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

Photonic crystal light emitting diode.  

E-Print Network [OSTI]

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

Leirset, Erlend

2010-01-01T23:59:59.000Z

2

Highly Efficient Silicon Light Emitting Diode  

E-Print Network [OSTI]

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

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

2000-01-01T23:59:59.000Z

3

Sandia National Laboratories: light-emitting diode  

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

light-emitting diode Sandian Receives the Illuminating Engineering Society of North America, South Region Technical Award On December 12, 2014, in Capabilities, Energy, Energy...

4

Surface Plasmon Coupled Light-emitting Diode  

Science Journals Connector (OSTI)

The fundamental phenomena, basic principles, and device fabrication and characterization of surface plasmon coupled InGaN/GaN quantum-well light-emitting diode are reviewed, including...

Chen, Horng-Shyang; Kuo, Yang; Lin, Chun-Han; Chen, Chia-Feng; Chou, Wang-Hsien; Chiu, Min-Hsuan; Shih, Pei-Ying; Su, Chia-Ying; Liao, Che-Hao; Hsieh, Chieh; Chen, Chih-Yen; Kiang, Yean-Woei; Yang, Chih-Chung

5

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

6

Optimization of freeform lightpipes for light-emitting-diode projectors  

Science Journals Connector (OSTI)

Standard nonimaging components used to collect and integrate light in light-emitting-diode-based projector light engines such as tapered rods and compound parabolic concentrators are...

Fournier, Florian; Rolland, Jannick

2008-01-01T23:59:59.000Z

7

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

8

Surface-Roughened Light-Emitting Diodes: An Accurate Model  

Science Journals Connector (OSTI)

Surface roughening is frequently employed to increase light extraction from light-emitting diodes (LEDs), especially in the important case of III-Nitride LEDs. We ...

David, Aurelien

2013-01-01T23:59:59.000Z

9

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

10

Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate  

Broader source: Energy.gov [DOE]

This project is producing high-efficiency semipolar light-emitting diodes (LEDs) on low-defect bulk gallium nitride (GaN) substrates.

11

Organic-Inorganic Hetero Junction White Light Emitting Diode.  

E-Print Network [OSTI]

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

Lubuna Beegum, Shafeek

2008-01-01T23:59:59.000Z

12

Light Emitting Diodes (LEDs) for General Illumiation  

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

13

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

14

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

E-Print Network [OSTI]

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

Wu, Shin-Tson

15

Light-emitting diode illumination design with a condensing sphere  

Science Journals Connector (OSTI)

An illumination system is described that comprises a glass or plastic sphere, an embedded light-emitting diode (LED) source, and a reflecting or scattering mirror. The rays from the...

Chi, Wanli; George, Nicholas

2006-01-01T23:59:59.000Z

16

Study on electroluminescence from porous silicon light-emitting diode  

Science Journals Connector (OSTI)

Porous silicon (PS) light-emitting diode (LED) with an ITO/PS/p-Si/Al structure was fabricated by anodic oxidation method. Photoluminescence (PL) of the PS LED was measured with a...

Yang, Yajun; Li, Qingshan; Liu, Xianyun

2006-01-01T23:59:59.000Z

17

Review Absorbance Based Light Emitting Diode Optical Sensors and Sensing Devices  

E-Print Network [OSTI]

emitting diodes (LEDs) as light sources is one strategy, which has been successfully applied in chemical

Dermot Diamond

18

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

19

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

E-Print Network [OSTI]

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

Ashworth, Stephen H.

20

Fluorinated Phenoxy Boron Subphthalocyanines in Organic Light-Emitting Diodes  

Science Journals Connector (OSTI)

Fluorinated Phenoxy Boron Subphthalocyanines in Organic Light-Emitting Diodes ... All nuclear magnetic resonance (NMR) spectra were acquired on a Varian Mercury 400 MHz system in deuterated chloroform (CDCl3) purchased from Cambridge Isotope Laboratories which was used as received. ... Mass spectrometry was performed on a Waters GC time-of-flight mass spectrometer with an electron ionization probe and accurate mass determination. ...

Graham E. Morse; Michael G. Helander; Jozef F. Maka; Zheng-Hong Lu; Timothy P. Bender

2010-06-22T23:59:59.000Z

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

Spatially correlated light emission from a resonant-cavity light-emitting diode  

Science Journals Connector (OSTI)

We present the angular-resolved intensity noise characteristics of a resonant-cavity light-emitting diode under quiet pumping conditions. Measurements by a sensitivity-enhanced...

Kappe, Philip; Kaiser, Joachim; Elsässer, Wolfgang

2003-01-01T23:59:59.000Z

22

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

E-Print Network [OSTI]

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

Seungeun Lee; Wonseok Oh; Sungchul Lee; Jongchan Choi

23

The growth and characterization of a-sexithienyl–based light–emitting diodes  

Science Journals Connector (OSTI)

...voltage required to drive the light-emitting diode at 0.5 mA drops by about...voltage required to drive the light- emitting diode at 0.5 mA drops by about...from a conjugated polymer light-emitting diode--implications for efficiency...

1997-01-01T23:59:59.000Z

24

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

25

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

26

Wavelength-stable rare earth-free green light-emitting diodes for energy efficiency  

Science Journals Connector (OSTI)

Solid state lighting seeks to replace both, incandescent and fluorescent lighting by energy efficient light-emitting diodes (LEDs). Just like compact fluorescent tubes, current white...

Wetzel, Christian; Detchprohm, Theeradetch

2011-01-01T23:59:59.000Z

27

Light-Emitting Diodes in the Solid-State Lighting Systems  

E-Print Network [OSTI]

Red and green light-emitting diodes (LEDs) had been produced for several decades before blue emitting diodes, suitable for lighting applications, were widely available. Today, we have the possibility of combining the three fundamental colours to have a bright white light. And therefore, a new form of lighting, the solid-state lighting, has now become a reality. Here we discuss LEDs and some of their applications in displays and lamps.

Sparavigna, Amelia Carolina

2014-01-01T23:59:59.000Z

28

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

Science Journals Connector (OSTI)

We apply a rigorous dipole model to analyze the light outcoupling and angular performance of quantum dot light emitting diode (QLED). To illustrate the design principles, we use a red...

Zhu, Ruidong; Luo, Zhenyue; Wu, Shin-Tson

2014-01-01T23:59:59.000Z

29

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,

30

Luminescence and Squeezing of a Superconducting Light Emitting Diode  

E-Print Network [OSTI]

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

Patrik Hlobil; Peter P. Orth

2015-02-17T23:59:59.000Z

31

Luminescence and Squeezing of a Superconducting Light Emitting Diode  

E-Print Network [OSTI]

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

Hlobil, Patrik

2015-01-01T23:59:59.000Z

32

Semiconductor Nanocrystals-Based White Light Emitting Diodes  

SciTech Connect (OSTI)

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

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

2010-01-01T23:59:59.000Z

33

Organic Light Emitting Diodes: materials, device structures and light extraction  

Science Journals Connector (OSTI)

Organic Light Emitting Devices (OLEDs) are presented with particular emphasis on materials, device structures and strategies to improve light extraction. For the fabrication of efficient OLEDs, two types of electroluminescent materials are used (small molecules and polymers) with efficiencies and lifetimes which are now acceptable for small size or low content information displays. Two main approaches are described to enhance external efficiency, one is based on direct modification of the species emission and the other on modification of emitted guided modes propagation within the device. The features of the different approaches are evidenced through examples of devices reported in the literature.

B. Geffroy; L. Rocha

2009-01-01T23:59:59.000Z

34

Establishing the operational durability of polymer light-emitting diodes  

SciTech Connect (OSTI)

This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Recent research has made it clear that polymer light-emitting diodes (PLEDs) have all the necessary device attributes (efficiency, emission colors, operating voltage) required to build a successful display technology. This project was initiated to establish meaningful device operating lifetimes and to understand PLED failure mechanisms in order to control device reliability and ultimately produce a viable commercial product. A PLED lifetime testing capability was established to measure the change in PLED light output and drive voltage at constant current bias as a function of time for different current bias levels, operating temperatures and device (polymer) thickness. The dominant failure mechanism of the polymer light emitting diodes, occurring at less than 1000 hours of operation, was identified as delamination of the electron-injecting metal contact. A new electroabsorption technique to measure the electric field distribution inside the PLEDs was developed and then used to assess relative device reliability. 2 figs.

Campbell, I.H.; Davids, P.S.; Heller, C.M. [and others

1998-12-31T23:59:59.000Z

35

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

36

Microlens array diffuser for a light-emitting diode backlight system  

Science Journals Connector (OSTI)

Microlens array (MLA) diffusers for light-emitting diode (LED) backlight systems have been developed. A high fill-factor photoresist mold for the MLA was fabricated using...

Chang, Sung-Il; Yoon, Jun-Bo; Kim, Hongki; Kim, Jin-Jong; Lee, Baik-Kyu; Shin, Dong Ho

2006-01-01T23:59:59.000Z

37

Spatial resolution and noise in organic light-emitting diode displays for medical imaging applications  

Science Journals Connector (OSTI)

We report on the resolution and noise characteristics of handheld and workstation organic light-emitting diode (OLED) displays in comparison with liquid crystal displays (LCDs). The...

Yamazaki, Asumi; Wu, Chih-Lei; Cheng, Wei-Chung; Badano, Aldo

2013-01-01T23:59:59.000Z

38

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

E-Print Network [OSTI]

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

Huebner, Christopher

2009-01-01T23:59:59.000Z

39

Optical Digital Audio Interconnect Based on Organic Light Emitting Diodes and Organic Photodiodes  

Science Journals Connector (OSTI)

An optical interconnect using solely organic optoelectronic components is presented. Careful optimization of the organic light emitting diodes and photodiodes allows us to successfully...

Valouch, Sebastian; Punke, Martin; Kettlitz, Siegfried W; Lemmer, Uli; Gerken, Martina

40

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

E-Print Network [OSTI]

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

Mayer, Alexandre

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

Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications  

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

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

42

Asymptotic analysis of double-carrier, space-charge-limited transport in organic light-emitting diodes  

Science Journals Connector (OSTI)

...charge recombination occurs on a much longer time scale than diffusion and drift. asymptotic analysis|organic light-emitting diode|drift-diffusion equations| 1. Introduction Organic light-emitting diodes (OLEDs) are solid-state lighting...

2013-01-01T23:59:59.000Z

43

Efficiency Droop Effect Reduction in a Light-emitting Diode with Surface Plasmon Coupling  

Science Journals Connector (OSTI)

The efficiency droop effect of a light-emitting diode is significantly reduced through the coherent coupling of its emitting quantum wells with the surface plasmons generated on the...

Lu, Chih-Feng; Liao, Che-Hao; Chen, Chih-Yen; Hsieh, Chieh; Yang, C C

44

Facile Fabrication of Free-Standing Light Emitting Diode by Combination of Wet Chemical Etchings  

Science Journals Connector (OSTI)

Facile Fabrication of Free-Standing Light Emitting Diode by Combination of Wet Chemical Etchings ... Free-standing GaN light-emitting diode (LED) structure with high crystalline quality was fabricated by combining electrochemical and photoelectrochemical etching followed by regrowth of LED structure and subsequent mechanical detachment from a substrate. ...

Lee-Woon Jang; Dae-Woo Jeon; Tae-Hoon Chung; Alexander Y. Polyakov; Han-Su Cho; Jin-Hyeon Yun; Jin-Woo Ju; Jong-Hyeob Baek; Joo-Won Choi; In-Hwan Lee

2013-12-25T23:59:59.000Z

45

Is the light emitting diode (LED) an ultimate lamp?  

Science Journals Connector (OSTI)

Simple diagrams are used to show the transformation of a thin “slab” of intrinsic semiconductor (direct gap k elec =k hole ) from an ideal “flat-band” photopumped recombination-radiation light source into an ultimate lamp a p–n junctionlight emitting diode(LED). A photoexcited intrinsic slab of semiconductor can be regarded as an ideal (“flat-band”) light source with however the photogenerated carriers and voltage available externally instead of as recombination radiation (light) if the slab is converted to half p type (one side) and half n type (the other side) i.e. to a p–n junction. If an equal a “bucking ” external voltage is applied resulting in an input current when the photoexcitation is removed the slab becomes again (remains) an ideal “flat-band” light source a p–n junctionLED. In practice the LED takes the form of a p–n heterostructure in order to improve electron–hole injection reduce the absorption of recombination radiation and to make possible—with proper geometries—improved photon escape.

N. Holonyak Jr.

2000-01-01T23:59:59.000Z

46

Dry formation of polymer hole injection layer for top emitting organic light emitting diodes  

Science Journals Connector (OSTI)

Dry formation of polymer hole injection layer is introduced as an effective method for improving the performance of top emitting organic light emitting diodes (TOLEDs). This method involves transferring a metal/polymer bilayer to the surface of organic layers of the device by pressing. An added advantage of this method is the ability to pattern the anode in the transfer process. Fabrication of the inverted TOLED by this method results in a drastic reduction of the turn-on voltage from 14.5 to 6.5 V when compared with a reference.

Soon-min Seo; Jong H. Kim; Hong H. Lee

2006-01-01T23:59:59.000Z

47

Micro- and Sub-nanosecond Lifetime Measurements Using a UV Light-Emitting Diode  

Science Journals Connector (OSTI)

The authors describe the use of an ultraviolet light-emitting diode (UV LED), Nichia NSHU590E, as a 373 nm excitation light source for fluorescence lifetime measurements. A...

Szmacinski, Henryk; Chang, Qing

2000-01-01T23:59:59.000Z

48

Designing light-emitting diode arrays for uniform near-field irradiance  

Science Journals Connector (OSTI)

We analyze the first-order design of light sources consisting of multiple light-emitting diodes (LEDs) to uniformly illuminate a near target plane by considering each single LED as...

Moreno, Ivan; Avendaño-Alejo, Maximino; Tzonchev, Rumen I

2006-01-01T23:59:59.000Z

49

City of Phildelphia: Light emitting diodes for traffic signal displays  

SciTech Connect (OSTI)

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

NONE

1995-12-01T23:59:59.000Z

50

Enhanced Light Extraction from Organic Light Emitting Diodes...  

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

Solar Photovoltaic Solar Photovoltaic Industrial Technologies Industrial Technologies Advanced Materials Advanced Materials Find More Like This Return to Search Enhanced Light...

51

Organic Light Emitting Diode for White Light Emission  

E-Print Network [OSTI]

During the last few years, research based on energy saving technologies is being given high priority all over the world. General lighting is one area in which large quantity of electrical energy is being spend and substantial energy saving is possible by using energy saving technologies. Conventional light sources like incandescent filament lamps in which a major

M. N. Kamalasanan; Ritu Srivastava; Gayatri Chauhan; An Kumar; Amit Kumar; M. N. Kamalasanan; Ritu Srivastava; Gayatri Chauhan; An Kumar; Priyanka Tayagi; Amit Kumar

52

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

53

Influence of optical fibers on the spectrum of transmitted light-emitting-diode radiation  

Science Journals Connector (OSTI)

Propagation of GaxIn1–xAsyP1–y light-emitting-diode radiation through an optical fiber was found to affect its spectral curve very strongly, and the origin of...

Zavadil, Jirí; Honc, Tomáš; Ctyroký, Jirí

1995-01-01T23:59:59.000Z

54

Organic solid laser pumped by an organic light-emitting diode  

Science Journals Connector (OSTI)

We have proposed what we believe is a novel organic device pumped by an organic light-emitting diode to avoid a strong charge-induced absorption and nonradiative loss in an...

Wei, Bin; Kobayashi, Nyoriko; Ichikawa, Musubu; Koyama, Toshiki; Taniguchi, Y; Fukuda, T

2006-01-01T23:59:59.000Z

55

High-Precision Fluorimetry with a Light-Emitting Diode Source  

Science Journals Connector (OSTI)

A simple fluorimeter which uses a light-emitting diode as a source of excitation and a photodiode as a detector has been constructed and evaluated. The exceptional stability of both...

