Chuan, E-mail: chengchuanhui@dlut.edu.cn; Shan Liang, Ze; Gang Wang, Li; Dong Gao, Guo; Zhou, Ting; Ming Bian, Ji; Min Luo, Ying [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Tong Du, Guo, E-mail: dugt@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

2014-01-27T23:59:59.000Z

415

Barrier performance optimization of atomic layer deposited diffusion barriers for organic light emitting diodes using x-ray reflectivity investigations  

SciTech Connect (OSTI)

The importance of O{sub 3} pulse duration for encapsulation of organic light emitting diodes (OLEDs) with ultra thin inorganic atomic layer deposited Al{sub 2}O{sub 3} layers is demonstrated for deposition temperatures of 50 °C. X-ray reflectivity (XRR) measurements show that O{sub 3} pulse durations longer than 15?s produce dense and thin Al{sub 2}O{sub 3} layers. Correspondingly, black spot growth is not observed in OLEDs encapsulated with such layers during 91 days of aging under ambient conditions. This implies that XRR can be used as a tool for process optimization of OLED encapsulation layers leading to devices with long lifetimes.

Singh, Aarti, E-mail: aarti.singh@namlab.com; Schröder, Uwe [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany)] [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany); Klumbies, Hannes; Müller-Meskamp, Lars; Leo, Karl [Dresden Innovation Center Energy Efficiency, Institut für Angewandte Photophysik, Technische Universität Dresden, 01062 Dresden (Germany)] [Dresden Innovation Center Energy Efficiency, Institut für Angewandte Photophysik, Technische Universität Dresden, 01062 Dresden (Germany); Geidel, Marion; Knaut, Martin; Hoßbach, Christoph; Albert, Matthias [Institute of Semiconductor and Microsystems Technology, Technische Universität Dresden, 01187 Dresden (Germany)] [Institute of Semiconductor and Microsystems Technology, Technische Universität Dresden, 01187 Dresden (Germany); Mikolajick, Thomas [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany) [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany); Institute of Semiconductor and Microsystems Technology, Technische Universität Dresden, 01187 Dresden (Germany)

2013-12-02T23:59:59.000Z

416

Enhancing the quantum efficiency of InGaN yellow-green light-emitting diodes by growth interruption  

SciTech Connect (OSTI)

We studied the effect of multiple interruptions during the quantum well growth on emission-efficiency enhancement of InGaN-based yellow-green light emitting diodes on c-plane sapphire substrate. The output power and dominant wavelength at 20?mA are 0.24 mW and 556.3?nm. High resolution x-ray diffraction, photoluminescence, and electroluminescence measurements demonstrate that efficiency enhancement could be partially attributed to crystal quality improvement of the active region resulted from reduced In clusters and relevant defects on the surface of InGaN layer by introducing interruptions. The less tilted energy band in the quantum well is also caused by the decrease of In-content gradient along c-axis resulted from In segregation during the interruptions, which increases spatial overlap of electron-hole wavefunction and thus the internal quantum efficiency. The latter also leads to smaller blueshift of dominant wavelength with current increasing.

Du, Chunhua; Ma, Ziguang; Zhou, Junming; Lu, Taiping; Jiang, Yang; Zuo, Peng; Jia, Haiqiang; Chen, Hong, E-mail: hchen@iphy.ac.cn [Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condense Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2014-08-18T23:59:59.000Z

417

Carrier recombination mechanisms and efficiency droop in GaInN/GaN light-emitting diodes  

SciTech Connect (OSTI)

We model the carrier recombination mechanisms in GaInN/GaN light-emitting diodes as R=An+Bn{sup 2} +Cn{sup 3} +f(n) , where f(n) represents carrier leakage out of the active region. The term f(n) is expanded into a power series and shown to have higher-than-third-order contributions to the recombination. The total third-order nonradiative coefficient (which may include an f(n) leakage contribution and an Auger contribution) is found to be 8×10{sup ?29} ?cm{sup 6} ?s{sup ?1} . Comparison of the theoretical ABC+f(n) model with experimental data shows that a good fit requires the inclusion of the f(n) term.

Dai, Qi; Shan, Qifeng; Wang, Jing; Chhajed, Sameer; Cho, Jaehee; Schubert, E. Fred; Crawford, Mary H.; Koleske, Daniel D.; Kim, Min-Ho; Park, Yongjo

2010-01-01T23:59:59.000Z

418

Highly efficient inverted top emitting organic light emitting diodes using a transparent top electrode with color stability on viewing angle  

SciTech Connect (OSTI)

We report a highly efficient phosphorescent green inverted top emitting organic light emitting diode with excellent color stability by using the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile/indium zinc oxide top electrode and bis(2-phenylpyridine)iridium(III) acetylacetonate as the emitter in an exciplex forming co-host system. The device shows a high external quantum efficiency of 23.4% at 1000?cd/m{sup 2} corresponding to a current efficiency of 110?cd/A, low efficiency roll-off with 21% at 10?000?cd/m{sup 2} and low turn on voltage of 2.4?V. Especially, the device showed very small color change with the variation of ?x?=?0.02, ?y?=?0.02 in the CIE 1931 coordinates as the viewing angle changes from 0° to 60°. The performance of the device is superior to that of the metal/metal cavity structured device.

Kim, Jung-Bum; Lee, Jeong-Hwan; Moon, Chang-Ki; Kim, Jang-Joo, E-mail: jjkim@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

2014-02-17T23:59:59.000Z

419

ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition  

SciTech Connect (OSTI)

We report a breakthrough in fabricating ZnO homojunction light-emitting diode by metal organic chemical vapor deposition. Using NO plasma, we are able to grow p-type ZnO thin films on n-type bulk ZnO substrates. The as-grown films on glass substrates show hole concentration of 10{sup 16}-10{sup 17} cm{sup -3} and mobility of 1-10 cm{sup 2} V{sup -1} s{sup -1}. Room-temperature photoluminescence spectra reveal nitrogen-related emissions. A typical ZnO homojunction shows rectifying behavior with a turn-on voltage of about 2.3 V. Electroluminescence at room temperature has been demonstrated with band-to-band emission at I=40 mA and defect-related emissions in the blue-yellow spectrum range.

Xu, W.Z.; Ye, Z.Z.; Zeng, Y.J.; Zhu, L.P.; Zhao, B.H.; Jiang, L.; Lu, J.G.; He, H.P.; Zhang, S.B. [State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

2006-04-24T23:59:59.000Z

420

LED Record Efficacy and Brightness  

Broader source: Energy.gov [DOE]

Designed for general lighting applications such as street, industrial, and parking garage lighting, the Cree XLamp® power LED sets new records for LED brightness and efficacy, up to 85 lm/W at 350 mA. The XLamp utilizes Cree's performance breakthrough EZBright™ LED chip; both products include technology that was developed in part with R&D funding support from DOE.

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Comparison of light out-coupling enhancements in single-layer blue-phosphorescent organic light emitting diodes using small-molecule or polymer hosts  

SciTech Connect (OSTI)

Single-layer blue phosphorescence organic light emitting diodes (OLEDs) with either small-molecule or polymer hosts are fabricated using solution process and the performances of devices with different hosts are investigated. The small-molecule device exhibits luminous efficiency of 14.7?cd/A and maximum power efficiency of 8.39?lm/W, which is the highest among blue phosphorescence OLEDs with single-layer solution process and small molecular hosts. Using the same solution process for all devices, comparison of light out-coupling enhancement, with brightness enhancement film (BEF), between small-molecule and polymer based OLEDs is realized. Due to different dipole orientation and anisotropic refractive index, polymer-based OLEDs would trap less light than small molecule-based OLEDs internally, about 37% better based simulation results. In spite of better electrical and spectroscopic characteristics, including ambipolar characteristics, higher carrier mobility, higher photoluminescence quantum yield, and larger triplet state energy, the overall light out-coupling efficiency of small molecule-based devices is worse than that of polymer-based devices without BEF. However, with BEF for light out-coupling enhancement, the improved ratio in luminous flux and luminous efficiency for small molecule based device is 1.64 and 1.57, respectively, which are significantly better than those of PVK (poly-9-vinylcarbazole) devices. In addition to the theoretical optical simulation, the experimental data also confirm the origins of differential light-outcoupling enhancement. The maximum luminous efficiency and power efficiency are enhanced from 14.7?cd/A and 8.39?lm/W to 23?cd/A and 13.2?lm/W, respectively, with laminated BEF, which are both the highest so far for single-layer solution-process blue phosphorescence OLEDs with small molecule hosts.

