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Note: This page contains sample records for the topic "white light emitting" 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.


1

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

2

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

3

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 generation using CdSe/ZnS core-shell nanocrystals hybridized with InGaN/GaN light emitting diodesGaN/conjugated polymer hybrid light-emitting diodes," Appl. Phys. Lett. 70, 2664-2666 (1997). 9. H. V. Demir, S

Demir, Hilmi Volkan

4

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

5

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

6

Semiconductor Nanocrystals-Based White Light Emitting Diodes  

Science Conference Proceedings (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

7

Green Light-Emitting Diode Makes Highly Efficient White Light; The Spectrum of Clean Energy Innovation (Fact Sheet)  

SciTech Connect

Fact sheet describing NREL's green light emitting diode that can lead to higher efficiency white light used in indoor lighting applications.

2010-06-01T23:59:59.000Z

8

White Light Emitting Diode Development for General Illumination Applications  

SciTech Connect

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

9

Nanocluster-based white-light-emitting material employing surface tuning  

DOE Patents (OSTI)

A method for making a nanocrystal-based material capable of emitting light over a sufficiently broad spectral range to appear white. Surface-modifying ligands are used to shift and broaden the emission of semiconductor nanocrystals to produce nanoparticle-based materials that emit white light.

Wilcoxon, Jess P. (Albuquerque, NM); Abrams, Billie L. (Albuquerque, NM); Thoma, Steven G. (Albuquerque, NM)

2007-06-26T23:59:59.000Z

10

Semiconductor-Nanocrystals-Based White Light-Emitting Diodes  

Science Conference Proceedings (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

11

Green Light-Emitting Diode Makes Highly Efficient White Light, The Spectrum of Clean Energy Innovation (Fact Sheet)  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectrum of Spectrum of Clean Energy Innovation innovati n Green Light-Emitting Diode Makes Highly Efficient White Light Scientists at the National Renewable Energy Laboratory (NREL) have invented a deep green light-emitting diode (LED) that can lead to higher efficiency white light, which is of prime value in the indoor lighting world. LEDs are fundamentally solar cells operating in reverse-that is, when an electrical current is applied to a thin-film semiconductor, the result is the emission of light. These devices are a key technology for producing a new generation of efficient lighting, in which the amount of light generated far outweighs the amount of heat produced. But at the moment, LEDs that emit white light are produced using an inefficient process known as phosphor conversion. In this process, light from a blue- or ultraviolet-emitting LED energizes

12

An Engineering-Economic Analysis of White Light-Emitting Diodes for General  

NLE Websites -- All DOE Office Websites (Extended Search)

An Engineering-Economic Analysis of White Light-Emitting Diodes for General An Engineering-Economic Analysis of White Light-Emitting Diodes for General Illumination for the U.S. Residential and Commercial Sectors Speaker(s): Inês Magarida Lima de Azevedo Date: February 15, 2008 - 12:00pm Location: 90-3122 Because lighting constitutes more than 20% of total US electricity consumption, and many current lighting technologies are highly inefficient, improved technologies for lighting hold great potential for energy savings and for reducing associated greenhouse gas emissions. Solid-state lighting is a technology that shows great promise as a source of efficient, affordable, color-balanced white light in the near future. Indeed, under a pure engineering-economic analysis, solid-state lighting already performs better than incandescent bulbs and is expected to surpass the most

13

Synthesis and luminescence properties of rare earth activated phosphors for near UV-emitting LEDs for efficacious generation of white light  

E-Print Network (OSTI)

Sun, Y. Luo, S. Lu. ?White light emitting diode by using a-silicates for near-UV light emitting diode applications,? J.Park, S.Y. Choi. ?White light-emitting diodes of GaN-based

Han, Jinkyu

2013-01-01T23:59:59.000Z

14

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

15

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

16

Development of White-Light Emitting Active Layers in Nitride Based Heterostructures for Phosphorless Solid State Lighting  

SciTech Connect

This report provides a summary of research activities carried out at the University of California, San Diego and Central Research of OSRAM SYLVANIA in Beverly, MA partially supported by a research contract from US Department of Energy, DE-FC26-04NT422274. The main objective of this project was to develop III-V nitrides activated by rare earth ions, RE{sup 3+}, which could eliminate the need for phosphors in nitride-based solid state light sources. The main idea was to convert electron-hole pairs injected into the active layer in a LED die to white light directly through transitions within the energy levels of the 4f{sup n}-manifold of RE{sup 3+}. We focused on the following materials: Eu{sup 3+}(red), Tb{sup 3+}(green), Er{sup 3+}(green), Dy{sup 3+}(yellow) and Tm{sup 3+}(blue) in AlN, GaN and alloys of AlN and GaN. Our strategy was to explore candidate materials in powder form first, and then study their behavior in thin films. Thin films of these materials were to be deposited on sapphire substrates using pulsed laser deposition (PLD) and metal organic vapor phase epitaxy (MOVPE). The photo- and cathode-luminescence measurements of these materials were used to investigate their suitability for white light generation. The project proceeded along this route with minor modifications needed to produce better materials and to expedite our progress towards the final goal. The project made the following accomplishments: (1) red emission from Eu{sup 3+}, green from Tb{sup 3+}, yellow from Dy{sup 3+} and blue from Tm{sup 3+} in AlN powders; (2) red emission from Eu{sup 3+} and green emission from Tb{sup 3+} in GaN powder; (3) red emission from Eu{sup 3+} in alloys of GaN and AlN; (4) green emission from Tb{sup 3+} in GaN thin films by PLD; (5) red emission from Eu{sup 3+} and Tb{sup 3+} in GaN thin films deposited by MOVPE; (6) energy transfer from host to RE{sup 3+}; (7) energy transfer from Tb{sup 3+} to Eu{sup 3+} in AlN powders; (8) emission from AlN powder samples codoped with (Eu{sup 3+} ,Tb{sup 3+} ) and (Dy{sup 3+}, Tm{sup 3+}); and (9) white emission from AlN codoped with Dy{sup 3+} and Tm{sup 3+}. We also extensively studied the stabilities of rare earth ions in GaN, and the nature of oxygen defects in GaN and its impact on the optical properties of the host material, using first principles method. Results from these theoretical calculations together with fluorescence measurements from the materials essentially proved the underlying concepts for generating white light using RE{sup 3+}-activated nitrides. For this project, we successfully built a horizontal MOVPE reactor and used it to deposit thin films of undoped and doped nitrides of GaN and InGaN, which is a very significant achievement. Since this reactor was designed and built by in-house experts, it could be easily modified and reassembled for specific research purposes. During this study, it was successfully modified for homogeneous distribution of rare earth ions in a deposited film. It will be an ideal tool for future research involving novel thin film material concepts. We examined carefully the suitability of various metal organic precursors for incorporating RE{sup 3+}. In order to avoid oxygen contamination, several oxygen-free RE{sup 3+} precursors were identified. Both oxygen-free and oxygen- containing metal organic precursors were used for certain rare earth ions (Eu{sup 3+}, Tb{sup 3+} and Er{sup 3+}). However, the suitability of any particular type of precursor for MOVPE deposition was not established during this study, and further study is needed. More intensive research in the future is needed to improve the film quality, and eliminate the separation of rare earth oxide phases during the deposition of thin films by MOVPE. The literature in the area of the chemistry of rare earth ions in nitrides is almost nonexistent, in spite of the significant research on luminescence of RE{sup 3+} in nitrides. Consequently, MOVPE as a method of deposition of RE{sup 3+}-activated nitrides is relatively unexplored. In the following sections of this report, the ou

Jan Talbot; Kailash Mishra

2007-12-31T23:59:59.000Z

17

Light Emitting Diodes and General Lighting  

NLE Websites -- All DOE Office Websites (Extended Search)

Light Emitting Diodes and General Lighting Speaker(s): Martin Moeck Date: August 6, 2009 - 12:00pm Location: 90-3122 We give a short overview on high-power light emitting diodes,...

18

Energy_Savings_Light_Emitting_Diodes_Niche_Lighting_Apps.pdf...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

EnergySavingsLightEmittingDiodesNicheLightingApps.pdf EnergySavingsLightEmittingDiodesNicheLightingApps.pdf EnergySavingsLightEmittingDiodesNicheLightingApps.p...

19

Light Emitting Diode (LED) Lighting and Systems  

Science Conference Proceedings (OSTI)

This EPRI Technical Update addresses the most promising and unique energy efficient light source light emitting diode (LED) lighting. Business and technical market factors (Chapter 2) explain the upcoming growth of the LED and LED lighting market. Future technical improvements to LEDs and systems are also emphasized. Discussion of the importance of utility involvement in helping their customers make the switch from traditional lighting to LED lighting is provided. LED lighting technologies are covered in...

2007-12-21T23:59:59.000Z

20

Long persistent light emitting diode  

Science Conference Proceedings (OSTI)

Light emitting diodes(LEDs)coated with Sr 2 Mg Si 2 O 7 : Eu 2 + Nd 3 + (blue) Sr Al 2 O 4 : Eu 2 + Dy 3 + (green) Sr S : Eu 2 + Y 3 + Ce 3 + (orange)

D. Jia; D. N. Hunter

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

Förster Resonance Energy Transfer Mediated White-Light-Emitting Rhodamine Fluorophore Derivatives-Gamma Phase Gallium Oxide Nanostructures.  

E-Print Network (OSTI)

??The global lighting source energy consumption accounts for about 22% of the total electricity generated. New high-efficiency solid-state light sources are needed to reduce the… (more)

Chiu, Wan Hang Melanie

2012-01-01T23:59:59.000Z

22

Towards Truly White LED Lighting | U.S. DOE Office of Science...  

NLE Websites -- All DOE Office Websites (Extended Search)

to emit light of different colors is a key step toward a new kind of organic light-emitting diode, or OLED, that can emit truly white light while improving efficiency and...

23

White light velocity interferometer  

DOE Patents (OSTI)

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

Erskine, D.J.

1997-06-24T23:59:59.000Z

24

White light velocity interferometer  

DOE Patents (OSTI)

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

Erskine, David J. (Oakland, CA)

1997-01-01T23:59:59.000Z

25

White light velocity interferometer  

DOE Patents (OSTI)

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

Erskine, David J. (Oakland, CA)

1999-01-01T23:59:59.000Z

26

White light velocity interferometer  

DOE Patents (OSTI)

The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

Erskine, D.J.

1999-06-08T23:59:59.000Z

27

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

28

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

29

Exciting White Lighting | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Exciting White Lighting Exciting White Lighting Exciting White Lighting April 23, 2010 - 10:27am Addthis Joshua DeLung In the future, your office building's windows might be replaced with windows that have transparent organic light-emitting diodes in them so that, during the day, you can see through them, but at night you might turn on your windows so that the OLEDs emit light into the room. That's what Janice Mahon, vice president of Technology Commercialization at New Jersey-based Universal Display, calls "a fun concept with real potential." Though Universal Display's PHOLED technology and materials can already be found in a variety of OLED displays for cell phones and TVs, OLED production for lighting may ramp up much faster because they are easier to manufacture. Universal Display specializes in developing patents in advanced

30

LIGHT EMITTING DIODE CHARACTERISTICS (SAMPLE LAB WRITEUP)  

E-Print Network (OSTI)

1 LIGHT EMITTING DIODE CHARACTERISTICS (SAMPLE LAB WRITEUP) John A. McNeill ECE Box 000 January 19, 1997 ABSTRACT This lab investigates the V-I characteristic of a light-emitting diode (LED

McNeill, John A.

31

Quantum Dot Light Emitting Diode  

SciTech Connect

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

Quantum Dot Light Emitting Diode  

SciTech Connect

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

33

Resonant energy transfer in light harvesting and light emitting applications.  

E-Print Network (OSTI)

??The performance of light emitting and light harvesting devices is improved by utilising resonant energy transfer. In lighting applications, the emission energy of a semiconductor… (more)

Chanyawadee, Soontorn

2009-01-01T23:59:59.000Z

34

Bright three-band white light generated from CdSe/ZnSe quantum dot-assisted Sr{sub 3}SiO{sub 5}:Ce{sup 3+},Li{sup +}-based white light-emitting diode with high color rendering index  

SciTech Connect

In this study, bright three-band white light was generated from the CdSe/ZnSe quantum dot (QD)-assisted Sr{sub 3}SiO{sub 5}:Ce{sup 3+},Li{sup +}-based white light-emitting diode (WLED). The CdSe/ZnSe core/shell structure was confirmed by energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. The CdSe/ZnSe QDs showed high quantum efficiency (79%) and contributed to the high luminous efficiency ({eta}{sub L}) of the fabricated WLED. The WLED showed bright natural white with excellent color rendering property ({eta}{sub L}=26.8 lm/W, color temperature=6140 K, and color rendering index=85) and high stability against the increase in forward bias currents from 20 to 70 mA.

Jang, Ho Seong; Kwon, Byoung-Hwa; Jeon, Duk Young [Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Yang, Heesun [Department of Materials Science and Engineering, Hongik University, 72-1, Sangsu-dong, Mapo-gu, Seoul 121-791 (Korea, Republic of)

2009-10-19T23:59:59.000Z

35

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 LEDsConfocal microphotoluminescence of InGaN-based light-emitting diodes Koichi Okamoto,a Akio Kaneta-well-structured light-emitting diodes LEDs with a yellow-green light 530 nm and an amber light 600 nm was measured

Okamoto, Koichi

36

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

37

Electrically driven nanopyramid green light emitting diode  

Science Conference Proceedings (OSTI)

An electrically driven nanopyramid green light emitting diode(LED) was demonstrated. The nanopyramid arrays were fabricated from a GaN substrate by patterned nanopillar etch

S.-P. Chang; Y.-C. Chen; J.-K. Huang; Y.-J. Cheng; J.-R. Chang; K.-P. Sou; Y.-T. Kang; H.-C. Yang; T.-C. Hsu; H.-C. Kuo; C.-Y. Chang

2012-01-01T23:59:59.000Z

38

Strong blue and white photoluminescence emission of BaZrO{sub 3} undoped and lanthanide doped phosphor for light emitting diodes application  

SciTech Connect

In this paper, we report the obtained strong broadband blue photoluminescence (PL) emission centered at 427 nm for undoped BaZrO{sub 3} observed after 266 nm excitation of submicron crystals prepared by hydrothermal/calcinations method. This emission is enhanced with the introduction of Tm{sup 3+} ions and is stronger than the characteristic PL blue emission of such lanthanide. The proposed mechanism of relaxation for host lattice emission is based on the presence of oxygen vacancies produced during the synthesis process and the charge compensation due to the difference in the electron valence between dopant and substituted ion in the host. Brilliant white light emission with a color coordinate of (x=0.29, y=0.32) was observed by combining the blue PL emission from the host with the green and red PL emission from Tb{sup 3+} and Eu{sup 3+} ions, respectively. The color coordinate can be tuned by changing the ratio between blue, green and red band by changing the concentration of lanthanides. - Graphical abstract: Strong blue emission from undoped BaZrO{sub 3} phosphor and white light emission by doping with Tb{sup 3+} (green) and Eu{sup 3+} (red) after 266 nm excitation. Highlights: Black-Right-Pointing-Pointer Blue emission from BaZrO{sub 3} phosphor. Black-Right-Pointing-Pointer Blue emission enhanced with Tm{sup 3+}. Black-Right-Pointing-Pointer White light from BaZrO{sup 3+} phosphor.

Romero, V.H. [Centro de Investigaciones en Optica, A. P. 1-948, Leon Gto., 37160 (Mexico)] [Centro de Investigaciones en Optica, A. P. 1-948, Leon Gto., 37160 (Mexico); De la Rosa, E., E-mail: elder@cio.mx [Centro de Investigaciones en Optica, A. P. 1-948, Leon Gto., 37160 (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico)] [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico); Velazquez-Salazar, J.J. [Department of Physics and Astronomy, The University of Texas at San Antonio One UTSA Circle, San Antonio TX 78249 (United States)] [Department of Physics and Astronomy, The University of Texas at San Antonio One UTSA Circle, San Antonio TX 78249 (United States)

2012-12-15T23:59:59.000Z

39

Light emitting device having peripheral emissive region  

DOE Patents (OSTI)

Light emitting devices are provided that include one or more OLEDs disposed only on a peripheral region of the substrate. An OLED may be disposed only on a peripheral region of a substantially transparent substrate and configured to emit light into the substrate. Another surface of the substrate may be roughened or include other features to outcouple light from the substrate. The edges of the substrate may be beveled and/or reflective. The area of the OLED(s) may be relatively small compared to the substrate surface area through which light is emitted from the device. One or more OLEDs also or alternatively may be disposed on an edge of the substrate about perpendicular to the surface of the substrate through which light is emitted, such that they emit light into the substrate. A mode expanding region may be included between each such OLED and the substrate.

Forrest, Stephen R

2013-05-28T23:59:59.000Z

40

Organic light-emitting diodes from homoleptic square planar complexes  

SciTech Connect

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 "white light emitting" 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

Lowering Color Temperature of Y3Al5O12:Ce3+ White Light  

E-Print Network (OSTI)

to light bulbs, which require high durability and low energy consumption. How- ever, for warm white indoorLowering Color Temperature of Y3Al5O12:Ce3+ White Light Emitting Diodes Using Reddish Light light emitting diodes LEDs coated with a single phosphor is realized by employing a tunable short wave

Lee, Yong-Hee

42

Enhanced Light Extraction from Organic Light Emitting Diodes  

Ames Laboratory researchers have developed a soft lithography microlens fabrication and array that enables more efficient organic light emitting diodes (OLEDs), improving their commercial viability.

43

Blue light emitting thiogallate phosphor  

DOE Patents (OSTI)

A crystalline blue emitting thiogallate phosphor of the formula RGa.sub.2 S.sub.4 :Ce.sub.x where R is selected from the group consisting of calcium, strontium, barium and zinc, and x is from about 1 to 10 atomic percent, the phosphor characterized as having a crystalline microstructure on the size order of from about 100 .ANG. to about 10,000 .ANG. is provided together with a process of preparing a crystalline blue emitting thiogallate phosphor by depositing on a substrate by CVD and resultant thin film electroluminescent devices including a layer of such deposited phosphor on an ordinary glass substrate.

Dye, Robert C. (Los Alamos, NM); Smith, David C. (Los Alamos, NM); King, Christopher N. (Portland, OR); Tuenge, Richard T. (Hillsboro, OR)

1998-01-01T23:59:59.000Z

44

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

45

Progress in Organic Light emitting Diodes  

NLE Websites -- All DOE Office Websites (Extended Search)

90-3075 Seminar HostPoint of Contact: Samuel Mao The development of organic light emitting diode (OLED) from its discovery in the Kodak Research Laboratories in the late 1970's...

46

ZnSe light?emitting diodes  

Science Conference Proceedings (OSTI)

We report the successful fabrication of ZnSe p?n junction light?emitting diodes in which Li and Cl are used as p?type and n?type dopants

J. Ren; K. A. Bowers; B. Sneed; D. L. Dreifus; J. W. Cook Jr.; J. F. Schetzina; R. M. Kolbas

1990-01-01T23:59:59.000Z

47

Resonant cavity light?emitting diode  

Science Conference Proceedings (OSTI)

A novel concept of a light?emitting diode(LED) is proposed and demonstrated in which the active region of the device is placed in a resonantoptical cavity. As a consequence

E. F. Schubert; Y.?H. Wang; A. Y. Cho; L.?W. Tu; G. J. Zydzik

1992-01-01T23:59:59.000Z

48

Photochemistry of Organic Light?Emitting Diodes  

Science Conference Proceedings (OSTI)

The optical properties and excited?state geometries of some organic light?emitting diodes have been investigated by the SAC?CI method. The absorption and emission spectra have been predicted in high accuracy and the chain?length dependence of transition energies has been precisely reproduced. The present study provides the useful basis for the theoretical design predicting the photo?physical properties of the organic light?emitting diodes.

Masahiro Ehara; Hiroshi Nakatsuji

2007-01-01T23:59:59.000Z

49

Bright White Light Emission from Ultrasmall Cadmium Selenide Nanocrystals  

Science Conference Proceedings (OSTI)

A simple treatment method using formic acid has been found to increase the fluorescence quantum yield of ultrasmall white light-emitting CdSe nanocrystals from 8% to 45%. Brighter white-light emission occurs with other carboxylic acids as well, and the magnitude of the quantum yield enhancement is shown to be dependent on the alkyl chain length. Additionally, the nanocrystal luminescence remains enhanced relative to the untreated nanocrystals over several days. This brightened emission opens the possibility for even further quantum yield improvement and potential for use of these white-light nanocrystals in solid-state lighting applications.

Rosson, Teresa [Vanderbilt University; Claiborne, Sarah [Vanderbilt University; McBride, James [Vanderbilt University; Stratton, Benjamin S [Vanderbilt University; Rosenthal, Sandra [ORNL

2012-01-01T23:59:59.000Z

50

Synthesis and luminescence properties of rare earth activated phosphors for near UV-emitting LEDs for efficacious generation of white light  

E-Print Network (OSTI)

efficient, high-color-rendering LED lamps using oxyfluoridePhosphor selection for near UV LED solid state lighting,?and application for near UV LED solid state lighting,? ECS.

Han, Jinkyu

2013-01-01T23:59:59.000Z

51

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

Sørensen, Henrik

52

LIGHT EMITTING DIODE (LED) TRAFFIC SIGNAL SURVEY RESULTS  

E-Print Network (OSTI)

CALIFORNIA ENERGY COMMISSION LIGHT EMITTING DIODE (LED) TRAFFIC SIGNAL SURVEY RESULTS STAFFREPORT: Assistance needs 26 Item 12: Information requested 28 Appendix A: Light Emitting Diode (LED) Traffic Signal efficiency upgrades. - 29 - #12;APPENDIX A - 30 - #12;California Energy Commission Light Emitting Diode (LED

53

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

54

Analysis of surface plasmon mediated light emitting diode efficiency enhancement.  

E-Print Network (OSTI)

?? The extraction of light from current light emitting diodes (LEDs) is very low due to the large index of refraction mismatch between the semiconductor… (more)

Holmstedt, Jason

2011-01-01T23:59:59.000Z

55

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

56

Light Emitting Diodes (LEDs) for General Illumiation  

NLE Websites -- All DOE Office Websites (Extended Search)

LIGHT LIGHT EMITTING DIODES (LEDS) FOR GENERAL ILLUMINATION AN OIDA TECHNOLOGY ROADMAP An OIDA Report March 2001 Co-Sponsored by DOE/BTS and OIDA Compiled by Eric D. Jones Sandia National Laboratories OIDA Member Use Only OIDA OPTOELECTRONICS INDUSTRY DEVELOPMENT ASSOCIATION 1133 Connecticut Avenue, NW Suite 600 Washington, DC 20036 Ph: (202) 785-4426 Fax: (202) 785-4428 Web: http://www.OIDA.org © 2001 OIDA Optoelectronics Industry Development Association All data contained in this report is proprietary to OIDA and may not be distributed in either original or reproduced form to anyone outside the client's internal organization within five years of the report date without prior written permission of the Optoelectronics Industry Development Association. Published by: Optoelectronics Industry Development Association

57

Proton damage effects on light emitting diodes  

SciTech Connect

We have studied the effects of 16-MeV proton irradiation on the performance of a variety of light emitting diodes (LED's) emitting between 820 and 1300 nm. Total light output and current were measured at room temperature as a function of forward bias prior to and following a sequence of room temperature 16-MeV proton irradiations. Our results indicate that the relative amount of proton-induced degradation from one LED type to another is similar to that observed for neutron and gamma irradiations. More specifically, the most sensitive device is the amphoterically Si-doped GaAs LED which is characterized by a long preirradiation minority carrier lifetime. The most resistant LEDs are the high radiance GaAlAs (820 nm) and InGaAsP (1300 nm) LEDs. As in the case of Si devices, the degradation rate per irradiating particle fluence is significantly greater for proton irradiation of these LEDs than it is for neutron exposure. Neutron damage data presented herein indicate that the ratio of proton-to-neutron degradation rates can be as high as 100. Lifetime-damage constant products for constant current operation are calculated for each LED type and vary from 1.5 x 10/sup -13/ cm/sup 2//p for the InGaAsP LED to 1.1 x 10/sup -10/ cm/sup 2//p for the amphoterically Si-doped GaAs LED.

Rose, B.H.; Barnes, C.E.

1982-03-01T23:59:59.000Z

58

Light Sterile Neutrinos: A White Paper  

E-Print Network (OSTI)

This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data.

K. N. Abazajian; M. A. Acero; S. K. Agarwalla; A. A. Aguilar-Arevalo; C. H. Albright; S. Antusch; C. A. Arguelles; A. B. Balantekin; G. Barenboim; V. Barger; P. Bernardini; F. Bezrukov; O. E. Bjaelde; S. A. Bogacz; N. S. Bowden; A. Boyarsky; A. Bravar; D. Bravo Berguno; S. J. Brice; A. D. Bross; B. Caccianiga; F. Cavanna; E. J. Chun; B. T. Cleveland; A. P. Collin; P. Coloma; J. M. Conrad; M. Cribier; A. S. Cucoanes; J. C. D'Olivo; S. Das; A. de Gouvea; A. V. Derbin; R. Dharmapalan; J. S. Diaz; X. J. Ding; Z. Djurcic; A. Donini; D. Duchesneau; H. Ejiri; S. R. Elliott; D. J. Ernst; A. Esmaili; J. J. Evans; E. Fernandez-Martinez; E. Figueroa-Feliciano; B. T. Fleming; J. A. Formaggio; D. Franco; J. Gaffiot; R. Gandhi; Y. Gao; G. T. Garvey; V. N. Gavrin; P. Ghoshal; D. Gibin; C. Giunti; S. N. Gninenko; V. V. Gorbachev; D. S. Gorbunov; R. Guenette; A. Guglielmi; F. Halzen; J. Hamann; S. Hannestad; W. Haxton; K. M. Heeger; R. Henning; P. Hernandez; P. Huber; W. Huelsnitz; A. Ianni; T. V. Ibragimova; Y. Karadzhov; G. Karagiorgi; G. Keefer; Y. D. Kim; J. Kopp; V. N. Kornoukhov; A. Kusenko; P. Kyberd; P. Langacker; Th. Lasserre; M. Laveder; A. Letourneau; D. Lhuillier; Y. F. Li; M. Lindner; J. M. Link; B. L. Littlejohn; P. Lombardi; K. Long; J. Lopez-Pavon; W. C. Louis; L. Ludhova; J. D. Lykken; P. A. N. Machado; M. Maltoni; W. A. Mann; D. Marfatia; C. Mariani; V. A. Matveev; N. E. Mavromatos; A. Melchiorri; D. Meloni; O. Mena; G. Mention; A. Merle; E. Meroni; M. Mezzetto; G. B. Mills; D. Minic; L. Miramonti; D. Mohapatra; R. N. Mohapatra; C. Montanari; Y. Mori; Th. A. Mueller; H. P. Mumm; V. Muratova; A. E. Nelson; J. S. Nico; E. Noah; J. Nowak; O. Yu. Smirnov; M. Obolensky; S. Pakvasa; O. Palamara; M. Pallavicini; S. Pascoli; L. Patrizii; Z. Pavlovic; O. L. G. Peres; H. Pessard; F. Pietropaolo; M. L. Pitt; M. Popovic; J. Pradler; G. Ranucci; H. Ray; S. Razzaque; B. Rebel; R. G. H. Robertson; W. Rodejohann; S. D. Rountree; C. Rubbia; O. Ruchayskiy; P. R. Sala; K. Scholberg; T. Schwetz; M. H. Shaevitz; M. Shaposhnikov; R. Shrock; S. Simone; M. Skorokhvatov; M. Sorel; A. Sousa; D. N. Spergel; J. Spitz; L. Stanco; I. Stancu; A. Suzuki; T. Takeuchi; I. Tamborra; J. Tang; G. Testera; X. C. Tian; A. Tonazzo; C. D. Tunnell; R. G. Van de Water; L. Verde; E. P. Veretenkin; C. Vignoli; M. Vivier; R. B. Vogelaar; M. O. Wascko; J. F. Wilkerson; W. Winter; Y. Y. Y. Wong; T. T. Yanagida; O. Yasuda; M. Yeh; F. Yermia; Z. W. Yokley; G. P. Zeller; L. Zhan; H. Zhang

2012-04-18T23:59:59.000Z

59

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

Kwok, Hoi S.