Smith, B W; Jones, B T; Winefordner, J D

1988-01-01T23:59:59.000Z

56

Angle-tuned, evanescently-decoupled reflector for high-efficiency red light-emitting diode  

Science Journals Connector (OSTI)

We propose and demonstrate evanescently-decoupled, solid-angle-optimized distributed Bragg reflectors (DBRs) for AlGaInP light-emitting diodes (LEDs). The thickness of each DBR layer...

Kim, Sun-Kyung; Cho, Hyun K; Park, Kyung K; Jang, Junho; Lee, Jeong S; Park, Kyung W; Park, Youngho; Kim, Ju-Young; Lee, Yong-Hee

2008-01-01T23:59:59.000Z

57

Compact light-emitting-diode sun photometer for atmospheric optical depth measurements  

Science Journals Connector (OSTI)

A new compact light-emitting diode (LED) sun photometer, in which a LED is used as a spectrally selective photodetector as well as a nonlinear feedback element in the operational...

Acharya, Y B; Jayaraman, A; Ramachandran, S; Subbaraya, B H

1995-01-01T23:59:59.000Z

58

Wideband squeezing in photon number fluctuations from a high-speed light-emitting diode  

Science Journals Connector (OSTI)

Wideband, highly noise-suppressed squeezing was observed by using a high-speed, high-quantum-efficiency light-emitting diode. The squeezing bandwidth extended over 200 MHz.

Abe, Jun'ichi; Kuga, Takahiro; Hirano, Takuya; Kobayashi, Masahide; Yamanishi, Masamichi

2000-01-01T23:59:59.000Z

59

Research on photoelectronics properties of array emitting diode and its light energy distribution in detection screen  

Science Journals Connector (OSTI)

Abstract According to the principle of multi-screen intersection target measure flying projectile parameters, the photoelectronics properties of array emitting diode that form detection screen in multi-screen intersection target and its light energy distributing were studied. The form of detection screen using array emitting diode and the measure principle of four screens intersection were analyzed. The properties of emitting diode were analyzed based on its compound emitting mechanism and P–N ties internal current carrier. The light energy superposition principle was applied to set up light energy distributing model and give out its arithmetic. Through calculation and analysis, the light energy distributing is asymmetric when being close to diode position and the output variation range of light energy is large relatively. When test position is far from diode, the light energy distributing is uniformity, but the energy is relatively feebleness in edge of screen. Detection screen light energy distribution is trapezoidal in whole screen. The variety of emitting diode luminous flux is very distinct when projectile close to pointing light source, the output signal in received detective circuit is very high which is propitious to improve acquirement rate.

Hanshan Li

2014-01-01T23:59:59.000Z

60

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

Science Journals Connector (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 "light emitting diodes" 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

Surface Plasmon Enhanced Phosphorescent Organic Light Emitting Diodes  

SciTech Connect (OSTI)

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

Guillermo Bazan; Alexander Mikhailovsky

2008-08-01T23:59:59.000Z

62

Semiconductor-Nanocrystals-Based White Light-Emitting Diodes  

SciTech Connect (OSTI)

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

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

2010-01-01T23:59:59.000Z

63

Enhancing the Light Extraction of InGaN Light-Emitting Diodes by Patterning the Dicing Streets  

Science Journals Connector (OSTI)

Patterning the dicing streets technology was used to define the high extraction efficiency region of InGaN-GaN multiple-quantum-well light-emitting diodes (LEDs). The external quantum...

Lin, Hung Cheng; Tseng, Yen Chun; Chyi, Jen Inn; Lee, Chia Ming

64

Use of light-emitting diodes as light sources to lower energy consumption for cultivation of photosynthesizing microorganisms  

Science Journals Connector (OSTI)

Experimental data are cited for the productivity of phototrophs subjected to interrupted illumination by light-emitting diodes. It is demonstrated that a significant reduction in energy consumption for the produc...

2011-03-01T23:59:59.000Z

65

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

DOE Patents [OSTI]

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

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

2014-10-21T23:59:59.000Z

66

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

67

Diffusion injected multi-quantum well light-emitting diode structure  

SciTech Connect (OSTI)

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

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

2014-02-24T23:59:59.000Z

68

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

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

69

Vanadium pentoxide modified polycrystalline silicon anode for active-matrix organic light-emitting diodes  

E-Print Network [OSTI]

Vanadium pentoxide modified polycrystalline silicon anode for active-matrix organic light to be an efficient anode for organic light-emitting diode OLED X. L. Zhu, J. X. Sun, H. J. Peng, Z. G. Meng, M. Wong an ultrathin vanadium pentoxide V2O5 layer on the p-Si anode, the performance of the OLED can be greatly

70

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,

71

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

72

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

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

73

Blue fluorescent organic light emitting diodes with multilayered graphene anode  

SciTech Connect (OSTI)

As an innovative anode for organic light emitting devices (OLEDs), we have investigated graphene films. Graphene has importance due to its huge potential in flexible OLED applications. In this work, graphene films have been catalytically grown and transferred to the glass substrate for OLED fabrications. We have successfully fabricated 2 mm × 2 mm device area blue fluorescent OLEDs with graphene anodes which showed 2.1% of external quantum efficiency at 1000 cd/m{sup 2}. This is the highest value reported among fluorescent OLEDs using graphene anodes. Oxygen plasma treatment on graphene has been found to improve hole injections in low voltage regime, which has been interpreted as oxygen plasma induced work function modification. However, plasma treatment also increases the sheet resistance of graphene, limiting the maximum luminance. In summary, our works demonstrate the practical possibility of graphene as an anode material for OLEDs and suggest a processing route which can be applied to various graphene related devices.

Hwang, Joohyun [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Choi, Hong Kyw [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Moon, Jaehyun; Shin, Jin-Wook; Joo, Chul Woong; Han, Jun-Han; Cho, Doo-Hee; Huh, Jin Woo [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Choi, Sung-Yool [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [Graphene Electronics Creative Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Lee, Jeong-Ik, E-mail: jiklee@etri.re.kr [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Chu, Hye Yong [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)] [OLED Lighting Research Team, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of)

2012-10-15T23:59:59.000Z

74

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

SciTech Connect (OSTI)

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

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

2014-06-09T23:59:59.000Z

75

High-Efficiency and Stable White Organic Light-Emitting Diode Using a Single Emitter  

Broader source: Energy.gov [DOE]

This project is demonstrating an efficient and stable white organic light-emitting diode (WOLED) using a single emitter on a planar glass substrate. Current WOLED technology requires the use of multiple emissive materials, which are expensive to manufacture and also generate color instability and color aging issues, affecting WOLED performance and operational lifetime.

76

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

SciTech Connect (OSTI)

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

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

2013-03-15T23:59:59.000Z

77

Is it viable to improve light output efficiency by nano-light-emitting diodes?  

SciTech Connect (OSTI)

Nanopillar arrays with InGaN/GaN multiple-quantum-disks (MQDs) are fabricated by focused-ion-beam milling with surface damage layer removed by KOH wet etching. Nano-light-emitting diodes (Nano-LEDs) made of the InGaN/GaN MQD nanopillars are found to have 19.49% less output power than that of a conventional LED. The reasons are analyzed in detail and considering their current-voltage and electroluminescence characteristics, internal quantum efficiency, external quantum efficiency, light extraction, and wall-plug efficiency. Our results suggest that nanopillar-LED can outperform if the density can be increased to 2.81?×?10{sup 9}?cm{sup ?2} with the size unchanged or the size can be increased to 854.4?nm with the density unchanged.

Wang, Chao-Hung; Huang, Yu-Wen [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China)] [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Wu, Shang-En [Genesis Photonics Incorporation, Tainan 70101, Taiwan (China)] [Genesis Photonics Incorporation, Tainan 70101, Taiwan (China); Liu, Chuan-Pu, E-mail: cpliu@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China) [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 70101, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 70101, Taiwan (China)

2013-12-02T23:59:59.000Z

78

Enhancing the emission directionality of organic light-emitting diodes by using photonic microstructures  

SciTech Connect (OSTI)

We report microstructured organic light-emitting diodes (OLEDs) with directional emission based on efficient solution-processable europium-OLEDs patterned by solvent assisted microcontact molding. The angle dependence of the light emission is characterized for OLEDs with square-array photonic crystals with periods between 275?nm and 335?nm. The microstructured devices have emission patterns strongly modified from the Lambertian emission of planar OLEDs and can approximately double the emitted power in a desired angle range in both s- and p-polarizations. The modified emission is attributed to light diffracted out of the waveguide modes of the OLEDs.

Zhang, Shuyu; Turnbull, Graham A., E-mail: gat@st-andrews.ac.uk, E-mail: idws@st-andrews.ac.uk; Samuel, Ifor D. W., E-mail: gat@st-andrews.ac.uk, E-mail: idws@st-andrews.ac.uk [Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)] [Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)

2013-11-18T23:59:59.000Z

79

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

80

Active packing method for blue light-emitting diodes with photosensitive polymerization: formation of self-focusing encapsulates  

Science Journals Connector (OSTI)

A novel light-emitting diode (LED) packaging method, named the active packaging (AP) method, is presented in this paper. In this method, during the LED packaging process, the light...

Wang, Hao; Ryu, Jae-Hyoung; Lee, Kyu-Seung; Tan, Chun Hua; Jin, Lihua; Li, Songmei; Hong, Chang-Hee; Cho, Yong-Hoon; Liu, Songhao

2008-01-01T23:59:59.000Z

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

Zinc Oxide and Nitride Nanowire Based Light Emitting Diodes  

E-Print Network [OSTI]

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

Lai, Elaine Michelle

2009-01-01T23:59:59.000Z

82

Zinc Oxide and Nitride Nanowire Based Light Emitting Diodes  

E-Print Network [OSTI]

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

Lai, Elaine Michelle

2009-01-01T23:59:59.000Z

83

An Optically Stabilized Fast-Switching Light Emitting Diode as a Light Source for Functional  

E-Print Network [OSTI]

experimental setups. This paper presents a method to control the brightness of a high-power light emitting

Daniel A. Wagenaar

84

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

SciTech Connect (OSTI)

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

Arto V. Nurmikko; Jung Han

2004-10-01T23:59:59.000Z

85

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)

86

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

DOE Patents [OSTI]

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

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

2014-07-22T23:59:59.000Z

87

Fabrication and Characterization of a GaN Light-emitting Diode (LED) with a Centered Island Cathode  

Science Journals Connector (OSTI)

Uniform spreading of injection current in light-emitting diodes (LEDs) is one of the crucial requirements for better device performances. It is reported that non-uniform current...

Park, Yun Soo; Lee, Hwan Gi; Yang, Chung-Mo; Kim, Dong-Seok; Bae, Jin-Hyuk; Cho, Seongjae; Lee, Jung-Hee; Kang, In Man

2012-01-01T23:59:59.000Z

88

Highly Efficient Bipolar Host Materials with Indenocarbazole and Pyrimidine Moieties for Phosphorescent Green Light-Emitting Diodes  

Science Journals Connector (OSTI)

Highly Efficient Bipolar Host Materials with Indenocarbazole and Pyrimidine Moieties for Phosphorescent Green Light-Emitting Diodes ... Cyclic voltammetry characteristics, energy diagram of fabricated devices, and synthetic processes of DPICz1 and DPICz2. ...

Gyeong Heon Kim; Raju Lampande; Mi Jin Park; Hyeong Woo Bae; Ji Hoon Kong; Jang Hyuk Kwon; Jung Hwan Park; Yong Wook Park; Choong Eui Song

2014-11-17T23:59:59.000Z

89

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

E-Print Network [OSTI]

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

Meng, Hsin-Fei

90

Highly efficient inverted top emitting organic light emitting diodes using a transparent top electrode with color stability on viewing angle  

SciTech Connect (OSTI)

We report a highly efficient phosphorescent green inverted top emitting organic light emitting diode with excellent color stability by using the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile/indium zinc oxide top electrode and bis(2-phenylpyridine)iridium(III) acetylacetonate as the emitter in an exciplex forming co-host system. The device shows a high external quantum efficiency of 23.4% at 1000?cd/m{sup 2} corresponding to a current efficiency of 110?cd/A, low efficiency roll-off with 21% at 10?000?cd/m{sup 2} and low turn on voltage of 2.4?V. Especially, the device showed very small color change with the variation of ?x?=?0.02, ?y?=?0.02 in the CIE 1931 coordinates as the viewing angle changes from 0° to 60°. The performance of the device is superior to that of the metal/metal cavity structured device.

Kim, Jung-Bum; Lee, Jeong-Hwan; Moon, Chang-Ki; Kim, Jang-Joo, E-mail: jjkim@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

2014-02-17T23:59:59.000Z

91

Two examples of organic opto-electronic devices: Light emitting diodes and solar cells  

Science Journals Connector (OSTI)

Organic and polymeric (plastic) opto-electronic devices have been developed over the past decade and some of them have made the leap from the research laboratory to commercial use. We present a simple and inexpensive method of fabricating organic light emitting diodes and organic photovoltaic cells. The devices are fabricated by the deposition of solid films based on the fluorescent polymer MEH:PPV using the spin-coating technique. The films were sandwiched between electrodes one of which was made of Bi-Pb-Cd-Sn alloy. An overview of these two devices is also provided.

J. L. Maldonado; G. Ramos-Ortíz; M. L. Miranda; S. Vázquez-Córdova; M. A. Meneses-Nava; O. Barbosa-García; M. Ortíz-Gutiérrez

2008-01-01T23:59:59.000Z

92

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

SciTech Connect (OSTI)

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

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

2010-01-01T23:59:59.000Z

93

Excitation resolved color conversion of CdSe/ZnS core/shell quantum dot solids for hybrid white light emitting diodes  

E-Print Network [OSTI]

-volume spectrum-specific applications in- cluding scotopic street lighting, greenhouse lighting, and high-CRI warm light emitting diodes Sedat Nizamoglu and Hilmi Volkan Demira Department of Electrical and Electronics light emitting diodes LEDs , we present spectrally resolved relative quantum efficiency and relative

Demir, Hilmi Volkan

94

A spin light emitting diode incorporating ability of electrical helicity switching  

SciTech Connect (OSTI)

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

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

2014-03-17T23:59:59.000Z

95

Green light emitting diode grown on thick strain-reduced GaN template  

Science Journals Connector (OSTI)

Abstract We report a green light-emitting diode (LED) grown on thick strain-reduced GaN template. As the injection current changes from 20 mA to 120 mA, blue-shift of EL peak wavelength reduces from 9.3 nm for the LED on sapphire substrate to 6.8 nm for the LED grown on thick strain-reduced GaN template. Furthermore, the light output power and external quantum efficiency of the LED on thick strain-reduced GaN template are respectively 1.48 mW and 2.5% at the forward current of 20 mA, which is twice as much as the LED on sapphire substrate. In contrast, the reverse current is 2 ?A lower than that of the LED on the sapphire at ?8 V.

Jiankun Yang; Tongbo Wei; Qiang Hu; Ziqiang Huo; Baojuan Sun; Ruifei Duan; Junxi Wang

2015-01-01T23:59:59.000Z

96

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

SciTech Connect (OSTI)

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

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

2014-04-28T23:59:59.000Z

97

General method to solution-process multilayer polymer light-emitting diodes  

E-Print Network [OSTI]

-emitting diodes. This method can be applied to arbitrary combinations of polymers with no restriction on solvents. One green- and two blue-emitting polymers are chosen as the emissive layers. The electron-hole balance But these methods are only restricted to spe- cific polymers combined with specific solvents. Until now

98

Efficient Charge Balance in Blue Phosphorescent Organic Light Emitting Diodes by Two Types of Mixed Layer  

Science Journals Connector (OSTI)

Abstract The authors have demonstrated a highly efficient and long-lifetime blue phosphorescent organic light emitting diode (PHOLED) that uses two types of mixed layers. The mixed layers play the role of carrier injection control and exciton generation zone extension. One of the layers is applied for mixing the hole transport layer (HTL) and host material at the HTL side for carrier injection control. The other works as a mixed electron transporting layer (ETL) and host material at the ETL side. The optimized blue PHOLED has been shown to achieve high performance owing to the mixed layer effects. It gave a maximum luminous efficiency of 25.55 cd/A, maximum external quantum efficiency of 13.05%, and lifetime of 7.24 h under 500 cd/m2. These results indicate that applying mixed layers is a simple and efficient method that does not require significant structural change.