Chang, Yung-Ting [Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11529, Taiwan (China); Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 10617, Taiwan (China); Liu, Shun-Wei [Department of Electronic Engineering, Mingchi University of Technology, New Taipei, Taiwan 24301, Taiwan (China); Yuan, Chih-Hsien; Lee, Chih-Chien [Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10607, Taiwan (China); Ho, Yu-Hsuan; Wei, Pei-Kuen [Research Center for Applied Science Academia Sinica, Taipei, Taiwan 11527, Taiwan (China); Chen, Kuan-Yu [Chilin Technology Co., LTD, Tainan City, Taiwan 71758, Taiwan (China); Lee, Yi-Ting; Wu, Min-Fei; Chen, Chin-Ti, E-mail: cchen@chem.sinica.edu.tw, E-mail: chihiwu@cc.ee.ntu.edu.tw [Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11529, Taiwan (China); Wu, Chih-I, E-mail: cchen@chem.sinica.edu.tw, E-mail: chihiwu@cc.ee.ntu.edu.tw [Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 10617, Taiwan (China)

2013-11-07T23:59:59.000Z

422

Fabrication of color tunable organic light-emitting diodes by an alignment free mask patterning method  

E-Print Network [OSTI]

that of the incandescent bulb and comparable with that of the fluorescent tube. OLEDs are a true sur- face/area lighting

423

Development of monolithic CMOS-compatible visible light emitting diode arrays on silicon  

E-Print Network [OSTI]

The synergies associated with integrating Si-based CMOS ICs and III-V-material-based light-emitting devices are very exciting and such integration has been an active area of research and development for quite some time ...

Chilukuri, Kamesh

2006-01-01T23:59:59.000Z

424

Comparing directed efficiency of III-nitride nanowire light-emitting diodes  

E-Print Network [OSTI]

III-nitride-based nanowires are a promising platform for solid-state lighting. III-nitride nanowires that act as natural waveguides to enhance directed extraction have previously been shown to be free of extended defects ...

Gradecak, Silvija

425

Photonic crystal light emitting diode based on Er and Si nanoclusters co-doped slot waveguide  

SciTech Connect (OSTI)

We report on the design, fabrication, and electro-optical characterization of a light emitting device operating at 1.54??m, whose active layer consists of silicon oxide containing Er-doped Si nanoclusters. A photonic crystal (PhC) is fabricated on the top-electrode to enhance the light extraction in the vertical direction, and thus the external efficiency of the device. This occurs if a photonic mode of the PhC slab is resonant with the Er emission energy, as confirmed by theoretical calculations and experimental analyses. We measure an increase of the extraction efficiency by a factor of 3 with a high directionality of light emission in a narrow vertical cone. External quantum efficiency and power efficiency are among the highest reported for this kind of material. These results are important for the realization of CMOS-compatible efficient light emitters at telecom wavelengths.

Lo Savio, R.; Galli, M.; Liscidini, M.; Andreani, L. C. [Dipartimento di Fisica, Università di Pavia, Via Bassi 6, 27100 Pavia (Italy); Franzò, G.; Iacona, F.; Miritello, M. [MATIS-IMM CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Irrera, A. [CNR-IPCF, Viale Ferdinando Stagno d'Alcontres 37, 98158 Messina (Italy); Sanfilippo, D.; Piana, A. [ST Microelectronics, Stradale Primosole 50, 95121 Catania (Italy); Priolo, F. [MATIS-IMM CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Scuola Superiore di Catania, Università di Catania, Via Valdisavoia 9, 95123 Catania (Italy)

2014-03-24T23:59:59.000Z

426

Light emitting diode with porous SiC substrate and method for fabricating  

DOE Patents [OSTI]

A method and apparatus for forming a porous layer on the surface of a semiconductor material wherein an electrolyte is provided and is placed in contact with one or more surfaces of a layer of semiconductor material. The electrolyte is heated and a bias is introduced across said electrolyte and the semiconductor material causing a current to flow between the electrolyte and the semiconductor material. The current forms a porous layer on the one or more surfaces of the semiconductor material in contact with the electrolyte. The semiconductor material with its porous layer can serve as a substrate for a light emitter. A semiconductor emission region can be formed on the substrate. The emission region is capable of emitting light omnidirectionally in response to a bias, with the porous layer enhancing extraction of the emitting region light passing through the substrate.

Li, Ting; Ibbetson, James; Keller, Bernd

2005-12-06T23:59:59.000Z

427

Development of a cost effective surface-patterned transparent conductive coating as top-contact of light emitting diodes  

SciTech Connect (OSTI)

Sol-gel process has been used to form indium zinc oxide films using an optimized combination of zinc to indium concentration in the precursor solutions. Different structures, like one (1D) and two-dimensional (2D) gratings and diffractive optical elements (DOEs) in the form of Fresnel lens are fabricated on the film surface of proposed top metal contact of LED by imprint soft lithography technique. These structures can enhance the LED's light extraction efficiency (LEE) or can shape the output beam pattern, respectively. Several characterizations are done to analyze the material and structural properties of the films. The presence of 1D and 2D gratings as well as DOEs is confirmed from field emission scanning electron and atomic force microscopes analyses. Although, X-ray diffraction shows amorphous nature of the film, but transmission electron microscopy study shows that it is nano crystalline in nature having fine particles (?8?nm) of hexagonal ZnO. Shrinkage behaviour of gratings as a function of curing temperature is explained by Fourier transform infra-red spectra and thermo gravimetric-differential thermal analysis. The visible transmission and sheet resistance of the sample are found comparable to tin doped indium oxide (ITO). Therefore, the film can compete as low cost substitute of ITO as top metal contact of LEDs.

Haldar, Arpita [Department of Applied Optics and Photonics, University of Calcutta, Kolkata-700009 (India); Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Bera, Susanta; Jana, Sunirmal, E-mail: sjana@cgcri.res.in, E-mail: srirajib@yahoo.com [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Bhattacharya, Kallol; Chakraborty, Rajib, E-mail: sjana@cgcri.res.in, E-mail: srirajib@yahoo.com [Department of Applied Optics and Photonics, University of Calcutta, Kolkata-700009 (India)

2014-05-21T23:59:59.000Z

428

Room temperature all-silicon photonic crystal nanocavity light emitting diode at sub-bandgap wavelengths  

E-Print Network [OSTI]

Silicon is now firmly established as a high performance photonic material. Its only weakness is the lack of a native electrically driven light emitter that operates CW at room temperature, exhibits a narrow linewidth in the technologically important 1300- 1600 nm wavelength window, is small and operates with low power consumption. Here, an electrically pumped all-silicon nano light source around 1300-1600 nm range is demonstrated at room temperature. Using hydrogen plasma treatment, nano-scale optically active defects are introduced into silicon, which then feed the photonic crystal nanocavity to enahnce the electrically driven emission in a device via Purcell effect. A narrow ({\\Delta}{\\lambda} = 0.5 nm) emission line at 1515 nm wavelength with a power density of 0.4 mW/cm2 is observed, which represents the highest spectral power density ever reported from any silicon emitter. A number of possible improvements are also discussed, that make this scheme a very promising light source for optical interconnects a...

Shakoor, A; Cardile, P; Portalupi, S L; Gerace, D; Welna, K; Boninelli, S; Franzo, G; Priolo, F; Krauss, T F; Galli, M; Faolain, L O

2013-01-01T23:59:59.000Z

429

Indium-tin-oxide-free tris(8-hydroxyquinoline) Al organic light-emitting diodes with 80% enhanced power efficiency  

SciTech Connect (OSTI)

Efficient indium tin oxide (ITO)-free small molecule organic light-emitting diodes (SMOLEDs) with multilayered highly conductive poly(3,4-ethylenedioxy thiophene):poly(styrenesulfonate) (PEDOT:PSS) as the anode are demonstrated. PEDOT:PSS/MoO{sub 3}/N,N'-diphenyl- N,N'-bis(1-naphthylphenyl)-1,1'-biphenyl-4,4'-diamine (NPD)/tris(8-hydroxyquinoline) Al (Alq{sub 3})/4,7-diphenyl-1,10-phenanthroline (BPhen)/LiF/Al SMOLEDs exhibited a peak power efficiency of 3.82 lm/W, 81% higher than that of similar ITO-based SMOLEDs (2.11 lm/W). The improved performance is believed to be due to the higher work function, lower refractive index, and decreased surface roughness of PEDOT:PSS vs ITO, and to Ohmic hole injection from PEDOT:PSS to the NPD layer via the MoO{sub 3} interlayer. The results demonstrate that PEDOT:PSS can substitute ITO in SMOLEDs with strongly improved device performance.

Cai, Min; Xiao, Teng; Liu, Rui; Chen, Ying; Shinar, Ruth; Shinar, Joseph

2011-10-11T23:59:59.000Z

430

Role of chemical reactions of arylamine hole transport materials in operational degradation of organic light-emitting diodes  

SciTech Connect (OSTI)

We report that the representative arylamine hole transport materials undergo chemical transformations in operating organic light-emitting diode (OLED) devices. Although the underlying chemical mechanisms are too complex to be completely elucidated, structures of several identified degradation products point at dissociations of relatively weak carbon-nitrogen and carbon-carbon bonds in arylamine molecules as the initiating step. Considering the photochemical reactivities, the bond dissociation reactions of arylamines occur by the homolysis of the lowest singlet excited states formed by recombining charge carriers in the operating OLED device. The subsequent chemical reactions are likely to yield long-lived, stabilized free radicals capable of acting as deep traps--nonradiative recombination centers and fluorescence quenchers. Their presence in the hole transport layer results in irreversible hole trapping and manifests as a positive fixed charge. The extent and localization of chemical transformations in several exemplary devices suggest that the free radical reactions of hole transporting materials, arylamines, can be sufficient to account for the observed luminance efficiency loss and voltage rise in operating OLEDs. The relative bond strengths and excited state energies of OLED materials appear to have a determining effect on the operational stability of OLED devices.