60

INVESTIGATION OF OPTICAL STRUCTURES FOR ENHANCING THE LIGHT EXTRACTION FICIENCY OF WHITE LED.  

E-Print Network (OSTI)

??Recently, phosphor-conversion has been widely used in producing white light-emitting diodes (LEDs). In phosphor-converted (pc) LEDs, the blue LED chip is surrounded by the phosphor… (more)

Chen, Wei-Liang

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

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

62

Efficiency enhancement of microcavity organic light emitting diodes  

Science Conference Proceedings (OSTI)

We report microcavity efficiency enhancement of organic electroluminescent devices based on the hole transporter bis(triphenyl) diamine and the electron transporter and light emitter tris(8?hydroxyquinoline) aluminum.Microcavityorganic light emitting diodes are described that emit four times the light measured in the forward direction (spectrally integrated)

R. H. Jordan; A. Dodabalapur; R. E. Slusher

1996-01-01T23:59:59.000Z

63

Application of light emitting diodes as solid state light sources in analytical chemistry.  

E-Print Network (OSTI)

??Several analytical systems were developed with light emitting diodes (LEDs) as solid state light sources. With an LED as a light source, liquid core waveguide… (more)

Eom, In Yong

2005-01-01T23:59:59.000Z

64

Si Heterostructures for Pure UV Light Emitting Diode with Carrier ...  

Science Conference Proceedings (OSTI)

Presentation Title, Development of ZnO/MgO/p+-Si Heterostructures for Pure UV Light Emitting Diode with Carrier Blocking Layer. Author(s), Byung Oh Jung, ...

65

Improved Performance of a Fluorescent Blue Organic Light Emitting ...  

Science Conference Proceedings (OSTI)

Presentation Title, Improved Performance of a Fluorescent Blue Organic Light Emitting Diode with Hole Blocking Materials as Dopants for Transport Layers.

66

Save Energy, Money and Prevent Pollution with Light-Emitting...  

NLE Websites -- All DOE Office Websites (Extended Search)

Save Energy, Money and Prevent Pollution with Light-Emitting Diode (LED) Exit Signs Secondary menu About us Press room Contact Us Portfolio Manager Login Facility owners and...

67

High power flip-chip light emitting diode.  

E-Print Network (OSTI)

??xiv, 74 leaves : ill. (some col.) ; 30 cm HKUST Call Number: Thesis ELEC 2004 Lai Recently, Light-emitting diodes (LEDs) are widely used in… (more)

Lai, Yin Hing

2004-01-01T23:59:59.000Z

68

Quantum Efficiency of Micron Scaled Organic Light Emitting Diodes ...  

Science Conference Proceedings (OSTI)

Jun 1, 2004 ... Quantum Efficiency of Micron Scaled Organic Light Emitting Diodes Using Atomic Force Electroluminescence Microscopy by L.S.C. Pingree ...

69

Electron traps in organic light-emitting diodes  

Science Conference Proceedings (OSTI)

This work presents the effects of electron traps in organic light-emitting diodes using a model which includes charge injection

Min-Jan Tsai; Hsin-Fei Meng

2005-01-01T23:59:59.000Z

70

Junction temperature measurement of light emitting diode by electroluminescence  

Science Conference Proceedings (OSTI)

Junction temperature (JT) is a key parameter of the performance and lifetime of light emitting diodes(LEDs). In this paper

S. M. He; X. D. Luo; B. Zhang; L. Fu; L. W. Cheng; J. B. Wang; W. Lu

2011-01-01T23:59:59.000Z

71

Power saving regulated light emitting diode circuit  

SciTech Connect

A power saving regulated light source circuit, comprising a light emitting diode (LED), a direct current source and a switching transistor connected in series with the LED, a control voltage producing resistor connected in series with the LED to produce a control voltage corresponding to the current through the LED, a storage capacitor connected in parallel with the series combination of the LED and the resistor, a comparator having its output connected to the input of the transistor, the comparator having a reference input and a control input, a stabilized biasing source for supplying a stabilized reference voltage to the reference input, the control input of the comparator being connected to the control voltage producing resistor, the comparator having a high output state when the reference voltage exceeds the control voltage while having a low output state when the control voltage exceeds the reference voltage, the transistor being conductive in response to the high state while being nonconductive in response to the low state, the transistor when conductive being effective to charge the capacitor and to increase the control voltage, whereby the comparator is cycled between the high and low output states while the transistor is cycled between conductive and nonconductive states.

Haville, G. D.

1985-03-12T23:59:59.000Z

72

Efficient semiconductor light-emitting device and method  

DOE Patents (OSTI)

A semiconductor light-emitting device and method. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL).

Choquette, Kent D. (Albuquerque, NM); Lear, Kevin L. (Albuquerque, NM); Schneider, Jr., Richard P. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

73

Efficient semiconductor light-emitting device and method  

DOE Patents (OSTI)

A semiconductor light-emitting device and method are disclosed. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL). 12 figs.

Choquette, K.D.; Lear, K.L.; Schneider, R.P. Jr.

1996-02-20T23:59:59.000Z

74

Visible light emitting vertical cavity surface emitting lasers  

DOE Patents (OSTI)

A vertical cavity surface emitting laser that emits visible radiation is built upon a substrate, then having mirrors, the first mirror on top of the substrate; both sets of mirrors being a distributed Bragg reflector of either dielectrics or other materials which affect the resistivity or of semiconductors, such that the structure within the mirror comprises a plurality of sets, each having a thickness of {lambda}/2n where n is the index of refraction of each of the sets; each of the mirrors adjacent to spacers which are on either side of an optically active bulk or quantum well layer; and the spacers and the optically active layer are from one of the following material systems: In{sub z}(Al{sub y}Ga{sub 1{minus}y}){sub 1{minus}z}P, InAlGaAs, AlGaAs, InGaAs, or AlGaP/GaP, wherein the optically active region having a length equal to m {lambda}/2n{sub eff} where m is an integer and n{sub eff} is the effective index of refraction of the laser cavity, and the spacer layer and one of the mirrors being transmissive to radiation having a wavelength of {lambda}/n, typically within the green to red portion of the visible spectrum. 10 figs.

Bryan, R.P.; Olbright, G.R.; Lott, J.A.; Schneider, R.P. Jr.

1995-06-27T23:59:59.000Z

75

Zinc Oxide and Nitride Nanowire Based Light Emitting Diodes  

E-Print Network (OSTI)

lumens/W, the LED beats the incandescent bulb and is on thefor an LED as opposed to an incandescent light bulb as shownbulb, fluorescent lamp, and blue light emitting diode. (24) (25) 2.2 LED

Lai, Elaine Michelle

2009-01-01T23:59:59.000Z

76

Functional Imprinting Structures on GaN-Based Light-Emitting ...  

Science Conference Proceedings (OSTI)

Keywords: GaN, light-emitting diode (LED), imprinting technology, far-field pattern modulation, light extraction. 1. Introduction. GaN-based light-emitting diodes ...

77

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

78

Visible light surface emitting semiconductor laser  

DOE Patents (OSTI)

A vertical-cavity surface-emitting laser is disclosed comprising a laser cavity sandwiched between two distributed Bragg reflectors. The laser cavity comprises a pair of spacer layers surrounding one or more active, optically emitting quantum-well layers having a bandgap in the visible which serve as the active optically emitting material of the device. The thickness of the laser cavity is m .lambda./2n.sub.eff where m is an integer, .lambda. is the free-space wavelength of the laser radiation and n.sub.eff is the effective index of refraction of the cavity. Electrical pumping of the laser is achieved by heavily doping the bottom mirror and substrate to one conductivity-type and heavily doping regions of the upper mirror with the opposite conductivity type to form a diode structure and applying a suitable voltage to the diode structure. Specific embodiments of the invention for generating red, green, and blue radiation are described.

Olbright, Gregory R. (Boulder, CO); Jewell, Jack L. (Bridgewater, NJ)

1993-01-01T23:59:59.000Z

79

Nanofabrication of gallium nitride photonic crystal light-emitting diodes  

Science Conference Proceedings (OSTI)

We describe a comparison of nanofabrication technologies for the fabrication of 2D photonic crystal structures on GaN/InGaN blue LEDs. Such devices exhibit enhanced brightness and the possibility of controlling the angular emission profile of emitted ... Keywords: GaN dry-etching, Light-emitting diodes, Nanolithography, Photonic crystals

Ali Z. Khokhar; Keith Parsons; Graham Hubbard; Faiz Rahman; Douglas S. Macintyre; Chang Xiong; David Massoubre; Zheng Gong; Nigel P. Johnson; Richard M. De La Rue; Ian M. Watson; Erdan Gu; Martin D. Dawson; Steve J. Abbott; Martin D. B. Charlton; Martin Tillin

2010-11-01T23:59:59.000Z

80

Comparing Light-Emitting Diode (LED) Street and Area Lighting to Traditional Lighting Technologies  

Science Conference Proceedings (OSTI)

Manufacturing advances have now made the use of light-emitting diode (LED) technology practical for street and area lighting. To better understand the application, the Electric Power Research Institute (EPRI) teamed with Southern Company and Gulf Power to install LED street lights at a demonstration site and measure their performance. The data showed several disadvantages for the LED lights, such as a lower efficacy compared to traditional technology and lower immunity to electrical disturbances, but an ...

2012-04-06T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

ZnO-graphene Hybrid Quantum Dots Light Emitting Diode  

Science Conference Proceedings (OSTI)

Presentation Title, ZnO-graphene Hybrid Quantum Dots Light Emitting Diode. Author(s), Won Kook Choi, Dong-Ick Son, Soon-Nam Kwon. On-Site Speaker ...

82

Highly efficient blue polyfluorene-based polymer light-emitting...  

NLE Websites -- All DOE Office Websites (Extended Search)

of Physics Volume 42 Pagination 5 Abstract A highly efficient blue polymer light-emitting diode based on poly(9,9-di(2-(2-(2-methoxy-ethoxy)ethoxy)ethyl)fluorenyl-2,7-diyl)...

83

A light emitting object and its environment  

E-Print Network (OSTI)

The object that is intentionally produced with the inherent spirit of "Fine Art," will always be placed with a reverence for its setting. "LIGHT GRID" is a light sculpture with flexibility to utilize the environment where ...

Jeibmann, Jon Karl

1983-01-01T23:59:59.000Z

84

Battery cell configuration for organic light emitting diode display in modern smartphones and tablet-PCs  

E-Print Network (OSTI)

Battery cell configuration for organic light emitting diode display in modern smartphones- spite of power efficiency of organic light emitting diode (OLED) display nature, the integrated display

Pedram, Massoud

85

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

86

Maximum Spectral Luminous Efficacy of White Light  

E-Print Network (OSTI)

As lighting efficiency improves, it is useful to understand the theoretical limits to luminous efficacy for light that we perceive as white. Independent of the efficiency with which photons are generated, there exists a spectrally-imposed limit to the luminous efficacy of any source of photons. We find that, depending on the acceptable bandpass and---to a lesser extent---the color temperature of the light, the ideal white light source achieves a spectral luminous efficacy of 250--370 lm/W. This is consistent with previous calculations, but here we explore the maximum luminous efficacy as a function of photopic sensitivity threshold, color temperature, and color rendering index; deriving peak performance as a function of all three parameters. We also present example experimental spectra from a variety of light sources, quantifying the intrinsic efficacy of their spectral distributions.

Murphy, T W

2013-01-01T23:59:59.000Z

87

Comparing Light Emitting Diode (LED) Street and Area Lighting to Traditional Lighting Technologies  

Science Conference Proceedings (OSTI)

High-power light-emitting diode (LED) technology holds great promise for outdoor illumination. This case study discusses the results of the LED Street and Area Lighting Demonstration performed by Tennessee Valley Authority (TVA), Knoxville Utilities Board (KUB), and EPRI. Data was collected on Wall Avenue, a busy thoroughfare in downtown Knoxville, using a specially developed computer-controlled mobile light measurement vehicle with a global positioning system.Early reports from the ...

2012-09-28T23:59:59.000Z

88

Comparing Light-Emitting Diode (LED) Street and Area Lighting to Traditional Lighting Technologies  

Science Conference Proceedings (OSTI)

Manufacturing advances have now made the use of light-emitting diode (LED) technology practical for street and area lighting. To better understand the application, the Electric Power Research Institute (EPRI) teamed with Southern Company and Alabama Power to install LED street lights at a demonstration site and measure the performance. The data showed several disadvantages such as a lower efficacy compared to traditional technology and lower immunity to electrical disturbances, but advantages in energy s...

2012-04-20T23:59:59.000Z

89

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

Office of Scientific and Technical Information (OSTI)

Science Showcase - Light-emitting Diode (LED) Lighting Research Science Showcase - Light-emitting Diode (LED) Lighting Research Light-emitting diode (LED) lighting is a type of solid-state lighting that uses a semiconductor to convert electricity to light. LED lighting products are beginning to appear in a wide variety of home, business, and industrial products such as holiday lighting, replacement bulbs for incandescent lamps, street lighting, outdoor area lighting and indoor ambient lighting. Over the past decade, LED technology research and development supported by the U.S. Department of Energy (DOE) has yielded impressive improvements in the cost, color performance, light output, efficacy, reliability, lifetime, and manufacturability of LED products and this upward trend is expected to continue. Read about the latest DOE research, the technology behind LEDs,

90

Optical switching in midinfrared light-emitting diodes  

Science Conference Proceedings (OSTI)

We report on the optical quenching of electroluminescence in midinfrared light-emitting diodes operating at 3.0 ?m. The source is based on a symmetrical double heterostructure with large band offsets and is effectively switched off using coherent visible light.

A. Krier; V. V. Sherstnev; H. H. Gao; A. M. Monahov; G. Hill

2002-01-01T23:59:59.000Z

91

Oxycarbonitride phosphors and light emitting devices using the same  

DOE Patents (OSTI)

Disclosed herein is a novel family of oxycarbidonitride phosphor compositions and light emitting devices incorporating the same. Within the sextant system of M--Al--Si--O--N--C--Ln and quintuplet system of M--Si--O--N--C--Ln (M=alkaline earth element, Ln=rare earth element), the phosphors are composed of either one single crystalline phase or two crystalline phases with high chemical and thermal stability. In certain embodiments, the disclosed phosphor of silicon oxycarbidonitrides emits green light at wavelength between 530-550 nm. In further embodiments, the disclosed phosphor compositions emit blue-green to yellow light in a wavelength range of 450-650 nm under near-UV and blue light excitation.

Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

2013-10-08T23:59:59.000Z

92

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

SciTech Connect

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

93

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

94

The Josephson light-emitting diode  

E-Print Network (OSTI)

We consider an optical quantum dot where an electron level and a hole level are coupled to respective superconducting leads. We find that electrons and holes recombine producing photons at discrete energies as well as a continuous tail. Further, the spectral lines directly probe the induced superconducting correlations on the dot. At energies close to the applied bias voltage eV, a parameter range exists, where radiation proceeds in pairwise emission of polarization correlated photons. At energies close to 2eV, emitted photons are associated with Cooper pair transfer and are reminiscent of Josephson radiation. We discuss how to probe the coherence of these photons in a SQUID geometry via single photon interference.

Patrik Recher; Yuli V. Nazarov; Leo P. Kouwenhoven

2009-02-25T23:59:59.000Z

95

Close-packed array of light emitting devices  

SciTech Connect

A close-packed array of light emitting diodes includes a nonconductive substrate having a plurality of elongate channels extending therethrough from a first side to a second side, where each of the elongate channels in at least a portion of the substrate includes a conductive rod therein. The conductive rods have a density over the substrate of at least about 1,000 rods per square centimeter and include first conductive rods and second conductive rods. The close-packed array further includes a plurality of light emitting diodes on the first side of the substrate, where each light emitting diode is in physical contact with at least one first conductive rod and in electrical contact with at least one second conductive rod.

Ivanov, Ilia N.; Simpson, John T.

2013-04-09T23:59:59.000Z

96

Fluorescence Enhancement of White-Light Cadmium Selenide Nanocrystals.  

E-Print Network (OSTI)

??Advances are being made in lighting technology, as incandescent and fluorescent light bulbs become less efficient compared to solid-state lighting devices, especially light-emitting diodes (LEDs).… (more)

Rosson, Teresa Ellen

2011-01-01T23:59:59.000Z

97

GaN light-emitting diodes with Archimedean lattice photonic crystals Aurlien David,a  

E-Print Network (OSTI)

GaN light-emitting diodes with Archimedean lattice photonic crystals Aurélien David,a Tetsuo Fujii 2005; published online 16 February 2006 We study GaN-based light emitting diodes incorporating light- emitting diodes LEDs , as they could extract the emitted light otherwise trapped inside

Recanati, Catherine

98

Dynamic fluctuations in ultrasmall nanocrystals induce white light emission  

Science Conference Proceedings (OSTI)

Nanocrystals typically emit monochromatically at their size-dependent energy gaps. Recently, it was found that by pushing the size of a nanocrystal to its lower limits, absorption occurs at increasingly larger energies, but the expected blue to ultraviolet emission does not occur. Instead, individual ultrasmall CdSe nanocrystals emit white light1-5. Here we show that following excitation, partial thermalization sets the ultrasmall nanocrystals into a fluxional6 state, with a continuously varying energy gap which results in white light emission. Even the larger, monochromatic nanocrystals have a fluxional surface but a stable crystal core. A degree of fluxionality persists even at room temperature and represents a radical change to the accepted view of nanocrystals, with wide-ranging ramifications for other applications. The results were obtained using a combination of state-of-the-art experiment and theory: dynamic imaging by aberration-corrected scanning transmission electron microscopy and finite-temperature quantum molecular dynamics simulations. The results show that small is different, but ultrasmall is different yet again.

Pennycook, Timothy J [ORNL; Mcbride, J. R. [Vanderbilt University; Rosenthal, Sandra [Vanderbilt University; Pennycook, Stephen J [ORNL; Pantelides, Sokrates T. [Vanderbilt University

2012-01-01T23:59:59.000Z

99

LIGHT EMITTING DlODE TESTING AND ANALYSIS  

SciTech Connect

This report covers the work done to analyze the optical output of a Light Emitting Diode. This diode consists' of a Monsanto MV2 LED chip in an MV50 package. A calculator based instrumentation system is described including programming techniques used to reduce and display data. A Light Instrumentation System with specially designed fiber optic cables is described which gathers data for processing by the calculator based instrumentation system. Future work will include analysis of the RCA 8571 Photomultiplier Tube.

Bowers, J L; Allen, T E

1973-08-01T23:59:59.000Z

100

Outdoor Light-Emitting Diode (LED) Digital Signage  

Science Conference Proceedings (OSTI)

Utilities have been supporting outdoor advertising companies and their traditional simple billboards for many years. The level of support these billboards needed was minimal because electricity for them was only used to power basic lighting technologies. The growth in the billboard industry combined with the explosion in available electronic and digital systems and the advancements made in light-emitting diodes (LEDs) has resulted in a new type of billboard8212the LED electronic billboard. Electronic bil...

2009-12-17T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

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

102

NREL: Technology Transfer - Brilliant White Light with Amber ...  

LED bulbs are the future of lighting for industry, business, and consumers. ... the LED bulbs can make brighter white light with better color more ...

103

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

104

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

105

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

106

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 for simple photobleaching pur- poses, we designed a simple but efficient lighting system using light emitting

Kaufman, Laura

107

Photonic-crystal GaN light-emitting diodes with tailored guided modes distribution  

E-Print Network (OSTI)

Photonic-crystal GaN light-emitting diodes with tailored guided modes distribution Aurélien David of photonic crystal PhC -assisted gallium nitride light-emitting diodes LEDs to the existence of unextracted a promising but challenging solution towards efficient solid-state lighting. Conventional GaN-based light-emitting

Recanati, Catherine

108

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.3670) Light-emitting diodes; (160.6000) Semiconductors; (130-0250) Optoelectronics. References and links 1. S

109

Developing quantum dot phosphor-based light-emitting diodes for aviation lighting applications  

Science Conference Proceedings (OSTI)

We have investigated the feasibility of employing quantum dot (QD) phosphor-based light-emitting diodes (LEDs) in aviation applications that request Night Vision Imaging Systems (NVIS) compliance. Our studies suggest that the emerging QD phosphorbased ...

Fengbing Wu; Dawei Zhang; Shuzhen Shang; Yiming Zhu; Songlin Zhuang; Jian Xu

2012-01-01T23:59:59.000Z

110

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.

111

Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Savings Estimates of Light Emitting Diodes Savings Estimates of Light Emitting Diodes in Niche Lighting Applications Prepared for: Building Technologies Program Office of Energy Efficiency and Renewable Energy U.S. Department of Energy Prepared by: Navigant Consulting Inc. 1801 K Street, NW Suite 500 Washington DC, 20006 September 2008 * Department of Energy Washington, DC 20585 Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications Released: September 2008 Revised: October 2008 This DOE report presents research findings for twelve different niche markets where LEDs are competing or poised to compete with traditional light sources (e.g., incandescent and fluorescent). Estimates of the energy saved due to current levels of LED market penetration as well as estimates of potential energy savings if these markets switched completely to LEDs

112

Organic light emitting device having multiple separate emissive layers  

DOE Patents (OSTI)

An organic light emitting device having multiple separate emissive layers is provided. Each emissive layer may define an exciton formation region, allowing exciton formation to occur across the entire emissive region. By aligning the energy levels of each emissive layer with the adjacent emissive layers, exciton formation in each layer may be improved. Devices incorporating multiple emissive layers with multiple exciton formation regions may exhibit improved performance, including internal quantum efficiencies of up to 100%.

Forrest, Stephen R. (Ann Arbor, MI)

2012-03-27T23:59:59.000Z

113

Integrated System Of White Led Visible-Light Communication And Power-Line Communication  

E-Print Network (OSTI)

White LEDs offer advantageous properties such as high brightness, reliability, lower power consumption and long lifetime. The biggest potential application for white LEDs will be general illumination and lighting. Indoor wireless optical communication systems employing white LED lighting have been proposed. This system will enable high QoS by the high power from this lighting equipment. But, it is difficult for existing offices communication using existing power-line is proposed. This system is emitted as visible-light from LED lighting according to the transmitted signal waveform without demodulating the signal from the power-line. This system is expected to be applicable from the existing illuminant easily like exchanging electric bulbs. This integrated system will surely have a big impact as a new signal transmission system and its economical effect will be great. The basic performance of this system is analyzed. The actual system is built and its feasibility is shown through experiments.

Toshihiko Komine; Masao Nakagawa

2002-01-01T23:59:59.000Z

114

Electroluminescence property of organic light emitting diode (OLED)  

Science Conference Proceedings (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)

2013-01-01T23:59:59.000Z

115

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

116

A Comparison of Infrared Light Emitting Diodes (IR-LED) versus Infrared  

E-Print Network (OSTI)

B. Characteristics of a typical IR LED analogous to the typeLight Emitting Diodes (IR-LED) versus Infrared Helium-Neon (light emitting diode (IR-LED) to quantitatively measure fuel

Girard, James W.; Bogin, Gregory E; Mack, John Hunter; Chen, J-Y; Dibble, Rober W

2005-01-01T23:59:59.000Z

117

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

118

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

119

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

120

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

SciTech Connect

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

Note: This page contains sample records for the topic "white light emitting" 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

Improvement of output coupling efficiency of organic light-emitting diodes by backside substrate modification  

E-Print Network (OSTI)

Improvement of output coupling efficiency of organic light-emitting diodes by backside substrate in determining the power efficiency of organic light emitting diodes OLEDs is the coupling effi- ciency ( cp 1999; accepted for publication 1 February 2000 The emission intensity of an organic light-emitting

122

A description and evaluation of light-emitting diode displays for generation of visual stimuli*  

E-Print Network (OSTI)

A description and evaluation of light-emitting diode displays for generation of visual stimuli 53706 A description of the design and function of light-emitting diode (LED) display modules is given (Time, April 1972). Light-emitting diodes (L~Ds) are examples of these spin-offs, LED display devices

Massaro, Dominic

123

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-color (red, green, and blue) polymer light-emitting diode displays was investigated in detail. After local.1063/1.1806548] I. INTRODUCTION Polymer light-emitting diodes (PLEDs) have emerged as a very promising candidate

124

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 and the spectra of organic light-emitting diodes made from these films can be successfully tuned by this method. S0003-6951 98 01339-4 A main goal of the field of organic light-emitting diodes OLEDs

125

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

126

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.

127

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

128

Far-field radiation of photonic crystal organic light-emitting diode  

E-Print Network (OSTI)

Far-field radiation of photonic crystal organic light-emitting diode Yong-Jae Lee, Se-Heon Kim, Guk-field profile of a photonic crystal organic light emitting diode is studied to understand the viewing angle.3670) Light- emitting diodes References and links 1. M. R. Krames, H. Amano, J. J. Brown, P. L. Heremans

Lee, Yong-Hee

129

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

130

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

131

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

132

Loss of Quantum Efficiency in Green Light Emitting Diode Dies at Low Temperature  

E-Print Network (OSTI)

Loss of Quantum Efficiency in Green Light Emitting Diode Dies at Low Temperature Yufeng Li1,2 , Wei, photoluminescence and cathodoluminescence of GaInN/GaN multiple quantum well light emitting diode dies are analyzed and efficient pure green light emitting diodes (LEDs) are of high economic value. However, when the emission

Wetzel, Christian M.

133

A Novel Hole-Confining Concept for Efficient Green Organic Light Emitting Diodes.  