Hyung Jin Yang; Ho Won Lee; Song Eun Lee; Yong Sun; Kyo Min Hwang; Han Kyu Yoo; Sung Kyu Lee; Woo Young Kim; Young Kwan Kim

2014-01-01T23:59:59.000Z

99

Sidewall passivation for InGaN/GaN nanopillar light emitting diodes  

SciTech Connect (OSTI)

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

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

2014-07-07T23:59:59.000Z

100

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

SciTech Connect (OSTI)

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

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

2014-05-19T23:59:59.000Z

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

Electroluminescence from colloidal semiconductor CdSe nanoplatelets in hybrid organic–inorganic light emitting diode  

Science Journals Connector (OSTI)

Abstract We report on the fabrication of a hybrid light-emitting-diode based on colloidal semiconductor CdSe nanoplatelets as emitters and organic TAZ [3-(Biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole] and TPD [N, N?-bis (3-methylphenyl)-N, N?-bis (phenyl)-benzidine] materials as the electron and hole transporting layers. Electroluminescent and current–voltage characteristics of the developed hybrid device with the turn-on voltage of 5.5 V and the radiation wavelength of 515 nm have been obtained. Semiconductor nanoplatelets like CdSe are attractive for the fabrication of hybrid \\{LEDs\\} with low operating voltages, spectrally pure color and short-wavelength electroluminescence, which is required for RGB devices.

A.G. Vitukhnovsky; V.S. Lebedev; A.S. Selyukov; A.A. Vashchenko; R.B. Vasiliev; M.S. Sokolikova

2015-01-01T23:59:59.000Z

102

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

E-Print Network [OSTI]

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

103

InGaN-based vertical light-emitting diodes with acid-modified graphene transparent conductor and highly reflective membrane current blocking layer  

Science Journals Connector (OSTI)

...Wang. 2011 Electrical characteristics of vertical light emitting diode with n-type contact on a selectively wet-etching...Measurement of electron overflow in 450 nm InGaN light-emitting diode structures. Appl. Phys. Lett. 94, 061116...

2013-01-01T23:59:59.000Z

104

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

E-Print Network [OSTI]

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

Demir, Hilmi Volkan

105

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

E-Print Network [OSTI]

and even competitors of well-established fluorescent tubes and inorganic LEDs thanks to their unique to outperform incandescent light bulbs and even fluorescent tubes in terms of luminous efficiencies[4]. A good triphenylamine molecule. ABSTRACT: We described an approach to achieve fine color control of fluorescent White

Paris-Sud XI, Université de

106

Highly enhanced light extraction from organic light emitting diodes with little image blurring and good color stability  

Science Journals Connector (OSTI)

Abstract We report a highly enhanced light extraction from a top emission organic light emitting diode with little image blurring and color variation with viewing angle. Direct integration of a high refractive index micro lens array on the top of the transparent indium zinc oxide top electrode of a green phosphorescent OLED showed a significant enhancement of light extraction to get EQE of 44.7% from 27.6%, the power efficiency of 134.7 lm/w from 85.9 lm/W and the current efficiency of 217.2 cd/A from 120.7 cd/A without image blurring. In addition, the device showed excellent color stability on viewing angle with Commission Internationale de l’Eclairage (CIE) coordinate of ?x = 0.01, ?y = 0.01 as the viewing angle varied from 0° to 60°.

Jung-Bum Kim; Jeong-Hwan Lee; Chang-Ki Moon; Kwon-Hyeon Kim; Jang-Joo Kim

2015-01-01T23:59:59.000Z

107

A fluctuational electrodynamics model for the optimization of light-extraction efficiency in thin-film light-emitting diodes  

SciTech Connect (OSTI)

The rapid development of thin film light-emitting diodes (LEDs) has enabled the enhancement of the light extraction beyond geometrical limits but more quantitative understanding of the underlying optical processes is required to fully optimize the extraction. We present first-principle calculations of the light extraction efficiency and optical energy flow in thin-film LEDs. The presented model generalizes the methods of fluctuational electrodynamics to excited semiconductors and simultaneously accounts for wave optical effects, e.g., interference and near-field coupling as well as the internal absorption of the light-emitting material in determining the rate of light emission and internal dissipation in the optical cavity formed by a planar LED. The calculations show that in structures with a metallic mirror, the emissivity of the active region can approach unity at selected wavelengths, even when the nominal emissivity of the active region is only moderate. However, the results also show that near-field coupling of emission from the active region to the mirror can provide a substantial non-radiative loss channel reducing the maximum light extraction efficiency to 0.67 in our example setup. These losses can be partly compensated by the efficient photon recycling enabled by thick active regions that quench emission to confined modes and thereby reduce parasitic absorption.

Heikkilä, Oskari, E-mail: oskari.heikkila@aalto.fi; Oksanen, Jani; Tulkki, Jukka [Department of Biomedical Engineering and Computational Science, Aalto University, Helsinki (Finland)

2013-12-14T23:59:59.000Z

108

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

SciTech Connect (OSTI)

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

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

2014-02-15T23:59:59.000Z

109

Efficient organic light-emitting diode using semitransparent silver as anode Huajun Peng, Xiuling Zhu, Jiaxin Sun, Zhiliang Xie, Shuang Xie,  

E-Print Network [OSTI]

Efficient organic light-emitting diode using semitransparent silver as anode Huajun Peng, Xiuling A semitransparent silver layer is investigated as the anode for organic light-emitting devices OLEDs. A bottom-emitting OLED using the modified, semitransparent silver anode, demonstrates improved current

110

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

Science Journals Connector (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

111

Color optimization of conjugated-polymer/InGaN Hybrid white light emitting diodes by incomplete energy transfer  

Science Journals Connector (OSTI)

Abstract By using the wavelength conversion method, white light emitting diodes (WLEDs) were produced by applying mixtures of polysiloxane and fluorescent polymers on InGaN based light emitting diodes. UV curable organic–inorganic hybrid materials with high refractive index (1.561), compromised optical, thermal and mechanical properties was used as encapsulants. Red light emitting fluorescent FABD polymer (with 9,9-dioctylfluorene (F), anthracene (A) and 2,1,3-benzothiadiazole (B), and 4,7-bis(2-thienyl)-2,1,3-benzothiadiazole (D) repeating units) and green light emitting fluorescent FAB polymer were used as wavelength converters. The encapsulant/fluorescent polymer mixture and InGaN produce the white light by incomplete energy transfer mechanism. \\{WLEDs\\} with high color rendering index (CRI, about 93), and tunable correlated color temperature (CCT) properties can be produced by controlling the composition and chemical structures of encapsulating polymer and fluorescent polymer in hybrid materials, offering cool-white and neutral-white LEDs.

Chi-Jung Chang; Chun-Feng Lai; P. Madhusudhana Reddy; Yung-Lin Chen; Wei-Yung Chiou; Shinn-Jen Chang

2014-01-01T23:59:59.000Z

112

Carbazole modified terphenyl based high triplet energy host materials for blue phosphorescent organic light-emitting diodes  

Science Journals Connector (OSTI)

Abstract Carbazole modified terphenyl based high triplet energy host materials were developed for application as host materials for blue phosphorescent organic light-emitting diodes. Two terphenyl based materials, 9-(5?-phenyl-[1,1?:2?,1?:3?,1???-quaterphenyl]-3-yl)-9H-carbazole (CzTPPh) and 9-(3?,5?-di(pyridin-3-yl)-[1,1:2?,1?-terphenyl]-3-yl)-9H-carbazole (CzTPPy), were synthesized as the host materials with high triplet energies of 2.75 eV and 2.73 eV, respectively. The two host materials were evaluated as the host materials for blue phosphorescent organic light-emitting diodes and high quantum efficiencies of 20.2% and 15.7% were obtained in the CzTPPh and CzTPPy devices, respectively.

Chil Won Lee; Jun Yeob Lee

2014-01-01T23:59:59.000Z

113

GaN nanorod light emitting diodes with suspended graphene transparent electrodes grown by rapid chemical vapor deposition  

SciTech Connect (OSTI)

Ordered and dense GaN light emitting nanorods are studied with polycrystalline graphene grown by rapid chemical vapor deposition as suspended transparent electrodes. As the substitute of indium tin oxide, the graphene avoids complex processing to fill up the gaps between nanorods and subsequent surface flattening and offers high conductivity to improve the carrier injection. The as-fabricated devices have 32% improvement in light output power compared to conventional planar GaN-graphene diodes. The suspended graphene remains electrically stable up to 300?°C in air. The graphene can be obtained at low cost and high efficiency, indicating its high potential in future applications.

Xu, Kun; Xu, Chen, E-mail: xuchen58@bjut.edu.cn; Deng, Jun; Zhu, Yanxu; Guo, Weiling; Mao, Mingming; Xun, Meng; Chen, Maoxing; Zheng, Lei [Key Laboratory of Optoelectronics Technology, Beijing University of Technology, Ministry of Education, Beijing 100124 (China)] [Key Laboratory of Optoelectronics Technology, Beijing University of Technology, Ministry of Education, Beijing 100124 (China); Xie, Yiyang [State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductor, Chinese Academy of Sciences, Beijing 100083 (China)] [State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductor, Chinese Academy of Sciences, Beijing 100083 (China); Sun, Jie, E-mail: jie.sun@chalmers.se [Key Laboratory of Optoelectronics Technology, Beijing University of Technology, Ministry of Education, Beijing 100124 (China) [Key Laboratory of Optoelectronics Technology, Beijing University of Technology, Ministry of Education, Beijing 100124 (China); Mikroteknologi och Nanovetenskap, Chalmers Tekniska Högskola AB, Göteborg 41296 (Sweden)

2013-11-25T23:59:59.000Z

114

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

Science Journals Connector (OSTI)

Artificial lighting systems are transitioning from incandescent to compact fluorescent lamp (CFL) and light-emitting diode (LED) bulbs in response to the U.S. Energy Independence and Security Act and the EU Ecodesign Directive, which leads to energy savings and reduced greenhouse gas emissions. ... The CFLs and LEDs have higher resource depletion and toxicity potentials than the incandescent bulb due primarily to their high aluminum, copper, gold, lead, silver, and zinc. ... mercury pollution; redn. in electricity demand from the substitution of incandescent bulbs with fluorescents leads to reduced mercury emissions during the use of the bulb. ...

Seong-Rin Lim; Daniel Kang; Oladele A. Ogunseitan; Julie M. Schoenung

2012-12-13T23:59:59.000Z

115

Development and Utilization of Host Materials for White Phosphorescent Organic Light-Emitting Diodes  

SciTech Connect (OSTI)

Our project was primarily focused on the MYPP 2015 goal for white phosphorescent organic devices (PhOLEDs or phosphorescent organic light-emitting diodes) for solid-state lighting with long lifetimes and high efficiencies. Our central activity was to synthesize and evaluate a new class of host materials for blue phosphors in the PhOLEDs, known to be a weak link in the device operating lifetime. The work was a collaborative effort between three groups, one primarily responsible for chemical design and characterization (Chen), one primarily responsible for device development (Tang) and one primarily responsible for mechanistic studies and degradation analysis (Rothberg). The host materials were designed with a novel architecture that chemically links groups with good ability to move electrons with those having good ability to move “holes” (positive charges), the main premise being that we could suppress the instability associated with physical separation and crystallization of the electron conducting and hole conducting materials that might cause the devices to fail. We found that these materials do prevent crystallization and that this will increase device lifetimes but that efficiencies were reduced substantially due to interactions between the materials creating new low energy “charge transfer” states that are non-luminescent. Therefore, while our proposed strategy could in principle improve device lifetimes, we were unable to find a materials combination where the efficiency was not substantially compromised. In the course of our project, we made several important contributions that are peripherally related to the main project goal. First, we were able to prepare the proposed new family of materials and develop synthetic routes to make them efficiently. These types of materials that can transport both electrons and holes may yet have important roles to play in organic device technology. Second we developed an important new method for controlling the deposition profile of material so that arbitrary concentration gradients can be implemented in layers with mixed composition. These concentration profiles are known to increase device efficiency and longevity and we confirmed that experimentally. Third, we investigated a new method for analyzing degradation in devices using mass spectrometry to look for degradation products. We showed that these methods are not simple to interpret unambiguously and need to be used with caution.

Tang, Ching; Chen, Shaw

2013-05-31T23:59:59.000Z

116

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

Science Journals Connector (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

117

Solid-State Lighting Home Page for Semiconductor light emitting diodes  

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

118

Local indium segregation and band structure in high efficiencygreen light emitting InGaN/GaN diodes  

SciTech Connect (OSTI)

GaN/InGaN light emitting diodes (LEDs) are commercialized for lighting applications because of the cost efficient way that they produce light of high brightness. Nevertheless, there is significant room for improving their external emission efficiency from typical values below 10 percent to more than 50 percent, which are obtainable by use of other materials systems that, however, do not cover the visible spectrum. In particular, green-light emitting diodes fall short in this respect, which is troublesome since the human eye is most sensitive in this spectral range. In this letter advanced electron microscopy is used to characterize indium segregation in InGaN quantum wells of high-brightness, green LEDs (with external quantum efficiency as high as 15 percent at 75 A/cm2). Our investigations reveal the presence of 1-3 nm wide indium rich clusters in these devices with indium concentrations as large as 0.30-0.40 that narrow the band gap locally to energies as small as 2.65 eV.

Jinschek, Joerg R.; Erni, Rolf; Gardner, Nathan F.; Kim, AndrewY.; Kisielowski, Christian

2004-11-23T23:59:59.000Z

119

An indole derivative as a high triplet energy hole transport material for blue phosphorescent organic light-emitting diodes  

Science Journals Connector (OSTI)

Abstract A thermally stable high triplet energy material derived from an indoloacridine core and indole hole transport units, 8,8-bis(4-(1H-indol-1-yl)phenyl)-8H-indolo[3,2,1-de]acridine (BIPIA), was synthesized as the hole transport material for deep blue phosphorescent organic light-emitting diodes. The BIPIA hole transport material showed a high triplet energy of 2.95 eV and high glass transition temperature of 142 °C. A high quantum efficiency of 19.3% was obtained in the deep blue device using BIPIA as the high triplet energy hole transport material.

Min Su Park; Jun Yeob Lee

2013-01-01T23:59:59.000Z

120

Carbazolyldibenzofuran-type high-triplet-energy bipolar host material for blue phosphorescent organic light-emitting diodes  

Science Journals Connector (OSTI)

Abstract A high-triplet-energy material, 9?-(4,4?-(phenylphosphoryl)bis(dibenzo[b,d]furan-6,2-diyl))bis(9H-carbazole) (44DFCzPO), was synthesized as a bipolar host material for blue phosphorescent organic light-emitting diodes (PHOLEDs). 44DFCzPO was synthesized by the selective lithiation of the 4-position of a carbazole-modified dibenzofuran, followed by phosphorylation. 44DFCzPO showed a high triplet energy of 2.91 eV for energy transfer to a blue phosphorescent dopant, and bipolar charge transport properties for balanced hole and electron density in the emitting layer. A high quantum efficiency of 16.7% at a low doping concentration of 3% was obtained using 44DFCzPO as the host in blue PHOLEDs.

Sook Hee Jeong; Jun Yeob Lee

2014-01-01T23:59:59.000Z

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

Photonic crystal light emitting diode based on Er and Si nanoclusters co-doped slot waveguide  

SciTech Connect (OSTI)

We report on the design, fabrication, and electro-optical characterization of a light emitting device operating at 1.54??m, whose active layer consists of silicon oxide containing Er-doped Si nanoclusters. A photonic crystal (PhC) is fabricated on the top-electrode to enhance the light extraction in the vertical direction, and thus the external efficiency of the device. This occurs if a photonic mode of the PhC slab is resonant with the Er emission energy, as confirmed by theoretical calculations and experimental analyses. We measure an increase of the extraction efficiency by a factor of 3 with a high directionality of light emission in a narrow vertical cone. External quantum efficiency and power efficiency are among the highest reported for this kind of material. These results are important for the realization of CMOS-compatible efficient light emitters at telecom wavelengths.