Kondakov, Denis Y. [Eastman Kodak Company, Rochester, New York 14650-2103 (United States)

2008-10-15T23:59:59.000Z

431

Highly-selective wettability on organic light-emitting-diodes patterns by sequential low-power plasmas  

SciTech Connect (OSTI)

Patterned organic light-emitting-diode substrates were treated by oxygen (O{sub 2}) and tetrafluoromethane (CF{sub 4}) radio-frequency (rf, 13.56 MHz) plasmas of low-power (close to 1 W) that were capacitively-coupled. An unexpected wettability contrast (water contact angle difference up to 90 deg. ) between the indium-tin-oxide anode and the bank resist regions was achieved, providing excellent conditioning prior to the ink-jet printing. This selectivity was found to be adjustable by varying the relative exposure time to the O{sub 2} and CF{sub 4} sequential plasmas. Static contact angle measurements and extensive x-ray photoelectron spectroscopy analyses showed that the wetting properties depend on the carbon and fluorine chemical functional groups formed at the outermost surface layers, whereas atomic force microscopy images did not show a morphological change. Plasma optical emission spectroscopy and ion mass spectroscopy suggested that surface functionalization was initiated by energy transfer from ionic species (O{sup +}, O{sub 2}{sup +}, CF{sup +}, CF{sub 2}{sup +}, and CF{sub 3}{sup +}) and excited neutrals (O{sup *} and F{sup *}). The absolute ion fluxes measured on the substrates were up to 10{sup 14} cm{sup -2} s{sup -1} and the ion energies up to 20 eV, despite the low powers applied during the process.

Svarnas, P.; Edwards, A. J.; Bradley, J. W. [Department of Electrical Engineering and Electronics, Technological Plasmas Group, University of Liverpool, Merseyside L69 3GJ (United Kingdom); Yang, L.; Munz, M.; Shard, A. G. [Analytical Science Division, National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex TW11 0LW (United Kingdom)

2010-05-15T23:59:59.000Z

432

Tests gauge LED sensors for fuel-dye measurements  

SciTech Connect (OSTI)

The goal of this work was to develop a low cost, robust sensor to allow direct measurement of Solvent Red 164 dye concentration in off-road fuel at refineries and fuel terminals. Optical absorption sensors based on light emitting diodes (LEDs) are rugged, low-cost, have low power consumption, and can be designed to be intrinsically safe.LED-based systems have been used in a variety of chemical detection applications including heavy metals, pH, CO2, and O2. The approach for this work was to develop a sensor that could be mounted on a pipeline sight glass, precluding the need for direct contact of the sensor with the fuel. Below is described the design and testing of three different LED/photodiode sensors utilizing reflectance spectrometry for the measurement of dye concentration.

Ozanich, Richard M.; Lucke, Richard B.; Melville, Angela M.; Wright, Bob W.

2009-10-19T23:59:59.000Z

433

Alternative p-doped hole transport material for low operating voltage and high efficiency organic light-emitting diodes  

SciTech Connect (OSTI)

We investigate the properties of N,N?-[(Diphenyl-N,N?-bis)9,9,-dimethyl-fluoren-2-yl]-benzidine (BF-DPB) as hole transport material (HTL) in organic light-emitting diodes (OLEDs) and compare BF-DPB to the commonly used HTLs N,N,N?,N?-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD), 2,2?,7,7?-tetrakis(N,N?-di-p-methylphenylamino)-9,9?-spirobifluorene (Spiro-TTB), and N,N?-di(naphtalene-1-yl)-N,N?-diphenylbenzidine (NPB). The influence of 2,2?-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6-TCNNQ p-dopant) concentration in BF-DPB on the operation voltage and efficiency of red and green phosphorescent OLEDs is studied; best results are achieved at 4?wt. % doping. Without any light extraction structure, BF-DPB based red (green) OLEDs achieve a luminous efficacy of 35?.1?lm/W (74?.0?lm/W) at 1000?cd/m{sup 2} and reach a very high brightness of 10?000 cd/m{sup 2} at a very low voltage of 3.2 V (3.1 V). We attribute this exceptionally low driving voltage to the high ionization potential of BF-DPB which enables more efficient hole injection from BF-DPB to the adjacent electron blocking layer. The high efficiency and low driving voltage lead to a significantly lower luminous efficacy roll-off compared to the other compounds and render BF-DPB an excellent HTL material for highly efficient OLEDs.

Murawski, Caroline, E-mail: caroline.murawski@iapp.de; Fuchs, Cornelius; Hofmann, Simone; Leo, Karl [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Str. 1, 01062 Dresden (Germany); Gather, Malte C. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Str. 1, 01062 Dresden (Germany); SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS Scotland (United Kingdom)

2014-09-15T23:59:59.000Z

434

Edge electroluminescence of the effective silicon point-junction light-emitting diode in the temperature range 80-300 K  

SciTech Connect (OSTI)

The edge electroluminescence spectra of silicon point-junction light-emitting diodes with a p-n junction area of 0.008 mm{sup 2} are studied at temperatures ranging from 80 to 300 K. Unprecedentedly high stability of the position of the spectral peak is observed at temperatures in the range between 130 and 300 K. The spectral characteristics of the light emitting diodes are studied at 80 K at different current densities up to 25 kA/cm{sup 2}. In contrast to the earlier reported data obtained at 300 K, the data obtained at 80 K do not show any noticeable Augerrecombination-related decrease in the quantum efficiency. From an analysis of the electroluminescence spectra at 80 K in a wide range of currents, it follows that radiative annihilation of free excitons is not a governing mechanism of electroluminescence in the entire emitting region in the base of the point-junction light-emitting diode at all currents used in the experiment.

Emel'yanov, A. M. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)], E-mail: Emelyanov@mail.ioffe.ru

2008-11-15T23:59:59.000Z

435

Measurement of the absorption coefficient for light laterally propagating in light-emitting diode structures with In{sub 0.2}Ga{sub 0.8}N/GaN quantum wells  

SciTech Connect (OSTI)

A procedure for measuring the absorption coefficient for light propagating parallel to the surface of a GaN-based light emitting diode chip on a sapphire substrate is suggested. The procedure implies the study of emission from one end face of the chip as the opposite end face is illuminated with a light emitting diode. The absorption coefficient is calculated from the ratio between the intensities of emission emerging from the end faces of the sapphire substrate and the epitaxial layer. From the measurements for chips based on p-GaN/In{sub 0.2}Ga{sub 0.8}N/n-GaN structures, the lateral absorption coefficient is determined at a level of (23 {+-} 3)cm{sup -1} at a wavelength of 465 nm. Possible causes for the discrepancy between the absorption coefficients determined in the study and those reported previously are analyzed.

Lelikov, Yu. S.; Bochkareva, N. I.; Gorbunov, R. I.; Martynov, I. A.; Rebane, Yu. T.; Tarkin, D. V.; Shreter, Yu. G. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)], E-mail: YShreter@mail.ioffe.ru

2008-11-15T23:59:59.000Z

436

Small Area Array-Based LED Luminaire Design  

SciTech Connect (OSTI)

This report contains a summary of technical achievements during a three-year project to demonstrate high efficiency LED luminaire designs based on small area array-based gallium nitride diodes. Novel GaN-based LED array designs are described, specifically addressing the thermal, optical, electrical and mechanical requirements for the incorporation of such arrays into viable solid-state LED luminaires. This work resulted in the demonstration of an integrated luminaire prototype of 1000 lumens cool white light output with reflector shaped beams and efficacy of 89.4 lm/W at CCT of 6000oK and CRI of 73; and performance of 903 lumens warm white light output with reflector shaped beams and efficacy of 63.0 lm/W at CCT of 2800oK and CRI of 82. In addition, up to 1275 lumens cool white light output at 114.2 lm/W and 1156 lumens warm white light output at 76.5 lm/W were achieved if the reflector was not used. The success to integrate small area array-based LED designs and address thermal, optical, electrical and mechanical requirements was clearly achieved in these luminaire prototypes with outstanding performance and high efficiency.