E-Print Network (OSTI)

??Organic light emitting diode (OLED) technology has initiated a lot of interest in the display and solid state lighting market during the last decade. The… (more)

Harikrishna Mohan, Siddharth

2008-01-01T23:59:59.000Z

134

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

135

Organic light-emitting devices using spin-dependent processes  

DOE Patents (OSTI)

The maximum luminous efficiency of organic light-emitting materials is increased through spin-dependent processing. The technique is applicable to all electro-luminescent processes in which light is produced by singlet exciton decay, and all devices which use such effects, including LEDs, super-radiant devices, amplified stimulated emission devices, lasers, other optical microcavity devices, electrically pumped optical amplifiers, and phosphorescence (Ph) based light emitting devices. In preferred embodiments, the emissive material is doped with an impurity, or otherwise modified, to increase the spin-lattice relaxation rate (i.e., decrease the spin-lattice time), and hence raise the efficiency of the device. The material may be a polymer, oligomer, small molecule, single crystal, molecular crystal, or fullerene. The impurity is preferably a magnetic or paramagnetic substance. The invention is applicable to IR, UV, and other electromagnetic radiation generation and is thus not limited to the visible region of the spectrum. The methods of the invention may also be combined with other techniques used to improve device performance.

Vardeny, Z. Valy (Salt Lake City, UT); Wohlgenannt, Markus (Salt Lake City, UT)

2010-03-23T23:59:59.000Z

136

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

137

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

138

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

139

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

140

Blue light emitting diode internal and injection efficiency  

Science Conference Proceedings (OSTI)

A simple experimental method of light emitting diode(LED) injection efficiency (IE) determination was suggested. IE and internal quantum efficiency(IQE) calculation is an actual and difficult problem in LED science. In this paper IE and IQE of blue LEDs were determined separately. The method is based on electroluminescence data fitting by the modified rate equation model. Efficiency droop caused by Auger recombination and poor injection were taken into account. Only one reasonable assumption was accepted during the calculations: IE tends to 1 at low current densities.

Ilya E. Titkov; Denis A. Sannikov; Young-Min Park; Joong-Kon Son

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

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

142

NREL: Buildings Research - Brilliant White Light with Amber LEDs...  

NLE Websites -- All DOE Office Websites (Extended Search)

Brilliant White Light with Amber LEDs; NREL Licensing Webinar December 10th November 12, 2013 LED bulbs are the future of lighting for industry, business, and consumers. As the...

143

NREL: Technology Transfer - Brilliant White Light with Amber...  

NLE Websites -- All DOE Office Websites (Extended Search)

Brilliant White Light with Amber LEDs; NREL Licensing Webinar December 10th November 12, 2013 LED bulbs are the future of lighting for industry, business, and consumers. As the...

144

NREL: Technology Deployment - Brilliant White Light with Amber...  

NLE Websites -- All DOE Office Websites (Extended Search)

Brilliant White Light with Amber LEDs; NREL Licensing Webinar December 10th November 12, 2013 LED bulbs are the future of lighting for industry, business, and consumers. As the...

145

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

146

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

SciTech Connect

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

147

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

148

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

DOE Green Energy (OSTI)

Some white light-emitting diode (LED) light sources haverecently attained levels of efficiency and cost that allow them tocompete with fluorescent lighting for off-grid applications in thedeveloping world. Additional attributes (optics, size, ruggedness, andservice life) make them potentially superior products. Enormousreductions in energy use and greenhouse-gas emissions are thus possible,and system costs can be much lower given the ability to downsize thecharging and energy storage components compared to a fluorescentstrategy. However, there is a high risk of "market-spoiling" if inferiorproducts are introduced and result in user dissatisfaction. Completesystems involve the integration of light sources and optics, energysupply, and energy storage. A natural starting point for evaluatingproduct quality is to focus on the individual light sources. This reportdescribes testing results for batches of 10 5mm white LEDs from 26manufacturers. Efficacies and color properties are presented.

Mills, Evan

2007-05-03T23:59:59.000Z

149

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

SciTech Connect

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

150

Package of Homojunction of Fully Conjugated Heterocyclic Aromatic Rigid-rod Polymer Light Emitting Diodes.  

E-Print Network (OSTI)

??The focus of this study is mono-layer polymer light emitting diode (PLED). The emitting layer is poly-p-phenylenebenzobisoxazole (PBO). PBO is a fully conjugated heterocyclic aromatic… (more)

Liao, Hung-chi

2004-01-01T23:59:59.000Z

151

Light Emitting Diode (LED) fiducial system: Setup and operation  

SciTech Connect

Streak cameras, either electronic or rotating mirror, are common diagnostic tools used to explore very fast phenomena. Often they are used to precisely time events or durations, and in most cases, it is important to have quality time marks on the film record. Many methods have been used to introduce time marks onto the film. Exploding bridge wires are frequently used, but they light up slowly and are difficult to read with consistent accuracy. It is also difficult to put more than a few bridge wires in the view of a camera slit, so there are only a few timing marks written to the film. In some cases the time scale on the film must be interpolated over long distances, creating a significant loss of accuracy. Interpolation is especially troublesome with those cameras that have a nonlinear sweep rate. Spark gaps located on the camera slit turn on a bit faster, but suffer from the same interpolation induced errors. A series of short duration laser pulses, accurately timed and introduced along the edges of the film, is a very fine solution. The problem with such a laser fiducial system is that the lasers are very expensive and difficult to maintain. There has been a need for many years for an inexpensive, very bright light source that can be repetitively pulsed accurately and with short duration. Various technologies have sufficiently developed over the past few years, allowing us to build a fiducial system based on light emitting diodes (LED) for the Cordin rotating mirror streak cameras.

Muelder, S.A.

1995-01-01T23:59:59.000Z

152

Method to generate high efficient devices which emit high quality light for illumination  

DOE Patents (OSTI)

An electroluminescent apparatus includes an OLED device emitting light in the blue and green spectrums, and at least one down conversion layer. The down conversion layer absorbs at least part of the green spectrum light and emits light in at least one of the orange spectra and red spectra.

Krummacher, Benjamin C. (Sunnyvale, CA); Mathai, Mathew (Santa Clara, CA); Choong, Vi-En (San Jose, CA); Choulis, Stelios A. (San Jose, CA)

2009-06-30T23:59:59.000Z

153

Wide-Area Thermal Processing of Light-Emitting Materials  

Science Conference Proceedings (OSTI)

Silicon carbide based materials and devices have been successfully exploited for diverse electronic applications. However, they have not achieved the same success as Si technologies due to higher material cost and higher processing temperatures required for device development. Traditionally, SiC is not considered for optoelectronic applications because it has an indirect bandgap. However, AppliCote Associates, LLC has developed a laser-based doping process which enables light emission in SiC through the creation of embedded p-n junctions. AppliCote laser irradiation of silicon carbide allows two different interaction mechanisms: (1) Laser conversion or induced phase transformation which creates carbon rich regions that have conductive properties. These conductive regions are required for interconnection to the light emitting semiconducting region. (2) Laser doping which injects external dopant atoms into the substrate that introduces deep level transition states that emit light when electrically excited. The current collaboration with AppliCote has focused on the evaluation of ORNL's unique Pulse Thermal Processing (PTP) technique as a replacement for laser processing. Compared to laser processing, Pulse Thermal Processing can deliver similar energy intensities (20-50 kW/cm2) over a much larger area (up to 1,000 cm2) at a lower cost and much higher throughput. The main findings of our investigation; which are significant for the realization of SiC based optoelectronic devices, are as follows: (1) The PTP technique is effective in low thermal budget activation of dopants in SiC similar to the laser technique. The surface electrical conductivity of the SiC samples improved by about three orders of magnitude as a result of PTP processing which is significant for charge injection in the devices; (2) The surface composition of the SiC film can be modified by the PTP technique to create a carbon-rich surface (increased local C:Si ratio from 1:1 to 2.9:1). This is significant as higher thermal and electrical conductivities of the surface layer are critical for a successful development of integrated optoelectronic devices; and (3) PTP provides low thermal budget dopant activation with a controlled depth profile, which can be exploited for high performance device development with selective patterning of the substrate. This project has successfully demonstrated that a low thermal budget annealing technique, such as PTP, is critical to defining the path for low cost electronic devices integrated on glass or polymeric substrates. This project is complimentary to the goals of the Solid State Lighting Program within DOE. It involves new manufacturing techniques for light emitting materials that are potentially much lower cost and energy efficient than existing products. Significant opportunity exists for further exploration of AppliCote's material and device technology in combination with ORNL's PTP technique, modeling, and characterization capabilities.

Duty, C.; Quick, N. (AppliCote Associates, LLC)

2011-09-30T23:59:59.000Z

154

Low Voltage, Low Power Organic Light Emitting Transistors for AMOLED Displays  

SciTech Connect

Low voltage, low power dissipation, high aperture ratio organic light emitting transistors are demonstrated. The high level of performance is enabled by a carbon nanotube source electrode that permits integration of the drive transistor and the organic light emitting diode into an efficient single stacked device. Given the demonstrated performance, this technology could break the technical logjam holding back widespread deployment of active matrix organic light emitting displays at flat panel screen sizes.

McCarthy, M. A. [University of Florida, Gainesville; Liu, B. [University of Florida, Gainesville; Donoghue, E. P. [University of Florida, Gainesville; Kravchenko, Ivan I [ORNL; Kim, D. Y. [University of Florida, Gainesville; Reynolds, J. R. [University of Florida, Gainesville; So, Franky [University of Florida, Gainesville; Rinzler, A. G. [University of Florida, Gainesville

2011-01-01T23:59:59.000Z

155

Effective hole-injection layer for non-doped inverted top-emitting organic light-emitting devices  

Science Conference Proceedings (OSTI)

Non-doped inverted top-emitting organic light-emitting diode with high efficiency is demonstrated through employing an effective hole-injection layer composed of MoO"x. One reason for high efficiency lies on the energy-level matching between MoO"x and ... Keywords: 78.60.Fi, 82.45.Mp, 85.60.Jb, Hole-injection, ITEOLEDs, MoOx

Yanlong Meng; Wenfa Xie; Ning Zhang; Shufen Chen; Jiang Li; Wei Hu; Yi Zhao; Jingying Hou; Shiyong Liu

2008-05-01T23:59:59.000Z

156

Engineering for Environmental Sustainability http://engineering.tufts.edu/ Energy-efficient Visible Light Communication  

E-Print Network (OSTI)

Light Communication What is the problem? The white light-emitting diode (LED) stands at the threshold

Tufts University

157

August 4, 2006 Eco-lights shine new hope on `gorillas in the mist'  

E-Print Network (OSTI)

of the Congo with ultra-efficient, solar-powered white light emitting diode (WLED) lighting systems and newly

Calgary, University of

158

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

SciTech Connect

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

159

Layering Mismatched Lattices Creates Long-Sought-After Green Light-Emitting Diode (Fact Sheet), NREL Highlights, Science, NREL (National Renewable Energy Laboratory)  

NLE Websites -- All DOE Office Websites (Extended Search)

Scientists at the National Renewable Energy Laboratory (NREL) Scientists at the National Renewable Energy Laboratory (NREL) invent a deep green LED that can lead to higher-efficiency white light, lower electric bills. The white light light-emitting diode (LED) that promises to revolutionize indoor lighting while dramatically lowering electricity costs had been confounded by the so-called "green gap:" the inability to develop light in the green spectrum that can be combined with red and blue to produce white light. NREL researchers conceptualized a green emission by taking a different look at how the laboratory's solar cell researchers had set a world efficiency record and by changing a key process that had created a red LED. A good green color of light is between 530 and 570 nanometers (nm) on the Color

160

The effect of anisotropy on light extraction of organic light-emitting diodes with photonic crystal structure  

Science Conference Proceedings (OSTI)

The light extraction efficiency of organic light-emitting diodes (OLED) is greatly limited due to the difference in refractive indexes betweenmaterials ofOLED.We fabricatedOLED with photonic crystal microstructures in the interface between the glass ...

Wei Xu, Yang Li

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

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

162

Fabrication and optimization of light emitting devices with core-shell quantum dots  

E-Print Network (OSTI)

Quantum dot light emitting devices (QD-LEDs) are promising options for the next generation of solid state lighting, color displays, and other optoelectronic applications. Overcoating quantum dots (QDs) -- semiconducting ...

Song, Katherine Wei

2013-01-01T23:59:59.000Z

163

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

164

City of Phildelphia: Light emitting diodes for traffic signal displays  

SciTech Connect

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.

1995-12-01T23:59:59.000Z

165

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.

166

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

SciTech Connect

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

167

Organic Light-Emitting Devices (OLEDS) and Their Optically Detected Magnetic Resonance (ODMR)  

DOE Green Energy (OSTI)

Organic Light-Emitting Devices (OLEDs), both small molecular and polymeric have been studied extensively since the first efficient small molecule OLED was reported by Tang and VanSlyke in 1987. Burroughes' report on conjugated polymer-based OLEDs led to another track in OLED development. These developments have resulted in full color, highly efficient (up to {approx} 20% external efficiency 60 lm/W power efficiency for green emitters), and highly bright (> 140,000 Cd/m{sup 2} DC, {approx}2,000,000 Cd/m{sup 2} AC), stable (>40,000 hr at 5 mA/cm{sup 2}) devices. OLEDs are Lambertian emitters, which intrinsically eliminates the view angle problem of liquid crystal displays (LCDs). Thus OLEDs are beginning to compete with the current dominant LCDs in information display. Numerous companies are now active in this field, including large companies such as Pioneer, Toyota, Estman Kodak, Philipps, DuPont, Samsung, Sony, Toshiba, and Osram, and small companies like Cambridge Display Technology (CDT), Universal Display Corporation (UDC), and eMagin. The first small molecular display for vehicular stereos was introduced in 1998, and polymer OLED displays have begun to appear in commercial products. Although displays are the major application for OLEDs at present, they are also candidates for nest generation solid-state lighting. In this case the light source needs to be white in most cases. Organic transistors, organic solar cells, etc. are also being developed vigorously.

Gang Li

2003-12-12T23:59:59.000Z

168

Development of high power green light emitting diode dies in piezoelectric GaInN/GaN  

E-Print Network (OSTI)

Development of high power green light emitting diode dies in piezoelectric GaInN/GaN Christian 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

Detchprohm, Theeradetch

169

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.

170

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

171

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

SciTech Connect

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

172

Phase estimation with weak measurement using a white light source  

E-Print Network (OSTI)

We report results of a high precision phase estimation based on a weak measurements scheme using commercial light-emitting diode. The method is based on a measurement of the imaginary part of the weak value of a polarization operator. The imaginary part of the weak value appeared due to the measurement interaction itself. The sensitivity of our method is equivalent to resolving light pulses of order of attosecond and it is robust against chromatic dispersion.

Xiao-Ye Xu; Yaron Kedem; Kai Sun; Lev Vaidman; Chuan-Feng Li; Guang-Can Guo

2013-06-20T23:59:59.000Z

173

Three-color organic light-emitting diodes patterned by masked dye Florian Pschenitzka and J. C. Sturma)  

E-Print Network (OSTI)

Three-color organic light-emitting diodes patterned by masked dye diffusion Florian Pschenitzka of Physics. S0003-6951 99 02913-7 Organic light-emitting diodes OLEDs have demon- strated a remarkable

174

Comparing Light-Emitting Diode (LED) Street and Area Lighting to Traditional Lighting Technologies  

Science Conference Proceedings (OSTI)

In 2008, the Tennessee Valley Authority (TVA) and Benton County Electric System partnered with the Electric Power Research Institute (EPRI) to launch an investigation into the use of LED technology for area lighting. The goal of the project—called the LED Street and Area Lighting Demonstration—was to discover a better light bulb, one that not only meets the outdoor lighting requirements of consumers, but also uses less electricity in doing so. This case study discusses the results of ...

2012-09-28T23:59:59.000Z

175

Optimization of light emitting diodes based on bipolar double-barrier resonant-tunneling structures  

Science Conference Proceedings (OSTI)

A bipolar double-barrier resonant-tunneling light emitting diode will have maximum emitted light intensity if (1) electrons and holes simultaneously resonant-tunnel into the quantum well, (2) the charge carriers are entirely trapped in the well as the ... Keywords: Poisson equation, Schrodinger equation, automated computer code, bipolar double-barrier RTD structures, charge carriers, chemical compositions, doping profiles, electroluminescence, electroluminescence spectrum profile, electron-hole recombination, electron-hole recombination rate, geometric structures, light emitting diodes, near zero-field condition, optimisation, quantum well, resonant tunnelling diodes, resonant-tunneling LED, semiconductor device models, semiconductor quantum wells, temperature stability, theoretical modeling, thermal stability

A. Kindlihagen; K. A. Chao; M. Willander; J. Genoe

1995-11-01T23:59:59.000Z

176

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

SciTech Connect

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 “whitelight 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

177

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

178

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

179

The fabrication of small molecule organic light-emitting diode pixels by laser-induced forward transfer  

E-Print Network (OSTI)

The fabrication of small molecule organic light-emitting diode pixels by laser-induced forward online 23 January 2013) Laser-induced forward transfer (LIFT) is a versatile organic light-emitting diode, a modified LIFT process has been used to fabricate small molecule Alq3 organic light-emitting diodes (SMOLEDs

180

Sequential Printing by Laser-Induced Forward Transfer To Fabricate a Polymer Light-Emitting Diode Pixel  

E-Print Network (OSTI)

Sequential Printing by Laser-Induced Forward Transfer To Fabricate a Polymer Light-Emitting Diode-1015, Lausanne, Switzerland ABSTRACT: Patterned deposition of polymer light-emitting diode (PLED Organic light-emitting diodes (OLEDs) have been investigated in detail for nearly a quarter of a century,1

Note: This page contains sample records for the topic "white light emitting" 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

Red-green-blue polymer light-emitting diode pixels printed by optimized laser-induced forward transfer  

E-Print Network (OSTI)

Red-green-blue polymer light-emitting diode pixels printed by optimized laser-induced forward tri-color organic light-emitting diode (OLED) pixels. At reduced pressures, and with a defined donor already been used to fabricate basic small-molecule organic light-emitting diodes (OLEDs)2,3 and polymeric

182

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

E-Print Network (OSTI)

a profound effect on the external quantum efficiency of dye-doped organic light-emitting diodes employing Institute of Physics. DOI: 10.1063/1.1469692 I. INTRODUCTION Thin-film organic light-emitting diodes LEDsEffect of carbazole­oxadiazole excited-state complexes on the efficiency of dye-doped light-emitting

183

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

184

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.

185

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.

186

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.

187

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

188

Discrete Steps in the Capacitance-Voltage Characteristics of GaInN/GaN Light Emitting Diode Structures  

E-Print Network (OSTI)

Discrete Steps in the Capacitance-Voltage Characteristics of GaInN/GaN Light Emitting Diode and GaInN/GaN heterostructures typically used for high efficiency light emitting diodes is of high materials for green, blue, and UV light emitting diodes (LED) [1-2]. It is known that huge piezoelectric

Wetzel, Christian M.

189

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"

190

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

191

passivation of InGaN/GaN nanopillar light emitting diodes.  

E-Print Network (OSTI)

??Recently, InGaN/GaN based blue light emitting diodes (LEDs) have become widely available commercially, but their efficiency is reduced due to the quantum confined Stark effect… (more)

Choi, Won

2013-01-01T23:59:59.000Z

192

Physical properties and design of light-emitting devices based on organic materials and nanoparticles  

E-Print Network (OSTI)

This thesis presents the detailed experimental and theoretical characterization of light-emitting devices (LEDs) based on organic semiconductors and colloidal quantum dots (QDs). This hybrid material system has several ...

Anikeeva, Polina Olegovna

2009-01-01T23:59:59.000Z

193

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

194

Tailoring optical properties of light-emitting diodes by nanostructuring with nanospheres.  

E-Print Network (OSTI)

???III-V nitride based light-emitting diodes (LEDs) have experienced rapid developments during past decade, proving their potential to substitute conventional incandescent bulbs and fluorescent lamps to… (more)

??

2012-01-01T23:59:59.000Z

195

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

196

Aspects of charge recombination and charge transport in organic solar cells and light-emitting devices  

E-Print Network (OSTI)

In this thesis, aspects of charge reconbination and charge transport in organic solar cells and light-emitting devices are presented. These devices show promise relative to traditional inorganic semiconductors. We show ...

Difley, Seth

2010-01-01T23:59:59.000Z

197

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

198

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

199

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

200

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

Note: This page contains sample records for the topic "white light emitting" 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

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

202

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

203

Zinc Oxide and Nitride Nanowire Based Light Emitting Diodes  

E-Print Network (OSTI)

light sources have wasted emission and energy as can be seenor in other words, wasted electrical energy). Extraction

Lai, Elaine Michelle

2009-01-01T23:59:59.000Z

204

Red-Emitting Phosphors for Solid-State Lighting - Energy ...  

Exceeds traditional LED color quality; Improved energy efficiency; Applications and Industries. Electronics; Solid-state lighting; Photocatalysis; Ion Conducting ...

205

Photonic crystal laser lift-off GaN light-emitting diodes Aurlien David,a  

E-Print Network (OSTI)

Photonic crystal laser lift-off GaN light-emitting diodes Aurélien David,a Tetsuo Fujii,b Brendan March 2006 We report on the fabrication and study of laser lift-off GaN-based light-emitting diodes-state lighting. However, as is the case for any light-emitting diode LED , light tends to be trapped in the high

Recanati, Catherine

206

Green emitting phosphors and blends thereof  

DOE Patents (OSTI)

Phosphor compositions, blends thereof and light emitting devices including white light emitting LED based devices, and backlights, based on such phosphor compositions. The devices include a light source and a phosphor material as described. Also disclosed are phosphor blends including such a phosphor and devices made therefrom.

Setlur, Anant Achyut (Niskayuna, NY); Siclovan, Oltea Puica (Rexford, NY); Nammalwar, Prasanth Kumar (Bangalore, IN); Sathyanarayan, Ramesh Rao (Bangalore, IN); Porob, Digamber G. (Goa, IN); Chandran, Ramachandran Gopi (Bangalore, IN); Heward, William Jordan (Saratoga Springs, NY); Radkov, Emil Vergilov (Euclid, OH); Briel, Linda Jane Valyou (Niskayuna, NY)

2010-12-28T23:59:59.000Z

207

Assessment of Electrical, Efficiency, and Photometric Performance of Advanced Lighting Sources: Dimmable Advanced Lighting Technolog ies -- Electronic Light-Emitting Diode (LED) Fixtures, Lamps, and Drivers  

Science Conference Proceedings (OSTI)

This EPRI Technical Update addresses the dimming performance of light-emitting diode (LED) lighting. Chapter 1 provides a discussion of basic lighting control, the importance of considering power quality in lighting control, lighting control methods and parameters, and the advantages and future of lighting control. Chapter 2 addresses in more depth the dimming methods used in advanced lighting sources and controls for incandescent, fluorescent, high-intensity discharge (HID) and LED sources. Chapter 3 ad...

2008-12-19T23:59:59.000Z

208

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

Office of Science (SC) Website

Understanding Drooping Light Emitting Understanding Drooping Light Emitting Diodes CEEM Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights Highlight Archives News & Events Publications Contact BES Home 04.27.12 Understanding Drooping Light Emitting Diodes CEEM Print Text Size: A A A RSS Feeds FeedbackShare Page Scientific Achievement New calculations demonstrate that LED "droop" is dominated by multi-particle interactions. Droop occurs when increasing energy input does not produce proportionally more light. Significance and Impact Understanding "droop" may result in cheaper, more efficient LEDs; LEDs are more energy efficient, smaller, and longer-lived than incandescent lamps or fluorescent lighting. Research Details Atomistic first-principles calculations indicated that increasing amounts

209

Demonstration Assessment of Light-Emitting Diode (LED) Post-Top Lighting at Central Park in New York City  

SciTech Connect

A review of five post-top light-emitting diode (LED) pedestrian luminaires installed in New York City's Central Park for possible replacement to the existing metal halide post-top luminaire. This report reviews the energy savings potential and lighting delivered by the LED post-top luminaires.

Myer, Michael; Goettel, Russell T.; Kinzey, Bruce R.

2012-09-30T23:59:59.000Z

210

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

E-Print Network (OSTI)

), and Light-Emitting Diode (LED) Bulbs Seong-Rin Lim, Daniel Kang, Oladele A. Ogunseitan,,§ and Julie M sources with compact fluorescent lamp (CFL) and light-emitting diode (LED) bulbs that use about 70% and 85 lighting systems are transitioning from incandes- cent to compact fluorescent lamp (CFL) and light

Short, Daniel

211

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

SciTech Connect

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

212

Assessment of Electrical, Efficiency, and Photometric Performance of Advanced Lighting Technologies: Dimmable Advanced Lighting Tech nologies -- Electronic Fluorescent, High-Intensity Discharge, and Light-Emitting Diode  

Science Conference Proceedings (OSTI)

This EPRI Technical Report is a compilation of four technical updates that address the basic dimming performance of advanced lighting sources: EPRI report 1018476 for linear fluorescent ballasts, 1018477 for hot and cold cathode compact fluorescent lamps, 1018479 for electronic high-intensity discharge (HID) ballasts, and 1018480 for light-emitting diode (LED) lighting. Chapter 1 provides a discussion of basic lighting control, the importance of considering power quality in lighting control, lighting con...

2008-12-22T23:59:59.000Z

213

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

SciTech Connect

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

214

Solid-State Lighting: Standards Development for Solid-State Lighting  

NLE Websites -- All DOE Office Websites (Extended Search)

IES G-2, Guideline for the Application of General Illumination ("White") Light-Emitting Diode (LED) Technologies Provides lighting and design professionals with a general...

215

Probing nonequilibrium dynamics with white-light femtosecond pulses  

Science Conference Proceedings (OSTI)

Femtosecond pulsed lasers have become an invaluable tool for examining ultrafast nonequilibrium dynamics. With pulsewidths of a few hundred femtoseconds (fs) to less than 10 fs, these lasers can clearly provide unprecedented temporal resolution. By amplifying ultrashort laser pulses to sufficient levels of energy per pulse, it is possible to exploit the nonlinear optical properties of certain materials to generate extremely broadband pulses. These pulses retain the time structure of the incident pulse, but contain a spectral bandwidth extending from the infrared to as far as the ultraviolet. By generating white-light pulses, it becomes possible to probe ultrafast nonlinear processes over a large range of energies. In this paper, the process of generating white-light ultrashort pulses will be presented, along with a discussion of different probing techniques and procedures necessary for modeling the transient optical data. Finally, results from pump–probe measurements using a white-light probe on indium phosphide (InP) films will be presented as a demonstration of this technique.