Lo Savio, R.; Galli, M.; Liscidini, M.; Andreani, L. C. [Dipartimento di Fisica, Università di Pavia, Via Bassi 6, 27100 Pavia (Italy); Franzò, G.; Iacona, F.; Miritello, M. [MATIS-IMM CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Irrera, A. [CNR-IPCF, Viale Ferdinando Stagno d'Alcontres 37, 98158 Messina (Italy); Sanfilippo, D.; Piana, A. [ST Microelectronics, Stradale Primosole 50, 95121 Catania (Italy); Priolo, F. [MATIS-IMM CNR and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, 95123 Catania (Italy); Scuola Superiore di Catania, Università di Catania, Via Valdisavoia 9, 95123 Catania (Italy)

2014-03-24T23:59:59.000Z

122

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

SciTech Connect (OSTI)

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

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

2014-03-07T23:59:59.000Z

123

Phosphor-free nanopyramid white light-emitting diodes grown on (101{sup ¯}1) planes using nanospherical-lens photolithography  

SciTech Connect (OSTI)

We reported a high-efficiency and low-cost nano-pattern method, the nanospherical-lens photolithography technique, to fabricate a SiO{sub 2} mask for selective area growth. By controlling the selective growth, we got a highly ordered hexagonal nanopyramid light emitting diodes with InGaN/GaN quantum wells grown on nanofacets, demonstrating an electrically driven phosphor-free white light emission. We found that both the quantum well width and indium incorporation increased linearly along the (101{sup ¯}1) planes towards the substrate and the perpendicular direction to the (101{sup ¯}1) planes as well. Such spatial distribution was responsible for the broadband emission. Moreover, using cathodoluminescence techniques, it was found that the blue emission originated from nanopyramid top, resembling the quantum dots, green emission from the InGaN quantum wells layer at the middle of sidewalls, and yellow emission mainly from the bottom of nanopyramid ridges, similar to the quantum wires.

Wu, Kui [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China) [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Department of Electronic Engineering, Tsinghua National Laboratory for Information Science and Technology/State Key Lab on Integrated Optoelectronics, Tsinghua University, Beijing 100084 (China); Wei, Tongbo, E-mail: tbwei@semi.ac.cn; Wei, Xuecheng; Zheng, Haiyang; Chen, Yu; Lu, Hongxi; Wang, Junxi; Li, Jinmin [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)] [State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Lan, Ding [National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080 (China)] [National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080 (China); Huang, Kai [Platform of Characterization and Test, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215000 (China)] [Platform of Characterization and Test, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215000 (China); Luo, Yi [Department of Electronic Engineering, Tsinghua National Laboratory for Information Science and Technology/State Key Lab on Integrated Optoelectronics, Tsinghua University, Beijing 100084 (China)] [Department of Electronic Engineering, Tsinghua National Laboratory for Information Science and Technology/State Key Lab on Integrated Optoelectronics, Tsinghua University, Beijing 100084 (China)

2013-12-09T23:59:59.000Z

124

Low-cost electrochemical treatment of indium tin oxide anodes for high-efficiency organic light-emitting diodes  

SciTech Connect (OSTI)

We demonstrate a simple low-cost approach as an alternative to conventional O{sub 2} plasma treatment to modify the surface of indium tin oxide (ITO) anodes for use in organic light-emitting diodes. ITO is functionalized with F{sup ?} ions by electrochemical treatment in dilute hydrofluoric acid. An electrode with a work function of 5.2?eV is achieved following fluorination. Using this electrode, a maximum external quantum efficiency of 26.0% (91?cd/A, 102?lm/W) is obtained, which is 12% higher than that of a device using the O{sub 2} plasma-treated ITO. Fluorination also increases the transparency in the near-infrared region.

Hui Cheng, Chuan, E-mail: chengchuanhui@dlut.edu.cn; Shan Liang, Ze; Gang Wang, Li; Dong Gao, Guo; Zhou, Ting; Ming Bian, Ji; Min Luo, Ying [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Tong Du, Guo, E-mail: dugt@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

2014-01-27T23:59:59.000Z

125

Barrier performance optimization of atomic layer deposited diffusion barriers for organic light emitting diodes using x-ray reflectivity investigations  

SciTech Connect (OSTI)

The importance of O{sub 3} pulse duration for encapsulation of organic light emitting diodes (OLEDs) with ultra thin inorganic atomic layer deposited Al{sub 2}O{sub 3} layers is demonstrated for deposition temperatures of 50 °C. X-ray reflectivity (XRR) measurements show that O{sub 3} pulse durations longer than 15?s produce dense and thin Al{sub 2}O{sub 3} layers. Correspondingly, black spot growth is not observed in OLEDs encapsulated with such layers during 91 days of aging under ambient conditions. This implies that XRR can be used as a tool for process optimization of OLED encapsulation layers leading to devices with long lifetimes.

Singh, Aarti, E-mail: aarti.singh@namlab.com; Schröder, Uwe [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany)] [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany); Klumbies, Hannes; Müller-Meskamp, Lars; Leo, Karl [Dresden Innovation Center Energy Efficiency, Institut für Angewandte Photophysik, Technische Universität Dresden, 01062 Dresden (Germany)] [Dresden Innovation Center Energy Efficiency, Institut für Angewandte Photophysik, Technische Universität Dresden, 01062 Dresden (Germany); Geidel, Marion; Knaut, Martin; Hoßbach, Christoph; Albert, Matthias [Institute of Semiconductor and Microsystems Technology, Technische Universität Dresden, 01187 Dresden (Germany)] [Institute of Semiconductor and Microsystems Technology, Technische Universität Dresden, 01187 Dresden (Germany); Mikolajick, Thomas [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany) [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany); Institute of Semiconductor and Microsystems Technology, Technische Universität Dresden, 01187 Dresden (Germany)

2013-12-02T23:59:59.000Z

126

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

SciTech Connect (OSTI)

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

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

2014-02-03T23:59:59.000Z

127

High triplet energy Al complex as a host material for blue phosphorescent organic light-emitting diodes  

Science Journals Connector (OSTI)

Abstract An Al complex, tris((2-(pyrazol-1-yl)pyridin-3-yl)oxy)aluminum (Al(pypy)3), was synthesized as a high triplet energy host material for blue phosphorescent organic light-emitting diodes. A high triplet energy ligand, 2-(1H-pyrazol-1-yl)pyridin-3-ol, was coordinated to the Al to develop the high triplet energy host material derived from Al. The Al(pypy)3 host showed a high triplet energy of 2.86 eV for efficient energy transfer to blue triplet emitter. A maximum quantum efficiency of 20.5% was achieved in blue device using the Al(pypy)3 host material.

Chan Seok Oh; Jun Yeob Lee

2014-01-01T23:59:59.000Z

128

Effects of internal fields on deep-level emission in InGaN/GaN quantum-well light-emitting diodes  

Science Journals Connector (OSTI)

We report on the important role played by internal quantum well (QW) fields in the anomalous inversion of capacitance transients in InGaN/GaN multi-QW light-emitting diodes (LEDs). This effect was observed by deep-level transient spectroscopy (DLTS) ... Keywords: Deep level, III-Nitride, Internal fields, Quantum well

L. Rigutti; A. Castaldini; A. Cavallini

2009-02-01T23:59:59.000Z

129

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

E-Print Network [OSTI]

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

Christian, Theresa M.

130

A highly color-stability white organic light-emitting diode by color conversion within hole injection layer  

Science Journals Connector (OSTI)

We demonstrated a novel-structure white organic light-emitting devices (WOLEDs) composed of a greenish blue fluorescent emitting layer and a red fluorescent dye-doped hole injection...

Li, C; Ichikawa, M; Wei, B; Taniguchi, Y; Kimura, H; Kawaguchi, K; Sakurai, K

2007-01-01T23:59:59.000Z

131

Bilirubin phototransformation in vitro using a battery-powered, solar-charged, high-intensity blue light-emitting diode phototherapy blanket  

Science Journals Connector (OSTI)

The availability of new, higher intensity Blue Light-Emitting Diodes (LEDs), as used in the development of our LED phototherapy blanket, led us to hypothesise that our blue LED phototherapy system would phototransform bilirubin more rapidly, in vitro, than the current commercially available, state-of-the-art phototherapy system. Furthermore, we theorised that increasing light intensity, beyond levels previously studied, would lead to increasing rates of bilirubin phototransformation.

Harel Rosen; Jerome J. Hric; Arye Rosen; Danielle Rosen; Shalom Komornik; Kathy Zaleski; Susan Yaron

2014-01-01T23:59:59.000Z

132

Enhancing the performance of organic-inorganic hybrid light-emitting diodes by inserting a conjugated polyelectrolyte interlayer  

Science Journals Connector (OSTI)

Hybrid light-emitting diodes (HyLEDs) incorporating the advantages of organic and inorganic semiconductors, were promising to realise efficient electroluminescence with air-stable charge-injection interfaces. However, HyLEDs with only inorganic semiconductor such as zinc oxide (ZnO) as electron-injection layer suffered from low devices efficiencies due to large electron injection barrier. To improve the electron injection, conjugated polyelectrolyte poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) was used together with ZnO as electron-injection layer by fabricating it on top of ZnO. Experimental data showed that the light efficiencies of HyLEDs were almost doubled after the insertion of PFN. The performances enhancement was attributed to the reduced energy barrier for electron injection from ZnO. The electron current increased. And therefore, the balance of electron and hole currents was improved.

Yongli Wang; Qiaoli Niu; Donghuan Qin; Hongmei Liu; Yong Zhang

2014-01-01T23:59:59.000Z

133

Phosphorescent Light–Emitting Iridium Complexes Serve as a Hypoxia-Sensing Probe for Tumor Imaging in Living Animals  

Science Journals Connector (OSTI)

...complex is a promising organic light-emitting diode material for next generation...required for use as organic light-emitting diode emitters. Furthermore, we...complex is a promising organic light-emitting diode material for next generation...

Shaojuan Zhang; Masahiro Hosaka; Toshitada Yoshihara; Kazuya Negishi; Yasuhiko Iida; Seiji Tobita; Toshiyuki Takeuchi

2010-06-01T23:59:59.000Z

134

A study on full color organic light emitting diodes with blue common layer under the patterned emission layer  

Science Journals Connector (OSTI)

Abstract Color patterning steps for red, green, and blue emission layers (EMLs) are crucial for the production of full color organic light-emitting diodes (OLEDs). The most common method to form individually patterned \\{EMLs\\} is to use a shadow mask as the key component for patterning. However, most pixel defects are caused by such kinds of patterning steps. Therefore, skipping certain color patterning steps could significantly improve the production yield during the fine metal masking process in the OLED fabrication. A representative example of such approach is the top blue common layer (TBCL) structure with a non-patterned BCL on top of both green and red EMLs. However, this structure could cause blue color mixing in green or red devices. To prevent this effect, we propose a newly devised bottom BCL (BBCL) structure with the BCL that is totally separated from both green and red EMLs. In particular, we utilized 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile interlayer (7 nm) between the underlying BCL and the hole injection layer to completely extinguish blue emission. As a result, both green and red devices with the BBCL structure showed relatively better efficiencies compared to those with the TBCL structure without any color mixing.

Hee Young Shin; Min Chul Suh

2014-01-01T23:59:59.000Z

135

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

SciTech Connect (OSTI)

Efficient indium tin oxide (ITO)-free small molecule organic light-emitting diodes (SMOLEDs) with multilayered highly conductive poly(3,4-ethylenedioxy thiophene):poly(styrenesulfonate) (PEDOT:PSS) as the anode are demonstrated. PEDOT:PSS/MoO{sub 3}/N,N'-diphenyl- N,N'-bis(1-naphthylphenyl)-1,1'-biphenyl-4,4'-diamine (NPD)/tris(8-hydroxyquinoline) Al (Alq{sub 3})/4,7-diphenyl-1,10-phenanthroline (BPhen)/LiF/Al SMOLEDs exhibited a peak power efficiency of 3.82 lm/W, 81% higher than that of similar ITO-based SMOLEDs (2.11 lm/W). The improved performance is believed to be due to the higher work function, lower refractive index, and decreased surface roughness of PEDOT:PSS vs ITO, and to Ohmic hole injection from PEDOT:PSS to the NPD layer via the MoO{sub 3} interlayer. The results demonstrate that PEDOT:PSS can substitute ITO in SMOLEDs with strongly improved device performance.

Cai, Min; Xiao, Teng; Liu, Rui; Chen, Ying; Shinar, Ruth; Shinar, Joseph

2011-10-11T23:59:59.000Z

136

Quantum-dot light-emitting diodes utilizing CdSe/ZnS nanocrystals embedded in TiO{sub 2} thin film  

SciTech Connect (OSTI)

Quantum-dot (QD) light-emitting diodes (LEDs) are demonstrated on Si wafers by embedding core-shell CdSe/ZnS nanocrystals in TiO{sub 2} thin films via plasma-enhanced metallorganic chemical vapor deposition. The n-TiO{sub 2}/QDs/p-Si LED devices show typical p-n diode current-voltage and efficient electroluminescence characteristics, which are critically affected by the removal of QD surface ligands. The TiO{sub 2}/QDs/Si system we presented can offer promising Si-based optoelectronic and electronic device applications utilizing numerous nanocrystals synthesized by colloidal solution chemistry.

Kang, Seung-Hee; Kumar, Ch. Kiran; Kim, Eui-Tae [Department of Materials Science and Engineering, Chungnam National University, Daeduk Science Town, Daejeon 305-764 (Korea, Republic of); Lee, Zonghoon [National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 72-150, Berkeley, California 94720 (United States); Kim, Kyung-Hyun; Huh, Chul [Electronics and Telecommunications Research Institute, Daeduk Science Town, Daejeon 305-350 (Korea, Republic of)

2008-11-10T23:59:59.000Z

137

Pseudomorphic Mid-Ultraviolet Light-Emitting Diodes for Water Purification  

Science Journals Connector (OSTI)

UVC light output of 66 mW at 300 mA CW has been achieved from LEDs on AlN substrates with extensive photon extraction. Proper vessel design allows for efficient irradiation of a water...

Moe, Craig; Chen, Jianfeng; Grandusky, James R; Mendrick, Mark C; Randive, Rajul; Rodak, Lee E; Sampath, Anand V; Wraback, Michael; Schowalter, Leo

138

Full phosphorescent white-light organic light-emitting diodes with improved color stability and efficiency by fine tuning primary emission contributions  

SciTech Connect (OSTI)

In this paper, a novel type of white-light organic light emitting diode (OLED) with high color stability was reported, in which the yellow-light emission layer of (4,4{sup ?}-N,N{sup ?}-dicarbazole)biphenyl (CBP) : tris(2-phenylquinoline-C2,N{sup ?})iridium(III) (Ir(2-phq){sub 3}) was sandwiched by double blue-light emission layers of 1,1-bis-[(di-4-tolylamino)pheny1]cyclohexane (TAPC) : bis[4,6-(di-fluorophenyl)-pyridinato-N,C2{sup ?}]picolinate (FIrpic) and tris[3-(3-pyridyl)mesityl]borane (3TPYMB):FIrpic. And, it exhibited the maximum current efficiency of 33.1 cd/A, the turn-on voltage at about 3 V and the maximum luminance in excess of 20000 cd/m{sup 2}. More important, it realized very stable white-light emission, and its CIE(x, y) coordinates only shift from (0.34, 0.37) to (0.33, 0.37) as applied voltage increased from 5 V to 12 V. It is believed that the new scheme in emission layer of white-light OLED can fine tune the contribution of primary emission with applied voltage changed, resulting in high quality white-light OLED.