Thomas Yuan

2008-01-09T23:59:59.000Z

437

Long-term Testing Results for the 2008 Installation of LED Luminaires at the I-35 West Bridge in Minneapolis  

SciTech Connect (OSTI)

This document reports the long-term testing results from an extended GATEWAY project that was first reported in “Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting at the I-35W Bridge, in Minneapolis, MN,” August 2009. That original report presented the results of lighting the newly reconstructed I 35W Bridge using LEDs in place of conventional high-pressure sodium (HPS) roadway luminaires, comparing energy use and illuminance levels with a simulated baseline condition. That installation was an early stage implementation of LED lighting and remains one of the oldest installations in continued operation today. This document provides an update of the LED system’s performance since its installation in September 2008.

Kinzey, Bruce R.; Davis, Robert G.

2014-09-30T23:59:59.000Z

438

LOW-COST LED LUMINAIRE FOR GENERAL ILLUMINATION  

SciTech Connect (OSTI)

During this two-year Solid-State Lighting (SSL) Manufacturing R&D project Cree developed novel light emitting diode (LED) technologies contributing to a cost-optimized, efficient LED troffer luminaire platform emitting at ~3500K correlated color temperature (CCT) at a color rendering index (CRI) of >90. To successfully achieve program goals, Cree used a comprehensive approach to address cost reduction of the various optical, thermal and electrical subsystems in the luminaire without impacting performance. These developments built on Cree’s high- brightness, low-cost LED platforms to design a novel LED component architecture that will enable low-cost troffer luminaire designs with high total system efficacy. The project scope included cost reductions to nearly all major troffer subsystems as well as assembly costs. For example, no thermal management components were included in the troffer, owing to the optimized distribution of compact low- to mid-power LEDs. It is estimated that a significant manufacturing cost savings will result relative to Cree’s conventional troffers at the start of the project. A chief project accomplishment was the successful development of a new compact, high-efficacy LED component geometry with a broad far-field intensity distribution and even color point vs. emission angle. After further optimization and testing for production, the Cree XQ series of LEDs resulted. XQ LEDs are currently utilized in Cree’s AR series troffers, and they are being considered for use in other platforms. The XQ lens geometry influenced the independent development of Cree’s XB-E and XB-G high-voltage LEDs, which also have a broad intensity distribution at high efficacy, and are finding wide implementation in Cree’s omnidirectional A-lamps.

Lowes, Ted

2014-07-31T23:59:59.000Z

439

E-Print Network 3.0 - avalanche diode array Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

diodes 5. The inductance, La... Improved Light Output of Photonic Crystal Light Emitting Diode Fabricated by Anodized Aluminum Oxide Nano... -patterns , , ( ), , ( ) 16:30...

440

Bicolor Mn-doped CuInS{sub 2}/ZnS core/shell nanocrystals for white light-emitting diode with high color rendering index  

SciTech Connect (OSTI)

We synthesized bicolor Mn-doped CuInS{sub 2} (CIS)/ZnS core/shell nanocrystals (NCs), in which Mn{sup 2+} ions and the CIS core were separated with a ZnS layer, and both Mn{sup 2+} ions and CIS cores could emit simultaneously. Transmission electron microscopy and powder X-ray diffraction measurements indicated the epitaxial growth of ZnS shell on the CuInS{sub 2} core, and electron paramagnetic resonance spectrum indicated that Mn{sup 2+} ions were on the lattice points of ZnS shell. By integrating these bicolor NCs with commercial InGaN-based blue-emitting diodes, tricolor white light-emitting diodes with color rendering index of 83 were obtained.

Huang, Bo; Dai, Qian; Zhang, Huichao; Liao, Chen; Cui, Yiping; Zhang, Jiayu, E-mail: jyzhang@seu.edu.cn [Advanced Photonic Center, Southeast University, Nanjing 210096 (China); Zhuo, Ningze; Jiang, Qingsong; Shi, Fenghua; Wang, Haibo [Research Institute of Electric Light Source Materials, Nanjing University of Technology, Nanjing 210015 (China)

2014-09-07T23:59:59.000Z

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

IMPACT OF NEW LIGHTING TECHNOLOGIES ON OFFICE ERGONOMICS  

E-Print Network [OSTI]

The goal of this study was to find the impact of cutting-edge light-emitting diodes (LED) lighting technologies on the office ergonomics in modern offices. An experiment was conducted in a windowless office at the University of Kansas...

Li, Linjie

2013-12-31T23:59:59.000Z

442

Solid-state lighting technology perspective.  

SciTech Connect (OSTI)

Solid-State Lighting (SSL) uses inorganic light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs) to convert electricity into light for illumination. SSL has the potential for enormous energy savings and accompanying environmental benefits if its promise of 50% (or greater) energy efficiencies can be achieved. This report provides a broad summary of the technologies that underlie SSL. The applications for SSL and potential impact on U.S. and world-wide energy consumption, and impact on the human visual experience are discussed. The properties of visible light and different technical metrics to characterize its properties are summarized. The many factors contributing to the capital and operating costs for SSL and traditional lighting sources (incandescent, fluorescent, and high-intensity discharge lamps) are discussed, with extrapolations for future SSL goals. The technologies underlying LEDs and OLEDs are also described, including current and possible alternative future technologies and some of the present limitations.

Tsao, Jeffrey Yeenien; Coltrin, Michael Elliott

2006-08-01T23:59:59.000Z

443

Feedback-Controlled LED Photobioreactor for Photophysiological Studies of Cyanobacteria  

SciTech Connect (OSTI)

A custom photobioreactor (PBR) was designed to enable automatic light adjustments using computerized feedback control. A black anodized aluminum enclosure, constructed to surround the borosilicate reactor vessel, prevents the transmission of ambient light and serves as a mount for arrays of light-emitting diodes (LEDs). The high-output LEDs provide narrow-band light of either 630 or 680 nm for preferential excitation of the cyanobacterial light-harvesting pigments, phycobilin or chlorophyll a, respectively. Custom developed software BioLume provides automatic control of optical properties and a computer feedback loop can automatically adjust the incident irradiance as necessary to maintain a fixed transmitted light through the culture, based on user-determined set points. This feedback control serves to compensate for culture dynamics which have optical effects, (e.g., changing cell density, pigment adaptations) and thus can determine the appropriate light conditions for physiological comparisons or to cultivate light-sensitive strains, without prior analyses. The LED PBR may also be controlled as a turbidostat, using a feedback loop to continuously adjust the rate of media-dilution based on the transmitted light measurements, with a fast and precise response. This cultivation system gains further merit as a high-performance analytical device, using non-invasive tools (e.g., dissolved gas sensors, online mass spectrometry) to automate real-time measurements, thus permitting unsupervised experiments to search for optimal growth conditions, to monitor physiological responses to perturbations, as well as to quantitate photophysiological parameters using an in situ light-saturation response routine.

Melnicki, Matthew R.; Pinchuk, Grigoriy E.; Hill, Eric A.; Kucek, Leo A.; Stolyar, Sergey; Fredrickson, Jim K.; Konopka, Allan; Beliaev, Alex S.

2013-04-09T23:59:59.000Z

444

LED-Induced Fluorescence System for Tea Classification and Quality Assessment  

E-Print Network [OSTI]

A fluorescence system is developed by using several light emitting diodes (LEDs) with different wavelengths as excitation light sources. The fluorescence detection head consists of multi LED light sources and a multimode fiber for fluorescence collection, where the LEDs and the corresponding filters can be easily chosen to get appropriate excitation wavelengths for different applications. By analyzing fluorescence spectra with the principal component analysis method, the system is utilized in the classification of four types of green tea beverages and two types of black tea beverages. Qualities of the Xihu Longjing tea leaves of different grades, as well as the corresponding liquid tea samples, are studied to further investigate the ability and application of the system in the evaluation of classification/quality of tea and other foods.

Dong, Yongjiang; Mei, Liang; Feng, Chao; Yan, Chunsheng; He, Sailing

2013-01-01T23:59:59.000Z

445

Demonstration of LED Street Lighting  

Office of Scientific and Technical Information (OSTI)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinan antagonist Journal Article: Crystal structureComposite--

446

LED Watch: The Outlook for LEDs  

Broader source: Energy.gov [DOE]

December 2014 LED Watch: The Outlook for LEDs James Brodrick, U.S. Department of Energy LD+A Magazine

447

Strategy Guideline: High Performance Residential Lighting  

SciTech Connect (OSTI)

The Strategy Guideline: High Performance Residential Lighting has been developed to provide a tool for the understanding and application of high performance lighting in the home. The high performance lighting strategies featured in this guide are drawn from recent advances in commercial lighting for application to typical spaces found in residential buildings. This guide offers strategies to greatly reduce lighting energy use through the application of high quality fluorescent and light emitting diode (LED) technologies. It is important to note that these strategies not only save energy in the home but also serve to satisfy the homeowner's expectations for high quality lighting.

Holton, J.

2012-02-01T23:59:59.000Z

448

Organic LEDs for optoelectronic neural networks  

E-Print Network [OSTI]

In this thesis, I investigate the characteristics of Organic Light Emitting Diodes (OLEDs) and assess their suitability for use in the Compact Optoelectronic Integrated Neural (COIN) coprocessor. The COIN coprocessor, a ...