John Klopf; Pam Norris

2007-05-01T23:59:59.000Z

216

A green-yellow emitting oxyfluoride solid solution phosphor Sr[subscript 2]Ba(AlO[subscript 4]F)[subscript 1;#8722;x](SiO[subscript 5])x:Ce[superscript 3+] for thermally stable, high color rendition solid state white lighting  

Science Conference Proceedings (OSTI)

A near-UV excited, oxyfluoride phosphor solid solution Sr{sub 1.975}Ce{sub 0.025}Ba(AlO{sub 4}F){sub 1-x}(SiO{sub 5}){sub x} has been developed for solid state white lighting applications. An examination of the host lattice, and the local structure around the Ce{sup 3+} activator ions through a combination of density functional theory, synchrotron X-ray and neutron powder diffraction and total scattering, and electron paramagnetic resonance, points to how chemical substitutions play a crucial role in tuning the optical properties of the phosphor. The maximum emission wavelength can be tuned from green ({lambda}{sub em} = 523 nm) to yellow ({lambda}{sub em} = 552 nm) by tuning the composition, x. Photoluminescent quantum yield is determined to be 70 {+-} 5% for some of the examples in the series. Excellent thermal properties were found for the x = 0.5 sample, with the photoluminescence intensity at 160 C only decreased to 82% of its room temperature value. Phosphor-converted LED devices fabricated using an InGaN LED ({lambda}{sub max} = 400 nm) exhibit high color rendering white light with R{sub a} = 70 and a correlated color temperature near 7000 K. The value of R{sub a} could be raised to 90 by the addition of a red component, and the correlated color temperature lowered to near 4000 K.

Denault, Kristin A.; George, Nathan C.; Paden, Sara R.; Brinkley, Stuart; Mikhailovsky, Alexander A.; Neuefeind, Jörg; DenBaars, Steven P.; Seshadri, Ram (UCSB); (ORNL)

2012-10-23T23:59:59.000Z

217

Improved property in organic light-emitting diode utilizing two Al/Alq3 layers  

Science Conference Proceedings (OSTI)

We reported on the fabrication of organic light-emitting devices (OLEDs) utilizing the two Al/Alq"3 layers and two electrodes. This novel green device with structure of Al(110nm)/tris(8-hydroxyquinoline) aluminum (Alq"3)(65nm)/Al(110nm)/Alq"3(50nm)/N,N'-dipheny1-N, ... Keywords: Emitting layer, OLEDS, Transporting layer

Chunlin Zhang; Su Liu; Fangcong Wang; Yong Zhang

2008-12-01T23:59:59.000Z

218

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

SciTech Connect

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

219

Amber LEDs for Solid-State Lighting: White light with unprecendented efficiencies  

NLE Websites -- All DOE Office Websites (Extended Search)

Amber LEDs for Solid-State Lighting: Amber LEDs for Solid-State Lighting: White light with unprecedented efficiencies Commercialization Webinar December 10, 2013 2 Agenda for Today's Webinar * Welcome/Logistics * Technology Overview * Commercialization Opportunity * Q&A 3 Presenters Yoriko Morita, PhD MBA licensing manager Kirstin Alberi, PhD inventor 4 Technology Overview * Background/Context * Limitations NREL's Technology Addresses o Substrate material o Efficiency o Manufacturing * Performance Testing Results * Summary of Benefits/Advantages NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. Amber LEDs for Solid-State Lighting: White light with unprecedented efficiencies

220

SciTech Connect: "light emitting diode"  

Office of Scientific and Technical Information (OSTI)

"light emitting diode" Find "light emitting diode" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office,

Note: This page contains sample records for the topic "white light emitting" 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

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

E-Print Network (OSTI)

??xiv, 81 leaves : ill. ; 30 cm HKUST Call Number: Thesis ECED 2007 Keung Matrix-addressable light emitting diode (LED) micro-arrays on sapphire substrates have… (more)

Keung, Chi Wing

2007-01-01T23:59:59.000Z

222

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

223

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

SciTech Connect

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

224

DC sputtered indium-tin oxide transparent cathode for organic light-emitting diodes  

E-Print Network (OSTI)

Abstract—The performance of top-emitting organic light-emitting diodes depends not just on the choice of the transparent cathodes but also on their techniques of formation. Compared to the damage induced by radio frequency sputtering of indium-tin oxide cathode, that induced by dc sputtering was verified to be less severe and relatively independent of the sputtering power. Consequently, a high dc sputtering power of 120 W could be employed to achieve a high deposition rate of 0.1 nm/s. Adequate emission efficiency was maintained, even with a relatively thin 7-nm copper (II) phthalocyanine buffer layer. Index Terms—Indium-tin oxide, organic light-emitting diodes, sputtering, top-emission, transparent cathode. I.

Haiying Chen; Chengfeng Qiu; Man Wong; Hoi Sing Kwok

2003-01-01T23:59:59.000Z

225

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

SciTech Connect

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

226

Ultra-thin ohmic contacts for p-type nitride light emitting devices  

DOE Patents (OSTI)

A semiconductor based Light Emitting Device (LED) can include a p-type nitride layer and a metal ohmic contact, on the p-type nitride layer. The metal ohmic contact can have an average thickness of less than about 25 .ANG. and a specific contact resistivity less than about 10.sup.-3 ohm-cm.sup.2.

Raffetto, Mark (Raleigh, NC); Bharathan, Jayesh (Cary, NC); Haberern, Kevin (Cary, NC); Bergmann, Michael (Chapel Hill, NC); Emerson, David (Chapel Hill, NC); Ibbetson, James (Santa Barbara, CA); Li, Ting (Ventura, CA)

2012-01-03T23:59:59.000Z

227

Measurements of the Cerenkov light emitted by a TeO2 crystal  

E-Print Network (OSTI)

Bolometers have proven to be good instruments to search for rare processes because of their excellent energy resolution and their extremely low intrinsic background. In this kind of detectors, the capability of discriminating alpha particles from electrons represents an important aspect for the background reduction. One possibility for obtaining such a discrimination is provided by the detection of the Cerenkov light which, at the low energies of the natural radioactivity, is only emitted by electrons. In this paper, the results of the analysis of the light emitted by a TeO2 crystal at room temperature when transversed by a cosmic ray are reported. Light is promptly emitted after the particle crossing and a clear evidence of its directionality is also found. These results represent a strong indication that Cerenkov light is the main, if not even the only, component of the light signal in a TeO2 crystal. They open the possibility to make large improvements in the performance of experiments based on this kind of materials

F. Bellini; N. Casali; I. Dafinei; M. Marafini; S. Morganti; F. Orio; D. Pinci; M. Vignati; C. Voena

2012-09-27T23:59:59.000Z

228

Current injection efficiency induced efficiency-droop in InGaN quantum well light-emitting diodes  

E-Print Network (OSTI)

Current injection efficiency induced efficiency-droop in InGaN quantum well light-emitting diodes]. The detail of the model for current injection model for quantum well heterostructure is described in Ref. [18 Keywords: III-Nitride InGaN QWs Light-emitting diodes Efficiency-droop a b s t r a c t Current injection

Gilchrist, James F.

229

Coupling Fibers to Semiconductor Sources To learn to couple an injection laser diode (ILD) and a light emitting diode  

E-Print Network (OSTI)

) and a light emitting diode (LED) to an optical fiber. Equipment: · 1 ~ 2 meters of F-MLD-50 multimode fiber off any other part of the circuit. Light Emitting Diode- 1.) Post mount the LED assembly the same way

Collins, Gary S.

230

Comparing Light-Emitting Diode (LED) Street and Area Lighting to Traditional Lighting Technologies: Assessing LED Performance at Gul f Power in Pensacola, Florida  

Science Conference Proceedings (OSTI)

Manufacturing advances have now made the use of light-emitting diode (LED) technology practical for street and area lighting. To better understand the application, the Electric Power research Institute (EPRI teamed with Southern Company and Gulf Power to install LED street lights at a demonstration site and measure the performance. The data showed several disadvantages such as a lower efficacy compared to traditional technology and lower immunity to electrical disturbances, but advantages in energy savin...

2012-04-21T23:59:59.000Z

231

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.

232

Highly Polarized Green Light Emitting Diode in m-Axis GaInN/GaN Shi You, Theeradetch Detchprohm, Mingwei Zhu  

E-Print Network (OSTI)

Highly Polarized Green Light Emitting Diode in m-Axis GaInN/GaN Shi You, Theeradetch Detchprohm in nonpolar light-emitting diodes (LEDs) covering the blue to green spectral range. In photo- luminescence, m's overall power efficiency. Linearly polarized light can be efficiently generated in GaInN/GaN-based light-emitting

Wetzel, Christian M.

233

Topology of "white" stars in relativistic fragmentation of light nuclei  

E-Print Network (OSTI)

In the present paper, experimental observations of the multifragmentation processes of light relativistic nuclei carried out by means of emulsions are reviewed. Events of the type of "white" stars in which the dissociation of relativistic nuclei is not accompanied by the production of mesons and the target-nucleus fragments are considered. A distinctive feature of the charge topology in the dissociation of the Ne, Mg, Si, and S nuclei is an almost total suppression of the binary splitting of nuclei to fragments with charges higher than 2. The growth of the nuclear fragmentation degree is revealed in an increase in the multiplicity of singly and doubly charged fragments with decreasing charge of the non-excited part of the fragmenting nucleus. The processes of dissociation of stable Li, Be, B, C, N, and O isotopes to charged fragments were used to study special features of the formation of systems consisting of the lightest $\\alpha$, d, and t nuclei. Clustering in form of the $^3$He nucleus can be detected in "white" stars via the dissociation of neutron-deficient Be, B, C, and N isotopes.

N. P. Andreeva; V. Bradnova; S. Vokal; A. Vokalova; A. Sh. Gaitinov; S. G. Gerasimov; L. A. Goncharova; V. A. Dronov; P. I. Zarubin; I. G. Zarubina; G. I. Orlova; A. D. Kovalenko; A. Kravchakova; V. G. Larionova; F. G. Lepekhin; O. V. Levitskaya; A. I. Malakhov; A. A. Moiseenko; G. I. Orlova; N. G. Peresadko; N. G. Polukhina; P. A. Rukoyatkin; V. V. Rusakova; N. A. Salmanova; V. R. Sarkisyan; B. B. Simonov; E. Stan; R. Stanoeva; M. M. Chernyavsky; M. Haiduc; S. P. Kharlamov; I. Tsakov; T. V. Shchedrina

2006-05-15T23:59:59.000Z

234

SciTech Connect: "light emitting diodes"  

Office of Scientific and Technical Information (OSTI)

light emitting diodes" Find light emitting diodes" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office, Atlanta, GA (United States) Atmospheric Radiation Measurement (ARM)

235

The use of LEDS (light-emitting diode) to simulate weak YAG-laser beams  

SciTech Connect

The purpose of this report is to determine whether and under what conditions a light-emitting diode may be used to simulate a weak YAG-laser beam that has been scattered by a distant reflecting object. By examining the differences between laser radiation and LED radiation, the author concludes that there is no theoretical reason that a LED may not be used in place of the laser beam.

Young, M.

1981-01-01T23:59:59.000Z

236

The Impact of the Transient Response of 0rg;anic Light Emitting Diodes on the Design of Active Matrix OLED Displays  

E-Print Network (OSTI)

The Impact of the Transient Response of 0rg;anic Light Emitting Diodes on the Design of Active, Princeton, NJ, U.S.A. Abstract Much of the organic light emitting diode (OLED) characterization published

237

Material system for tailorable white light emission and method for making thereof  

DOE Patents (OSTI)

A method of processing a composite material to tailor white light emission of the resulting composite during excitation. The composite material is irradiated with a predetermined power and for a predetermined time period to reduce the size of a plurality of nanocrystals and the number of a plurality of traps in the composite material. By this irradiation process, blue light contribution from the nanocrystals to the white light emission is intensified and red and green light contributions from the traps are decreased.

Smith, Christine A. (Livermore, CA); Lee, Howard W. H. (Fremont, CA)

2009-05-19T23:59:59.000Z

238

EFFECTIVENESS OF RED LIGHT CAMERAS A Texas Transportation Institute White Paper  

E-Print Network (OSTI)

1 EFFECTIVENESS OF RED LIGHT CAMERAS A Texas Transportation Institute White Paper By Brian Bochner and Troy Walden April 2010; corrected July 6, 2010 In This White Paper Background, education, and enforcement. This paper addresses only the enforcement component through use of red light

239

Demonstration Assessment of Light-Emitting Diode Parking Structure Lighting at U.S. Department of Labor Headquarters  

SciTech Connect

This report documents a solid-state lighting (SSL) technology demonstration at the parking structure of the U.S. Department of Labor (DOL) Headquarters in Washington, DC, in which light-emitting diode (LED) luminaires were substituted for the incumbent high-pressure sodium (HPS) luminaires and evaluated for relative light quantity and performance. The demonstration results show energy savings of 52% from the initial conversion of HPS to the LED product. These savings were increased to 88% by using occupancy sensor controls that were ultimately set to reduce power to 10% of high state operation after a time delay of 2.5 minutes. Because of the relatively high cost of the LED luminaires at their time of purchase for this project (2010), the simple payback periods were 6.5 years and 4.9 years for retrofit and new construction scenarios, respectively. Staff at DOL Headquarters reported high satisfaction with the operation of the LED product.

Kinzey, Bruce R.; Myer, Michael

2013-03-01T23:59:59.000Z

240

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.

Note: This page contains sample records for the topic "white light emitting" 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

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

242

Charge Profiling of the p-AlGaN Electron Blocking Layer in AlGaInN Light Emitting Diode Structures  

E-Print Network (OSTI)

Charge Profiling of the p-AlGaN Electron Blocking Layer in AlGaInN Light Emitting Diode Structures, U.S.A. ABSTRACT Characterization of operational AlGaInN heterostructure light emitting diodes (LEDs the device lifetime in a non-destructive mode. INTRODUCTION Group ­ III nitride light emitting diodes (LEDs

Wetzel, Christian M.

243

Solid-State Lighting Home Page for Semiconductor light emitting diodes  

NLE Websites -- All DOE Office Websites (Extended Search)

Since 04/21/2002 Since 04/21/2002 Solid-State Lighting Archival Website As of September 1, 2006, this website is not being actively maintained. We hope that the collected news items, tracking reports, literature summaries, and links to various industry resources will be of archival value to the SSL community. Please visit Sandia's current and active Solid-State Lighting Energy Frontier Research Center website at http://ssls.sandia.gov/. Solid-State Lighting Science Energy Frontier Research Center The Mission of this site was to provide a comprehensive portal to the emerging knowledge that will enable the promise of solid-state lighting The site was active between December 2001 and September 2006, and the goal was: " Â… to gather together information relevant to solid-state lighting, and

244

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

DOE Green Energy (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

245

X-RAY EMISSION FROM AN ASYMMETRIC BLAST WAVE AND A MASSIVE WHITE DWARF IN THE GAMMA-RAY EMITTING NOVA V407 Cyg  

SciTech Connect

Classical nova events in symbiotic stars, although rare, offer a unique opportunity to probe the interaction between ejecta and a dense environment in stellar explosions. In this work, we use X-ray data obtained with Swift and Suzaku during the recent classical nova outburst in V407 Cyg to explore such an interaction. We find evidence of both equilibrium and non-equilibrium ionization plasmas at the time of peak X-ray brightness, indicating a strong asymmetry in the density of the emitting region. Comparing a simple model to the data, we find that the X-ray evolution is broadly consistent with nova ejecta driving a forward shock into the dense wind of the Mira companion. We detect a highly absorbed soft X-ray component in the spectrum during the first 50 days of the outburst that is consistent with supersoft emission from the nuclear burning white dwarf. The high temperature and short turnoff time of this emission component, in addition to the observed breaks in the optical and UV light curves, indicate that the white dwarf in the binary is extremely massive. Finally, we explore the connections between the X-ray and GeV {gamma}-ray evolution, and propose that the gamma-ray turnoff is due to the stalling of the forward shock as the ejecta reach the red giant surface.

Nelson, Thomas; Donato, Davide; Mukai, Koji [CRESST and X-ray Astrophysics Laboratory NASA/GSFC, Greenbelt, MD 20771 (United States); Sokoloski, Jennifer [Columbia Astrophysics Laboratory, 550 W. 220th Street, 1027 Pupin Hall, Columbia University, New York, NY 10027 (United States); Chomiuk, Laura, E-mail: tnelson@physics.umn.ed [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-03-20T23:59:59.000Z

246

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.

247

The synthesis of inorganic semiconductor nanocrystalline materials for the purpose of creating hybrid organic/inorganic light-emitting devices  

E-Print Network (OSTI)

Colloidal semiconductor nanocrystals (NCs) or quantum dots (QDs) can be synthesized to efficiently emit light from the ultraviolet, across the entire visible spectrum, and into the near infrared. This is now possible due ...

Steckel, Jonathan S. (Jonathan Stephen)

2006-01-01T23:59:59.000Z

248

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

SciTech Connect

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

249

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

SciTech Connect

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

250

White Dwarf Light Curves: Constraining Convection and Mode Identification Using Non-sinusoidal Light Curves  

E-Print Network (OSTI)

In this paper we show how the formalism of Wu & Goldreich developed for weakly nonlinear white dwarf pulsations can be extended to the fully nonlinear case. Due to the computational simplification this affords over the simulations of Brickhill (1992) and Ising & Koester (2001), we are able to obtain the first ever fits of observed light curves. These fits allow us to obtain not only mode identifications but also to constrain the average depth of the convection zone and its sensitivity to changes in effective temperature. We are thus able to probe the fundamental physics of convection in these objects.

M. H. Montgomery

2004-11-14T23:59:59.000Z

251

AlGaInN-based light emitting diodes with a transparent p-contact based on thin ITO films  

SciTech Connect

A method for obtaining transparent conductive ITO (indium-tin oxide) films aimed for use in light emitting diodes of the blue spectral range is developed. The peak external quantum efficiency of light-emitting diodes with a p-contact based on the obtained films reaches 25%, while for similar light-emitting diodes with a standard semitransparent metal contact, it is <10%. An observed increase in the direct voltage drop from 3.15 to 3.37 V does not significantly affect the possibility of applying these films in light-emitting diodes since the optical power of light-emitting diodes with a transparent p-contact based on ITO films exceeds that of chips with metal semitransparent p-contacts with a working current of 20 mA by a factor of almost 2.5. Light-emitting diodes with p-contacts based on ITO films successfully withstand a pumping current that exceeds their calculated working current by a factor of 5 without the appearance of any signs of degradation.

Smirnova, I. P., E-mail: irina@quantum.ioffe.ru; Markov, L. K.; Pavlyuchenko, A. S. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Kukushkin, M. V. [ZAO Innovation Company 'TETIS' (Russian Federation)

2012-03-15T23:59:59.000Z

252

Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes  

SciTech Connect

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

253

Manipulating Lasers A laser is a very special kind of light. For example, light from a laser is emitted in only one  

E-Print Network (OSTI)

Manipulating Lasers A laser is a very special kind of light. For example, light from a laser is emitted in only one direction, in contrast to other sources, such as incandescent bulbs, in which different directions occur. Lasers can contain one or different colors combined, like sun light. It can even

Dantus, Marcos

254

Manganese-doped indium oxide and its application in organic light-emitting diodes  

SciTech Connect

Thin films of manganese-doped indium oxide (IMO) deposited by electron beam evaporation have been investigated as anodes in organic light-emitting diodes (OLEDs). The IMO films have a high work function of 5.35 eV, a desirable surface morphology with an average roughness of 1.1 nm, a high average optical transmittance of 87.2% in the visible region, and a maximum optical transmittance of 92% at 460 nm. It is demonstrated that an IMO anode can effectively improve hole injection at the anode/organic interface, resulting in OLEDs with an increased electroluminescent efficiency.

Liao Yaqin [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Graduate School of Chinese Academy of Sciences, Beijing 100080 (China); Lu Qipeng; Fan Yi; Liu Xingyuan [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

2011-07-11T23:59:59.000Z

255

Design of an efficient light-emitting diode with 10 GHz modulation bandwidth  

Science Conference Proceedings (OSTI)

We present a high-speed light-emitting-diode (LED) design for efficient modulation at speeds higher than 10 GHz. It relies on a tensile-strain GaAsPquantum well coupled with surface plasmon polaritons on a silversurface. We present optical pumping experiments showing a tenfold reduction in carrier lifetime when the quantum well is located 40 nm above the silversurface. We believe this represents the first step toward an efficient LED compatible with 10 GHz modulation speed for use in short distance optical communication systems.

D. Fattal; M. Fiorentino; M. Tan; D. Houng; S. Y. Wang; Raymond G. Beausoleil

2008-01-01T23:59:59.000Z

256

Process development for the fabrication of light emitting vacuum field emission triodes  

E-Print Network (OSTI)

In order to be widely accepted by industry, the field of vacuum microelectronics is in need of a highly manufacturable and integrable device. A vacuum diode meeting these requirements has been developed at Texas A&M University by Weichold, et al. Legg has extended the diode structure by designing a vacuum triode. This work deals with development of a process for fabricating the triode structure using current microelectronic processing techniques. Subsequently, triodes are fabricated for testing. Light emitting diodes and triodes are also fabricated to address the feasibility of their application to flat panel displays.

Williams, Roger T.

1994-01-01T23:59:59.000Z

257

Novel phosphors for solid state lighting  

E-Print Network (OSTI)

Solid state white light emitting diode lighting devices outperform conventional light sources in terms of lifetime, durability, and lumens per watt. However, the capital contribution is still to high to encourage widespread adoption. Furthermore...

Furman, Joshua D

2010-11-16T23:59:59.000Z

258

Detection of Single Molecules Illuminated by a Light-Emitting Diode  

E-Print Network (OSTI)

Optical detection and spectroscopy of single molecules has become an indispensable tool in biological imaging and sensing. Its success is based on fluorescence of organic dye molecules under carefully engineered laser illumination. In this paper we demonstrate optical detection of single molecules on a wide-field microscope with an illumination based on a commercially available, green light-emitting diode. The results are directly compared with laser illumination in the same experimental configuration. The setup and the limiting factors, such as light transfer to the sample, spectral filtering and the resulting signal-to-noise ratio are discussed. A theoretical and an experimental approach to estimate these parameters are presented. The results can be adapted to other single emitter and illumination schemes.

Ilja Gerhardt; Lijian Mai; Antia Lamas-Linares; Christian Kurtsiefer

2011-01-14T23:59:59.000Z

259

Low Power, Red, Green and Blue Carbon Nanotube Enabled Vertical Organic Light Emitting Transistors for Active Matrix OLED Displays  

SciTech Connect

Organic semiconductors are potential alternatives to polycrystalline silicon as the semiconductor used in the backplane of active matrix organic light emitting diode displays. Demonstrated here is a light-emitting transistor with an organic channel, operating with low power dissipation at low voltage, and high aperture ratio, in three colors: red, green and blue. The single-wall carbon nanotube network source electrode is responsible for the high level of performance demonstrated. A major benefit enabled by this architecture is the integration of the drive transistor, storage capacitor and light emitter into a single device. Performance comparable to commercialized polycrystalline-silicon TFT driven OLEDs is demonstrated.

McCarthy, M. A. [University of Florida, Gainesville; Liu, B. [University of Florida, Gainesville; Donoghue, E. P. [University of Florida, Gainesville; Kravchenko, Ivan I [ORNL; Kim, D. Y. [University of Florida, Gainesville; So, Franky [University of Florida, Gainesville; Rinzler, A. G. [University of Florida, Gainesville

2011-01-01T23:59:59.000Z

260

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

E-Print Network (OSTI)

Stewart Craine collected the LED samples in Shenzen, China4. Variation in efficacy of LEDs tested. Figure 5. Figure 6.Performance of 5mm White LED Light Sources for Developing-

Mills, Evan

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

A novel white-light scanning interferometer for absolute nano-scale gap thickness measurement  

E-Print Network (OSTI)

This paper presents a special configuration of white-light scanning interferometer, in which the measured gap is not located in any interference arm of the interferometer, but acts as an amplitude-and-phase modulator of ...

Xu, Zhiguang

262

White-light scanning interferometer for absolute nano-scale gap thickness measurement  

E-Print Network (OSTI)

A special configuration of white-light scanning interferometer is described for measuring the absolute air gap thickness between two planar plates brought into close proximity. The measured gap is not located in any ...

Xu, Zhiguang

263

Green route synthesis of high quality CdSe quantum dots for applications in light emitting devices  

SciTech Connect

Investigation was made on light emitting diodes fabricated using CdSe quantum dots. CdSe quantum dots were synthesized chemically using olive oil as the capping agent, instead of toxic phosphine. Room temperature photoluminescence investigation showed sharp 1st excitonic emission peak at 568 nm. Bi-layer organic/inorganic (P3HT/CdSe) hybrid light emitting devices were fabricated by solution process. The electroluminescence study showed low turn on voltage ({approx}2.2 V) .The EL peak intensity was found to increase by increasing the operating current. - Graphical abstract: Light emitting diode was fabricated using CdSe quantum dots using olive oil as the capping agent, instead of toxic phosphine. Bi-layer organic/inorganic (P3HT/CdSe) hybrid light emitting device shows strong electroluminescence in the range 630-661 nm. Highlights: Black-Right-Pointing-Pointer CdSe Quantum dots were synthesized using olive oil as the capping agent. Black-Right-Pointing-Pointer Light emitting device was fabricated using CdSe QDs/P3HT polymer heterojunction. Black-Right-Pointing-Pointer The I-V characteristics study showed low turn on voltage at {approx}2.2 V. Black-Right-Pointing-Pointer The EL peak intensity increases with increasing the operating current.

Bera, Susnata, E-mail: susnata.bera@gmail.com [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Singh, Shashi B. [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Ray, S.K., E-mail: physkr@phy.iitkgp.ernet.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

2012-05-15T23:59:59.000Z

264

Light output enhancement of InGaN/GaN light-emitting diodes with contrasting indium tin-oxide nanopatterned structures  

Science Conference Proceedings (OSTI)

Various nanopatterns on the transparent conducting indium tin oxide (ITO) layer are investigated to enhance the light extraction efficiency of the InGaN/GaN light-emitting diodes (LEDs). Triangular, square, and circular nanohole patterns with the square ...

Sang Hyun Jung, Keun Man Song, Young Su Choi, Hyeong-Ho Park, Hyun-Beom Shin, Ho Kwan Kang, Jaejin Lee

2013-01-01T23:59:59.000Z

265

Highly efficient blue organic light emitting devices with indium-free transparent anode on flexible substrates  

Science Conference Proceedings (OSTI)

Indium-free transparent conducting oxides may provide a lower cost solution for the transparent anode in flexible displays and energy efficient solid state lighting. We report herein a near room temperature sputtering process for generating an indium-free transparent conductive oxide (TCO) coating on a flexible substrate. Specifically, we deposited gallium-doped zinc oxide (GZO) uniformly over a 12” diameter area at room temperature on polyethylene terephthalate (PET). During deposition, the system heats to about 60oC due to the energetic sputtering conditions, without any noticeable damage to the PET substrate. The GZO films exhibit excellent physical, optical and electrical properties: roughness ~7 nm, transmittance >85% and resistivity ~ 10-3 ohm• cm. Phosphorescent blue organic light-emitting devices (OLEDs) were fabricated on these substrates with comparable performance (16% external quantum efficiency and 33 lm/W power efficiency at 1mA/cm2) to that of devices fabricated on GZO (or ITO) deposited on glass substrates, suggesting flexible GZO/PET substrates may be used instead of high-cost and rigid ITO and glass for flexible displays and solid state lighting.