Hua, Wang, E-mail: wmsu2008@sinano.ac.cn, E-mail: wanghua001@tyut.edu.cn; Du, Xiaogang [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China) [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China); Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Su, Wenming, E-mail: wmsu2008@sinano.ac.cn, E-mail: wanghua001@tyut.edu.cn; Zhang, Dongyu [Printable Electronics Research Centre, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, suzhou 215123 (China)] [Printable Electronics Research Centre, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, suzhou 215123 (China); Lin, Wenjing [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China) [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China); Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Printable Electronics Research Centre, Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, suzhou 215123 (China)

2014-02-15T23:59:59.000Z

139

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

SciTech Connect (OSTI)

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

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

2014-09-01T23:59:59.000Z

140

Modification of polycrystalline silicon as efficient anode for active-matrix organic light-emitting diodes  

E-Print Network [OSTI]

Modification of polycrystalline silicon as efficient anode for active- matrix organic light silicon (p-Si) on the performance of p-Si anode OLEDs have been studied. UV-ozone treatment of p. By depositing ultra-thin high work function metal oxides, such as V2O5 and MoO3, on p-Si anode, the performance

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141

Fabrication of color tunable organic light-emitting diodes by an alignment free mask patterning method  

E-Print Network [OSTI]

that of the incandescent bulb and comparable with that of the fluorescent tube. OLEDs are a true sur- face/area lighting as that of a point source like LEDs. OLEDs are mercury free thus environmentally friendly. More impor- tantly, OLEDs electrochemical doping to make the two color polymer LEDs, in which two colors can be obtained by changing

142

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

E-Print Network [OSTI]

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

Okamoto, Koichi

143

Semitransparent metal or distributed Bragg reflector for wide-viewing-angle organic light-emitting-diode microcavities  

Science Journals Connector (OSTI)

Microcavities for organic light-emitting devices (OLED’s) with a metal mirror on one side and a distributed Bragg reflector (DBR) on the other side have been extensively studied in...

Neyts, Kristiaan; De Visschere, Patrick; Fork, David K; Anderson, Greg B

2000-01-01T23:59:59.000Z

144

Enhancing the performance of organic light emitting diodes by using nanostructured composite films  

Science Journals Connector (OSTI)

Recent achievements on the use of nanocomposites such as nanostructured composites with a structure of nanoparticles embedded in polymers (NIP) and nanocomposites with a structure of polymers deposited on nanoporous thin films (PON) for OLEDs are presented in this report. The influence of nanooxides on the photoelectric properties of the NIPs is explained with regard to the fact that TiO2 particles usually form a type-II heterojunction with a polymer matrix, which essentially results in the separation of non-equilibrium electrons and holes. MEH-PPV luminescence quenching is strongly dependent on the nature of nanostructural particles embedded in polymer matrix. Actually, the higher quenching of the polymer fluorescence observed in the presence of titania nanoparticles proves that the transfer of the photogenerated electrons to the TiO2 is more efficient for rods. Characterisation of the nanocomposite films showed that both the current-voltage characteristics and the photoluminescent properties of the NIP nanocomposite materials were significantly enhanced in comparison with the standard polymers. OLEDs made from these layers demonstrate high photonic efficiency. For a PON-like hybrid layer of MEH-PPV/nc-TiO2, the photoluminescence enhancement was observed when the MEHPPV-PON films were excited by a 325 nm wavelength laser, and the excitation of a 470 nm wavelength light resulted in the strong polymer fluorescence quenching. Current-voltage characteristics of laminar layer devices with a structure of Ti/PON/Al-Ag in comparison with that of Ti/MEH-PPV/Al-Ag showed that the turn-on voltage of the devices was lowered considerably. Therefore, PONs are suitable for use in a reverse OLED, where the light goes out through a transparent or semi-transparent cathode; moreover, it is much easier to make ohmic contact to the metallic Ti electrode.

Nguyen Nang Dinh; Le Ha Chi; Tran Quang Trung

2011-01-01T23:59:59.000Z

145

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

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

146

Comparison of light out-coupling enhancements in single-layer blue-phosphorescent organic light emitting diodes using small-molecule or polymer hosts  

SciTech Connect (OSTI)

Single-layer blue phosphorescence organic light emitting diodes (OLEDs) with either small-molecule or polymer hosts are fabricated using solution process and the performances of devices with different hosts are investigated. The small-molecule device exhibits luminous efficiency of 14.7?cd/A and maximum power efficiency of 8.39?lm/W, which is the highest among blue phosphorescence OLEDs with single-layer solution process and small molecular hosts. Using the same solution process for all devices, comparison of light out-coupling enhancement, with brightness enhancement film (BEF), between small-molecule and polymer based OLEDs is realized. Due to different dipole orientation and anisotropic refractive index, polymer-based OLEDs would trap less light than small molecule-based OLEDs internally, about 37% better based simulation results. In spite of better electrical and spectroscopic characteristics, including ambipolar characteristics, higher carrier mobility, higher photoluminescence quantum yield, and larger triplet state energy, the overall light out-coupling efficiency of small molecule-based devices is worse than that of polymer-based devices without BEF. However, with BEF for light out-coupling enhancement, the improved ratio in luminous flux and luminous efficiency for small molecule based device is 1.64 and 1.57, respectively, which are significantly better than those of PVK (poly-9-vinylcarbazole) devices. In addition to the theoretical optical simulation, the experimental data also confirm the origins of differential light-outcoupling enhancement. The maximum luminous efficiency and power efficiency are enhanced from 14.7?cd/A and 8.39?lm/W to 23?cd/A and 13.2?lm/W, respectively, with laminated BEF, which are both the highest so far for single-layer solution-process blue phosphorescence OLEDs with small molecule hosts.

Chang, Yung-Ting [Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11529, Taiwan (China); Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 10617, Taiwan (China); Liu, Shun-Wei [Department of Electronic Engineering, Mingchi University of Technology, New Taipei, Taiwan 24301, Taiwan (China); Yuan, Chih-Hsien; Lee, Chih-Chien [Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10607, Taiwan (China); Ho, Yu-Hsuan; Wei, Pei-Kuen [Research Center for Applied Science Academia Sinica, Taipei, Taiwan 11527, Taiwan (China); Chen, Kuan-Yu [Chilin Technology Co., LTD, Tainan City, Taiwan 71758, Taiwan (China); Lee, Yi-Ting; Wu, Min-Fei; Chen, Chin-Ti, E-mail: cchen@chem.sinica.edu.tw, E-mail: chihiwu@cc.ee.ntu.edu.tw [Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11529, Taiwan (China); Wu, Chih-I, E-mail: cchen@chem.sinica.edu.tw, E-mail: chihiwu@cc.ee.ntu.edu.tw [Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan 10617, Taiwan (China)

2013-11-07T23:59:59.000Z

147

Using interlayer step-wise triplet transfer to achieve an efficient white organic light-emitting diode with high color-stability  

SciTech Connect (OSTI)

An efficient phosphorescent white organic light emitting-diode with a red-green-blue tri-emitting-layer structure is reported. The host of the red dopant possesses a lower triplet-energy than the green dye. An interlayer step-wise triplet transfer via blue dye ? green dye ? red host ? red dye is achieved. This mechanism allows an efficient triplet harvesting by the three dopants, thus maintaining a balanced white light and reducing energy loss. Moreover, the color stability of the device is improved significantly. The white device not only achieves a peak external quantum efficiency of 21.1?±?0.8% and power efficiency of 37.5?±?1.4?lm/W but shows no color shift over a wide range of voltages.

Wang, Qi [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China); Department of Electrical Engineering and Computer Sciences, College of Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Ma, Dongge, E-mail: mdg1014@ciac.jl.cn; Ding, Junqiao; Wang, Lixiang [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China); Leo, Karl [Tech. Univ. Dresden, Inst. Angew. Photophys., D-01062 Dresden (Germany); Qiao, Qiquan [Department of Electrical Engineering and Computer Sciences, College of Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Jia, Huiping; Gnade, Bruce E. [Department of Materials Science and Engineering and Erik Jonsson School of Engineering and Computer Science, University of Texas at Dallas, Richardson, Texas 75083 (United States)

2014-05-12T23:59:59.000Z

148

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

E-Print Network [OSTI]

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

149

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

SciTech Connect (OSTI)

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

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

2014-02-03T23:59:59.000Z

150

Improved power efficiency in blue phosphorescent organic light-emitting diodes using diphenylmethyl linkage based high triplet energy hole transport materials  

Science Journals Connector (OSTI)

Improved power efficiency in blue phosphorescent organic light-emitting diodes (PHOLEDs) was demonstrated by using new high triplet energy hole-transport materials based on the diphenylmethyl linkage. Two high triplet energy hole-transport materials with diphenylamine or ditolyamine moieties linked through a diphenylmethyl linkage, 4,4?-(diphenylmethylene)bis(N,N-diphenylaniline) (TCBPA) and 4,4?-(diphenylmethylene)bis(N,N-di-p-tolylaniline), were synthesized and evaluated as hole-transport materials for blue PHOLEDs. The power efficiency of TCBPA was superior to that of standard 1,1-bis[4-[N,N?-di(p-tolyl)amino]phenyl]cyclohexane.

Chil Won Lee; Jun Yeob Lee

2013-01-01T23:59:59.000Z

151

The effect of nocturnal blue light exposure from light-emitting diodes on wakefulness and energy metabolism the following morning  

Science Journals Connector (OSTI)

The control of sleep/wakefulness is associated with the regulation of energy metabolism. The present experiment was designed to assess the effect of nocturnal blue light exposure on the control of sleep/wakefulne...

Momoko Kayaba; Kaito Iwayama; Hitomi Ogata…

2014-09-01T23:59:59.000Z

152

Thermally activated delayed fluorescence from {sup 3}n?* to {sup 1}n?* up-conversion and its application to organic light-emitting diodes  

SciTech Connect (OSTI)

Intense n?* fluorescence from a nitrogen-rich heterocyclic compound, 2,5,8-tris(4-fluoro-3-methylphenyl)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3MF), is demonstrated. The overlap-forbidden nature of the n?* transition and the higher energy of the {sup 3}??* state than the {sup 3}n?* one lead to a small energy difference between the lowest singlet (S{sub 1}) and triplet (T{sub 1}) excited states of HAP-3MF. Green-emitting HAP-3MF has a moderate photoluminescence quantum yield of 0.26 in both toluene and doped film. However, an organic light-emitting diode containing HAP-3MF achieved a high external quantum efficiency of 6.0%, indicating that HAP-3MF harvests singlet excitons through a thermally activated T{sub 1} ? S{sub 1} pathway in the electroluminescent process.

Li, Jie; Zhang, Qisheng; Nomura, Hiroko [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Miyazaki, Hiroshi [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Functional Materials Laboratory, Nippon Steel and Sumikin Chemical Co., Ltd, 46–80 Nakabaru, Sakinohama, Tobata, Kitakyushu, Fukuoka 804–8503 (Japan); Adachi, Chihaya, E-mail: adachi@cstf.kyushu-u.ac.jp [Department of Chemistry and Biochemistry, and Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan)

2014-07-07T23:59:59.000Z

153

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

SciTech Connect (OSTI)

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

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

2008-11-10T23:59:59.000Z

154

Tunnel-injection quantum dot deep-ultraviolet light-emitting diodes with polarization-induced doping in III-nitride heterostructures  

SciTech Connect (OSTI)

Efficient semiconductor optical emitters in the deep-ultraviolet spectral window are encountering some of the most deep rooted problems of semiconductor physics. In III-Nitride heterostructures, obtaining short-wavelength photon emission requires the use of wide bandgap high Al composition AlGaN active regions. High conductivity electron (n-) and hole (p-) injection layers of even higher bandgaps are necessary for electrical carrier injection. This approach requires the activation of very deep dopants in very wide bandgap semiconductors, which is a difficult task. In this work, an approach is proposed and experimentally demonstrated to counter the challenges. The active region of the heterostructure light emitting diode uses ultrasmall epitaxially grown GaN quantum dots. Remarkably, the optical emission energy from GaN is pushed from 365?nm (3.4?eV, the bulk bandgap) to below 240?nm (>5.2?eV) because of extreme quantum confinement in the dots. This is possible because of the peculiar bandstructure and band alignments in the GaN/AlN system. This active region design crucially enables two further innovations for efficient carrier injection: Tunnel injection of carriers and polarization-induced p-type doping. The combination of these three advances results in major boosts in electroluminescence in deep-ultraviolet light emitting diodes and lays the groundwork for electrically pumped short-wavelength lasers.

Verma, Jai, E-mail: jverma@nd.edu; Islam, S. M.; Protasenko, Vladimir; Kumar Kandaswamy, Prem; Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2014-01-13T23:59:59.000Z

155

Studying singlet fission and triplet fusion by magneto-electroluminescence method in singlet–triplet energy-resonant organic light-emitting diodes  

Science Journals Connector (OSTI)

Abstract Organic light emitting diodes (OLEDs) utilizing a singlet–triplet energy-resonant (ES ? 2ET) layer (rubrene) were fabricated to investigate the singlet fission and triplet fusion by the magneto-electroluminescence (MEL) of device from R.T. to 20 K. A large positive MEL (23.5%) was obtained at R.T. due to magnetic-field-suppressed singlet fission. With decreasing temperatures, the \\{MELs\\} changed their signs both at low-field and high-field components because of a gradual decrease in singlet fission simultaneously followed by an increasing triplet fusion, leading to a negative MEL around ?7.5% at 20 K. Moreover, transient electroluminescence and \\{MELs\\} from the control devices were used to further confirm the exciton fission and fusion processes in rubrene-based OLEDs. Our findings of MEL may provide a useful pathway to study the microscopic dynamics of excited states in organic optoelectronic devices.

J.W. Bai; P. Chen; Y.L. Lei; Y. Zhang; Q.M. Zhang; Z.H. Xiong; F. Li

2014-01-01T23:59:59.000Z

156

Enhancement of hole injection and electroluminescence by ordered Ag nanodot array on indium tin oxide anode in organic light emitting diode  

SciTech Connect (OSTI)

We report the enhancement of hole injection and electroluminescence (EL) in an organic light emitting diode (OLED) with an ordered Ag nanodot array on indium-tin-oxide (ITO) anode. Until now, most researches have focused on the improved performance of OLEDs by plasmonic effects of metal nanoparticles due to the difficulty in fabricating metal nanodot arrays. A well-ordered Ag nanodot array is fabricated on the ITO anode of OLED using the nanoporous alumina as an evaporation mask. The OLED device with Ag nanodot arrays on the ITO anode shows higher current density and EL enhancement than the one without any nano-structure. These results suggest that the Ag nanodot array with the plasmonic effect has potential as one of attractive approaches to enhance the hole injection and EL in the application of the OLEDs.

Jung, Mi, E-mail: jmnano00@gmail.com, E-mail: Dockha@kist.re.kr [Sensor System Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); School of Mechanical Systems Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Mo Yoon, Dang; Kim, Miyoung [Korea Printed Electronics Center, Korea Electronics Technology Institute, Jeollabuk-do, 561-844 (Korea, Republic of); Kim, Chulki; Lee, Taikjin; Hun Kim, Jae; Lee, Seok; Woo, Deokha, E-mail: jmnano00@gmail.com, E-mail: Dockha@kist.re.kr [Sensor System Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Lim, Si-Hyung [School of Mechanical Systems Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of)

2014-07-07T23:59:59.000Z

157

Zigzag and helical AlN layer prepared by glancing angle deposition and its application as a buffer layer in a GaN-based light-emitting diode  

Science Journals Connector (OSTI)

This study investigates an aluminum nitride (AlN) nanorod structure sputtered by glancing angle deposition (GLAD) and its application as a buffer layer for GaN-based light-emitting diodes (LEDs) that are fabricated on sapphire substrates. The ray tracing ...

Lung-Chien Chen; Ching-Ho Tien; Liu Xuguang; Xu Bingshe

2012-01-01T23:59:59.000Z

158

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

SciTech Connect (OSTI)

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

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

2014-07-07T23:59:59.000Z

159

Abstract --This letter presents highly-polarized edge light emitting diodes with high-confinement, strained, multiple  

E-Print Network [OSTI]

power. We characterize InGaAsP MQW ELED devices with different lengths and optical confinement factors that transitions involving the HH band provide gain/absorption to TE polarized light and those involving the LH band provide gain/absorption mostly to TM polarized light, and to a lesser extent to TE light [7

Coldren, Larry A.