Mars, Risha R

2012-01-01T23:59:59.000Z

449

LIGHT EMITTING DIODE  

E-Print Network [OSTI]

NOTES: 1. Dimensions for all drawings are in inches (mm). 2. Tolerance of ±.010 (.25) on all non-nominal dimensions unless otherwise specified.

High Output Power

450

Active region based on graded-gap InGaN/GaN superlattices for high-power 440- to 470-nm light-emitting diodes  

SciTech Connect (OSTI)

The structural and optical properties of light-emitting diode structures with an active region based on ultrathin InGaN quantum wells limited by short-period InGaN/GaN superlattices from both sides have been investigated. The dependences of the external quantum efficiency on the active region design are analyzed. It is shown that the use of InGaN/GaN structures as limiting graded-gap short-period superlattices may significantly increase the quantum efficiency.

Tsatsulnikov, A. F., E-mail: Andrew@beam.ioffe.ru; Lundin, W. V.; Sakharov, A. V.; Zavarin, E. E.; Usov, S. O.; Nikolaev, A. E.; Cherkashin, N. A.; Ber, B. Ya.; Kazantsev, D. Yu. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Mizerov, M. N. [Russian Academy of Sciences, Center for Microelectronics, Ioffe Physicotechnical Institute (Russian Federation); Park, Hee Seok [Samsung Electro-Mechanics Co. Ltd. (Korea, Republic of); Hytch, M.; Hue, F. [National Center for Scientific Research, Center for Material Elaboration and Structural Studies (France)

2010-01-15T23:59:59.000Z

451

Vapochromic LED  

DOE Patents [OSTI]

A sandwich device was prepared by electrodeposition of an insoluble layer of oligomerized tris(4-(2-thienyl)phenyl)amine onto conducting indium-tin oxide coated glass, spin coating the stacked platinum compound, tetrakis(p-decylphenylisocyano)platinum tetranitroplatinate, from toluene onto the oligomer layer, and then coating the platinum complex with aluminum by vapor deposition. This device showed rectification of current and gave electroluminescence. The electroluminescence spectrum (.lambda..sub.max =545 nm) corresponded to the photoluminescence spectrum of the platinum complex. Exposure of the device to acetone vapor caused the electroemission to shift to 575 nm. Exposure to toluene vapor caused a return to the original spectrum. These results demonstrate a new type of sensor that reports the arrival of organic vapors with an electroluminescent signal. The sensor comprises (a) a first electrode; (b) a hole transport layer formed on the first electrode; (c) a sensing/emitting layer formed on the hole transport layer, the sensing/emitting layer comprising a material that changes color upon exposure to the analyte vapors; (d) an electron conductor layer formed on the sensing layer; and (e) a second electrode formed on the electron conductor layer. The hole transport layer emits light at a shorter wavelength than the sensing/emitting layer and at least the first electrode comprises an optically transparent material.

Kunugi, Yoshihito (Hiroshima, JP); Mann, Kent R. (North Oaks, MN); Miller, Larry L. (Minnetonka, MN); Exstrom, Christopher L. (Kearney, NE)

2003-06-17T23:59:59.000Z

452

Vapochromic LED  

DOE Patents [OSTI]

A sandwich device was prepared by electrodeposition of an insoluble layer of oligomerized tris(4-(2-thienyl)phenyl)amine onto conducting indium-tin oxide coated glass, spin coating the stacked platinum compound, tetrakis(p-decylphenylisocyano)platinum tetranitroplatinate, from toluene onto the oligomer layer, and then coating the platinum complex with aluminum by vapor deposition. This device showed rectification of current and gave electroluminescence. The electroluminescence spectrum (.mu..sub.max =545 nm) corresponded to the photoluminescence spectrum of the platinum complex. Exposure of the device to acetone vapor caused the electroemission to shift to 575 nm. Exposure to toluene vapor caused a return to the original spectrum. These results demonstrate a new type of sensor that reports the arrival of organic vapors with an electroluminescent signal. The sensor comprises (a) a first electrode; (b) a hole transport layer formed on the first electrode; (c) a sensing/emitting layer formed on the hole transport layer, the sensing/emitting layer comprising a material that changes color upon exposure to the analyte vapors; (d) an electron conductor layer formed on the sensing layer; and (e) a second electrode formed on the electron conductor layer. The hole transport layer emits light at a shorter wavelength than the sensing/emitting layer and at least the first electrode comprises an optically transparent material.

Kunugi, Yoshihito (Hiroshima, JP); Mann, Kent R. (North Oaks, MN); Miller, Larry L. (Minnetonka, MN); Exstrom, Christopher L. (Kearney, NE)

2002-01-15T23:59:59.000Z

453

Synergies Connecting the Photovoltaics and Solid-State Lighting Industries  

SciTech Connect (OSTI)

Recent increases in the efficiencies of phosphide, nitride, and organic light-emitting diodes (LEDs) inspire a vision of a revolution in lighting. If high efficiencies, long lifetimes, and low cost can be achieved, solid-state lighting could save our country many quads of electricity in the coming years. The solid-state lighting (SSL) and photovoltaic (PV) industries share many of the same challenges. This paper explores the similarities between the two industries and how they might benefit by sharing information.

Kurtz, S.

2003-05-01T23:59:59.000Z

454

Synthesis and luminescence properties of rare earth activated phosphors for near UV-emitting LEDs for efficacious generation of white light  

E-Print Network [OSTI]

lighting using incandescent lights and fluorescent lamps, asenergy used for the incandescent lamp is wasted as infraredsource to replace incandescent and fluorescent lighting [2].

Han, Jinkyu

2013-01-01T23:59:59.000Z

455

Tunnel-injection quantum dot deep-ultraviolet light-emitting diodes with polarization-induced doping in III-nitride heterostructures  

SciTech Connect (OSTI)

Efficient semiconductor optical emitters in the deep-ultraviolet spectral window are encountering some of the most deep rooted problems of semiconductor physics. In III-Nitride heterostructures, obtaining short-wavelength photon emission requires the use of wide bandgap high Al composition AlGaN active regions. High conductivity electron (n-) and hole (p-) injection layers of even higher bandgaps are necessary for electrical carrier injection. This approach requires the activation of very deep dopants in very wide bandgap semiconductors, which is a difficult task. In this work, an approach is proposed and experimentally demonstrated to counter the challenges. The active region of the heterostructure light emitting diode uses ultrasmall epitaxially grown GaN quantum dots. Remarkably, the optical emission energy from GaN is pushed from 365?nm (3.4?eV, the bulk bandgap) to below 240?nm (>5.2?eV) because of extreme quantum confinement in the dots. This is possible because of the peculiar bandstructure and band alignments in the GaN/AlN system. This active region design crucially enables two further innovations for efficient carrier injection: Tunnel injection of carriers and polarization-induced p-type doping. The combination of these three advances results in major boosts in electroluminescence in deep-ultraviolet light emitting diodes and lays the groundwork for electrically pumped short-wavelength lasers.

Verma, Jai, E-mail: jverma@nd.edu; Islam, S. M.; Protasenko, Vladimir; Kumar Kandaswamy, Prem; Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2014-01-13T23:59:59.000Z

456

Using interlayer step-wise triplet transfer to achieve an efficient white organic light-emitting diode with high color-stability  

SciTech Connect (OSTI)

An efficient phosphorescent white organic light emitting-diode with a red-green-blue tri-emitting-layer structure is reported. The host of the red dopant possesses a lower triplet-energy than the green dye. An interlayer step-wise triplet transfer via blue dye ? green dye ? red host ? red dye is achieved. This mechanism allows an efficient triplet harvesting by the three dopants, thus maintaining a balanced white light and reducing energy loss. Moreover, the color stability of the device is improved significantly. The white device not only achieves a peak external quantum efficiency of 21.1?±?0.8% and power efficiency of 37.5?±?1.4?lm/W but shows no color shift over a wide range of voltages.

Wang, Qi [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China); Department of Electrical Engineering and Computer Sciences, College of Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Ma, Dongge, E-mail: mdg1014@ciac.jl.cn; Ding, Junqiao; Wang, Lixiang [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China); Leo, Karl [Tech. Univ. Dresden, Inst. Angew. Photophys., D-01062 Dresden (Germany); Qiao, Qiquan [Department of Electrical Engineering and Computer Sciences, College of Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Jia, Huiping; Gnade, Bruce E. [Department of Materials Science and Engineering and Erik Jonsson School of Engineering and Computer Science, University of Texas at Dallas, Richardson, Texas 75083 (United States)

2014-05-12T23:59:59.000Z

457

Recipient luminophoric mediums having narrow spectrum luminescent materials and related semiconductor light emitting devices and methods  

DOE Patents [OSTI]

Light emitting devices include a light emitting diode ("LED") and a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED. In some embodiments, the recipient luminophoric medium includes a first broad-spectrum luminescent material and a narrow-spectrum luminescent material. The broad-spectrum luminescent material may down-convert radiation emitted by the LED to radiation having a peak wavelength in the red color range. The narrow-spectrum luminescent material may also down-convert radiation emitted by the LED into the cyan, green or red color range.