Wang, Liang; Swensen, James S.; Polikarpov, Evgueni; Matson, Dean W.; Bonham, Charles C.; Bennett, Wendy D.; Gaspar, Daniel J.; Padmaperuma, Asanga B.

2010-09-30T23:59:59.000Z

266

Growth condition dependence of spin-polarized electroluminescence in Fe/MgO/light-emitting diodes  

SciTech Connect

We compared the electroluminescence (EL) polarization of two Fe/MgO/light-emitting-diode (LED) structures grown at different substrate temperatures for MgO growth: room temperature and 400 deg. C. Two spin-LED wafers were prepared on molecular beam epitaxy grown LEDs by e-beam evaporation: one was LED/MgO (RT)/Fe (RT)/Au cap (RT), and the other was LED/MgO (400 deg. C)/Fe (150 deg. C)/Au cap (90 deg. C). Spin-polarized EL was clearly observed in the latter sample, while the EL polarization was hardly observed in the former sample. The reasons for the near absence of EL polarization in the former sample are considered to be the degradation of the tunneling junction resulting from the crystallinity and the As-rich surface of the LED.

Manago, Takashi; Sinsarp, Asawin; Akinaga, Hiro [Department of Electronics and Computer Science, Tokyo University of Science, Yamaguchi, 1-1-1 Daigaku-Dori, Sanyo-Onoda, Yamaguchi 756-0884 (Japan); Nanotechnology Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

2007-10-15T23:59:59.000Z

267

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

268

Using light emitting diode arrays as touchsensitive input and output devices  

E-Print Network (OSTI)

Light Emitting Diodes (LEDs) offer long life, low cost, efficiency, brightness, and a full range of colors. Because of these properties, they are widely used for simple displays in electronic devices. A previously characterized, but little known property of LEDs allows them to be used as photo sensors. In this paper, we show how this capability can be used to turn unmodified, off the shelf, LED arrays into touch sensitive input devices (while still remaining capable of producing output). The technique is simple and requires little or no extra hardware – in some cases operating with the same micro-controller based circuitry normally used to produce output, requiring only software changes. We will describe a simple hybrid input/output device prototype implemented with this technique, and discuss the design opportunities that this type of device opens up. Categories and Subject Descriptors:

Scott E. Hudson

2004-01-01T23:59:59.000Z

269

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

Science Conference Proceedings (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

270

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

SciTech Connect

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

271

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.

272

IntenCity - 2 Solid State Outdoor Luminaire SL-3200 High Output LED Street Light  

Science Conference Proceedings (OSTI)

The product under assessment is an advanced lighting technology8212a solid state outdoor luminarie light emitting diode (LED) street lighting system designed to provide various levels of direct white light.

2008-06-12T23:59:59.000Z

273

Efficient and Color-Tunable Oxyfluoride Solid Solution Phosphors for Solid-State White Lighting  

Science Conference Proceedings (OSTI)

A solid solution strategy helps increase the efficiency of Ce{sup 3+} oxyfluoride phosphors for solid-state white lighting. The use of a phosphor-capping architecture provides additional light extraction. The accompanying image displays electroluminescence spectra from a 434-nm InGaN LED phosphor that has been capped with the oxyfluoride phosphor.

Im, Won Bin; George, Nathan; Kurzman, Joshua; Brinkley, Stuart; Mikhailovsky, Alexander; Hu, Jerry; Chmelka, Bradley F.; DenBaars, Steven P.; Seshadri, Ram (UCSB)

2012-09-06T23:59:59.000Z

274

The Electric and Optical Properties of Doped Small Molecular Organic Light-Emitting Devices  

SciTech Connect

Organic light-emitting devices (OLEDs) constitute a new and exciting emissive display technology. In general, the basic OLED structure consists of a stack of fluorescent organic layers sandwiched between a transparent conducting-anode and metallic cathode. When an appropriate bias is applied to the device, holes are injected from the anode and electrons from the cathode; some of the recombination events between the holes and electrons result in electroluminescence (EL). Until now, most of the efforts in developing OLEDs have focused on display applications, hence on devices within the visible range. However some organic devices have been developed for ultraviolet or infrared emission. Various aspects of the device physics of doped small molecular OLEDs were described and discussed. The doping layer thickness and concentration were varied systematically to study their effects on device performances, energy transfer, and turn-off dynamics. Low-energy-gap DCM2 guest molecules, in either {alpha}-NPD or DPVBi host layers, are optically efficient fluorophores but also generate deep carrier trap-sites. Since their traps reduce the carrier mobility, the current density decreases with increased doping concentration. At the same time, due to efficient energy transfer, the quantum efficiency of the devices is improved by light doping or thin doping thickness, in comparison with the undoped neat devices. However, heavy doping induces concentration quenching effects. Thus, the doping concentration and doping thickness may be optimized for best performance.

Kwang-Ohk Cheon

2003-08-05T23:59:59.000Z

275

Supporting the Next Generation of White Lighting Technology  

NLE Websites -- All DOE Office Websites (Extended Search)

per watt, it will be possible to achieve a low- cost LED competitive with incandescent light bulbs. We think it will take a ten-year sustained R&D investment to reach 160 lumens...

276

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

SciTech Connect

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

277

Effects of extending the light phase on diapause induction in a ...  

Science Conference Proceedings (OSTI)

white light emitting diode (LED) (NSPW500BS; Nichia Co., Tokushima, Japan) that was wired to externally mounted time switches (TB23; Matsushita Electric ...

278

Optimized Phosphors for Warm White LED Light Engines  

Science Conference Proceedings (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

279

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

SciTech Connect

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

280

N-polar III-nitride quantum well light-emitting diodes with polarization-induced doping  

Science Conference Proceedings (OSTI)

Nitrogen-polar III-nitride heterostructures present unexplored advantages over Ga(metal)-polar crystals for optoelectronic devices. This work reports N-polar III-nitride quantum-well ultraviolet light-emitting diodes grown by plasma-assisted molecular beam epitaxy that integrate polarization-induced p-type doping by compositional grading from GaN to AlGaN along N-face. The graded AlGaN layer simultaneously acts as an electron blocking layer while facilitating smooth injection of holes into the active region, while the built-in electric field in the barriers improves carrier injection into quantum wells. The enhanced doping, carrier injection, and light extraction indicate that N-polar structures have the potential to exceed the performance of metal-polar ultraviolet light-emitting diodes.

Verma, Jai; Simon, John; Protasenko, Vladimir; Kosel, Thomas; Xing, Huili Grace; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)

2011-10-24T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

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

282

An Engineering-Economic Analysis of White Light-Emitting Diodes...  

NLE Websites -- All DOE Office Websites (Extended Search)

bulbs by the end of this decade. However, a large literature indicates that households do not make their decisions using pure engineering-economic evaluations. We compare...

283

Development of InAsSb-based light emitting diodes for chemical sensing systems  

SciTech Connect

Mid-infrared (3--6 {micro}m) LED`s are being developed for use in chemical sensor systems. As rich, InAsSb heterostructures are particularly suited for optical emitters in the mid-infrared region. The authors are investigating both InAsSb-InAs multiple quantum well (MQW) and InAsSb-InAsP strained layer superlattice (SLS) structures for use as the active region for light emitting diodes (LED`s). The addition of phosphorus to the InAs barriers increases the light and heavy hole splitting and hence reduces non-radiative Auger recombination and provides for better electron and hole confinement in the InAsSb quantum well. Low temperature (< 20 K) photoluminescence (PL) emission from MQW structures is observed between 3.2 to 6.0 {micro}m for InAsSb wells between 70 to 100 {angstrom} and antimony mole fractions between 0.04 to 0.18. Room temperature PL has been observed to 6.4 {micro}m in MQW structures. The additional confinement by InAsP barriers results in low temperature PL being observed over a narrower range (3.2 to 5.0 {micro}m) for the similar well thicknesses with antimony mole fractions between 0.10 to 0.24. Room temperature photoluminescence was observed to 5.8 {micro}m in SLS structures. The addition of a p-AlAsSb layer between the n-type active region (MQW or SLS) and a p-GaAsSb contact layer improves electron confinement of the active region and increases output power by a factor of 4. Simple LED emitters have been fabricated which exhibit an average power at room temperature of > 100 {micro}W at 4.0 {micro}m for SLS active regions. These LED`s have been used to detect CO{sub 2} concentrations down to 24 ppm in a first generation, non-cryogenic sensor system. They will report on the development of novel LED device designs that are expected to lead to further improvements in output power.

Allerman, A.A.; Kurtz, S.R.; Biefeld, R.M.; Baucom, K.C.; Burkhatt, J.H.

1998-02-01T23:59:59.000Z

284

nature materials | VOL 3 | SEPTEMBER 2004 | www.nature.com/naturematerials 601 ince 1993, InGaN light-emitting diodes (LEDs) have been  

E-Print Network (OSTI)

not fulfilled their original promise as solid-state replacements for light bulbs as their light, InGaN light-emitting diodes (LEDs) have been improved and commercialized1,2 , but these devices have and the spontaneous emissionrateinthesemiconductor3­9 ,andleadtotheenhancementof light emission by SP­QW coupling10

Okamoto, Koichi

285

Investigation of an Electromagnetic Interference (EMI) Problem Involving Light-Emitting Diode Streetlights and an Amateur Radio Tran sceiver  

Science Conference Proceedings (OSTI)

Any type of electronic device is susceptible to energy from the electromagnetic environment. This technical update describes an investigation of electromagnetic interference (EMI) problems associated with amateur radio, distribution hardware, and streetlights at a customer's home in Camden, Tennessee. Because light-emitting diode (LED) streetlights were deemed the direct cause of the EMI problem, an investigational plan involving a two-level effort was customized to fit the situation. First, field observ...

2011-10-06T23:59:59.000Z

286

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

SciTech Connect

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

287

Rapid Microwave Preparation of Highly Efficient Ce[superscript 3+]-Substituted Garnet Phosphors for Solid State White Lighting  

SciTech Connect

Ce{sup 3+}-substituted aluminum garnet compounds of yttrium (Y{sub 3}Al{sub 5}O{sub 12}) and lutetium (Lu{sub 3}Al{sub 5}O{sub 12}) - both important compounds in the generation of (In,Ga)N-based solid state white lighting - have been prepared using a simple microwave heating technique involving the use of a microwave susceptor to provide the initial heat source. Carbon used as the susceptor additionally creates a reducing atmosphere around the sample that helps stabilize the desired luminescent compound. High quality, phase-pure materials are prepared within a fraction of the time and using a fraction of the energy required in a conventional ceramic preparation; the microwave technique allows for a reduction of about 95% in preparation time, making it possible to obtain phase pure, Ce{sup 3+}-substituted garnet compounds in under 20 min of reaction time. It is estimated that the overall reduction in energy compared with ceramic routes as practiced in the lab is close to 99%. Conventionally prepared material is compared with material prepared using microwave heating in terms of structure, morphology, and optical properties, including quantum yield and thermal quenching of luminescence. Finally, the microwave-prepared compounds have been incorporated into light-emitting diode 'caps' to test their performance characteristics in a real device, in terms of their photon efficiency and color coordinates.

Birkel, Alexander; Denault, Kristin A.; George, Nathan C.; Doll, Courtney E.; Héry, Bathylle; Mikhailovsky, Alexander A.; Birkel, Christina S.; Hong, Byung-Chul; Seshadri, Ram (UCSB); (Mitsubishi)

2012-04-30T23:59:59.000Z

288

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

SciTech Connect

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

289

2002 Archived Selected Headlines of Solid-State Lighting Headlines...  

NLE Websites -- All DOE Office Websites (Extended Search)

has applied for WIPO protection for a garnet phosphor for converting UV and blue LED light to white light. A device incorporating a UV LED and the garnet phosphor emits at 490...

290

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

Science Conference Proceedings (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

291

Detecting indentations on documents pressed by pen tip force using a near infrared light emitting diode (NIR LED) and shape from shading  

Science Conference Proceedings (OSTI)

We proposed the new method that detected indentations pressed by pen tip force on paper using an oblique near infrared (NIR) emitting by light emitting diodes (LEDs). According to conventional methods indentations were observed by document examiners' ... Keywords: NIR LED, handwriting, indentations, shape from shading

Takeshi Furukawa

2010-11-01T23:59:59.000Z

292

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

293

Integrated optics for astronomical interferometry. II. First laboratory white-light interferograms  

E-Print Network (OSTI)

We report first white-light interferograms obtained with an integrated optics beam combiner on a glass plate. These results demonstrate the feasability of single-mode interferometric beam combination with integrated optics technology presented and discussed in paper I. The demonstration is achieved in laboratory with off-the-shelves components coming from micro-sensor applications, not optimized for astronomical use. These two-telescope beam combiners made by ion exchange technique on glass substrate provide laboratory white-light interferograms simultaneously with photometric calibration. A dedicated interferometric workbench using optical fibers is set up to characterize these devices. Despite the rather low match of the component parameters to astronomical constraints, we obtain stable contrasts higher than 93% with a 1.54-\\micron laser source and up to 78% with a white-light source in the astronomical H band. Global throughput of 27% for a potassium ion exchange beam combiner and of 43% for a silver one are reached. This work validates our approach for combining several stellar beams of a long baseline interferometer with integrated optics components.

J. -P. Berger; K. Rousselet-Perraut; P. Kern; F. Malbet; I. Schanen-Duport; F. Reynaud; P. Haguenauer; P. Benech

1999-07-02T23:59:59.000Z

294

Metal-assisted electroless fabrication of nanoporous p-GaN for increasing the light extraction efficiency of light emitting diodes  

SciTech Connect

We report metal-assisted electroless fabrication of nanoporous p-GaN to improve the light extraction efficiency of GaN-based light emitting diodes (LEDs). Although it has long been believed that p-GaN cannot be etched at room temperature, in this study we find that Ag nanocrystals (NCs) on the p-GaN surface enable effective etching of p-GaN in a mixture of HF and K{sub 2}S{sub 2}O{sub 8} under ultraviolet (UV) irradiation. It is further shown that the roughened GaN/air interface enables strong scattering of photons emitted from the multiple quantum wells (MQWs). The light output power measurements indicate that the nanoporous LEDs obtained after 10 min etching show a 32.7% enhancement in light-output relative to the conventional LEDs at an injection current of 20 mA without significant increase of the operating voltage. In contrast, the samples etched for 20 min show performance degradation when compared with those etched for 10 min, this is attributed to the current crowding effect and increased surface recombination rate.

Wang Ruijun; Liu Duo; Zuo Zhiyuan; Yu Qian; Feng Zhaobin; Xu Xiangang [State Key Laboratory of Crystal Materials, Shandong University, 27 South Shanda Road, Jinan, Shandong 250100 (China)

2012-03-15T23:59:59.000Z

295

MoO3 as combined hole injection layer and tapered spacer in combinatorial multicolor microcavity organic light emitting diodes  

SciTech Connect

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

296

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

297

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

298

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

299

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

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

300

Emitting Diode (LED) Fixture Design and Installation Criteria for Exterior Lighting Applications in Contingency Environments  

E-Print Network (OSTI)

1. Purpose. This ETL provides technical guidance and criteria for specifying, designing, and installing solar LED luminaire exterior lighting applications at Air Force overseas contingency locations only. For the purposes of this ETL, “contingency locations ” are defined as locations where a “named ” operation is the primary mission and the location utilizes expeditionary equipment for all or some of the support facilities in use. Requirements in this ETL are mandatory. Deviations require approval from the Air Force Electrical Engineering subject matter expert (SME), AFCESA/CEOA. Requests for deviations must be coordinated through the major command (MAJCOM) before submitting to AFCESA/CEOA. 2. Application. This ETL does not apply to LED airfield lighting systems, including, but not limited to, taxiway, obstruction, runway edge, threshold, or approach lighting systems

unknown authors

2012-01-01T23:59:59.000Z

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301

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

SciTech Connect

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

302

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

SciTech Connect

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

303

ZnO light-emitting diode grown by plasma-assisted metal organic chemical vapor deposition  

SciTech Connect

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

304

The use of short-period InGaN/GaN superlattices in blue-region light-emitting diodes  

SciTech Connect

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

305

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

306

Improving light output power of InGaN-based light emitting diodes with pattern-nanoporous p-type GaN:Mg surfaces  

SciTech Connect

InGaN-based light emitting diodes (LEDs) with a top pattern-nanoporous p-type GaN:Mg surface were fabricated by using a photoelectrochemical (PEC) process. The peak wavelengths of electroluminescence (EL) and operating voltages were measured as 461.2 nm (3.1 V), 459.6 nm (9.2 V), and 460.1 nm (3.3 V) for conventional, nanoporous, and pattern-nanoporous LEDs using 20 mA operation current. The EL spectrum of the nanoporous LED had a larger blueshift phenomenon as a result of a partial compression strain release in the InGaN active layer through the formation of a top nanoporous surface. The light output power had 12.1% and 26.4% enhancements for the nanoporous and the pattern-nanoporous LEDs compared with conventional LEDs. The larger operating voltage of the nanoporous LED was due to the non-ohmic contact on the PEC treated p-type GaN:Mg surface. By using a pattern-nanoporous p-type GaN:Mg structure, the operating voltage of the pattern-nanoporous LED was reduced to 3.3 V. A lower compression strain in the InGaN active layer and a higher light extraction efficiency at the top nanoporous surface were observed in pattern-nanoporous LEDs for higher efficiency nitride-based LED applications.

Yang, C.C.; Lin, C.F.; Lin, C.M.; Chang, C.C.; Chen, K.T.; Chien, J.F.; Chang, C.Y. [Department of Materials Engineering, National Chung Hsing University, Taichung 402, Taiwan (China)

2008-11-17T23:59:59.000Z

307

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

SciTech Connect

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

308

Efficiency Improvement of Nitride-Based Solid State Light Emitting Materials -- CRADA Final Report  

SciTech Connect

The development of In{sub x}Ga{sub 1-x} N/GaN thin film growth by Molecular Beam Epitaxy has opened a new route towards energy efficient solid-state lighting. Blue and green LED's became available that can be used to match the whole color spectrum of visible light with the potential to match the eye response curve. Moreover, the efficiency of such devices largely exceeds that of incandescent light sources (tungsten filaments) and even competes favorably with lighting by fluorescent lamps. It is, however, also seen in Figure 1 that it is essential to improve on the luminous performance of green LED's in order to mimic the eye response curve. This lack of sufficiently efficient green LED's relates to particularities of the In{sub x}Ga{sub 1-x}N materials system. This ternary alloy system is polar and large strain is generated during a lattice mismatched thin film growth because of the significantly different lattice parameters between GaN and InN and common substrates such as sapphire. Moreover, it is challenging to incorporate indium into GaN at typical growth temperatures because a miscibility gap exists that can be modified by strain effects. As a result a large parameter space needs exploration to optimize the growth of In{sub x}Ga{sub 1-x}N and to date it is unclear what the detailed physical processes are that affect device efficiencies. In particular, an inhomogeneous distribution indium in GaN modifies the device performance in an unpredictable manner. As a result technology is pushed forward on a trial and error basis in particular in Asian countries such as Japan and Korea, which dominate the market and it is desirable to strengthen the competitiveness of the US industry. This CRADA was initiated to help Lumileds Lighting/USA boosting the performance of their green LED's. The tasks address the distribution of the indium atoms in the active area of their blue and green LED's and its relation to internal and external quantum efficiencies. Procedures to measure the indium distribution with near atomic resolution were developed and applied to test samples and devices that were provided by Lumilids. Further, the optical performance of the device materials was probed by photoluminescence, electroluminescence and time resolved optical measurements. Overall, the programs objective is to provide a physical basis for the development of a simulation program that helps making predictions to improve the growth processes such that the device efficiency can be increased to about 20%. Our study addresses all proposed aspects successfully. Carrier localization, lifetime and recombination as well as the strain-induced generation of electric fields were characterized and modeled. Band gap parameters and their relation to the indium distribution were characterized and modeled. Electron microscopy was developed as a unique tool to measure the formation of indium clusters on a nanometer length scale and it was demonstrated that strain induced atom column displacements can reliably be determined in any materials system with a precision that approaches 2 pm. The relation between the local indium composition x and the strain induced lattice constant c(x) in fully strained In{sub x}Ga{sub 1-x}N quantum wells was found to be: c(x) = 0.5185 + {alpha}x with {alpha} = 0.111 nm. It was concluded that the local indium concentration in the final product can be modulated by growth procedures in a predictable manner to favorably affect external quantum efficiencies that approached target values and that internal quantum efficiencies exceeded them.

Kisielowski, Christian; Weber, Eicke

2010-05-13T23:59:59.000Z

309

Demonstration of a Tunable-Bandwidth White Light Interferometer using Anomalous Dispersion in Atomic Vapor  

E-Print Network (OSTI)

Recently, the design of a white-light-cavity has been proposed using negative dispersion in an intra-cavity medium to make the cavity resonate over a large range of frequencies and still maintain a high cavity build-up. This paper presents the demonstration of this effect in a free-space cavity. The negative dispersion of the intra-cavity medium is caused by bi-frequency Raman gain in an atomic vapor cell. A significantly broad cavity response over a bandwidth greater than 20 MHz has been observed. The experimental results agree well with the theoretical model, taking into account effects of residual absorption. A key application of this device would be in enhancing the sensitivity-bandwidth product of the next generation gravitational wave detectors that make use of the so-called signal-recycling mirror.

G. S. Pati; M. Salit; K. Salit; M. S. Shahriar

2006-10-04T23:59:59.000Z

310

Light-Emitting Tag Testing in Conjunction with Testing of the Minimum Gap Runner Turbine Design at Bonneville Dam Powerhouse 1  

DOE Green Energy (OSTI)

This report describes a pilot study conducted by Tom Carlson of PNNL and Mark Weiland of MEVATEC Corp to test the feasibility of using light-emitting tags to visually track objects passing through the turbine environment of a hydroelectric dam. Light sticks were released at the blade tip, mid-blade, and hub in the MGR turbine and a Kaplan turbine at Bonneville Dam and videotaped passing thru the dam to determine visibility and object trajectories.

Carlson, Thomas J

2001-01-30T23:59:59.000Z

311

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

Science Conference Proceedings (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

312

Indium-tin-oxide-free tris(8-hydroxyquinoline) Al organic light-emitting diodes with 80% enhanced power efficiency  

Science Conference Proceedings (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

313

Highly-selective wettability on organic light-emitting-diodes patterns by sequential low-power plasmas  

SciTech Connect

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

314

INITIATION AND DEVELOPMENT OF THE WHITE-LIGHT AND RADIO CORONAL MASS EJECTION ON 2001 APRIL 15  

SciTech Connect

The 2001 April 15 event was one of the largest of the last solar cycle. A former study established that this event was associated with a coronal mass ejection (CME) observed both at white light and radio frequencies. This radio CME is illuminated by synchrotron emission from relativistic electrons. In this paper, we investigate the relation of the radio CME to its extreme-ultraviolet (EUV) and white-light counterpart and reach four main conclusions. (1) The radio CME corresponds to the white-light flux rope cavity. (2) The presence of a reconnecting current sheet behind the erupting flux rope is framed, both from below and above, by bursty radio sources. This reconnection is the source of relativistic radiating electrons which are injected down along the reconnected coronal arches and up along the flux rope border forming the radio CME. (3) Radio imaging reveals an important lateral overexpansion in the low corona; this overexpansion is at the origin of compression regions where type II and III bursts are imaged. (4) Already in the initiation phase, radio images reveal large-scale interactions of the source active region (AR) with its surroundings, including another AR and open magnetic fields. Thus, these complementary radio, EUV, and white-light data validate the flux rope eruption model of CMEs.

Demoulin, P.; Pick, M.; Bouteille, A. [LESIA, UMR 8109 CNRS, UPMC, Universite Paris-Diderot, Observatoire de Paris-Meudon, Meudon 92195 (France); Vourlidas, A., E-mail: Pascal.Demoulin@obspm.fr [Space Sciences Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2012-05-10T23:59:59.000Z

315

Edge electroluminescence of the effective silicon point-junction light-emitting diode in the temperature range 80-300 K  

SciTech Connect

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

316

Phosphor-Free Solid State Light Sources  

SciTech Connect

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.

Nause, Jeff E; Ferguson, Ian; Doolittle, Alan

2007-02-28T23:59:59.000Z

317

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

E-Print Network (OSTI)

coating Han-Cheng Yeh a , Hsin-Fei Meng b, , Hao-Wu Lin c, , Teng-Chih Chao d , Mei-Rurng Tseng d , Hsiao the electron transport layer. In general highly water-absorbing materials like CsF or Li salt doping

318

The Hybridization of CdSe/ZnS Quantum Dot on InGaN Light-Emitting Diodes for Color Conversion  

Science Conference Proceedings (OSTI)

We have demonstrated the fabrication and characterization of hybrid CdSe/ZnS quantum dot (QD)-InGaN blue LEDs. The chemically synthesized red light (lambda = 623 nm) QD solutions with different concentrations were dropped onto the blue InGaN LEDs with ... Keywords: CdSe/ZnS quantum dots, CdSe/ZnS quantum dots (QDs), InGaN quantum well and hybrid LEDs, InGaN quantum well and hybrid light-emitting diodes

Ying-Chih Chen; Chun-Yuan Huang; Yan-Kuin Su; Wen-Liang Li; Chia-Hsien Yeh; Yu-Cheng Lin

2008-07-01T23:59:59.000Z

319

White light interferometry for quantitative surface characterization in ion sputtering experiments.  

SciTech Connect

White light interferometry (WLI) can be used to obtain surface morphology information on dimensional scale of millimeters with lateral resolution as good as {approx}1 {micro}m and depth resolution down to 1 nm. By performing true three-dimensional imaging of sample surfaces, the WLI technique enables accurate quantitative characterization of the geometry of surface features and compares favorably to scanning electron and atomic force microscopies by avoiding some of their drawbacks. In this paper, results of using the WLI imaging technique to characterize the products of ion sputtering experiments are reported. With a few figures, several example applications of the WLI method are illustrated when used for (i) sputtering yield measurements and time-to-depth conversion, (ii) optimizing ion beam current density profiles, the shapes of sputtered craters, and multiple ion beam superposition and (iii) quantitative characterization of surfaces processed with ions. In particular, for sputter depth profiling experiments of {sup 25}Mg, {sup 44}Ca and {sup 53}Cr ion implants in Si (implantation energy of 1 keV per nucleon), the depth calibration of the measured depth profile curves determined by the WLI method appeared to be self-consistent with TRIM simulations for such projectile-matrix systems. In addition, high depth resolution of the WLI method is demonstrated for a case of a Genesis solar wind Si collector surface processed by gas cluster ion beam: a 12.5 nm layer was removed from the processed surface, while the transition length between the processed and untreated areas was 150 {micro}m.