160

Permanent polarization and charge distribution in organic light-emitting diodes (OLEDs): Insights from near-infrared charge-modulation spectroscopy of an operating OLED  

SciTech Connect (OSTI)

Vapor-deposited Alq{sub 3} layers typically possess a strong permanent electrical polarization, whereas NPB layers do not. (Alq{sub 3} is tris(8-quinolinolato)aluminum(III); NPB is 4,4?-bis[N-(1-naphthyl)-N-phenylamino]biphenyl.) The cause is a net orientation of the Alq{sub 3} molecules with their large dipole moments. Here we report on consequences for an organic light-emitting diode (OLED) with an NPB hole-transport layer and Alq{sub 3} electron-transport layer. The discontinuous polarization at the NPB|Alq{sub 3} interface has the same effect as a sheet of immobile negative charge there. It is more than compensated by a large concentration of injected holes (NPB{sup +}) when the OLED is running. We discuss the implications and consequences for the quantum efficiency and the drive voltage of this OLED and others. We also speculate on possible consequences of permanent polarization in organic photovoltaic devices. The concentration of NPB{sup +} was measured by charge-modulation spectroscopy (CMS) in the near infrared, where the NPB{sup +} has a strong absorption band, supplemented by differential-capacitance and current-voltage measurements. Unlike CMS in the visible, this method avoids complications from modulation of the electroluminescence and electroabsorption.

Marchetti, Alfred P.; Haskins, Terri L.; Young, Ralph H.; Rothberg, Lewis J. [Department of Chemistry, University of Rochester, Rochester, New York 14627 (United States)

2014-03-21T23:59:59.000Z

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161

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

SciTech Connect (OSTI)

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

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

2014-06-15T23:59:59.000Z

162

Distinguishing triplet energy transfer and trap-assisted recombination in multi-color organic light-emitting diode with an ultrathin phosphorescent emissive layer  

SciTech Connect (OSTI)

An ultrathin layer of deep-red phosphorescent emitter tris(1-phenylisoquinoline) iridium (III) (Ir(piq){sub 3}) is inserted within different positions of the electron blocking layer fac-tris (1-phenylpyrazolato-N,C{sup 2?})-iridium(III) (Ir(ppz){sub 3}) to distinguish the contribution of the emission from the triplet exciton energy transfer/diffusion from the adjacent blue phosphorescent emitter and the trap-assisted recombination from the narrow band-gap emitter itself. The charge trapping effect of the narrow band-gap deep-red emitter which forms a quantum-well-like structure also plays a role in shaping the electroluminescent characteristics of multi-color organic light-emitting diodes. By accurately controlling the position of the ultrathin sensing layer, it is considerably easy to balance the white emission which is quite challenging for full-color devices with multiple emission zones. There is nearly no energy transfer detectable if 7 nm thick Ir(ppz){sub 3} is inserted between the blue phosphorescent emitter and the ultrathin red emitter.

Xue, Qin, E-mail: xueqin19851202@163.com; Liu, Shouyin [Department of Physical Science and Technology, Central China Normal University, Wuhan 430079 (China); Xie, Guohua; Chen, Ping; Zhao, Yi; Liu, Shiyong [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

2014-03-21T23:59:59.000Z

163

Ligand-Passivated Eu:Y2O3 Nanocrystals as a Phosphor for White Light Emitting Diodes  

Science Journals Connector (OSTI)

As a comparison, incandescent bulbs have a CCT of 2800 K, cool white fluorescent bulbs have a CCT of 6000 K, and daylight is 4500 K. ... We review the history of lighting, discuss the benefits and challenges of the solid-state lighting technologies, and compare two approaches for generating white light from solid-state sources based on phosphor LEDs (which could be considered as solid-state replacement of fluorescent tubes) and multichip LED lamps, which offer many advantages, such as chromaticity control, better light quality, and higher efficiency. ... In addn., several water channels (putative proton pathways) leading from the QB pocket to the surface of the RC were delineated, one of which leads directly to the membrane surface. ...

Qilin Dai; Megan E. Foley; Christopher J. Breshike; Adrian Lita; Geoffrey F. Strouse

2011-08-24T23:59:59.000Z

164

Co-sputtered Aluminum Doped Zinc Oxide Thin Film as Transparent Anode for Organic Light-emitting Diodes  

E-Print Network [OSTI]

Co-sputtered Aluminum Doped Zinc Oxide Thin Film as Transparent Anode for Organic Light and Technology, Clear Water Bay, Kowloon, Hong Kong, China ABSTRACT Aluminum doped zinc oxide (AZO that MTDATA matches better with AZO than CuPc, which served as hole injection layer. Keywords: Aluminum doped

165

Development of a Selective Light-Emitting Diode Photolytic NO2 Converter for Continuously Measuring NO2 in the Atmosphere  

Science Journals Connector (OSTI)

Pyrex glass is cheaper and easier to process than quartz, and the transmission efficiency of UV light for Pyrex (ca. ... Zero air was passed through the PAN (or HONO) source to generate a standard PAN (or HONO) gas, which was introduced into the PLC, Mo, NO, and NO2 lines. ... The missing data in March (from 20 to 24) and April (11 and from 15 to 18) were due to a power outage of the dc power supply for the LEDs and errors in data acquisition, respectively. ...

Yasuhiro Sadanaga; Yuki Fukumori; Tadashi Kobashi; Makoto Nagata; Norimichi Takenaka; Hiroshi Bandow

2010-10-25T23:59:59.000Z

166

Development of a cost effective surface-patterned transparent conductive coating as top-contact of light emitting diodes  

SciTech Connect (OSTI)

Sol-gel process has been used to form indium zinc oxide films using an optimized combination of zinc to indium concentration in the precursor solutions. Different structures, like one (1D) and two-dimensional (2D) gratings and diffractive optical elements (DOEs) in the form of Fresnel lens are fabricated on the film surface of proposed top metal contact of LED by imprint soft lithography technique. These structures can enhance the LED's light extraction efficiency (LEE) or can shape the output beam pattern, respectively. Several characterizations are done to analyze the material and structural properties of the films. The presence of 1D and 2D gratings as well as DOEs is confirmed from field emission scanning electron and atomic force microscopes analyses. Although, X-ray diffraction shows amorphous nature of the film, but transmission electron microscopy study shows that it is nano crystalline in nature having fine particles (?8?nm) of hexagonal ZnO. Shrinkage behaviour of gratings as a function of curing temperature is explained by Fourier transform infra-red spectra and thermo gravimetric-differential thermal analysis. The visible transmission and sheet resistance of the sample are found comparable to tin doped indium oxide (ITO). Therefore, the film can compete as low cost substitute of ITO as top metal contact of LEDs.

Haldar, Arpita [Department of Applied Optics and Photonics, University of Calcutta, Kolkata-700009 (India); Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Bera, Susanta; Jana, Sunirmal, E-mail: sjana@cgcri.res.in, E-mail: srirajib@yahoo.com [Sol-Gel Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Bhattacharya, Kallol; Chakraborty, Rajib, E-mail: sjana@cgcri.res.in, E-mail: srirajib@yahoo.com [Department of Applied Optics and Photonics, University of Calcutta, Kolkata-700009 (India)

2014-05-21T23:59:59.000Z

167

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

SciTech Connect (OSTI)

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

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

2014-03-10T23:59:59.000Z

168

We describe the characteristics and application of a 265nm AlGaN light-emitting diode (LED) operated at 1 MHz repetition rate, 1.2 ns pulse duration, 1.32 W average power, 2.3 mW peak  

E-Print Network [OSTI]

We describe the characteristics and application of a 265nm AlGaN light-emitting diode (LEDnm bandwidth. The LED enables the fluorescence decay of weakly emitting phenylalanine to be measured and resonance energy transfer from phenylalanine to tyrosine and tryptophan, the convenience of the 265nm LED

Strathclyde, University of

169

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

SciTech Connect (OSTI)

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

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

1983-10-01T23:59:59.000Z

170

Wafer-scale surface roughening for enhanced light extraction of high power AlGaInP-based light-emitting diodes  

Science Journals Connector (OSTI)

A new approach to surface roughening was established and optimized in this paper for enhancing the light extraction of high power AlGaInP-based LEDs, by combining ultraviolet (UV)...

Park, Hyeong-Ho; Zhang, Xin; Cho, Yunae; Kim, Dong-Wook; Kim, Joondong; Lee, Keun Woo; Choi, Jehyuk; Lee, Hee Kwan; Jung, Sang Hyun; Her, Eun Jin; Kim, Chang Hwan; Moon, A-Young; Shin, Chan-Soo; Shin, Hyun-Beom; Sung, Ho Kun; Park, Kyung Ho; Park, Hyung-Ho; Kim, Hi-Jung; Kang, Ho Kwan

2014-01-01T23:59:59.000Z

171

Light emitting device comprising phosphorescent materials for white light generation  

DOE Patents [OSTI]

The present invention relates to phosphors for energy downconversion of high energy light to generate a broadband light spectrum, which emit light of different emission wavelengths.

Thompson, Mark E.; Dapkus, P. Daniel

2014-07-22T23:59:59.000Z

172

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

173

Broadband laser diode emitting at 1. 28. mu. m wavelength  

SciTech Connect (OSTI)

This letter presents a broadband laser diode (LD) emitting at the 1.28 ..mu..m wavelength fabricated by introducing an absorption region (300 ..mu..m long) into a conventional 600-..mu..m-long InGaAsP laser diode. The LD operates by the pulsed modulation of a high peak current whose repetition rate and duty cycle are respectively 200 kHz and 5%. The typical output power and the spectral width of the LD are 3.8 mW and 58 A, and the measured coherence length is 210 ..mu..m.

Takada, K.; Noda, J.

1985-10-15T23:59:59.000Z

174

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

175

Recipient luminophoric mediums having narrow spectrum luminescent materials and related semiconductor light emitting devices and methods  

SciTech Connect (OSTI)

Light emitting devices include a light emitting diode ("LED") and a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED. In some embodiments, the recipient luminophoric medium includes a first broad-spectrum luminescent material and a narrow-spectrum luminescent material. The broad-spectrum luminescent material may down-convert radiation emitted by the LED to radiation having a peak wavelength in the red color range. The narrow-spectrum luminescent material may also down-convert radiation emitted by the LED into the cyan, green or red color range.

LeToquin, Ronan P; Tong, Tao; Glass, Robert C

2014-12-30T23:59:59.000Z

176

Spectral optimization of the color temperature tunable white light-emitting diode (LED) cluster consisting of direct-emission blue and red LEDs and a diphosphor conversion LED  

Science Journals Connector (OSTI)

The correlated color temperature (CCT) tunable white-light LED cluster, which consists of direct-emission blue and red LEDs as well as phosphor-conversion (PC) LEDs packaged by...

Zhong, Ping; He, Guoxing; Zhang, Minhao

2012-01-01T23:59:59.000Z

177

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

Science Journals Connector (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

178

Organic light emitting devices for illumination  

SciTech Connect (OSTI)

An organic light emitting device an a method of obtaining illumination from such a device is provided. The device has a plurality of regions, each region having an organic emissive layer adapted to emit a different spectrum of light. The regions in combination emit light suitable for illumination purposes. The area of each region may be selected such that the device is more efficient than an otherwise equivalent device having regions of equal size. The regions may have an aspect ratio of at least about four. All parts of any given region may be driven at the same current.

Hack, Michael (Lambertville, NJ); Lu, Min-Hao Michael (Lawrenceville, NJ); Weaver, Michael S. (Princeton, NJ)

2012-01-24T23:59:59.000Z

179

Organic light emitting devices for illumination  

DOE Patents [OSTI]

An organic light emitting device is provided. The device has a plurality of regions, each region having an organic emissive layer adapted to emit a different spectrum of light. The regions in combination emit light suitable for illumination purposes. The area of each region may be selected such that the device is more efficient that an otherwise equivalent device having regions of equal size. The regions may have an aspect ratio of at least about four. All parts of any given region may be driven at the same current.

Hack, Michael (Lambertville, NJ); Lu, Min-Hao Michael (Lawrenceville, NJ); Weaver, Michael S. (Princeton, NJ)

2010-02-16T23:59:59.000Z

180

Power Quality Improvements in Lighting Systems Mr. Ashish Shrivastava  

E-Print Network [OSTI]

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

Kumar, M. Jagadesh

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

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

182

Stable blue phosphorescent organic light emitting devices  

DOE Patents [OSTI]

Novel combination of materials and device architectures for organic light emitting devices is provided. An organic light emitting device, is provided, having an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer includes a host and a phosphorescent emissive dopant having a peak emissive wavelength less than 500 nm, and a radiative phosphorescent lifetime less than 1 microsecond. Preferably, the phosphorescent emissive dopant includes a ligand having a carbazole group.

Forrest, Stephen R.; Thompson, Mark; Giebink, Noel

2014-08-26T23:59:59.000Z

183

Diode-pumped Nd:YAG laser emitting at 899 nm Marc Castaing  

E-Print Network [OSTI]

Diode-pumped Nd:YAG laser emitting at 899 nm and below Marc Castaing Laboratoire Charles Fabry de l); published March 5, 2007 We present what is, to the best of our knowledge, the first diode-pumped Nd, or diode- pumped solid-state (DPSS) lasers. Classical wave- lengths of frequency-doubled DPSS blue lasers

Boyer, Edmond

184

Method of making organic light emitting devices  

DOE Patents [OSTI]

The present invention provides a method for the preparation of organic light-emitting devices comprising a bilayer structure made by forming a first film layer comprising an electroactive material and an INP precursor material, and exposing the first film layer to a radiation source under an inert atmosphere to generate an interpenetrating network polymer composition comprising the electroactive material. At least one additional layer is disposed on the reacted first film layer to complete the bilayer structure. The bilayer structure is comprised within an organic light-emitting device comprising standard features such as electrodes and optionally one or more additional layers serving as a bipolar emission layer, a hole injection layer, an electron injection layer, an electron transport layer, a hole transport layer, exciton-hole transporting layer, exciton-electron transporting layer, a hole transporting emission layer, or an electron transporting emission layer.

Shiang, Joseph John (Niskayuna, NY); Janora, Kevin Henry (Schenectady, NY); Parthasarathy, Gautam (Saratoga Springs, NY); Cella, James Anthony (Clifton Park, NY); Chichak, Kelly Scott (Clifton Park, NY)

2011-03-22T23:59:59.000Z

185

Green-Yellow Electroluminescence from a host-dopant blended system as the active layer in a bilayer polymer light emitting diode: Poly(n-vinyl carbazole) as the host and a new soluble thiophene based copolymer [poly(2,2?-BT)-co-(3-DDT)] as the dopant  

Science Journals Connector (OSTI)

Abstract A new type of bilayer Polymer Light Emitting Diode (PLED) which emits green-yellow light is reported. In this PLED, a novel thiophene-based copolymer [poly(2,2?-BT)-co-(3-DDT)] with an excellent electron transporting property has been doped in hole transporting and electron blocking poly(n-vinylcarbazole) (PVK). Formation of type-II heterojunctions among nm-size features in PVK:poly(2,2?-BT)-co-(3-DDT) blended system makes exciplex and electroplex emissions would be dominant in the Electroluminescence (EL) spectrum of the device. These cross recombinations between electrons in the LUMO of poly(2,2?-BT)-co-(3-DDT) and holes in the HOMO of PVK is a reason for the low driving voltage of the PLED because there is no need for the charge carriers to hop or tunnel to the adjacent polymer. Morphological investigations demonstrate that the mixing degree between the components is high, favoring formation of exciplexes and electroplexes at the interface of the components.

Afshin Shahalizad; Sohrab Ahmadi-Kandjani; Hossein Movla; Hafez Omidi; Bakhshali Massoumi; Mohammad Sadegh Zakerhamidi; Ali Akbar Entezami

2014-01-01T23:59:59.000Z

186

Characterizing Ion Profiles in Dynamic Junction Light-Emitting...  

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

advantage in applications such as light-emitting devices, transistors, and electrochromic devices, among others. Evidence suggests that the profiles of ions and...