LeToquin, Ronan P; Tong, Tao; Glass, Robert C

2014-12-30T23:59:59.000Z

458

Phosphor-Free Solid State Light Sources  

SciTech Connect (OSTI)

The objective of this work was to demonstrate a light emitting diode that emitted white light without the aid of a phosphor. The device was based on the combination of a nitride LED and a fluorescing ZnO substrate. The early portion of the work focused on the growth of ZnO in undoped and doped form. The doped ZnO was successfully engineered to emit light at specific wavelengths by incorporating various dopants into the crystalline lattice. Thereafter, the focus of the work shifted to the epitaxial growth of nitride structures on ZnO. Initially, the epitaxy was accomplished with molecular beam epitaxy (MBE). Later in the program, metallorganic chemical vapor deposition (MOCVD) was successfully used to grow nitrides on ZnO. By combining the characteristics of the doped ZnO substrate with epitaxially grown nitride LED structures, a phosphor-free white light emitting diode was successfully demonstrated and characterized.

Jeff E. Nause; Ian Ferguson; Alan Doolittle

2007-02-28T23:59:59.000Z

459

Nanoengineering for solid-state lighting.  

SciTech Connect (OSTI)

This report summarizes results from a 3-year Laboratory Directed Research and Development project performed in collaboration with researchers at Rensselaer Polytechnic Institute. Our collaborative effort was supported by Sandia's National Institute for Nanoengineering and focused on the study and application of nanoscience and nanoengineering concepts to improve the efficiency of semiconductor light-emitting diodes for solid-state lighting applications. The project explored LED efficiency advances with two primary thrusts: (1) the study of nanoscale InGaN materials properties, particularly nanoscale crystalline defects, and their impact on internal quantum efficiency, and (2) nanoscale engineering of dielectric and metal materials and integration with LED heterostructures for enhanced light extraction efficiency.

Schubert, E. Fred (Rensselaer Polytechnic Institute,Troy, NY); Koleske, Daniel David; Wetzel, Christian (Rensselaer Polytechnic Institute,Troy, NY); Lee, Stephen Roger; Missert, Nancy A.; Lin, Shawn-Yu (Rensselaer Polytechnic Institute,Troy, NY); Crawford, Mary Hagerott; Fischer, Arthur Joseph

2009-09-01T23:59:59.000Z

460

DOI: 10.1002/adfm.200700251 Control of Specular and Diffuse Reflection of Light Using Particle  

E-Print Network [OSTI]

reflectors are widely used in the back-light units of liquid crystal display (LCD) panels,[1­4] light-emitting diodes (LED)[5,6] and solar cell devices.[7,8] A perfect diffuse reflector is matter that reflects and low solar absorption, metals easily satisfy the general requirements for diffuse reflectors

Lee, Ilsoon

Note: This page contains sample records for the topic "diode led lights" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Depth-resolved confocal micro-Raman spectroscopy for characterizing GaN-based light emitting diode structures  

SciTech Connect (OSTI)

In this work, we demonstrate that depth-resolved confocal micro-Raman spectroscopy can be used to characterize the active layer of GaN-based LEDs. By taking the depth compression effect due to refraction index mismatch into account, the axial profiles of Raman peak intensities from the GaN capping layer toward the sapphire substrate can correctly match the LED structural dimension and allow the identification of unique Raman feature originated from the 0.3 ?m thick active layer of the studied LED. The strain variation in different sample depths can also be quantified by measuring the Raman shift of GaN A{sub 1}(LO) and E{sub 2}(high) phonon peaks. The capability of identifying the phonon structure of buried LED active layer and depth-resolving the strain distribution of LED structure makes this technique a potential optical and remote tool for in operando investigation of the electronic and structural properties of nitride-based LEDs.

Chen, Wei-Liang; Lee, Yu-Yang; Chang, Yu-Ming, E-mail: ymchang@ntu.edu.tw [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China)] [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China); Chang, Chiao-Yun; Huang, Huei-Min; Lu, Tien-Chang [Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan (China)] [Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan (China)

2013-11-15T23:59:59.000Z

462

Abstract --This letter presents highly-polarized edge light emitting diodes with high-confinement, strained, multiple  

E-Print Network [OSTI]

power. We characterize InGaAsP MQW ELED devices with different lengths and optical confinement factors that transitions involving the HH band provide gain/absorption to TE polarized light and those involving the LH band provide gain/absorption mostly to TM polarized light, and to a lesser extent to TE light [7

Coldren, Larry A.

463

Nanoscale-accuracy transfer printing of ultra-thin AlInGaN light-emitting diodes onto mechanically flexible substrates  

SciTech Connect (OSTI)

The transfer printing of 2 ?m-thick aluminum indium gallium nitride (AlInGaN) micron-size light-emitting diodes with 150?nm (±14?nm) minimum spacing is reported. The thin AlInGaN structures were assembled onto mechanically flexible polyethyleneterephthalate/polydimethylsiloxane substrates in a representative 16 × 16 array format using a modified dip-pen nano-patterning system. Devices in the array were positioned using a pre-calculated set of coordinates to demonstrate an automated transfer printing process. Individual printed array elements showed blue emission centered at 486?nm with a forward-directed optical output power up to 80??W (355 mW/cm{sup 2}) when operated at a current density of 20?A/cm{sup 2}.

Trindade, A. J., E-mail: antonio.trindade@strath.ac.uk; Guilhabert, B.; Massoubre, D.; Laurand, N.; Gu, E.; Watson, I. M.; Dawson, M. D. [Institute of Photonics, SUPA, University of Strathclyde, 106 Rottenrow, Glasgow G4 0NW (United Kingdom)] [Institute of Photonics, SUPA, University of Strathclyde, 106 Rottenrow, Glasgow G4 0NW (United Kingdom); Zhu, D.; Humphreys, C. J. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)] [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2013-12-16T23:59:59.000Z

464

Migration enhanced lateral epitaxial overgrowth of AlN and AlGaN for high reliability deep ultraviolet light emitting diodes  

SciTech Connect (OSTI)

We report on the growth of low-defect thick films of AlN and AlGaN on trenched AlGaN/sapphire templates using migration enhanced lateral epitaxial overgrowth. Incoherent coalescence-related defects were alleviated by controlling the tilt angle of growth fronts and by allowing Al adatoms sufficient residence time to incorporate at the most energetically favorable lattice sites. Deep ultraviolet light emitting diode structures (310 nm) deposited over fully coalesced thick AlN films exhibited cw output power of 1.6 mW at 50 mA current with extrapolated lifetime in excess of 5000 hours. The results demonstrate substantial improvement in the device lifetime, primarily due to the reduced density of growth defects.

Jain, R.; Sun, W.; Yang, J.; Shatalov, M.; Hu, X.; Sattu, A.; Lunev, A.; Deng, J.; Shturm, I.; Bilenko, Y.; Gaska, R. [Sensor Electronic Technology, Inc., 1195 Atlas Road, Columbia, South Carolina 29209 (United States); Shur, M. S. [Electrical Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy New York 12180 (United States)

2008-08-04T23:59:59.000Z

465

Experimental verification of effects of barrier dopings on the internal electric fields and the band structure in InGaN/GaN light emitting diodes  

SciTech Connect (OSTI)

We experimentally clarify the effects of barrier dopings on the polarization induced electric fields and the band structure in InGaN/GaN blue light emitting diodes. Both effects were independently verified by using electric field modulated reflectance and capacitance-voltage measurement. It is shown that the Si barrier doping does reduce the polarization induced electric field in the quantum wells. But the benefit of Si-doping is nullified by modification of the band structure and depletion process. With increased number of doped barriers, smaller number of quantum wells remains in the depletion region at the onset of the diffusion process, which can reduce the effective active volume and enhance the electron overflow.

Song, Jung-Hoon; Kim, Tae-Soo; Park, Ki-Nam; Lee, Jin-Gyu [Department of Physics, Kongju National University, Kongju, Chungnam 314-701 (Korea, Republic of); Hong, Soon-Ku, E-mail: soonku@cnu.ac.kr [Department of Advanced Materials Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Cho, Sung-Royng; Lee, Seogwoo; Whan Cho, Meoung [Wasvesquare Co., Inc., Yongin, Gyeonggi 449-863 (Korea, Republic of)

2014-03-24T23:59:59.000Z

466

Top-emission Si-based phosphor organic light emitting diode with Au doped ultrathin n-Si film anode and bottom Al mirror  

SciTech Connect (OSTI)

We report a highly efficient top-emission Si-based phosphor organic light emitting diode (PhOLED) with an ultrathin polycrystalline n-Si:Au film anode and a bottom Al mirror. This anode is formed by magnetron sputtering followed by Ni induced crystallization and then Au diffusion. By optimizing the thickness of the n-Si:Au film anode, the Au diffusion temperature, and the other parameters of the PhOLED, the highest current and power efficiencies of the n-Si:Au film anode PhOLED reached 85{+-}9 cd/A and 80{+-}8 lm/W, respectively, corresponding to an external quantum efficiency of 21{+-}2% and a power conversion efficiency of 15{+-}2%, respectively, which are about 60% and 110% higher than those of the indium tin oxide anode counterpart and 70% and 50% higher than those of the bulk n{sup +}-Si:Au anode counterpart, respectively.