Baryshev, S. V.; Zinovev, A. V.; Tripa, C. E.; Erck, R. A.; Veryovkin, I. V. (Energy Systems); ( MSD)

2012-07-01T23:59:59.000Z

320

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

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

Note: This page contains sample records for the topic "white light emitting" 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

Please cite this article in press as: J. Shaw-Stewart, et al., The optimisation of the laser-induced forward transfer process for fabrication of polyfluorene-based organic light-emitting diode pixels, Appl. Surf. Sci. (2012), http://dx.doi.org/10.1016/j.a  

E-Print Network (OSTI)

-induced forward transfer process for fabrication of polyfluorene-based organic light-emitting diode pixels, Appl-induced forward transfer process for fabrication of polyfluorene-based organic light-emitting diode pixels James been used to fabricate various types of organic light- emitting diodes (OLEDs), and the process itself

322

Tunable surface plasmons in coupled metallo-dielectric multiple layers for light-emission efficiency enhancement  

E-Print Network (OSTI)

ul- timately the replacement of light bulbs for white lighting. Towards this goal, several techniquesTunable surface plasmons in coupled metallo-dielectric multiple layers for light films is a promising technique to increase the efficiency of light-emitting devices. Here we propose

Paiella, Roberto

323

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

324

LED Street and Area Lighting Technologies  

Science Conference Proceedings (OSTI)

Light emitting diodes (LEDs) are being used for applications beyond just indicator lights. One of those applications, street and area lighting, is of considerable interest. This interest is generated by potential reductions that can be achieved in operating costs resulting from lower maintenance costs as well as potentially lower electricity costs that result from the higher efficiency of LED lamps in the systems, the capability to dim and control LED systems, and better light quality. This white paper l...

2008-07-09T23:59:59.000Z

325

Active region based on graded-gap InGaN/GaN superlattices for high-power 440- to 470-nm light-emitting diodes  

SciTech Connect

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

326

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

SciTech Connect

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

327

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

SciTech Connect

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

328

Top-emission Si-based phosphor organic light emitting diode with Au doped ultrathin n-Si film anode and bottom Al mirror  

SciTech Connect

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

329

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

SciTech Connect

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

330

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

331

LED Lighting  

Energy.gov (U.S. Department of Energy (DOE))

Light-emitting diodes (LEDs) are light sources that differ from more traditional sources of light in that they are semiconductor devices that produce light when an electrical current is applied....

332

SATURATION LEVELS FOR WHITE-LIGHT FLARES OF FLARE STARS: VARIATION OF MINIMUM FLARE DURATION FOR SATURATION  

Science Conference Proceedings (OSTI)

Taking into account results obtained from models and from statistical analyses of obtained parameters, we discuss flare activity levels and flare characteristics of five UV Ceti stars. We present the parameters of unpublished flares detected over two years of observations of V1005 Ori. We compare parameters of the U-band flares detected over several seasons of observations of AD Leo, EV Lac, EQ Peg, V1054 Oph, and V1005 Ori. Flare frequencies calculated for all program stars and maximum energy levels of the flares are compared, and we consider which is the most correct parameter as an indicator of flare activity levels. Using the One Phase Exponential Association function, the distributions of flare equivalent duration versus flare total duration are modeled for each program star. We use the Independent Samples t-Test in the statistical analyses of the parameters obtained from the models. The results reveal some properties of flare processes occurring on the surfaces of UV Ceti type stars. (1) Flare energies cannot be higher than a specific value regardless of the length of the flare total duration. This must be a saturation level for white-light flares occurring in flare processes observed in the U band. Thus, for the first time it is shown that white-light flares have a saturation in a specific energy range. (2) The span values, which are the difference between the equivalent durations of flares with the shortest and longest total durations, are almost equal for each star. (3) The half-life values, minimum flare durations for saturation, increase toward the later spectral types. (4) Both maximum total durations and maximum rise times computed from the observed flares decrease toward the later spectral types among the UV Ceti stars. According to the maximum energy levels obtained from the models, both EV Lac and EQ Peg are more active than the other three program stars, while AD Leo is the most active flare star according to the flare frequencies.

Dal, H. A.; Evren, S., E-mail: ali.dal@ege.edu.tr [Department of Astronomy and Space Sciences, University of Ege, Bornova, 35100 Izmir (Turkey)

2011-02-15T23:59:59.000Z

333

Numerical Simulation of Annealing of CdSe Quantum Dots for White Light LEDs  

Science Conference Proceedings (OSTI)

The pulsed thermal processing (PTP) of CdSe Quantum Dots (QD) using a High Density plasma arc lamp. The single layer of CdSe QD was deposited on sapphire and was encapsulated in an alumina matrix. A computational methodology is proposed to understand the energy transport and annealing of QD material for solid-state lighting applications. It was found that the energy balance in the system was affected by the QD. The QD monolayer of spheres was found to alter the total reflectivity, even though the energy absorbed in QD was relatively small. The numerical simulations can be an effective tool to predict the narrow range of processing parameters and dramatically reduce expensive trial-and-error procedures while enabling the enhanced properties of nanostructured materials to be realized.

Sabau, Adrian S [ORNL; Duty, Chad E [ORNL; Ott, Ronald D [ORNL; Jellison Jr, Gerald Earle [ORNL

2008-01-01T23:59:59.000Z

334

Life tests of Nichia AlGaN/InGaN/GaN blue-light-emitting diodes  

SciTech Connect

We report on results of life testing Nichia NLPB500 blue LEDs in a temperature controlled chamber, with computer automation of equipment operation and data collection. The tests began with 18 newer (Nichia batch 4B0001) and two older (Nichia batch S403024, acquired a year earlier) LEDs, operated at 20 mA continuous wave (CW) and 23{degree}C. Light from each LED was coupled to an optical fiber and fed directly to individual photodetectors. General trend for the 18 newer LEDs was for the output intensity to increase at a faster rate within the first 50 h and then at a slower rate of the remainder of the first test. The output intensity of the two older LEDs increase within the first 50 h then decreased during the remainder of the first 1000 h. All 20 of the LEDs in the first 1000-h test were subjected to a second 1650-h test at 23{degree}C and at currents 20-70 mA CW. Only one LED, an older device, suffered a soft failure during this second test. The remaining LEDs underwent a third test at 30{degree}C and a fourth test at 35{degree}C, all at various currents. We will perform failure analysis.

Helms, C.J.; Berg, N.H.; Barton, D.L.; Osinski, M

1996-03-01T23:59:59.000Z

335

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

336

Edmund G. Brown Jr. LIGHTING CALIFORNIA'S FUTURE  

E-Print Network (OSTI)

. Keywords: Solidstate lighting, LED, light emitting diode, indirect downlight, energy efficiency #12;viii, advanced light emitting diode downlighting system. Performance objectives included compliance with ENERGY an advanced light emitting diode downlight system, retooling the traditional downlight and optimizing

337

Highly efficient blue organic light emitting device using indium-free transparent anode Ga:ZnO with scalability for large area coating  

Science Conference Proceedings (OSTI)

The availability of economically-produced and environmentally-stable transparent conductive oxide (TCO) coatings is critical for the development of a variety of electronic devices requiring transparent electrodes. Such devices include liquid crystal display pixels and organic light emitting diodes (OLEDs),[1, 2] solar cell applications,[3, 4] and electrically heated windows.[5, 6] The materials fulfilling these requirements are usually wide band gap inorganic transparent conductive oxides (TCOs). Tin-doped indium oxide, or ITO, has traditionally been used for electronic TCO applications because of its low resistivity, high work function and transparency. Due to the increasing cost and limited supply of indium and its tendency to migrate in to the device, there has been increasing research interest to substitute ITO with an indium-free material. A number of alternative metal oxides and doped oxides have been evaluated as TCO materials with varying degrees of success.[7, 8] Among these alternatives to ITO, gallium-doped zinc oxide (GZO) [2, 9] and aluminium-doped zinc oxide (AZO) [10, 11] have drawn particular attention. These materials have been demonstrated to have resistivities and transparencies approaching those of the best ITO, low toxicity, and much lower materials cost. Although AZO is attractive as a TCO electrode material, GZO features a greater resistance to oxidation as a result of gallium’s greater electronegativity compared to Submitted to 2 aluminum.[12, 13

Wang, Liang (Frank); Matson, Dean W.; Polikarpov, Evgueni; Swensen, James S.; Bonham, Charles C.; Cosimbescu, Lelia; Berry, J. J.; Ginley, D. S.; Gaspar, Daniel J.; Padmaperuma, Asanga B.

2010-02-15T23:59:59.000Z

338

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

SciTech Connect

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

339

FAQ of Overview of Solid-State Lighting  

NLE Websites -- All DOE Office Websites (Extended Search)

FREQUENTLY ASKED QUESTIONS 3 Leds FREQUENTLY ASKED QUESTIONS 3 Leds 1. What is solid-state lighting? 2. What is a semiconductor? 3. What is a semiconductor LED (light emitting diode)? 4. What is an organic LED (OLED)? 5. Where can I see LED lighting today? 6. How do you produce white light using LEDs? 7. How does solid-state lighting differ from conventional lighting? 8. What is the energy efficiency of solid-state lighting today? How does the energy efficiency compare with incandescent and fluorescent lamps? 9. What is the cost of solid-state lighting today? How does the cost compare with incandescent and fluorescent lamps? 10. What is the quality of the white light using solid-state lighting today? How does it compare with incandescent and fluorescent lamps?

340

Mitigation of light rail transit construction on jurisdictional areas in the White Rock Creek floodplain, Dallas, Texas  

E-Print Network (OSTI)

and consulting in Dallas, Texas. In this capacity, Ms.WHITE ROCK CREEK FLOODPLAIN, DALLAS, TEXAS Emily Schieffer (Boulevard, Suite 510, Dallas, Texas 75207, Phone: 214-741-

Schieffer, Emily; Smiley, Jerry

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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

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

342

Efficient White SSL Component for General Illumination  

SciTech Connect

Cree has developed a new, high-efficiency, low-cost, light emitting diode (LED) 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, package and phosphor efficiency improvements to establish a technology platform suitable for low-cost, high-efficiency commercial luminaires. New phosphor materials with improved quantum efficiency at 'real-life' operating conditions were developed along with new package technology to improve the efficiency of warm white LED modules compared to the baseline technology. Specifically, Cree has successfully demonstrated warm white LED modules providing 540 lumens at a correlated color temperature (CCT) of 3000 K. The LED module had an efficacy of 102.8 lumens per watt (LPW) using 1 mm2 chips biased at 350 mA - a 27% improvement over the technology at project start (81 LPW at 3000K). The white modules also delivered an efficacy of 88 LPW at elevated junction temperatures of 125 C. In addition, a proof-of-concept 4-inch downlight luminaire produced a flux of 1183 lumens at a CCT of 2827 K and a color rendering index (CRI) of 80 using this project's phosphor developments.

Sean Evans

2011-01-31T23:59:59.000Z

343

LightBox -Exploring Interaction Modalities with Colored Light  

E-Print Network (OSTI)

-bright multi- colored light-emitting diodes (LEDs) of our system can generate any visible lighting color

344

White LED with High Package Extraction Efficiency  

Science Conference Proceedings (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

345

Mitigation of light rail transit construction on jurisdictional areas in the White Rock Creek floodplain, Dallas, Texas  

E-Print Network (OSTI)

MITIGATION OF LIGHT RAIL TRANSIT CONSTRUCTION ONmile extension of its light rail transit (LRT) system fromadequately protect the new rail bed from flooding, it needed

Schieffer, Emily; Smiley, Jerry

2001-01-01T23:59:59.000Z

346

Luminescence properties of light-emitting diodes based on GaAs with the up-conversion Y{sub 2}O{sub 2}S:Er,Yb luminophor  

SciTech Connect

Y{sub 2}O{sub 2}S luminophors doped with Er{sup 3+} and Yb{sup 3+} ions are produced by means of solid-phase synthesis and deposited onto standard AL123A infrared light-emitting diodes. When excited with 940 nm radiation from a light-emitting diode, the structures exhibit intense visible up-conversion luminescence. A maximal brightness of 2340 cd/m{sup 2} of green and red up-conversion luminescence at corresponding wavelengths around 550 and 600 nm is observed for the Y{sub 2}O{sub 2}S compound doped with 2 at % Er{sup 3+} ions and 6 at % Yb{sup 3+} ions. The ratio of the intensity of green (or red) up-conversion luminescence to the intensity of infrared Stokes luminescence increases with increasing applied voltage. The efficiency of visible emission of the light-emitting diode structures is {eta} = 1.2 lm/W at an applied voltage of 1.5 V.

Gruzintsev, A. N., E-mail: gran@ipmt-hpm.ac.ru [Russian Academy of Sciences, Institute of Problems of Microelectronics Technology (Russian Federation); Barthou, C.; Benalloul, P. [Institute des NanoSciences (France)

2008-03-15T23:59:59.000Z

347

Quantum Dot Light Enhancement Substrate for OLED Solid-State Lighting  

SciTech Connect

With DOE Award No. DE-EE00000628, QD Vision developed and demonstrated a cost-competitive solution for increasing the light extraction efficiency of OLEDs with efficient and stable color rendering index (CRI) for solid state lighting (SSL). Solution processable quantum dot (QD) films were integrated into OLED ITO-glass substrates to generate tunable white emission from blue emitting OLED) devices as well as outcouple light from the ITO film. This QD light-enhancement substrate (QD-LED) technology demonstrated a 60% increase in OLED forward light out-coupling, a value which increases to 76% when considering total increase in multi-directional light output. The objective for the first year was an 80% increase in light output. This project seeks to develop and demonstrate a cost-competitive solution for realizing increased extraction efficiency organic light emitting devices (OLEDs) with efficient and stable color rendering index (CRI) for SSL. Solution processible quantum dot (QD) films will be utilized to generate tunable white emission from blue emitting phosphorescent OLED (Ph-OLED) devices.

James Perkins; Matthew Stevenson; Gagan Mahan; Seth Coe-Sullivan; Peter Kazlas

2011-01-21T23:59:59.000Z

348

High Efficiency LED Lamp for Solid-State Lighting  

SciTech Connect

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

349

Edmund G. Brown Jr. LIGHTING CALIFORNIA'S FUTURE  

E-Print Network (OSTI)

Edmund G. Brown Jr. Governor LIGHTING CALIFORNIA'S FUTURE: SMART LIGHT-EMITTING DIODE LIGHTING's Future: Smart LightEmitting Diode Lighting in Residential Fans. California Energy Commission, PIER. For the Smart Light emitting Diode Lighting in Residential Fans Project, the California Lighting Technology

350

Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)  

SciTech Connect

Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3- hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A thin LiF layer serves typically as the electron injection layer in OLEDs and electron collection interlayer in the OSCs. However, several reports showed that it can also assist in holeinjection in OLEDs. Here we first demonstrate that it assists hole-collection in OSCs, which is more obvious after air-plasma treatment, and explore this intriguing dual role. For OLEDs, we focus on solution processing methods to fabricate highly efficient phosphorescent OLEDs. First, we investigated OLEDs with a polymer host matrix, and enhanced charge injection by adding hole- and electron-transport materials into the system. We also applied a hole-blocking and electron-transport material to prevent luminescence quenching by the cathode. Finally, we substituted the polymer host by a small molecule, to achieve more efficient solution processed small molecular OLEDs (SMOLEDs); this approach is cost-effective in comparison to the more common vacuum thermal evaporation. All these studies help us to better understand the underlying relationship between the organic semiconductor materials and the OSCs and OLEDs’ performance and will subsequently assist in further enhancing the efficiencies of OSCs and OLEDs. With better efficiency and longer lifetime, the OSCs and OLEDs will be competitive with their inorganic counterparts.

Xiao, Teng

2012-04-27T23:59:59.000Z

351

Lighting.  

SciTech Connect

Since lighting accounts for about one-third of the energy used in commercial buildings, there is opportunity to conserve. There are two ways to reduce lighting energy use: modify lighting systems so that they used less electricity and/or reduce the number of hours the lights are used. This booklet presents a number of ways to do both. Topics covered include: reassessing lighting levels, reducing lighting levels, increasing bulb & fixture efficiency, using controls to regulate lighting, and taking advantage of daylight.

United States. Bonneville Power Administration.

1992-09-01T23:59:59.000Z

352

DOE Lighting Program Update: LED Validation Activities  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DOE Lighting Program Update DOE Lighting Program Update LED Validation Activities Kelly Gordon Pacific Northwest National Laboratory Federal Utility Partnership Working Group April 15, 2010 Providence, RI www.ssl.energy.gov 2 | Solid-State Lighting Program Legislative Mandate The DOE is directed by U.S. government policy (EPACT 2005, Section 912) to: "...support research, development, demonstration, and commercial application activities related to advanced solid-state lighting technologies based on white light emitting diodes." DOE Lighting Program www.ssl.energy.gov 3 | Solid-State Lighting Program SSL Energy Saving Potential By 2030: * Potential to cut U.S. lighting electricity use by 25% * Cumulative energy savings: $120 billion * Annual energy savings equivalent to:

353

Lighting  

Energy.gov (U.S. Department of Energy (DOE))

There are many different types of artificial lights, all of which have different applications and uses. Types of lighting include:

354

Lighting Group: Sources and Ballasts: LED Task Light  

NLE Websites -- All DOE Office Websites (Extended Search)

light The goal of this project is to accelerate the use of energy efficient light emitting diode (LED) technology for general lighting applications by developing a task lamp...

355

Plant and Lighting  

NLE Websites -- All DOE Office Websites (Extended Search)

publicationshouseplantligh t.html Sincerely, Anthony R. Brach "Artificial" light comes from many kinds of bulbs that emit different wavelengths of light; Many plants...

356

Infrared emitting device and method  

DOE Patents (OSTI)

An infrared emitting device and method. The infrared emitting device comprises a III-V compound semiconductor substrate upon which are grown a quantum-well active region having a plurality of quantum-well layers formed of a ternary alloy comprising InAsSb sandwiched between barrier layers formed of a ternary alloy having a smaller lattice constant and a larger energy bandgap than the quantum-well layers. The quantum-well layers are preferably compressively strained to increase the threshold energy for Auger recombination; and a method is provided for determining the preferred thickness for the quantum-well layers. Embodiments of the present invention are described having at least one cladding layer to increase the optical and carrier confinement in the active region, and to provide for waveguiding of the light generated within the active region. Examples have been set forth showing embodiments of the present invention as surface- and edge-emitting light emitting diodes (LEDs), an optically-pumped semiconductor laser, and an electrically-injected semiconductor diode laser. The light emission from each of the infrared emitting devices of the present invention is in the midwave infrared region of the spectrum from about 2 to 6 microns.

Kurtz, Steven R. (Albuquerque, NM); Biefeld, Robert M. (Albuquerque, NM); Dawson, L. Ralph (Albuquerque, NM); Howard, Arnold J. (Albuquerque, NM); Baucom, Kevin C. (Albuquerque, NM)

1997-01-01T23:59:59.000Z

357

Lighting Group: Sources and Ballasts  

NLE Websites -- All DOE Office Websites (Extended Search)

incorporating LEDs into tomorrows task lights, to reducing light entrapment within the LED, to fundamental research into how Organic Lighting Emitting Diodes operate. LED and...

358

A LIGHT LINK COUPLED CURRENT MONITOR L. ROHRER and H. SCHNITTER  

E-Print Network (OSTI)

to frequency converter and a light emitting diode. The emitted light pulses are transmitted by a light pipe of a battery operated current to frequency converter which feeds a light emitting diode, an acrylic light guide

Paris-Sud XI, Université de

359

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

360

Color tuning of Y{sub 3}Al{sub 5}O{sub 12}:Ce phosphor and their blend for white LEDs  

SciTech Connect

Gadolinium or lanthanum co-doped (0.5 mole) yttrium aluminum garnet doped with cerium phosphors were synthesized by a citric acid gel method and the effect of co-dopants on the structural and luminescent properties were studied. A significant peak shift in the photoluminescence spectra of yttrium aluminum garnet doped cerium was observed from 535 to 556 and 576 nm for gadolinium or lanthanum co-doped phosphors, respectively. The color tuned phosphor were blended with yttrium aluminum garnet doped cerium which showed a considerable improvement in the Commission International De Eclairage chromaticity co-ordinate values of gallium nitride based blue light emitting diode pumped white light. White light emitted from yttrium aluminum garnet doped cerium shows a Commission International De Eclairage value of (0.229, 0.182) whereas the yttrium aluminum garnet doped cerium phosphor blended with gadolinium or lanthanum co-doped phosphor shows (0.262, 0.243) and (0.295, 0.282), respectively. These results demonstrate the possibility to use these phosphor blends to enhance the white light generation in the field of white-light emitting diode solid-state lighting.

Kottaisamy, M. [Materials Research Laboratory, Kalasalingam University, Krishnankoil 626 190 (India)], E-mail: mmksamy66@yahoo.com; Thiyagarajan, P.; Mishra, J.; Ramachandra Rao, M.S. [Materials Science Research Centre, Indian Institute of Technology Madras, Chennai 600 036 (India); Department of Physics, Indian Institute of Technology Madras, Chennai 600 036 (India)

2008-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "white light emitting" 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.


361

Infrared emitting device and method  

DOE Patents (OSTI)

The infrared emitting device comprises a III-V compound semiconductor substrate upon which are grown a quantum-well active region having a plurality of quantum-well layers formed of a ternary alloy comprising InAsSb sandwiched between barrier layers formed of a ternary alloy having a smaller lattice constant and a larger energy bandgap than the quantum-well layers. The quantum-well layers are preferably compressively strained to increase the threshold energy for Auger recombination; and a method is provided for determining the preferred thickness for the quantum-well layers. Embodiments of the present invention are described having at least one cladding layer to increase the optical and carrier confinement in the active region, and to provide for waveguiding of the light generated within the active region. Examples have been set forth showing embodiments of the present invention as surface- and edge-emitting light emitting diodes (LEDs), an optically-pumped semiconductor laser, and an electrically-injected semiconductor diode laser. The light emission from each of the infrared emitting devices of the present invention is in the midwave infrared region of the spectrum from about 2 to 6 microns. 8 figs.

Kurtz, S.R.; Biefeld, R.M.; Dawson, L.R.; Howard, A.J.; Baucom, K.C.

1997-04-29T23:59:59.000Z

362

High efficiency light source using solid-state emitter and down-conversion material  

SciTech Connect

A light emitting apparatus includes a source of light for emitting light; a down conversion material receiving the emitted light, and converting the emitted light into transmitted light and backward transmitted light; and an optic device configured to receive the backward transmitted light and transfer the backward transmitted light outside of the optic device. The source of light is a semiconductor light emitting diode, a laser diode (LD), or a resonant cavity light emitting diode (RCLED). The down conversion material includes one of phosphor or other material for absorbing light in one spectral region and emitting light in another spectral region. The optic device, or lens, includes light transmissive material.

Narendran, Nadarajah (Clifton Park, NY); Gu, Yimin (Troy, NY); Freyssinier, Jean Paul (Troy, NY)

2010-10-26T23:59:59.000Z

363

LED Lighting | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

LED Lighting LED Lighting August 16, 2013 - 10:07am Addthis Light-emitting diodes (LEDs) are light sources that differ from more traditional sources of light in that they are...

364

Spin-out in cutting-edge light source technology  

E-Print Network (OSTI)

and Biochemsitry Organic light emitting diode (OLED) synthesis Information and Safety Research Facilities Education: Vojislav Sradnov Faculty Supervisor: Department: Chemistry and Biochemistry ORGANIC LIGHT EMITTING DIODE

Mottram, Nigel

365

Lighting  

SciTech Connect

The lighting section of ASHRAE standard 90.1 is discussed. It applies to all new buildings except low-rise residential, while excluding specialty lighting applications such as signage, art exhibits, theatrical productions, medical and dental tasks, and others. In addition, lighting for indoor plant growth is excluded if designed to operate only between 10 p.m. and 6 a.m. Lighting allowances for the interior of a building are determined by the use of the system performance path unless the space functions are not fully known, such as during the initial stages of design or for speculative buildings. In such cases, the prescriptive path is available. Lighting allowances for the exterior of all buildings are determined by a table of unit power allowances. A new addition the exterior lighting procedure is the inclusion of facade lighting. However, it is no longer possible to trade-off power allotted for the exterior with the interior of a building or vice versa. A significant change is the new emphasis on lighting controls.

McKay, H.N. (Hayden McKay Lighting Design, New York, NY (US))

1990-02-01T23:59:59.000Z

366

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

367

The Early History of White’s Illusion  

E-Print Network (OSTI)

The illusion that is now commonly referred to as ‘White’s illusion ’ involves changes in the lightness of the mid-grey test elements that replace sections of the black or white bars of a black–white square–wave grating. This paper describes the discovery of White’s illusion; an attempt to explain it in terms of assimilation theory; the interest it has generated amongst vision researchers; the subsequent discovery of dotted versions of the illusion; and the earlier discovery by other researchers of coloured versions.

Michael White

2010-01-01T23:59:59.000Z

368

Arnold Schwarzenegger LIGHTING RESEARCH PROGRAM  

E-Print Network (OSTI)

fluorescent task lamp. The prototype used commercially available materials: 1watt light emitting diodes to the mounting board. Development of LightEmitting Diode Task Lamp using Advanced Technologies: Prototype 2 lightemitting diode task lamp. The problem of developing an energy efficient light emitting diode task lamp

369

Non-contact pumping of light emitters via non-radiative energy transfer  

DOE Patents (OSTI)

A light emitting device is disclosed including a primary light source having a defined emission photon energy output, and, a light emitting material situated near to said primary light source, said light emitting material having an absorption onset equal to or less in photon energy than the emission photon energy output of the primary light source whereby non-radiative energy transfer from said primary light source to said light emitting material can occur yielding light emission from said light emitting material.

Klimov, Victor I. (Los Alamos, NM); Achermann, Marc (Los Alamos, NM)

2010-01-05T23:59:59.000Z

370

Microsoft 2.4GHz Wireless Protocol White Paper  

E-Print Network (OSTI)

to turn on the light-emitting diode in the keyboard's Caps Lock, or change the functions of the mouse

Narasayya, Vivek

371

Side-emitting fiber optic position sensor  

SciTech Connect

A side-emitting fiber optic position sensor and method of determining an unknown position of an object by using the sensor. In one embodiment, a concentrated beam of light source illuminates the side of a side-emitting fiber optic at an unknown axial position along the fiber's length. Some of this side-illuminated light is in-scattered into the fiber and captured. As the captured light is guided down the fiber, its intensity decreases due to loss from side-emission away from the fiber and from bulk absorption within the fiber. By measuring the intensity of light emitted from one (or both) ends of the fiber with a photodetector(s), the axial position of the light source is determined by comparing the photodetector's signal to a calibrated response curve, look-up table, or by using a mathematical model. Alternatively, the side-emitting fiber is illuminated at one end, while a photodetector measures the intensity of light emitted from the side of the fiber, at an unknown position. As the photodetector moves further away from the illuminated end, the detector's signal strength decreases due to loss from side-emission and/or bulk absorption. As before, the detector's signal is correlated to a unique position along the fiber.