187

Belgirate, Italy, 28-30 September 2005 MECHANISM AND THERMAL EFFECT OF DELAMINATION IN LIGHT-EMITTING  

E-Print Network [OSTI]

for the investigation of the thermal behavior of the delaminated LEDs. Increase of thermal resistance with the degreeBelgirate, Italy, 28-30 September 2005 MECHANISM AND THERMAL EFFECT OF DELAMINATION IN LIGHT-EMITTING DIODE PACKAGES Jianzheng Hu, Lianqiao Yang, and Moo Whan Shin Department of Materials Science

Paris-Sud XI, Université de

188

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

E-Print Network [OSTI]

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

Little, Thomas

189

Impact of Lighting Requirements on VLC Systems J. Gancarz, H. Elgala, T.D.C. Little  

E-Print Network [OSTI]

Report No. 11-01-2013 Abstract Advances in Solid State Lighting (SSL) are enabling Light-Emitting Diodes

Little, Thomas

190

Alternative approaches of SiC & related wide bandgap materials in light emitting & solar cell applications  

Science Journals Connector (OSTI)

Materials for optoelectronics give a fascinating variety of issues to consider. Increasingly important are white light emitting diode (LED) and solar cell materials. Profound energy savings can be done by addressing new materials. White light emitting diodes are becoming common in our lighting scene. There is a great energy saving in the transition from the light bulb to white light emitting diodes via a transition of fluorescent light tubes. However, the white LEDs still suffer from a variety of challenges in order to be in our daily use. Therefore there is a great interest in alternative lighting solutions that could be part of our daily life. All materials create challenges in fabrication. Defects reduce the efficiency of optical transitions involved in the light emitting diode materials. The donor-acceptor co-doped SiC is a potential light converter for a novel monolithic all-semiconductor white LED. In spite of considerable research, the internal quantum efficiency is far less than theoretically predicted and is likely a fascinating scientific field for studying materials growth, defects and optical transitions. Still, efficient Si-based light source represents an ongoing research field in photonics that requires high efficiency at room temperature, wavelength tuning in a wide wavelength range, and easy integration in silicon photonic devices. In some of these devices, rare earth doped materials is considered as a potential way to provide luminescence spanning in a wide wavelength range. Divalent and trivalent oxidation states of Eu provide emitting centers in the visible region. In consideration, the use of Eu in photonics requires Eu doped thin films that are compatible with CMOS technology but for example faces material science issues like a low Eu solid solubility in silica. Therefore approaches aim to obtain efficient light emission from silicon oxycarbide which has a luminescence in the visible range and can be a host material for rare earth ions. The silicon oxycarbide material can provide potential applications of the Eu luminescent materials to challenging conditions like high temperatures or aggressive environments where the silica has weaknesses. In some approaches, silicon rich silicon oxide that contain silicon nanoclusters emit red to near infrared luminescence due to quantum confinement effects while luminescence at shorter wavelength is difficult due to the interplay of defects and quantum confinement effects. In addition it is applicable as low-k dielectric, etch-stop and passivation layers. It also has an optical band-gap that is smaller than that of SiO2 which may facilitate carrier injection at lower voltages that is suitable for optoelectronics. From materials perspective of emerging materials, it seems distant to consider system related issues. The future demands on communication and lighting devices require higher information flows in modernized optical devices, for example by replacing electrical interconnects with their optical counterparts and tunable backgrounds filters for integrated optics or photonics applications. However, there are materials issues related to such device performance, for example by a non-linearity, that provide the possibility for selective removal or addition of wavelengths using hetero structures in which one side of the structure enhances the light-to-dark sensitivity of long and medium wavelength channels and diminish others, and an opposite behavior in other face of the structure. Certainly materials may be applied in various innovative ways to provide new performances in devices and systems. In any materials and device evaluation, reliability issues in passivation and packaging of semiconductor device structures provide a base knowledge that may be used to evaluate new concepts. Fundamental aspects of dielectric constant, bandgap and band offsets between the valence and conduction band edges between the passivation layer and the semiconductor create a foundation for understanding the device performance. In relation to these, the surface pre-treatment and deposit

Peter Wellmann; Mikael Syv?j?rvi; Haiyan Ou

2014-01-01T23:59:59.000Z

191

An unsuccessful attempt to elicit orientation responses to linearly polarized light in hatchling loggerhead sea turtles (Caretta caretta)  

Science Journals Connector (OSTI)

...a steady course towards a light-emitting diode (LED) light source while...tethered in the tank with a light-emitting diode (LED) light source placed...a steady course towards a light-emitting diode (LED) light source while...

2011-01-01T23:59:59.000Z

192

Oxycarbonitride phosphors and light emitting devices using the same  

DOE Patents [OSTI]

Disclosed herein is a novel family of oxycarbonitride 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 oxycarbonitrides 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

2014-07-08T23:59:59.000Z

193

Organic light emitting device structure for obtaining chromaticity stability  

DOE Patents [OSTI]

The present invention relates to organic light emitting devices (OLEDs). The devices of the present invention are efficient white or multicolored phosphorescent OLEDs which have a high color stability over a wide range of luminances. The devices of the present invention comprise an emissive region having at least two emissive layers, with each emissive layer comprising a different host and emissive dopant, wherein at least one of the emissive dopants emits by phosphorescence.

Tung, Yeh-Jiun (Princeton, NJ); Ngo, Tan (Levittown, PA)

2007-05-01T23:59:59.000Z

194

Sandia National Laboratories: (Lighting and) Solid-State Lighting...  

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

on the third and upcoming revolution (illumination). Topics cover the basics of light-emitting diode (LED) operation; a 200-year history of lighting technology; the importance of...

195

138 JOURNAL OF DISPLAY TECHNOLOGY, VOL. 2, NO. 2, JUNE 2006 Improving the Performance of Organic Light-Emitting  

E-Print Network [OSTI]

­LiF­Al is believed to be due to the enhancement of elec- tron injection by thermal treatment. Secondary ion mass spec Light-Emitting Diodes Containing BCP/LiF/Al by Thermal Annealing J. X. Sun, Student Member, IEEE, X. L. However, other devices consisting of Alq3 LiF/Al were less affected. It is believed that the thermal

196

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

Office of Environmental Management (EM)

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

197

Energy Implications of Solid-State Lighting Technology  

Science Journals Connector (OSTI)

The efficient yet highly controllable generation of light can be accomplished by light-emitting diodes that can have a 20 times greater efficiency than incandescent light sources....

Schubert, E Fred; Kim, Jong Kyu

198

Mid-ultraviolet Light-Emitting Diode Detects Dipicolinic Acid  

Science Journals Connector (OSTI)

Dipicolinic acid (DPA, 2,6-pyridinedicarboxylic acid) is a substance uniquely present in bacterial spores such as that from anthrax (B. anthracis). It is known that DPA can be...

Li, Qingyang; Dasgupta, Purnendu K; Temkin, Henryk; Crawford, M H; Fischer, A J; Allerman, A A; Bogart, K H A; Lee, S R

2004-01-01T23:59:59.000Z

199

Functional Polymer Architectures for Solution Processed Organic Light Emitting Diodes  

E-Print Network [OSTI]

through formation of the tetrazole from 4-bromobenzonitrile13 5-(4-Bromophenyl)tetrazole, 7 2-(4-tert- Butylphenyl)-5-(

Poulsen, Daniel Andrew

2010-01-01T23:59:59.000Z

200

3D Printed Quantum Dot Light-Emitting Diodes  

Science Journals Connector (OSTI)

Developing the ability to 3D print various classes of materials possessing distinct properties could enable the freeform generation of active electronics in unique functional, interwoven architectures. ... Finally, we show that novel architectures that are not easily accessed using standard microfabrication techniques can be constructed, by 3D printing a 2 × 2 × 2 cube of encapsulated LEDs, in which every component of the cube and electronics are 3D printed. ... These include (1) increasing the resolution of the 3D printer such that smaller devices can be printed, (2) improving the performance and yield of the printed devices, and (3) incorporating other classes of nanoscale functional building blocks and devices, including semiconductor, plasmonic, and ferroelectric materials. ...

Yong Lin Kong; Ian A. Tamargo; Hyoungsoo Kim; Blake N. Johnson; Maneesh K. Gupta; Tae-Wook Koh; Huai-An Chin; Daniel A. Steingart; Barry P. Rand; Michael C. McAlpine

2014-10-31T23:59:59.000Z

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

Lensless digital holographic microscope with light-emitting diode illumination  

Science Journals Connector (OSTI)

We demonstrate the operation of a digital in-line microscope with LED illumination. We show with a practical example that, for typical setups, the limited temporal coherence and the...

Repetto, L; Piano, E; Pontiggia, C

2004-01-01T23:59:59.000Z

202

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

203

Bright Light-Emitting Diodes based on Organometal Halide Perovskite  

E-Print Network [OSTI]

this class of materials to be excellent semiconductors for optoelectronic devices.1-7 Their primary advantages lie in the fact that they can be easily solution processed, require no high temperature heating, and they possess an optical bandgap which...

Tan, Zhi-Kuang; Moghaddam, Reza Saberi; Lai, May Ling; Docampo, Pablo; Higler, Ruben; Deschler, Felix; Price, Michael; Sadhanala, Aditya; Pazos, Luis M.; Credgington, Dan; Hanusch, Fabian; Bein, Thomas; Snaith, Henry J.; Friend, Richard H.

2014-08-03T23:59:59.000Z

204

LIGHT EMITTING DIODE (LED) TRAFFIC SIGNAL SURVEY RESULTS  

E-Print Network [OSTI]

Forest Norco Belmont El Monte Lakewood Norwalk Berkeley Encinitas Lancaster Oakdale Beverly Hills Escalon Downey Laguna Hills Newark Bell Gardens Dublin Laguna Niguel Newport Beach Bellflower El Cajon Lake Hills Glendora Mammoth Lakes Piedmont Chowchilla Grand Terrace Manhattan Beach Pismo Beach Chula Vista

205

Functional Polymer Architectures for Solution Processed Organic Light Emitting Diodes  

E-Print Network [OSTI]

for high energy blue phosphorescent materials. Therefore,this high triplet energy block copolymer as host material, afind materials with sufficiently high triplet energy to be

Poulsen, Daniel Andrew

2010-01-01T23:59:59.000Z

206

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...

207

Concave-hemisphere-patterned organic top-light emitting device  

DOE Patents [OSTI]

A first device is provided. The first device includes an organic light emitting device, which further comprises a first electrode, a second electrode, and an organic emissive layer disposed between the first and second electrode. Preferably, the second electrode is more transparent than the first electrode. The organic emissive layer has a first portion shaped to form an indentation in the direction of the first electrode, and a second portion shaped to form a protrusion in the direction of the second electrode. The first device may include a plurality of organic light emitting devices. The indentation may have a shape that is formed from a partial sphere, a partial cylinder, a pyramid, or a pyramid with a mesa, among others. The protrusions may be formed between adjoining indentations or between an indentation and a surface parallel to the substrate.

Forrest, Stephen R; Slootsky, Michael; Lunt, Richard

2014-01-21T23:59:59.000Z

208

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

209

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

E-Print Network [OSTI]

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

Perebeinos, Vasili

210

Diode-pumped Nd:YVO4/Yb:S-FAP laser emitting at 985 and 492.5 nm  

E-Print Network [OSTI]

Diode-pumped Nd:YVO4/Yb:S-FAP laser emitting at 985 and 492.5 nm Marc Castaing,1,2, * François, 2008 For the first time, to the best of our knowledge, Yb:S-FAP crystals have been intracavity pumped by a Nd:YVO4 laser at 914 nm. This original pumping scheme allows efficient laser action on the three

Paris-Sud XI, Université de

211

Tunable White-Light-Emitting Mn-Doped ZnSe Nanocrystals Vijay Kumar Sharma,  

E-Print Network [OSTI]

Tunable White-Light-Emitting Mn-Doped ZnSe Nanocrystals Vijay Kumar Sharma, Burak Guzelturk, Talha report white-light-emitting Mn-doped ZnSe nanocrystals (NCs) that are synthesized using modified orange emission (580 nm), allowed us to achieve excitation wavelength tailorable white-light generation

Demir, Hilmi Volkan

212

Wide-Area Thermal Processing of Light-Emitting Materials  

SciTech Connect (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) [AppliCote Associates, LLC

2011-09-30T23:59:59.000Z

213

Triplet Energy Confinement Effect in Blue Phosphorescent Organic Light Emitting Devices  

Science Journals Connector (OSTI)

The Effects of triplet energy confinement and charge balance by hole and electron transport layers are investigated on blue phosphorescent organic light emitting devices (PHOLEDs).

Lee, Jaewon; Chopra, Neetu; So, Franky

214

E-Print Network 3.0 - apd light readout Sample Search Results  

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

Photonics Conference Summary: Improved Light Output of Photonic Crystal Light Emitting Diode Fabricated by Anodized Aluminum Oxide Nano... an equivalent circuit model for...

215

A High-Speed LED Driver That Sweeps Out the Remaining Carriers for Visible Light Communications  

Science Journals Connector (OSTI)

The modulation speed of light-emitting diodes (LEDs) must be increased to improve the speed, increase the bandwidth, and miniaturize the hardware of visible light communication (VLC)...

Kishi, Toshiki; Tanaka, Hiroyuki; Umeda, Yohtaro; Takyu, Osamu

2013-01-01T23:59:59.000Z

216

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

217

Organic light-emitting device with a phosphor-sensitized fluorescent emission layer  

DOE Patents [OSTI]

The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters. The emissive region of the devices of the present invention comprise at least one phosphor-sensitized layer which has a combined emission from a phosphorescent emitter and a fluorescent emitter. In preferred embodiments, the invention relates to white-emitting OLEDS (WOLEDs).

Forrest, Stephen (Ann Arbor, MI); Kanno, Hiroshi (Osaka, JP)

2009-08-25T23:59:59.000Z

218

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

219

High-speed delay tuning of slow light in pin-diode-incorporated photonic crystal waveguide  

Science Journals Connector (OSTI)

We demonstrate the high-speed electrical delay tuning of slow light pulses using Si photonic crystal waveguides. The device has an i-region-chirped pin diode, within which thermo-optic...

Hayakawa, Ryo; Ishikura, Norihiro; Nguyen, Hong C; Baba, Toshihiko

2013-01-01T23:59:59.000Z

220

Carbonitride based phosphors and light emitting devices using the same  

DOE Patents [OSTI]

Disclosed herein is a novel group of carbidonitride phosphors and light emitting devices which utilize these phosphors. In certain embodiments, the present invention is directed to a novel family of carbidonitride-based phosphors expressed as follows: Ca.sub.1-xAl.sub.x-xySi.sub.1-x+xyN.sub.2-x-xyC.sub.xy:A; (1) Ca.sub.1-x-zNa.sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xyC.sub.xy:- A; (2) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x- -xyC.sub.xy:A; (3) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xy-2w/- 3C.sub.xyO.sub.w-v/2H.sub.v:A; and (4) M(II).sub.1-x-zM(I).sub.zM(III).sub.x-xy-zSi.sub.1-x+xy+zN.sub.2-x-xy-2w/- 3-v/3C.sub.xyO.sub.wH.sub.v:A, (4a) wherein 0xy+z, and 0

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

2013-08-20T23:59:59.000Z

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

The Influence of Photoperiod History on Circadian Response to Light  

E-Print Network [OSTI]

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

Glickman, Gena Lynne

222

Nanoscale engineering boosts performance of quantum dot light...  

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

engineering boosts performance of quantum dot light emitting diodes Quantum dots are nano-sized semiconductor particles whose emission color can be tuned by simply changing...

223

Do Embedded Roadway Lights Protect Sea Turtles?  

Science Journals Connector (OSTI)

Street lighting on coastal roadways is often visible at ... Our objective was to determine whether an alternative lighting system (light-emitting diodes, embedded in the roadway pavement ... the beach oriented no...

Lesley Bertolotti; Michael Salmon

2005-11-01T23:59:59.000Z

224

Residential energy-efficient lighting adoption survey  

Science Journals Connector (OSTI)

Artificial lighting has transformed how humans relate to the world, by improving productivity and making spaces habitable. The adoption of energy-efficient solid-state lighting, light emitting diodes (LED), ha...