Li, Y. Z.; Xu, W. J.; Ran, G. Z. [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Qin, G. G. [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Key Lab of Semiconductor Materials, CAS, Beijing 100083 (China)

2009-07-20T23:59:59.000Z

467

Enhancement of hole injection and electroluminescence by ordered Ag nanodot array on indium tin oxide anode in organic light emitting diode  

SciTech Connect (OSTI)

We report the enhancement of hole injection and electroluminescence (EL) in an organic light emitting diode (OLED) with an ordered Ag nanodot array on indium-tin-oxide (ITO) anode. Until now, most researches have focused on the improved performance of OLEDs by plasmonic effects of metal nanoparticles due to the difficulty in fabricating metal nanodot arrays. A well-ordered Ag nanodot array is fabricated on the ITO anode of OLED using the nanoporous alumina as an evaporation mask. The OLED device with Ag nanodot arrays on the ITO anode shows higher current density and EL enhancement than the one without any nano-structure. These results suggest that the Ag nanodot array with the plasmonic effect has potential as one of attractive approaches to enhance the hole injection and EL in the application of the OLEDs.

Jung, Mi, E-mail: jmnano00@gmail.com, E-mail: Dockha@kist.re.kr [Sensor System Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); School of Mechanical Systems Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Mo Yoon, Dang; Kim, Miyoung [Korea Printed Electronics Center, Korea Electronics Technology Institute, Jeollabuk-do, 561-844 (Korea, Republic of); Kim, Chulki; Lee, Taikjin; Hun Kim, Jae; Lee, Seok; Woo, Deokha, E-mail: jmnano00@gmail.com, E-mail: Dockha@kist.re.kr [Sensor System Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Lim, Si-Hyung [School of Mechanical Systems Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of)

2014-07-07T23:59:59.000Z

468

Thermally activated delayed fluorescence from {sup 3}n?* to {sup 1}n?* up-conversion and its application to organic light-emitting diodes  

SciTech Connect (OSTI)

Intense n?* fluorescence from a nitrogen-rich heterocyclic compound, 2,5,8-tris(4-fluoro-3-methylphenyl)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3MF), is demonstrated. The overlap-forbidden nature of the n?* transition and the higher energy of the {sup 3}??* state than the {sup 3}n?* one lead to a small energy difference between the lowest singlet (S{sub 1}) and triplet (T{sub 1}) excited states of HAP-3MF. Green-emitting HAP-3MF has a moderate photoluminescence quantum yield of 0.26 in both toluene and doped film. However, an organic light-emitting diode containing HAP-3MF achieved a high external quantum efficiency of 6.0%, indicating that HAP-3MF harvests singlet excitons through a thermally activated T{sub 1} ? S{sub 1} pathway in the electroluminescent process.

Li, Jie; Zhang, Qisheng; Nomura, Hiroko [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Miyazaki, Hiroshi [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Functional Materials Laboratory, Nippon Steel and Sumikin Chemical Co., Ltd, 46–80 Nakabaru, Sakinohama, Tobata, Kitakyushu, Fukuoka 804–8503 (Japan); Adachi, Chihaya, E-mail: adachi@cstf.kyushu-u.ac.jp [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan)

2014-07-07T23:59:59.000Z

469

Inversion by metalorganic chemical vapor deposition from N- to Ga-polar gallium nitride and its application to multiple quantum well light-emitting diodes  

SciTech Connect (OSTI)

We demonstrate a metalorganic chemical vapor deposition growth approach for inverting N-polar to Ga-polar GaN by using a thin inversion layer grown with high Mg flux. The introduction of this inversion layer allowed us to grow p-GaN films on N-polar GaN thin film. We have studied the dependence of hole concentration, surface morphology, and degree of polarity inversion for the inverted Ga-polar surface on the thickness of the inversion layer. We then use this approach to grow a light emitting diode structure which has the MQW active region grown on the advantageous N-polar surface and the p-layer grown on the inverted Ga-polar surface.

Hosalli, A. M.; Van Den Broeck, D. M.; Bedair, S. M. [Department of Electrical and Computer Engineering, NCSU, Raleigh, North Carolina 27695 (United States)] [Department of Electrical and Computer Engineering, NCSU, Raleigh, North Carolina 27695 (United States); Bharrat, D.; El-Masry, N. A. [Department of Material Science and Engineering, NCSU, Raleigh, North Carolina 27695 (United States)] [Department of Material Science and Engineering, NCSU, Raleigh, North Carolina 27695 (United States)

2013-12-02T23:59:59.000Z

470

Challenges in LED Research and Development  

Broader source: Energy.gov [DOE]

View the video about LED lighting technology, where it is headed, and the DOE’s role in its continued R&D.

471

LED Replacements for Linear Fluorescent Lamps Webcast  

Broader source: Energy.gov [DOE]

In this June 20, 2011 webcast on LED products marketed as replacements for linear fluorescent lamps, Jason Tuenge of the Pacific Northwest National Laboratory (PNNL) discussed current Lighting...

472

Model Specification for LED Roadway Luminaires Webcast  

Broader source: Energy.gov [DOE]

This November 15, 2011 webcast presented information about the Model Specification for LED Roadway Luminaires developed by DOE's Municipal Solid-State Street Lighting Consortium. During the webcast...

473

Integrated ultrasonic particle positioning and low excitation light fluorescence imaging  

SciTech Connect (OSTI)

A compact hybrid system has been developed to position and detect fluorescent micro-particles by combining a Single Photon Avalanche Diode (SPAD) imager with an acoustic manipulator. The detector comprises a SPAD array, light-emitting diode (LED), lenses, and optical filters. The acoustic device is formed of multiple transducers surrounding an octagonal cavity. By stimulating pairs of transducers simultaneously, an acoustic landscape is created causing fluorescent micro-particles to agglomerate into lines. The fluorescent pattern is excited by a low power LED and detected by the SPAD imager. Our technique combines particle manipulation and visualization in a compact, low power, portable setup.

Bernassau, A. L.; Al-Rawhani, M.; Beeley, J.; Cumming, D. R. S. [School of Engineering, University of Glasgow, Glasgow, G12 8LT (United Kingdom)] [School of Engineering, University of Glasgow, Glasgow, G12 8LT (United Kingdom)

2013-12-09T23:59:59.000Z

474

High Efficiency m-plane LEDs on Low Defect Density Bulk GaN Substrates  

SciTech Connect (OSTI)

Solid-state lighting is a key technology for reduction of energy consumption in the US and worldwide. In principle, by replacing standard incandescent bulbs and other light sources with sources based on light-emitting diodes (LEDs), ultimate energy efficiency can be achieved. The efficiency of LEDs has improved tremendously over the past two decades, however further progress is required for solid- state lighting to reach its full potential. The ability of an LED at converting electricity to light is quantified by its internal quantum efficiency (IQE). The material of choice for visible LEDs is Gallium Nitride (GaN), which is at the basis of blue-emitting LEDs. A key factor limiting the performance of GaN LEDs is the so-called efficiency droop, whereby the IQE of the LED decreases significantly at high current density. Despite decades of research, efficiency droop remains a major issue. Since high-current operation is necessary for practical lighting applications, reducing droop is a major challenge for the scientific community and the LED industry. Our approach to solving the droop issue is the use of newly available low-defect-density bulk GaN non-polar substrates. In contrast to the standard foreign substrates (sapphire, silicon carbide, silicon) used in the industry, we have employed native bulk GaN substrates with very low defect density, thus ensuring exquisite material quality and high IQE. Whereas all commercial LEDs are grown along the c-plane crystal direction of GaN, we have used m-plane non-polar substrates; these drastically modify the physical properties of the LED and enable a reduction of droop. With this approach, we have demonstrated very high IQE performance and low droop. Our results focused on violet and blue LEDs. For these, we have demonstrated very high peak IQEs and current droops of 6% and 10% respectively (up to a high current density of 200A.cm-2). All these results were obtained under electrical operation. These high IQE and low droop values are in line with the program’s milestones. They demonstrate that bulk non-polar GaN substrates represent a disruptive technology for LED performance. Application of this technology to real-world products is feasible, provided that the cost of GaN substrates is compatible with the market’s requirement.