Weiss, Jonathan D. (Albuquerque, NM)

2008-02-12T23:59:59.000Z

372

Lighting Controls | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

fluorescent lighting fixtures rather than replace them. Dimmers and LEDs Some light-emitting diode (LED) lightbulbs can be used with dimmers. LED bulbs and fixtures must be...

373

Background Overview of Solid-State Lighting  

NLE Websites -- All DOE Office Websites (Extended Search)

light sources Dramatic changes are unfolding in lighting technology. Semiconductor light-emitting diodes (LEDs), until recently used mainly as simple indicator lamps in...

374

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

Matsik, Steven G.

375

Continuous-wave laser annealing of free-standing Si/SiO{sub 2} superlattice: Modification of optical, structural, and light-emitting properties  

SciTech Connect

Raman, optical, and photoluminescence studies of a free-standing Si/SiO{sub 2} superlattice (SL) are described with emphasis on laser-induced thermal effects (laser annealing). The Si/SiO{sub 2} SL (500 repeats of 2-nm-thick Si and SiO{sub 2} layers) on a Si substrate was grown by a molecular beam deposition method and annealed at 1100 deg. C for 1 h in an oven, which promoted Si nanocrystals. Then the Si substrate was partially chemically etched producing free-standing areas. Continuous-wave laser annealing ({approx}10{sup 4} W/cm{sup 2}) of the as-prepared free-standing SL strongly increases the Raman band of Si nanocrystals at {approx}515 cm{sup -1}, which features laser-induced crystallization and presumably originates from melting of Si nanostructures. The obtained results show that thermal annealing at 1100 deg. C does not finish structural reorganization of the Si/SiO{sub 2} SL material and a large proportion of Si excess can be undetectable by Raman spectroscopy in related thermally annealed materials. For the laser-crystallized samples, various material characteristics (Raman spectra, light emission, and absorption) have been measured as a function of laser-induced temperature and period of laser annealing. The light emission is found to be a straightforward function of the temperature whereas the absorption coefficient depends on the laser-annealing period suggesting additional laser-induced structural reorganization.

Khriachtchev, Leonid; Raesaenen, Markku; Novikov, Sergei [Laboratory of Physical Chemistry, University of Helsinki, P.O. Box 55, Helsinki FIN-00014 (Finland); Electron Physics Laboratory, Helsinki University of Technology, P.O. Box 3000, Helsinki FIN-02015 HUT (Finland)

2006-09-01T23:59:59.000Z

376

White Paper: Cross-Disciplinary Science Research Program Project name  

E-Print Network (OSTI)

for optoelectronics is hampered by the indirect nature of the bandgap. A silicon based light emitting diode (LED-based light emitting diodes with acceptable room temperature efficiency and radiative response time are ideal on the development of a room temperature silicon light emitting diode compatible with advanced CMOS technology

Fiory, Anthony

377

Lighting the Way with Compact Fluorescent Lighting | Department...  

NLE Websites -- All DOE Office Websites (Extended Search)

and compact fluorescent lights. And I've already purchased a few of the new light emitting diode (LED) solid-state lighting lights-but that's the topic of a future blog. Stay...

378

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

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

379

Future Challenges and Directions for Nitride Materials and Light Emitters  

E-Print Network (OSTI)

. Keywords--High-temperature techniques, light emitting diodes, materials science and technology@meijo-u.ac.jp). Publisher Item Identifier S 0018-9219(97)08491-0. blue light emitting diode (LED) devices emitted

Wetzel, Christian M.

380

EK101 Engineering Light Smart Lighting  

E-Print Network (OSTI)

extensively in concert lighting and are finding increased usage in dance lighting because refers to the upstage back curtain (is white or a light color), which can be us for lighting or special Mixer #12;Monitor House speaker Lighting System Control Board: Similar to the sound board, the light

Bifano, Thomas

Note: This page contains sample records for the topic "white light emitting" 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.


381

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

382

High-Efficiency Nitride-Based Solid-State Lighting  

SciTech Connect

In this final technical progress report we summarize research accomplished during Department of Energy contract DE-FC26-01NT41203, entitled ''High-Efficiency Nitride-Based Solid-State Lighting''. Two teams, from the University of California at Santa Barbara (Principle Investigator: Dr. Shuji Nakamura) and the Lighting Research Center at Rensselaer Polytechnic Institute (led by Dr. N. Narendran), pursued the goals of this contract from thin film growth, characterization, and packaging/luminaire design standpoints. The UCSB team initially pursued the development of blue gallium nitride (GaN)-based vertical-cavity surface-emitting lasers, as well as ultraviolet GaN-based light emitting diodes (LEDs). In Year 2, the emphasis shifted to resonant-cavity light emitting diodes, also known as micro-cavity LEDs when extremely thin device cavities are fabricated. These devices have very directional emission and higher light extraction efficiency than conventional LEDs. Via the optimization of thin-film growth and refinement of device processing, we decreased the total cavity thickness to less than 1 {micro}m, such that micro-cavity effects were clearly observed and a light extraction efficiency of over 10% was reached. We also began the development of photonic crystals for increased light extraction, in particular for so-called ''guided modes'' which would otherwise propagate laterally in the device and be re-absorbed. Finally, we pursued the growth of smooth, high-quality nonpolar a-plane and m-plane GaN films, as well as blue light emitting diodes on these novel films. Initial nonpolar LEDs showed the expected behavior of negligible peak wavelength shift with increasing drive current. M-plane LEDs in particular show promise, as unpackaged devices had unsaturated optical output power of {approx} 3 mW at 200 mA drive current. The LRC's tasks were aimed at developing the subcomponents necessary for packaging UCSB's light emitting diodes, and packaging them to produce a white light fixture. During the third and final year of the project, the LRC team investigated alternate packaging methods for the white LED device to achieve at least 25 percent more luminous efficacy than traditional white LEDs; conducted optical ray-tracing analyses and human factors studies to determine the best form factor for the white light source under development, in terms of high luminous efficacy and greater acceptance by subjects; and developed a new die encapsulant using silicone-epoxy resins that showed less yellowing and slower degradation. At the conclusion of this project, the LRC demonstrated a new packaging method, called scattered photon extraction (SPE), that produced an average luminous flux and corresponding average efficacy of 90.7 lm and 36.3 lm/W, respectively, compared with 56.5 lm and 22.6 lm/W for a similar commercial white LED package. At low currents, the SPE package emitted white light with an efficacy of over 80 lm/W and had chromaticity values very close to the blackbody locus. The SPE package showed an overall improvement of 61% for this particular comparison, exceeding the LRC's third-year goal of 25% improvement.

Paul T. Fini; Shuji Nakamura

2005-07-30T23:59:59.000Z

383

Lighting and Surfaces 11.1 Introduction to Lighting  

E-Print Network (OSTI)

-object-at-a-time. "Intrinsic" light is the light emitted by the object itself, such as the glow from a TV screen, a light-emitting diode, or a star. "Ambient" light is an illumination that seems to come from all sides. In the real

Boyd, John P.

384

Franny White  

Energy.gov (U.S. Department of Energy (DOE))

Franny White is a News & Media Relations Specialist at the Energy Department’s Pacific Northwest National Laboratory.

385

Cathode encapsulation of organic light emitting diodes by atomic layer deposited Al{sub 2}O{sub 3} films and Al{sub 2}O{sub 3}/a-SiN{sub x}:H stacks  

SciTech Connect

Al{sub 2}O{sub 3} thin films synthesized by plasma-enhanced atomic layer deposition (ALD) at room temperature (25 deg. C) have been tested as water vapor permeation barriers for organic light emitting diode devices. Silicon nitride films (a-SiN{sub x}:H) deposited by plasma-enhanced chemical vapor deposition served as reference and were used to develop Al{sub 2}O{sub 3}/a-SiN{sub x}:H stacks. On the basis of Ca test measurements, a very low intrinsic water vapor transmission rate of {<=} 2 x 10{sup -6} g m{sup -2} day{sup -1} and 4 x 10{sup -6} g m{sup -2} day{sup -1} (20 deg. C/50% relative humidity) were found for 20-40 nm Al{sub 2}O{sub 3} and 300 nm a-SiN{sub x}:H films, respectively. The cathode particle coverage was a factor of 4 better for the Al{sub 2}O{sub 3} films compared to the a-SiN{sub x}:H films and an average of 0.12 defects per cm{sup 2} was obtained for a stack consisting of three barrier layers (Al{sub 2}O{sub 3}/a-SiN{sub x}:H/Al{sub 2}O{sub 3}).

Keuning, W.; Weijer, P. van de; Lifka, H.; Kessels, W. M. M.; Creatore, M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Philips Research Laboratories, High Tech Campus 4, P.O. Box WAG12, 5656 AE Eindhoven (Netherlands); Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2012-01-15T23:59:59.000Z

386

Article #11, May 23, 2006 AJ's Technical Tips: Technologies for Lighting in Rural Africa  

E-Print Network (OSTI)

- enriched light (PAM 101 light emitting diode, 650 nm) for 5 min, during which time fluorescence emission measurements, PS I-enriched light (PAM 102 FR light emitting diode, 730 nm) was added to the PS II light

Jacobson, Arne

387

STATEMENT OF CONSIDERATIONS REQUEST BY LUMILEDS LIGHTING, U.S. FOR AN ADVANCE WAIVER OF  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

STATEMENT OF CONSIDERATIONS STATEMENT OF CONSIDERATIONS REQUEST BY LUMILEDS LIGHTING, U.S. FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN INVENTION RIGHTS UNDER DOE COOPERATIVE AGREEMENT NO. DE-FC26-01NT41251; W(A)-02-005, CH-1089 The Petitioner, LumiLeds Lighting U.S. LLC (LumiLeds), was awarded this cooperative agreement for the performance of work entitled, "Development of Key Technologies for White Lighting Based on LEDs". According to the State of Project Objectives attached to the waiver petition, the objective of the project is to improve the efficiency of III-N alloy light emitting diodes (LEDs) for use in white lighting. This will be accomplished by investigation of three areas: 1) the use of low defect density substrates to be used for the growth of standard and well

388

Department of Energy Office of Energy Efficiency and Renewable Energy Solid Lighting Core Technologies  

Science Conference Proceedings (OSTI)

The overall objective of this project is to demonstrate an ultra-effective light extraction mechanism that can be universally applied to all top-emitting white OLEDs (TE-WOLEDs) and can be integrated with thin film encapsulation techniques. The scope of work proposed in this project includes four major areas: (1) optical modeling; (2) microlens and array fabrication; (3) fabrication, encapsulation, and characterization of TE-WOLEDs; and (4) full device integration and characterization. First, the light extraction efficiency in a top-emitting OLED with or without a microlens array are modeled using wave optics. Second, individual microlenses and microlens arrays are fabricated by inkjet printing of microdroplets of a liquid thiol-ene monomer with high refractive index followed by photopolymerization. Third, high efficiency top-emitting white OLEDs are fabricated, and fully characterized. Finally, optimized microlens arrays are fabricated on TE-WOLEDs with dielectric barrier layers. The overall light extraction efficiency of these devices, as well as its wavelength and angular dependencies, are measured by comparing the efficiencies of devices with and without microlens arrays. In conclusion, we have demonstrated the feasibility of applying inkjet printed microlens arrays to enhance the light extraction efficiency of top-emitting white OLEDs. We have shown that the geometry (contact angle) of the printed microlenses can be controlled by controlling the surface chemistry prior to printing the lenses. A 90% enhancement in the light extraction efficiency has been achieved with printed microlens array on a top-emitting white OLED, which can be further improved to 140% using a more close-packed microlens array fabricated from a molding process. Future work will focus on improvement of the microlens fabrication process to improve the array fill factor and the contact angle, as well as use transparent materials with a higher index of refraction. We will also further optimize the procedures for integrating the microlenses on the top-emitting white OLEDs and characterize the overall light extraction enhancement factor when the microlens array is attached.

Jiangeng Xue; Elliot Douglas

2011-03-31T23:59:59.000Z

389

Quantum Dot Light-emitting Diodes  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Optical Nanomaterials for Photonics/Biophotonics. Presentation Title, Quantum ...

390

Organic light emitting diodes with structured electrodes  

DOE Patents (OSTI)

A cathode that contain nanostructures that extend into the organic layer of an OLED has been described. The cathode can have an array of nanotubes or a layer of nanoclusters extending out from its surface. In another arrangement, the cathode is patterned and etched to form protruding nanostructures using a standard lithographic process. Various methods for fabricating these structures are provided, all of which are compatible with large-scale manufacturing. OLEDs made with these novel electrodes have greatly enhanced electron injection, have good environmental stability.

Mao, Samuel S.; Liu, Gao; Johnson, Stephen G.

2012-12-04T23:59:59.000Z

391

National Initiatives and Programs in Solid-State Lighting  

NLE Websites -- All DOE Office Websites (Extended Search)

these results is called "The Promise of Solid-State Lighting for General Illumination: Light Emitting Diodes and Organic Light Emitting Diodes" (pdf - 329kb). The full SSL-LED...

392

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

393

Types of Lighting | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

selection. Types of lighting include: Fluorescent Incandescent Outdoor solar Light-emitting diode (LED) Also learn how energy-efficient lightbulbs compare to traditional...

394

Implementation of Double Pulse Width Modulation for Uniformity of LED Light Bars in LCD Back-Light.  

E-Print Network (OSTI)

??This thesis proposes a dimming approach with Double Pulse Width Modulation for equalizing the light output of the back light with light emitted diodes (LEDs)… (more)

Huang, Chao-Hsuan

2011-01-01T23:59:59.000Z

395

High Efficiency, Illumination Quality OLEDs for Lighting  

SciTech Connect

The goal of the program was to demonstrate a 45 lumen per watt white light device based upon the use of multiple emission colors through the use of solution processing. This performance level is a dramatic extension of the team's previous 15 LPW large area illumination device. The fundamental material system was based upon commercial polymer materials. The team was largely able to achieve these goals, and was able to deliver to DOE a 90 lumen illumination source that had an average performance of 34 LPW a 1000 cd/m{sup 2} with peak performances near 40LPW. The average color temperature is 3200K and the calculated CRI 85. The device operated at a brightness of approximately 1000cd/m{sup 2}. The use of multiple emission colors particularly red and blue, provided additional degrees of design flexibility in achieving white light, but also required the use of a multilayered structure to separate the different recombination zones and prevent interconversion of blue emission to red emission. The use of commercial materials had the advantage that improvements by the chemical manufacturers in charge transport efficiency, operating life and material purity could be rapidly incorporated without the expenditure of additional effort. The program was designed to take maximum advantage of the known characteristics of these material and proceeded in seven steps. (1) Identify the most promising materials, (2) assemble them into multi-layer structures to control excitation and transport within the OLED, (3) identify materials development needs that would optimize performance within multilayer structures, (4) build a prototype that demonstrates the potential entitlement of the novel multilayer OLED architecture (5) integrate all of the developments to find the single best materials set to implement the novel multilayer architecture, (6) further optimize the best materials set, (7) make a large area high illumination quality white OLED. A photo of the final deliverable is shown. In 2003, a large area, OLED based illumination source was demonstrated that could provide light with a quality, quantity, and efficiency on par with what can be achieved with traditional light sources. The demonstration source was made by tiling together 16 separate 6-inch x 6-inch blue-emitting OLEDs. The efficiency, total lumen output, and lifetime of the OLED based illumination source were the same as what would be achieved with an 80 watt incandescent bulb. The devices had an average efficacy of 15 LPW and used solution-processed OLEDs. The individual 6-inch x 6-inch devices incorporated three technology strategies developed specifically for OLED lighting -- downconversion for white light generation, scattering for outcoupling efficiency enhancement, and a scalable monolithic series architecture to enable large area devices. The downconversion approach consists of optically coupling a blue-emitting OLED to a set of luminescent layers. The layers are chosen to absorb the blue OLED emission and then luminescence with high efficiency at longer wavelengths. The composition and number of layers are chosen so that the unabsorbed blue emission and the longer wavelength re-emission combine to make white light. A downconversion approach has the advantage of allowing a wide variety of colors to be made from a limited set of blue emitters. In addition, one does not have to carefully tune the emission wavelength of the individual electro-luminescent species within the OLED device in order to achieve white light. The downconversion architecture used to develop the 15LPW large area light source consisted of a polymer-based blue-emitting OLED and three downconversion layers. Two of the layers utilized perylene based dyes from BASF AG of Germany with high quantum efficiency (>98%) and one of the layers consisted of inorganic phosphor particles (Y(Gd)AG:Ce) with a quantum efficiency of {approx}85%. By independently varying the optical density of the downconversion layers, the overall emission spectrum could be adjusted to maximize performance for lighting (e.g. blackbody temp

Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

2008-03-31T23:59:59.000Z

396

Solid-State Lighting: 2012 Solid-State Lighting Manufacturing...  

NLE Websites -- All DOE Office Websites (Extended Search)

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

397

Collimated light from a waveguide for a display Adrian Travis,1,2*  

E-Print Network (OSTI)

between this light-guide and a liquid crystal panel guides light from color light-emitting diodes by light emitting diodes but these are point #116996 - $15.00 USD Received 9 Sep 2009; revised 9 Oct 2009

Rajamani, Sriram K.

398

Light Computing  

E-Print Network (OSTI)

A configuration of light pulses is generated, together with emitters and receptors, that allows computing. The computing is extraordinarily high in number of flops per second, exceeding the capability of a quantum computer for a given size and coherence region. The emitters and receptors are based on the quantum diode, which can emit and detect individual photons with high accuracy.

Gordon Chalmers

2006-10-13T23:59:59.000Z

399

Science and Technology of Future Light Sources  

E-Print Network (OSTI)

DESY) Herman Winick (SLAC) Mike Zisman (LBNL) WHITE PAPER of Future Light Sources A White Paper Report prepared byheart of the all- 24  WHITE PAPER  Science and Technology of

Bergmann, Uwe

2009-01-01T23:59:59.000Z

400

DOE Science Showcase - Read about Energy-Efficient Lighting | OSTI, US  

Office of Scientific and Technical Information (OSTI)

DOE Science Showcase - Read about Energy-Efficient Lighting DOE Science Showcase - Read about Energy-Efficient Lighting From the DOE Press Release: "These investments in cutting-edge lighting technologies will support American innovation, create new manufacturing jobs for U.S. workers, and help ensure that the United States leads the world in this rapidly evolving industry," said Secretary Chu. "These next-generation lighting technologies have the potential to transform the way we light our homes and businesses and generate enormous energy and cost savings for families and businesses across the country." From the Databases Energy Citations Database DOE Solid-State Lighting in Higher Ed Facilities Semiconductor Nanocrystals-Based White Light Emitting Diodes Walmart Experimental Store Performance Stories: Preprint

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401

Photonic bands in two-dimensionally patterned multimode GaN waveguides for light extraction  

E-Print Network (OSTI)

have emerged as a reference blue-green solid-state light source. As for any light emitting diode LED

Recanati, Catherine

402

White Deer  

NLE Websites -- All DOE Office Websites (Extended Search)

White Deer White Deer Name: sally Location: N/A Country: N/A Date: N/A Question: i live in Willits, Ca. where there is what we call "Ridgewood Ranch" Many years ago the owner became friends with Mr. Hearst who gave him a gift of some white deer. we had thought they had originated in Asia somewhere but some say Europe. They have webbed antlers similiar to some elk and they have a larger snout than a brown deer. There fawns are incredibly beautiful as they are born brown with white spots. They seem to stay in large groups and are quite timid. My question is, "Do you know if these deer shed their antlers like the others?" We know they are not albino deer. Their eyes seem to be brown and their hair is a little longer than the brown deer. Thank you.

403

Prospects for LED lighting.  

SciTech Connect

Solid-state lighting using light-emitting diodes (LEDs) has the potential to reduce energy consumption for lighting by 50% while revolutionizing the way we illuminate our homes, work places, and public spaces. Nevertheless, substantial technical challenges remain in order for solid-state lighting to significantly displace the well-developed conventional lighting technologies. We review the potential of LED solid-state lighting to meet the long-term cost goals.

Tsao, Jeffrey Yeenien; Gee, James Martin; Simmons, Jerry Alvon

2003-08-01T23:59:59.000Z

404

High Efficiency Organic Light Emitting Devices for Lighting  

SciTech Connect

Incorporate internal scattering layers and microlens arrays in high efficiency OLED to achieve up to 70% EQE.

So, Franky; Tansu, Nelson; Gilchrist, James

2013-06-30T23:59:59.000Z

405

Light-Emitting Diode Street and Area Lighting Technologies Assessment  

Science Conference Proceedings (OSTI)

Iberdrola has been investigating the use of energy-efficient technologies and systems for several years to better understand the needs of their customers in both residential and commercial sectors. Through a combination of Ibedrola’s own work and their membership in the Electric Power Research Institute (EPRI) Energy Efficiency Program 170, Iberdrola has kept up to date on the developments of various energy efficiency and distributed generation options. Although energy-efficiency technologies ...

2014-01-09T23:59:59.000Z

406

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

407

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

408

Lighting Group: Sources and Ballasts: LED Reflector Lamp  

NLE Websites -- All DOE Office Websites (Extended Search)

LED Reflector Lamp LED Reflector Lamp LED Reflector Lamp Objective LED reflector lamp The goal of this project is to develop a revolutionary new reflector lamp which offers many advantages over current incandescent reflector lamps, including: three times greater efficiency ten times the rated life greater optical and performance properties use of light emitting diodes (LEDs) to generate the light. Although LEDs have been commercially available since the late 1960Â’s, recent dramatic improvements in LED technology have led to white light devices with efficiencies that meet or exceed those of a standard incandescent lamp. This project will build upon these improvements to develop a new type of source for focusing light. Contact Information For more information on this project, please contact:

409

Flexible liquid core light guide with focusing and light shaping attachments  

DOE Patents (OSTI)

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. 12 figs.

Kross, B.J.; Majewski, S.; Zorn, C.J.; Majewski, L.A.

1997-11-04T23:59:59.000Z

410

Flexible liquid core light guide with focusing and light shaping attachments  

DOE Patents (OSTI)

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures.

Kross, Brian J. (Yorktown, VA); Majewski, Stanislaw (Grafton, VA); Zorn, Carl J. (Yorktown, VA); Majewski, Lukasz A. (Grafton, VA)

1997-01-01T23:59:59.000Z

411

Very high radiance edge-emitting LED  

SciTech Connect

A new light-emitting diode (LED) whose radiance is 1000 W/cm/sup 2/sr, an order of magnitude higher than any previous LED, is described. The LED is an (AlGa)As double-heterojunction edge-emitting structure. This structure acts as a waveguide for the internally generated light, and with appropriate Al concentration difference at the heterojunctions (..delta..x approximately equal to 0.3) and active region width (approximately 500 A), the radiation pattern perpendicular to the junction can be less than 30/sup 0/ (FWHM). For fiber-optic communications this LED is capable of coupling 850 ..mu..w, at a coupling loss of only -10 dB into a 0.14-numerical-aperture (NA), 90-..mu..m-diam low-loss fiber. The LED is capable of being directly modulated at 250 MHz and has a spectral width of less than 300 A.

Ettenberg, M.; Kressel, H.; Wittke, J.P.

1976-06-01T23:59:59.000Z

412

Ralph White  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Ralph White Ralph White Dean, College of Engineering and Information Technology University of South Carolina Swearingen Engineering Center Columbia, South Carolina 29208 803-777-3270, white@engr.sc.edu Nuclear Engineering at USC September 30, 2002 Background * Naval Nuclear Power School, Enlisted ('61-2) * Engineering Laboratory Technician, USS Woodrow Wilson ('64-'68) * BS, Chemical Engineering, U. of SC ('68-'71) * MS, PhD, Chemical Engineering, U. of Calif., Berkeley ('71-'77) * Asst. Prof. - Prof. Texas A&M ('77-'92) * Chairman, Dept. of Chem. Eng., U. of SC ('93-'00) * Dean, College of Eng. and Info. Tech., U. of SC (2000-present) Nuclear Power in the World * 434 operating plants in 31 countries * France 76% * Belgium 55% * Sweden 46% * Switzerland 41% * Korea 41%, Japan 36% * US 20%

413

NIST Highlight about spectrally tunable lighting facility  

Science Conference Proceedings (OSTI)

... white light produced by fluorescent lamps? Which spectral combination gives the best color quality and energy efficiency? ...

2012-10-02T23:59:59.000Z

414

Saving Energy in Altoona Where it Counts: City Lights | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Saving Energy in Altoona Where it Counts: City Lights Saving Energy in Altoona Where it Counts: City Lights Saving Energy in Altoona Where it Counts: City Lights July 20, 2010 - 1:53pm Addthis Installed next to an original streetlight, a new LED unit (right) emits a whiter light in addition to saving energy. | Photo courtesy of the city of Altoona, Pa. That's why their first priority after receiving a $205,700 Energy Efficiency and Conservation Block Grant (EECBG) was to replace 169 downtown streetlights with energy-efficient LED units. Funded as part of the American Recovery and Reinvestment Act (ARRA), the project also gives Altoona a much brighter appearance when the sun goes down.The city of Altoona, Pa. can trace 85 percent of its energy costs back to one area: lights. "Downtown sure looks different with all of that white LED light," says Lee

415

Saving Energy in Altoona Where it Counts: City Lights | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Saving Energy in Altoona Where it Counts: City Lights Saving Energy in Altoona Where it Counts: City Lights Saving Energy in Altoona Where it Counts: City Lights July 20, 2010 - 1:53pm Addthis Installed next to an original streetlight, a new LED unit (right) emits a whiter light in addition to saving energy. | Photo courtesy of the city of Altoona, Pa. That's why their first priority after receiving a $205,700 Energy Efficiency and Conservation Block Grant (EECBG) was to replace 169 downtown streetlights with energy-efficient LED units. Funded as part of the American Recovery and Reinvestment Act (ARRA), the project also gives Altoona a much brighter appearance when the sun goes down.The city of Altoona, Pa. can trace 85 percent of its energy costs back to one area: lights. "Downtown sure looks different with all of that white LED light," says Lee

416

Lighting: Past, Present and Future 2010 IEEE Lester Eastman Conference  

E-Print Network (OSTI)

. Unlike incandescent bulbs, LEDs do not emit light in a full 360° radiation pattern. Instead, they emit that is quintessential to the research and development of LEDs. As LEDs move to dominance in the lighting market

Salama, Khaled

417

Using the genetic algorithm to design gallium indium nitride/gallium nitride light-emitting diodes with reduced efficiency droop and reduced spectral instability with respect to injection current  

Science Conference Proceedings (OSTI)

Today we are witnessing a fast growing trend that is redefining the concept of lighting. Numerous governments from all over the world have passed legislation to phase out incandescent light bulbs, with the objective of encouraging energy-efficient ...