David, Aurelien

2012-10-15T23:59:59.000Z

475

LED exit signs: Improved technology leads the way to energy savings  

SciTech Connect (OSTI)

Recent innovations in light-emitting diode (LED) exit signs may make LED signs the best choice among the energy efficient options available. In the past, LED signs have offered low power consumption, projected long lamp life, and low maintenance requirements. Now, the best of the LED signs also offer improved optical designs that reduce their already low power consumption while improving visibility and appearance, and even reduce their cost. LED exit signs are gaining market share, and E Source expects this technology to eventually dominate over incandescent, compact fluorescent, and electroluminescent signs. More research is needed, however, to confirm manufacturers` claims of 20-year operating lives for LED signs. Conservative estimates place the number of exit signs in US buildings at about 40 million. Although each sign represents a very small part of a building`s load, exit signs are ready targets for energy efficiency upgrades -- they operate continuously and most use inefficient incandescent sources. With an LED sign, annual energy and maintenance costs can be reduced by more than 90 percent compared to a typical incandescent sign. Low annual costs help to offset the LED sign`s relatively high first cost. More than 25 utilities offer DSM incentives for energy efficient exit signs, and efficient alternatives are becoming more readily available. Recent improvements in optical designs enable many LED signs to visually out perform other sources. In addition to these benefits, LED exit signs have lower life cycle cost than most other options. The biggest barrier to their success, however, is that their first cost has been considerably higher than competing technologies. LED sign prices are falling rapidly, though, because manufacturers are continually improving optical designs of the fixtures to use fewer LEDs and thus even less energy while providing better performance.

Sardinsky, R.; Hawthorne, S.

1994-12-31T23:59:59.000Z

476

Characterization of failure modes in deep UV and deep green LEDs utilizing advanced semiconductor localization techniques.  

SciTech Connect (OSTI)

We present the results of a two-year early career LDRD that focused on defect localization in deep green and deep ultraviolet (UV) light-emitting diodes (LEDs). We describe the laser-based techniques (TIVA/LIVA) used to localize the defects and interpret data acquired. We also describe a defect screening method based on a quick electrical measurement to determine whether defects should be present in the LEDs. We then describe the stress conditions that caused the devices to fail and how the TIVA/LIVA techniques were used to monitor the defect signals as the devices degraded and failed. We also describe the correlation between the initial defects and final degraded or failed state of the devices. Finally we show characterization results of the devices in the failed conditions and present preliminary theories as to why the devices failed for both the InGaN (green) and AlGaN (UV) LEDs.

Tangyunyong, Paiboon; Miller, Mary A.; Cole, Edward Isaac, Jr.

2012-03-01T23:59:59.000Z

477

Energy Efficiency of LEDs  

Broader source: Energy.gov (indexed) [DOE]

Efficiency of LEDs The energy efficiency of LEDs has increased substantially since the first general illumination products came to market, with currently available lamps and...

478

A portable time-domain LED fluorimeter for nanosecond fluorescence lifetime measurements  

SciTech Connect (OSTI)

Fluorescence lifetime measurements are becoming increasingly important in chemical and biological research. Time-domain lifetime measurements offer fluorescence multiplexing and improved handling of interferers compared with the frequency-domain technique. In this paper, an all solid-state, filterless, and highly portable light-emitting-diode based time-domain fluorimeter (LED TDF) is reported for the measurement of nanosecond fluorescence lifetimes. LED based excitation provides more wavelengths options compared to laser diode based excitation, but the excitation is less effective due to the uncollimated beam, less optical power, and longer latency in state transition. Pulse triggering and pre-bias techniques were implemented in our LED TDF to improve the peak optical power to over 100 mW. The proposed pulsing circuit achieved an excitation light fall time of less than 2 ns. Electrical resetting technique realized a time-gated photo-detector to remove the interference of the excitation light with fluorescence. These techniques allow the LED fluorimeter to accurately measure the fluorescence lifetime of fluorescein down to concentration of 0.5 ?M. In addition, all filters required in traditional instruments are eliminated for the non-attenuated excitation/emission light power. These achievements make the reported device attractive to biochemical laboratories seeking for highly portable lifetime detection devices for developing sensors based on fluorescence lifetime changes. The device was initially validated by measuring the lifetimes of three commercial fluorophores and comparing them with reported lifetime data. It was subsequently used to characterize a ZnSe quantum dot based DNA sensor.

Wang, Hongtao; Salthouse, Christopher D., E-mail: salthouse@ecs.umass.edu [Electrical and Computer Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Qi, Ying; Mountziaris, T. J. [Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States) [Center for Personalized Health Monitoring, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Chemical Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003 (United States)

2014-05-15T23:59:59.000Z

479

Research Resources and Centers Research plays an integral role in Rensselaer's vision of the  

E-Print Network [OSTI]

in materials, devices, systems, nanotechnology, light emitting diodes (LEDs), organic light emitting diodes

Varela, Carlos

480

Co-sputtered Aluminum Doped Zinc Oxide Thin Film as Transparent Anode for Organic Light-emitting Diodes  

E-Print Network [OSTI]

Co-sputtered Aluminum Doped Zinc Oxide Thin Film as Transparent Anode for Organic Light and Technology, Clear Water Bay, Kowloon, Hong Kong, China ABSTRACT Aluminum doped zinc oxide (AZO that MTDATA matches better with AZO than CuPc, which served as hole injection layer. Keywords: Aluminum doped

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481

LEDs Go Ivy League: Princeton’s Dillon Gymnasium  

Broader source: Energy.gov [DOE]

View the video about LED lighting in Dillon Gymnasium, a focal point of sports and recreation at Princeton since 1947. William Evans discusses measurable benefits of LED lighting in the gym and...

482

Surface plasmon dispersion engineering via double-metallic AU/AG layers for nitride light-emitting diodes  

DOE Patents [OSTI]

A double-metallic deposition process is used whereby adjacent layers of different metals are deposited on a substrate. The surface plasmon frequency of a base layer of a first metal is tuned by the surface plasmon frequency of a second layer of a second metal formed thereon. The amount of tuning is dependent upon the thickness of the metallic layers, and thus tuning can be achieved by varying the thicknesses of one or both of the metallic layers. In a preferred embodiment directed to enhanced LED technology in the green spectrum regime, a double-metallic Au/Ag layer comprising a base layer of gold (Au) followed by a second layer of silver (Ag) formed thereon is deposited on top of InGaN/GaN quantum wells (QWs) on a sapphire/GaN substrate.

Tansu, Nelson; Zhao, Hongping; Zhang, Jing; Liu, Guangyu

2014-04-01T23:59:59.000Z

483

Effects of metallic absorption and the corrugated layer on the optical extraction efficiency of organic light-emitting diodes  

E-Print Network [OSTI]

The absorption of a metallic cathode in OLEDs is analyzed by using FDTD calculation. As the light propagates parallel to the layer, the intensity of Ez polarization decreases rapidly. The intensity at 2.0 um from the dipole is less than a quarter of that at 0.5 um. The strong absorption by a cathode can be a critical factor when considering the increase of optical extraction by means of bending the optical layers. The calculation indicates that the corrugation of layers helps the guided light escape the guiding layer, but also increases the absorption into a metallic cathode. The final optical output power of the corrugated OLED can be smaller than that of the flat OLED. On the contrary, the corrugated structure with a non-absorptive cathode increases the optical extraction by nearly two times.

Lee, Baek-Woon

2011-01-01T23:59:59.000Z

484

Correlation of Beam Electron and LED Signal Losses under Irradiation and Long-term Recovery of Lead Tungstate Crystals  

E-Print Network [OSTI]

Radiation damage in lead tungstate crystals reduces their transparency. The calibration that relates the amount of light detected in such crystals to incident energy of photons or electrons is of paramount importance to maintaining the energy resolution the detection system. We report on tests of lead tungstate crystals, read out by photomultiplier tubes, exposed to irradiation by monoenergetic electron or pion beams. The beam electrons themselves were used to measure the scintillation light output, and a blue light emitting diode (LED) was used to track variations of crystals transparency. We report on the correlation of the LED measurement with radiation damage by the beams and also show that it can accurately monitor the crystals recovery from such damage.

V. A. Batarin; J. Butler; A. M. Davidenko; A. A. Derevschikov; Y. M. Goncharenko; V. N. Grishin; V. A. Kachanov; A. S. Konstantinov; V. I. Kravtsov; Y. Kubota; V. S. Lukanin; Y. A. Matulenko; Y. M. Melnick; A. P. Meschanin; N. E. Mikhalin; N. G. Minaev; V. V. Mochalov; D. A. Morozov; L. V. Nogach; A. V. Ryazantsev; P. A. Semenov; V. K. Semenov; K. E. Shestermanov; L. F. Soloviev; S. Stone; A. V. Uzunian; A. N. Vasiliev; A. E. Yakutin; J. Yarba

2005-04-13T23:59:59.000Z

485

Dual LED/incandescent security fixture  

DOE Patents [OSTI]

A dual LED and incandescent security lighting system uses a hybrid approach to LED illumination. It combines an ambient LED illuminator with a standard incandescent lamp on a motion control sensor. The LED illuminator will activate with the onset of darkness (daylight control) and typically remain on during the course of the night ("always on"). The LED illumination, typically amber, is sufficient to provide low to moderate level lighting coverage to the wall and ground area adjacent to a