Roya Mirhosseini / Partha S. Dutta

2010-01-01T23:59:59.000Z

418

Energy Basics: LED Lighting  

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

positivenegative junction of the diode, the electrons slow down to orbit at a lower energy level. The electrons emit the excess energy as photons of light. LEDs are often used...

419

Low Light Imaging for Power Outage and Fire Detection  

E-Print Network (OSTI)

.Metal halide 7.High pressure sodium 8.Low pressure sodium 9.Light emitting diode #12;Spectral Signatures

420

Lighting Overview Page 6-1 2008 Residential Compliance Manual August 2009  

E-Print Network (OSTI)

intensity discharge lamps (like metal halide lamps) light emitting diode (LED) luminaires (dedicated LED Manual August 2009 §119(m); Table 150(c) LED Certification Requirements. Light emitting diode (LED Lighting Source Systems. For a light emitting diode (LED) lighting source system to qualify as high

Note: This page contains sample records for the topic "white light emitting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

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

SciTech Connect

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

422

Solid-State Lighting Issue 12: Selected Business & Technology...  

NLE Websites -- All DOE Office Websites (Extended Search)

News. Osram Opto Semiconductors white LED lights were on display inthe 2002 Lincoln Navigator on display at the 2002 Chicago Auto Show. Osrams white Power TOPLED,...

423

Another Side of Light - D  

NLE Websites -- All DOE Office Websites (Extended Search)

D. Three quantum phenomena D. Three quantum phenomena In fluorescence, matter absorbs light waves of a high frequency and then emits light of the same or lower frequency. This process was studied and named by George Gabriel Stokes in the mid-19th century. Today, fluorescence is familiar to us from fluorescent light bulbs. A fluorescent bulb's filament produces ultraviolet light, which is absorbed by the bulb's inner coating, which then emits lower-frequency visible light-more visible light than an incandescent bulb produces with the same wattage. According to the hypothesis of light quanta, during fluorescence an atom absorbs a quantum of light whose energy is proportional to the light wave's frequency. If the atom doesn't supply any extra energy of its own, the light quantum emitted should either have the same energy or less energy

424

DOE Science Showcase - Read about Energy-Efficient Lighting ...  

Office of Scientific and Technical Information (OSTI)

Development Novel Smart Windows Based on Transparent Phosphorescent OLEDs Illuminating Solar Decathlon Homes: Exploring Next Generation Lighting Technology - Light Emitting Diodes...

425

Lighting Choices to Save You Money | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

EPA's website for more information. LEDs -- about 75%-80% energy savings The light emitting diode (LED) are a type of solid-state lighting -- semiconductors that convert...

426

Solid-State Lighting Issue 21: Selected Business & Technology...  

NLE Websites -- All DOE Office Websites (Extended Search)

(February 2, 2004). Electronic Engineering Times Asia carried the article, "Light-emitting diode-based lighting positioned for profit" on February 2, 2004. IEEE Spectrum has...

427

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

U.S. Energy Information Administration (EIA)

"Other" includes light-emitting diode (LED) lamps as well as other lamps such as fiber optic lights, induction lamps, and lamps of unknown ...

428

Northern Lights  

NLE Websites -- All DOE Office Websites (Extended Search)

Northern Lights Northern Lights Nature Bulletin No. 178-A February 6, 1965 Forest Preserve District of Cook County Seymour Simon, President Roland F. Eisenbeis, Supt. of Conservation NORTHERN LIGHTS To a person seeing the Aurora Borealis or "northern lights" for the first time, it is an uncanny awe-inspiring spectacle. Sometimes it begins as a glow of red on the northern horizon, ominously suggesting a great fire, gradually changing to a curtain of violet-white, or greenish-yellow light extending from east to west. Some times this may be transformed to appear as fold upon fold of luminous draperies that march majestically across the sky; sometimes as a vast multitude of gigantic flaming swords furiously slashing at the heavens; sometimes as a flowing crown with long undulating colored streamers fanning downward and outward.

429

White Paper DHS Response to the NIST Cybersecurity ...  

Science Conference Proceedings (OSTI)

... NIST RFI in turn, this White Paper summarizes DHS ... Where relevant, this paper also references related DHS ... consider these resources in light of the ...

2013-05-28T23:59:59.000Z

430

Advanced Lighting Program Development (BG9702800) Final Report  

E-Print Network (OSTI)

form the basis of a new street light that would not only beefficient “white light” alternative to street lighting, CECstreet lighting design is best performed using scotopic lumens as the key design variable (i.e. , scotopic light

Rubinstein, Francis; Johnson, Steve

1998-01-01T23:59:59.000Z

431

PHYSICS 359 THE SPEED OF LIGHT  

E-Print Network (OSTI)

in this experiment using a high speed light emitting diode (LED) modulated at 40 MHz as the source, and a PIN

Landstreet, John D.

432

Light trapping beyond the 4n2 limit in thin waveguides Jeremy N. Munday, Dennis M. Callahan, and Harry A. Atwater  

E-Print Network (OSTI)

of guided light in light-emitting diodes Appl. Phys. Lett. 100, 171105 (2012) Nonreciprocal optical Bloch

Heaton, Thomas H.

433

THE WHITE HOUSE | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

THE WHITE HOUSE THE WHITE HOUSE THE WHITE HOUSE More Documents & Publications THE WHITE HOUSE White House Mission Requests Memorandum...

434

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

435

EK101 Engineering Light Smart Lighting  

E-Print Network (OSTI)

represents high usage of an engine and the violet end represents low usage. A light blue coloring represents from red to light blue), and slowly increase their usage of engine A. The seventh row show a patternModeling Long-Term Search Engine Usage Ryen W. White, Ashish Kapoor, and Susan T. Dumais Microsoft

Bifano, Thomas

436

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

437

Document  

NLE Websites -- All DOE Office Websites (Extended Search)

Initia- tive Consortium established under section 5(b). (2) INORGANIC WHITE LIGHT EMITTING DIODE.-The term ''inorganic white light emitting diode'' means a semiconducting...

438

Carnegie Mellon University Energy Efficiency in the U.S. Residential Sector  

E-Print Network (OSTI)

]. ....................................................277& Figure 63 - UV-phosphor based white light emitting diode...........................................283& Figure 64 ­ UV-phosphor based white light emitting diode

439

White Ash Biology  

NLE Websites -- All DOE Office Websites (Extended Search)

White Ash Biology Name: blondi Location: NA Country: NA Date: NA Question: 1. Is the white ash tree endangered or is it a protected variety? 2. How does the white ash tree...

440

Solid-State Lighting: The Fifth Annual DOE Solid-State Lighting...  

NLE Websites -- All DOE Office Websites (Extended Search)

for Sapphire Wafers Intended for Use for Manufacturing High Brightness-Light Emitting Diode Devices," and recently approved SEMI Draft Document 5420A, "Specification for...

Note: This page contains sample records for the topic "white light emitting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Advanced Lighting Technologies  

Science Conference Proceedings (OSTI)

This report continues the technical assessment of advanced lighting technologies in the following product areasdimmable light-emitting diode (LED) screw-in replacement lamp, hybrid compact fluorescent lamp/halogen screw-in replacement lamp, replacement recessed can LED downlight, organic LED (OLED) disc, replacement mini high-intensity discharge (HID) lamp and ballast system, and solid-state plasma lighting (miniature HID technology) high-bay fixture. The research in this project helps to demonstrate how...

2011-12-21T23:59:59.000Z

442

Baseline vs. Replacement High Bay Lighting Evaluation  

Science Conference Proceedings (OSTI)

Energy efficient lighting has been a means to significant energy savings for many facilities around the world. New developments in fluorescent, induction, LED (light-emitting diode), and plasma lighting technologies have spurred various building managers to replace or retrofit existing lighting fixtures. These advances in lighting sources often allow conservation of electricity, better quality of light, and more flexibility in the control of light. However, these new lighting sources still have ...

2013-11-06T23:59:59.000Z

443

Abstract Photosynthetic efficiency is often quantified as the light-limited, maximum quantum yield in eco-  

E-Print Network (OSTI)

by an integrated red- blue light-emitting diode (LED) source (model 6400-02, Li-Cor, Inc.), and the CO2 mole TD (1995) Efficiency of photo- synthesis in continuous and pulsed light emitting diode irradi- ation

DeLucia, Evan H.

444

Smart Lighting ERC Industrial Speaker Series  

E-Print Network (OSTI)

. About Crystal IS Crystal IS Inc. is the world leading manufacturer of ultraviolet light emitting diodes on native AlN high-quality substrates. These layers are fabricated into mid- ultraviolet light emitting diodes with peak wavelengths in the range of 240-275 nm. The low threading dislocation density

Varela, Carlos

445

On the advantages of using green light to study fluorescence yield changes in leaves  

E-Print Network (OSTI)

, the emission spectrum of a light emitting diode is chosen for the incident beam. Second, three (one each

Wollman, Francis-André

446

Phototactic personality in fruit flies and its suppression by serotonin and white  

E-Print Network (OSTI)

one choice tube leads to a lit light-emitting diode (LED) (Fig. 1A, Fig. S1 A and B, and Movie S1). Af

de Bivort, Benjamin

447

IBM Certification White Paper  

E-Print Network (OSTI)

IBM Certification White Paper The value of IT Certification #12;The value of IT Certification White · Respect and admiration of peers · Entrance into a community of like-minded professionals This white paper that can be evaluated in terms of ROI. Those most often #12;The value of IT Certification White paper

448

The History of the Light Bulb | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

Future is Here One of the fastest developing lighting technologies today is the light-emitting diode (or LED). A type of solid-state lighting, LEDs use a semiconductor to convert...

449

IEEE Transactions on Consumer Electronics Visible Light Communication for Audio Systems  

E-Print Network (OSTI)

to be constantly illuminated. Keywords: audio systems, light emitting diodes; audio broadcasting. 1. Introduction. Conclusions An audio system made up of light emitting diode (LED) and LED dot matrix display is described.G. Craford, "High Brightness Light Emitting Diodes", Semiconductors and Semimetals Vol. 48, Academic Press

Pang, Grantham

450

Lighting Choices - White Background | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

All of these lightbulbs-CFLs, LEDs, and energy-saving incandescents-meet the new energy standards that take effect from 2012-2014. allbulbshiresweb.eps...

451

Lighting Choices - White Background | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

lightingallbulbs.jpg Description All of these lightbulbs-CFLs, LEDs, and energy-saving incandescents-meet the new energy standards that take effect from 2012-2014....

452

White Papers on Materials for Photoelectrochemical Water Splitting  

NLE Websites -- All DOE Office Websites (Extended Search)

viable from a stable and efficient material with an absorber cost of 150m 2 . Light emitting diode III-V synthesis has seen a dramatic reduction in semiconductor cost by...

453

New Family of Tiny Crystals Glow Bright in LED Lights | Advanced Photon  

NLE Websites -- All DOE Office Websites (Extended Search)

How Serotonin Receptors Can Shape Drug Effects, from LSD to Migraine How Serotonin Receptors Can Shape Drug Effects, from LSD to Migraine Medication X-rays Paint a Picture of Picasso's Pigments Antibody Evolution Could Guide HIV Vaccine Development Blue Ruthenium Dimer Catalysis for Hydrogen Generation A High-Pressure Nano-imaging Breakthrough Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed New Family of Tiny Crystals Glow Bright in LED Lights JUNE 7, 2013 Bookmark and Share Laue microdiffraction pattern acquired from a nanoribbon in experiments at the APS. Minuscule crystals that glow different colors may be the missing ingredient for white light-emitting diode (LED) lighting that illuminates homes and

454

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

SciTech Connect

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

455

Hybrid Infrared and Visible Light Projection for Location Tracking  

E-Print Network (OSTI)

-output light emitting diodes. Figure 5. Inside our projector: A) LED light source B) culminating lens C) DMD for application content. In [4], Nii et al. created an infrared projector prototype using discrete light emitting diodes (LEDs). The projection lens focused directly onto the LED array creating a low resolution infrared

Olsen Jr., Dan R.

456

Light from cosmic strings  

Science Conference Proceedings (OSTI)

The time-dependent metric of a cosmic string leads to an effective interaction between the string and photons--the ''gravitational Aharonov-Bohm'' effect--and causes cosmic strings to emit light. We evaluate the radiation of pairs of photons from cosmic strings and find that the emission from cusps, kinks and kink-kink collisions occurs with a flat spectrum at all frequencies up to the string scale. Further, cusps emit a beam of photons, kinks emit along a curve, and the emission at a kink-kink collision is in all directions. The emission of light from cosmic strings could provide an important new observational signature of cosmic strings that is within reach of current experiments for a range of string tensions.

Steer, Daniele A.; Vachaspati, Tanmay [APC 10 rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France); Physics Department, Arizona State University, Tempe, Arizona 85287 (United States)

2011-02-15T23:59:59.000Z

457

Smart Lighting ERC Industrial Speaker Series  

E-Print Network (OSTI)

Flexible LEDs bring light to fingertips Oct 19, 2010 Glowing gloves Light-emitting diodes ­ or LEDs ­ have already found their way into traffic lights, TV screens and incredibly efficient light bulbs and colleagues have exploited a new printing technique for forming arrays of incredibly small red LEDs

Lü, James Jian-Qiang

458

Today LED Holiday Lights, Tomorrow the World?  

SciTech Connect

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

459

The Influence of Photoperiod History on Circadian Response to Light  

E-Print Network (OSTI)

bulbs (F4T5) (105 µW/cm 2 ) for the photophase and narrowband light-emitting diodes (LEDs)bulbs (F4T5) (105 µW/cm2) while dark phases (scotophases) were dimly illuminated by narrowband light-emitting diodes (LEDs)bulbs (F4T5) (105 µW/cm2) while dark phases (scotophases) were dimly illuminated by narrowband light-emitting diodes (LEDs)

Glickman, Gena Lynne

460

A Novel Light Source Based on a RF-Driven High Intensity Discharge...  

NLE Websites -- All DOE Office Websites (Extended Search)

90-3122 Almost all the lighting news recently has been about advances in LED (Light Emitting Diode) lighting. But several companies are quietly developing new light sources that...

Note: This page contains sample records for the topic "white light emitting" 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

APS Renewal White Paper  

NLE Websites -- All DOE Office Websites (Extended Search)

| 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed APS Renewal White Paper NOVEMBER 21, 2008 Bookmark and Share The white paper prepared for the...

462

Black and White Sight  

NLE Websites -- All DOE Office Websites (Extended Search)

Black and White Sight Name: Andy Location: NA Country: NA Date: NA Question: Why do some animals see in black and White? Replies: In the animal kingdom, sight is accomplished by...

463

New Jersey | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

23, 2010 Exciting White Lighting Windows that emit light and are more energy efficient? Universal Display's PHOLED technology enables windows that have transparent light-emitting...

464

2012 10 16 LEDLEDLEDLED  

E-Print Network (OSTI)

A novel phosphor for glareless white light-emitting diodes Hisayoshi Daicho, Takeshi Iwasaki, Kiminori

465

Dr. Christopher C. White  

Science Conference Proceedings (OSTI)

... Dr. White has published numerous peer reviewed papers and conference proceedings, and has served as a reviewer for numerous journals. ...

2013-03-26T23:59:59.000Z

466

OLED lighting devices having multi element light extraction and luminescence conversion layer  

DOE Patents (OSTI)

An apparatus such as a light source has a multi element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

Krummacher, Benjamin Claus (Regensburg, DE); Antoniadis, Homer (Mountain View, CA)

2010-11-16T23:59:59.000Z

467

Device structure for OLED light device having multi element light extraction and luminescence conversion layer  

DOE Patents (OSTI)

An apparatus such as a light source has a multi-element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

Antoniadis; Homer (Mountain View, CA), Krummacher; Benjamin Claus (Regensburg, DE)

2008-01-22T23:59:59.000Z

468

Growing Glowing Nanowires to Light Up the Nanoworld  

Science Conference Proceedings (OSTI)

... to the peak wavelength emitted with electric field perpendicular to the wire. ... in high light output compared to the bulk material.** The wires also can ...

2013-03-27T23:59:59.000Z

469

Solid-State Lighting Issue 28: Selected Business and Technology...  

NLE Websites -- All DOE Office Websites (Extended Search)

be arranged in modules designed to replace cold cathode fluorescent lamps (CCFL), surface light emitting devices such as electro-luminescent panels, and bulbs for car headlights....

470

Rare Earth Activated Oxides for Solid State Lighting  

Science Conference Proceedings (OSTI)

... Nd-Fe-B Permanent Magnets · Unique Exchange Bias Induced by Antiferromagnetic Cr-oxide · ZnO-graphene Hybrid Quantum Dots Light Emitting Diode ...

471

TOMORROW: Department of Energy to Announce Philips Lighting North...  

NLE Websites -- All DOE Office Websites (Extended Search)

American consumers and businesses money. Philips developed a highly efficient light emitting diode (LED) bulb to meet rigorous requirements of the L Prize competition - ensuring...

472

STATEMENT OF CONSIDERATIONS REQUEST BY CREE LIGHTING COMPANY...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

of the cooperative agreement is to develop high efficiency, high radiance light emitting diode (LED) chip and packaging technology that is expected to lead to novel solid...

473

Solid-State Lighting Issue 13: Scientific Literature (April ...  

NLE Websites -- All DOE Office Websites (Extended Search)

in periodically corrugated layers: the grating-assisted resonant-cavity light-emitting diode." Delbeke, D., Bienstman, P., Bockstaele, R., and Baets, R. in Journal of the...

474

Solid-State Lighting Issue 22: Scientific Literature (Early Feb...  

NLE Websites -- All DOE Office Websites (Extended Search)

(France): "Measurements of composition and electronic structure in an operating light-emitting diode using analytical electron microscopy." M. Bosman, M. Sitarz, A.Z. Sikorski, and...

475

Solid-State Lighting Issue 28: Scientific Literature (Mid May...  

NLE Websites -- All DOE Office Websites (Extended Search)

National University of Kaohsiung (Taiwan): "Wavelength shift of gallium nitride light emitting diode with p-down structure." W.H. Lan, IEEE Transactions on Electron Devices,...

476

LED Lighting | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

LED Lighting LED Lighting LED Lighting July 29, 2012 - 4:43pm Addthis LED Lighting What are the key facts? Quality LED products can last 25 times longer than an incandescent bulb and use 75% less energy. LEDs are directional, focusing light in ways that are useful in homes and commercial settings. The light-emitting diode (LED) is one of today's most energy-efficient and rapidly-developing lighting technologies. Quality LED light bulbs last longer, are more durable, and offer comparable or better light quality than other types of lighting. Check out the top 8 things about LEDs to learn more. Energy Savings LED is a highly energy efficient lighting technology, and has the potential to fundamentally change the future of lighting in the United States. Residential LEDs -- especially ENERGY STAR rated products -- use at least

477

Electrically injected visible vertical cavity surface emitting laser diodes  

DOE Patents (OSTI)

Visible laser light output from an electrically injected vertical cavity surface emitting laser (VSCEL) diode is enabled by the addition of phase-matching spacer layers on either side of the active region to form the optical cavity. The spacer layers comprise InAlP which act as charge carrier confinement means. Distributed Bragg reflector layers are formed on either side of the optical cavity to act as mirrors. 5 figs.

Schneider, R.P.; Lott, J.A.

1994-09-27T23:59:59.000Z

478

Solar lighting | Open Energy Information  

Open Energy Info (EERE)

lighting lighting Jump to: navigation, search Introductory Facts About Solar Lights It is not just a normal light bulb.The solar light consists of a LED or Light Emitting Diode, which draw little power. Coupled with constantly recharging batteries, you will never run out of light! They will save the customer money. By Replacing all outdoor lighting with solar lights there is no need to plug in to the electrical system. The lights will automatically turn on at dusk and will be charged during the day. They help out the environment.Not only does not plugging in to the power system save money but also energy, therefore protecting the Earth. Easy to Install No wires necessary, just pop in the battery. They come in all designs Just because they are solar lights doesn't

479

Organic light-emitting diodes with carbon nanotube cathode ...  

parent indium-tin-oxide !IT O " anode in combination with ... OfÞce of Ener gy EfÞciency and Renewable Ener gy , under Contract No. DE-AC02-05CH1 1231. 1C. W .

480

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...

Note: This page contains sample records for the topic "white light emitting" 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.


481

V7, Quantum Dot Light Emitting Devices and Exciton Recombination ...  

Science Conference Proceedings (OSTI)

DD3, A New Approach to Make ZnO-Cu2O Heterojunctions for Solar Cells ... E2, AlGaAs/GaAs/GaN Wafer Fused HBTs with Ar Implanted Extrinsic Collectors.

482

Functional Polymer Architectures for Solution Processed Organic Light Emitting Diodes  

E-Print Network (OSTI)

OLED emitter and indium tin oxide (ITO) as the transparentanode (typically indium tin oxide, ITO) and the cathode (solution on pre-treated indium-tin-oxide (ITO)-coated glass

Poulsen, Daniel Andrew

2010-01-01T23:59:59.000Z

483

Indium Recovery from Discarded Light Emitting Diode (LED) Liquid ...  

Science Conference Proceedings (OSTI)

... devices, causing the excessive discharge of LCD, decreasing the landfills life cycle. ... Life Cycle Based Greenhouse Gas Footprints of Metal Production with ...

484

Microdisplays based upon organic light-emitting diodes  

Science Conference Proceedings (OSTI)

Microdisplays, some of which exploit the dense electronic circuitry in a silicon chip, are enabling a new wave of ultraportable information products, including headsets for viewing movies and cell phones with full-screen Internet access. This paper reports ...

W. E. Howard; O. F. Prache

2001-01-01T23:59:59.000Z

485

Zinc Oxide and Nitride Nanowire Based Light Emitting Diodes  

E-Print Network (OSTI)

1-x)Ga(x)N alloys: Full-solar-spectrum photovoltaic materialas compared to solar spectrum, taken from LBL website (as compared to solar spectrum, taken from LBL website (50)

Lai, Elaine Michelle

2009-01-01T23:59:59.000Z

486

K3: Advanced Display Applications of Quantum Dot Light Emitting ...  

Science Conference Proceedings (OSTI)

Synthesis of Monolithic Iron Incorporated Silica Aerogels by Ambient Pressure Drying · Synthesis of Ultrahigh-density Sub 10 nm Co Nanowires Arrays by the ...

487

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

488

Toxicity and Resource Depletion Potentials of Light-Emitting Diodes  

Science Conference Proceedings (OSTI)

2010 Vittorio de Nora Award Winner: Designing Crushing and Grinding Circuits for ... Materialization of Manganese by Selective Precipitation from Used Battery.

489

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

490

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

491

Nanobeam Photonic Crystal Cavity Light-Emitting Diodes  

E-Print Network (OSTI)

We present results on electrically driven nanobeam photonic crystal cavities formed out of a lateral p-i-n junction in gallium arsenide. Despite their small conducting dimensions, nanobeams have robust electrical properties with high current densities possible at low drive powers. Much like their two-dimensional counterparts, the nanobeam cavities exhibit bright electroluminescence at room temperature from embedded 1,250 nm InAs quantum dots. A small room temperature differential gain is observed in the cavities with minor beam self-heating suggesting that lasing is possible. These results open the door for efficient electrical control of active nanobeam cavities for diverse nanophotonic applications.

Shambat, Gary; Petykiewicz, Jan; Mayer, Marie A; Sarmiento, Tomas; Harris, James; Haller, Eugene E; Vuckovic, Jelena

2011-01-01T23:59:59.000Z

492

Highly Efficient Polymer Light-Emitting Diodes Using Graphene ...  

Science Conference Proceedings (OSTI)

A30: Study on Super Stable All-solid-state Battery at High Temperature · A3: Investigation on Co-combustion Kinetics of Anthracite Coal and Biomass Char by  ...

493

Intermediate connector for stacked organic light emitting devices  

DOE Patents (OSTI)

A device is provided, having an anode, a cathode, and an intermediate connector disposed between the anode and the cathode. A first organic layer including an emissive sublayer is disposed between the anode and the intermediate connector, and a second including an emissive sublayer is disposed between the intermediate connector and the cathode. The intermediate connector includes a first metal having a work function lower than 4.0 eV and a second metal having a work function lower than 5.0 eV. The work function of the first metal is at least 0.5 eV less than the work function of the second metal. The first metal is in contact with a sublayer of the second organic layer that includes a material well adapted to receive holes from a low work function metal.

D& #x27; Andrade, Brian

2013-02-12T23:59:59.000Z

494

Light emitting polymers on flexible substrates for Naval firefighting applications .  

E-Print Network (OSTI)

??Display technologies in the current market range from the simple and cheap incandescent bulb behind a graphic overlay to the upwardly expensive flat panel high… (more)

Brisar, Jon David

2005-01-01T23:59:59.000Z

495

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

Office of Science (SC) Website

A RSS Feeds FeedbackShare Page Scientific Achievement New calculations demonstrate that LED "droop" is dominated by multi-particle interactions. Droop occurs when increasing...

496

Nanoscale-Structured Gallium Nitride Pillars for Light-Emitting ...  

Science Conference Proceedings (OSTI)

... using top-down fabrication scheme, D. Paramanik, A. Motayed, GS Aluri, J.-Y. Ha, S. Krylyuk, AV Davydov, M. King, S. McLaughlin, S. Gupta, and H ...

2013-01-18T23:59:59.000Z

497

Flexible, liquid core light guide with focusing and light shaping attachments  

DOE Patents (OSTI)

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. The end closures include a metal crimping arrangement that utilizes two layers of deformable materials to prevent cracking of endplugs. 19 figs.

Wojcik, R.F.; Majewski, S.; Zorn, C.J.; Kross, B.

1999-04-20T23:59:59.000Z

498

Flexible, liquid core light guide with focusing and light shaping attachments  

DOE Patents (OSTI)

A liquid light guide system for ultraviolet light is disclosed that has a light shaping arrangement for the emitted light, a stable liquid core and sheath and reliable and effective end closures. The end closures include a metal crimping arrangement that utilizes two layers of deformable materials to prevent cracking of endplugs.

Wojcik, Randolph Frank (Yorktown, VA); Majewski, Stanislaw (Grafton, VA); Zorn, Carl John (Yorktown, VA); Kross, Brian (Yorktown, VA)

1999-01-01T23:59:59.000Z

499

Green Light Pulse Oximeter  

DOE Patents (OSTI)

A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.

Scharf, John Edward (Oldsmar, FL)

1998-11-03T23:59:59.000Z

500

On the advantages of using green light to study fluorescence yield changes in leaves  

E-Print Network (OSTI)

, at variance with the commonly used set-ups, uses of a weakly absorbed light source (light-emitting diodes. Although the exciting light is weakly absorbed, the possibility to tune the intensity of the light emitting diodes allows one to reach photochemical rates ranging from 104 s- 1 to 0.25 s- 1 rendering