Andrea L. Hicks; Thomas L. Theis

2014-04-01T23:59:59.000Z

225

One-Step Synthesis of White-Light-Emitting Quantum Dots at Low Temperature  

Science Journals Connector (OSTI)

‡ National Sun Yat-sen University?Kaohsiung Medical University Joint Research Center, Kaohsiung 804, Taiwan ... Results from previous studies on white-light-emitting organic LEDs have led to the idea that white light could be generated by combining lights of the three primary colors (blue, green, and red). ... Finally, we developed a white-light, solid-state lighting device by using a 365-nm UV lamp as the pump source. ...

Chien-Chih Shen; Wei-Lung Tseng

2009-08-17T23:59:59.000Z

226

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

227

Asynchronous indoor positioning system based on visible light  

E-Print Network [OSTI]

employ fluorescent lamps and light-emitting diodes (LEDs). VLC-based techniques have the advantage of light-emitting diode bulbs. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10. Most of the VLC-based techniques use LEDs as the light source, since they can be modulated more easily

Kavehrad, Mohsen

228

A Dual Strategy to Cope with High Light in Chlamydomonas reinhardtii  

Science Journals Connector (OSTI)

...photons m2 s1) white light provided by a WH 100 light-emitting diode panel (JBeamBio) to induce the accumulation of...were provided by a green (lambda = 520 nm) light-emitting diode array. Measurements were done 15 min after high-light...

Guillaume Allorent; Ryutaro Tokutsu; Thomas Roach; Graham Peers; Pierre Cardol; Jacqueline Girard-Bascou; Daphné Seigneurin-Berny; Dimitris Petroutsos; Marcel Kuntz; Cécile Breyton; Fabrice Franck; Francis-André Wollman; Krishna K. Niyogi; Anja Krieger-Liszkay; Jun Minagawa; Giovanni Finazzi

2013-02-19T23:59:59.000Z

229

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

E-Print Network [OSTI]

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

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

2010-01-01T23:59:59.000Z

230

Solid State Lighting ECE 198 Lab Manual  

E-Print Network [OSTI]

commonly available light bulbs: halogen, incandescent, compact fluorescent, and light-emitting diode (LED will look at the spectrum of the light emitted from the each light bulb, using the spectrometers you). Over the course of the lab, you will perform variety of tests on each of the light bulbs in order

Wasserman, Daniel M.

231

High performance flexible top-emitting warm-white organic light-emitting devices and chromaticity shift mechanism  

SciTech Connect (OSTI)

Flexible warm-white top-emitting organic light-emitting devices (TEOLEDs) are fabricated onto PET substrates with a simple semi-transparent cathode Sm/Ag and two-color phosphors respectively doped into a single host material TCTA. By adjusting the relative position of the orange-red EML sandwiched between the blue emitting layers, the optimized device exhibits the highest power/current efficiency of 8.07 lm/W and near 13 cd/A, with a correlated color temperature (CCT) of 4105 K and a color rendering index (CRI) of 70. In addition, a moderate chromaticity variation of (-0.025, +0.008) around warm white illumination coordinates (0.45, 0.44) is obtained over a large luminance range of 1000 to 10000 cd/m{sup 2}. The emission mechanism is discussed via delta-doping method and single-carrier device, which is summarized that the carrier trapping, the exciton quenching, the mobility change and the recombination zone alteration are negative to color stability while the energy transfer process and the blue/red/blue sandwiched structure are contributed to the color stability in our flexible white TEOLEDs.

Shi, Hongying; Deng, Lingling; Chen, Shufen, E-mail: iamsfchen@njupt.edu.cn, E-mail: wei-huang@njupt.edu.cn; Xu, Ying; Zhao, Xiaofei; Cheng, Fan [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China)] [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China); Huang, Wei, E-mail: iamsfchen@njupt.edu.cn, E-mail: wei-huang@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China) [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China); Jiangsu-Singapore Joint Research Center for Organic/Bio- Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Technology, Nanjing 211816 (China)

2014-04-15T23:59:59.000Z

232

A Flavin Binding Cryptochrome Photoreceptor Responds to Both Blue and Red Light in Chlamydomonas reinhardtii  

Science Journals Connector (OSTI)

...TCEP, Tris(2-carboxyethyl)phosphine|LED, light-emitting diode|qPCR, quantitative PCR|FWHM, full width at...The samples were exposed to blue light from a light-emitting diode (LED) with an output at 455 nm (Figure 5A...

Benedikt Beel; Katja Prager; Meike Spexard; Severin Sasso; Daniel Weiss; Nico Müller; Mark Heinnickel; David Dewez; Danielle Ikoma; Arthur R. Grossman; Tilman Kottke; Maria Mittag

2012-07-06T23:59:59.000Z

233

Sandia National Laboratories: Solid-State Lighting  

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

Optical performance of top-down fabricated InGaNGaN nanorod light emitting diode arrays On November 30, 2011, in Energy, Energy Efficiency, Solid-State Lighting EFRC researchers...

234

Easy and inexpensive demonstration of light interference  

Science Journals Connector (OSTI)

Interference of scattered light is easy and inexpensive to observe using a flashlight mirror and talcum powder. Using this phenomenon the thickness of plastic wrap was measured using a light emitting diode point source.

Charles A. Sawicki

2001-01-01T23:59:59.000Z

235

Organic light emitting device architecture for reducing the number of organic materials  

DOE Patents [OSTI]

An organic light emitting device is provided. The device includes an anode and a cathode. A first emissive layer is disposed between the anode and the cathode. The first emissive layer includes a first non-emitting organic material, which is an organometallic material present in the first emissive layer in a concentration of at least 50 wt %. The first emissive layer also includes a first emitting organic material. A second emissive layer is disposed between the first emissive layer and the cathode, preferably, in direct contact with the first emissive layer. The second emissive material includes a second non-emitting organic material and a second emitting organic material. The first and second non-emitting materials, and the first and second emitting materials, are all different materials. A first non-emissive layer is disposed between the first emissive layer and the anode, and in direct contact with the first emissive layer. The first non- emissive layer comprises the first non-emissive organic material.

D'Andrade, Brian (Westampton, NJ); Esler, James (Levittown, PA)

2011-10-18T23:59:59.000Z

236

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

237

From carbon to light: a new framework for estimating greenhouse gas emissions reductions from replacing fuel-based lighting with LED systems  

Science Journals Connector (OSTI)

There is considerable well-intended, yet wishful anticipation about reducing greenhouse gas emissions by replacing fuel-based lighting in the developing world with grid-independent light-emitting diode (LED) lighting

Evan Mills; Arne Jacobson

2011-11-01T23:59:59.000Z

238

Device Optimization and Transient Electroluminescence Studies of Organic light Emitting Devices  

SciTech Connect (OSTI)

Organic light emitting devices (OLEDs) are among the most promising for flat panel display technologies. They are light, bright, flexible, and cost effective. And while they are emerging in commercial product, their low power efficiency and long-term degradation are still challenging. The aim of this work was to investigate their device physics and improve their performance. Violet and blue OLEDs were studied. The devices were prepared by thermal vapor deposition in high vacuum. The combinatorial method was employed in device preparation. Both continuous wave and transient electroluminescence (EL) were studied. A new efficient and intense UV-violet light emitting device was developed. At a current density of 10 mA/cm{sup 2}, the optimal radiance R could reach 0.38 mW/cm{sup 2}, and the quantum efficiency was 1.25%. using the delayed EL technique, electron mobilities in DPVBi and CBP were determined to be {approx} 10{sup -5} cm{sup 2}/Vs and {approx} 10{sup -4} cm{sup 2}/Vs, respectively. Overshoot effects in the transient El of blue light emitting devices were also observed and studied. This effect was attributed to the charge accumulation at the organic/organic and organic/cathode interfaces.

Lijuan Zou

2003-08-05T23:59:59.000Z

239

E-Print Network 3.0 - algan-based laser diodes Sample Search...  

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

GaN and GaNAlGaN quantum structures for UV electroabsorption modulators Summary: optoelectronics industry.1,2 In the visible spectral range, light emitting diodes,3 laser...

240

Energy - LEDs to light UT arena | ornl.gov  

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

to 85 percent more efficient than conventional arena metal halide lights. The light-emitting diode fixtures developed by Oak Ridge-based LED North America incorporate an Oak...

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

Sandia National Laboratories: solid-state lighting technology  

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

in the ... Optical performance of top-down fabricated InGaNGaN nanorod light emitting diode arrays On November 30, 2011, in Energy, Energy Efficiency, Solid-State Lighting...

242

Is blue optical filter necessary in high speed phosphor-based white light LED visible light communications?  

Science Journals Connector (OSTI)

Optical blue filter is usually regarded as a critical optical component for high speed phosphor-based white light emitting diode (LED) visible-light-communication (VLC). However, the...

Sung, Jiun-Yu; Chow, Chi-Wai; Yeh, Chien-Hung

2014-01-01T23:59:59.000Z

243

Red light emitting solid state hybrid quantum dot–near-UV GaN LED devices  

Science Journals Connector (OSTI)

We produced core–shell (CdSe)ZnSe quantum dots by direct colloidal chemical synthesis and the surface-passivation method—an overcoating of the core CdSe with a larger-bandgap material ZnSe. The (CdSe)ZnSe quantum dots(QDs) play the role of a colour conversion centre. We call these quantum dots nanophosphors. We fabricated red light emitting hybrid devices of (CdSe)ZnSe QDs and a near-UV GaN LED by combining red light emitting (CdSe)ZnSe quantum dots (as a colour conversion centre) with a near-UV(NUV) GaN LED chip (as an excitation source). A few good red phosphors have been known for UV excitation wavelengths, and red phosphors for UV excitation have been sought for a long time. Here we tested the possibility of using (CdSe)ZnSe QDs as red nanophosphors for UV excitation. The fabricated red light emitting hybrid device of (CdSe)ZnSe and a NUV GaN LED chip showed a good luminance. We demonstrated that the (CdSe)ZnSe quantum dots were promising red nanophosphors for NUV excitation and that a red LED made of QDs and a NUV excitation source was a highly efficient hybrid device.

Hongjoo Song; Seonghoon Lee

2007-01-01T23:59:59.000Z

244

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

245

Semiconductor light-emitting devices having concave microstructures providing improved light extraction efficiency and method for producing same  

SciTech Connect (OSTI)

A conventional semiconductor LED is modified to include a microlens layer over its light-emitting surface. The LED may have an active layer including at least one quantum well layer of InGaN and GaN. The microlens layer includes a plurality of concave microstructures that cause light rays emanating from the LED to diffuse outwardly, leading to an increase in the light extraction efficiency of the LED. The concave microstructures may be arranged in a substantially uniform array, such as a close-packed hexagonal array. The microlens layer is preferably constructed of curable material, such as polydimethylsiloxane (PDMS), and is formed by soft-lithography imprinting by contacting fluid material of the microlens layer with a template bearing a monolayer of homogeneous microsphere crystals, to cause concave impressions, and then curing the material to fix the concave microstructures in the microlens layer and provide relatively uniform surface roughness.

Tansu, Nelson; Gilchrist, James F; Ee, Yik-Khoon; Kumnorkaew, Pisist

2013-11-19T23:59:59.000Z

246

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

247

Sandia National Laboratories: Solid-State Lighting  

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

electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

248

Self assembly of CdSe/ZnS quantum dots for organic/inorganic light emitting devices for the next generation display technology  

Science Journals Connector (OSTI)

We have investigated the effect of quantum dot (QD) concentrations, spin speed and temperature on the self assembly of CdSe/ZnS QDs on substrate for the optimisation of QDs used in organic light-emitting devices (OLEDs) applications. The atomic force microscopy (AFM) results showed that surface morphology and coverage are varied with different process parameters. There is also a tendency for the formation of aggregates/islands on a smooth substrate that could be caused by spinodal phase separation. The uniform distribution of QDs with controllable density was achieved using the conventional spin-coating method. We fabricated and investigated the effect of CdSe/ZnS QD concentrations on the self-assembly hybrid organic/inorganic light emitting diodes (QD-OLEDs) for the tuning of performance. There was a QD threshold concentration below which there was no emission from the QDs. The estimated QD concentration was around 9 × 1011 cm?2 for the best performance of QD-OLED. The annealing of QD-OLED increased the QD emission about three times. No wavelength shift was observed in the electroluminescence spectra from the QD before and after the annealing of QD-OLEDs. The mechanism of this emission improvement is discussed.

A. Uddin; C.C. Teo

2009-01-01T23:59:59.000Z

249

Modelling and simulation of electronic relaxation processes in phosphorescent molecules in organic light emitting diodes  

Science Journals Connector (OSTI)

Simulation is made for the temperature dependences of emission intensity of phosphorescent tris(2-phenylpyridine) iridium [Ir ppy)3] molecules doped in fluorescent N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-benzidine (TPD) molecules from numerical calculation and compared them with the experimental result. Rate equations are constructed for the three zero-field splitting substates in the spin-triplet state T1 of the Ir(ppy)3 guest and for the TT1 state of the TPD host. It is concluded that (1) the increase of emission intensity above 100 K is due to the endothermic energy transfer from host to guest and (2) the decrease of PL intensity observed above 200 K is due to the energy transfer from the excited host to the neighbouring unexcited host. Calculation is extended to the case of Ir(ppy)3 doped in aluminium tris 8-hydroxyquinoline (Alq3) where the T1 state of Alq3 lies at much deeper energy than the case of TPD host.

Nadeer Aljaroudi; Taiju Tsuboi

2006-01-01T23:59:59.000Z

250

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

E-Print Network [OSTI]

modification C. F. Madigan, M.-H. Lu, and J. C. Sturma) Center for Photonics and Optoelectronic Materials, Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 Received 8 November and at least triple it when high-index plastic substrates are used. The work is accompa- nied by modeling

251

Colloidal Quantum Dot Light-Emitting Diodes Employing Phosphorescent Small Organic Molecules as Efficient Exciton  

E-Print Network [OSTI]

engineer, the potential energy transfer pumping scheme. Only Zhang et al. reported an enhancement enhancement factor in the external quantum efficiency over the conventional QLED structure, in which energy as Efficient Exciton Harvesters Evren Mutlugun,,,§, Burak Guzelturk,,§, Agus Putu Abiyasa,§, Yuan Gao,§ Xiao

Demir, Hilmi Volkan

252

Structurally Integrated Photoluminescent Chemical and Biological Sensors: An Organic Light-Emitting Diode-Based Platform  

Science Journals Connector (OSTI)

The chapter describes the development, advantages, challenges, and potential of an emerging, compact photoluminescence-based sensing platform for chemical and biological analytes, including multiple analytes. In ...

J. Shinar; R. Shinar

2008-01-01T23:59:59.000Z

253

Quantum Dot Light-Emitting Diode with Quantum Dots Inside the Hole Transporting Layers  

E-Print Network [OSTI]

architecture using a noninverted structure with the QDs sandwiched between hole transporting layers (HTLs

Demir, Hilmi Volkan

254

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

Science Journals Connector (OSTI)

Utilizing the near- to far-field transformation based on the 3-D finite difference time domain (FDTD) method and Fourier transformation, the far-field profile of a photonic crystal...

Lee, Yong-Jae; Kim, Se-Heon; Kim, Guk-Hyun; Lee, Yong-Hee; Cho, Sang-Hwan; Song, Young-Woo; Kim, Yoon-Chang; Do, Young Rag

2005-01-01T23:59:59.000Z

255

Efficient organic light-emitting diodes using polycrystalline silicon thin films as semitransparent anode  

E-Print Network [OSTI]

anode X. L. Zhu, J. X. Sun, H. J. Peng, Z. G. Meng, M. Wong, and H. S. Kwok Center for Display Research. In this letter, we propose and demonstrate the application of boron-doped p-Si as a semi-transparent anode better performance to conventional OLEDs which use ITO as anodes. The present technique has the advantage

256

Design and modelling of novel waveguide and light-emitting-diode-based photoreactors.  

E-Print Network [OSTI]

??In this dissertation, investigations on a range of photocatalytic reactors based on waveguides (optical fibres and quartz tubes) are presented. A study on a coupled… (more)

Denny, Frans

2010-01-01T23:59:59.000Z

257

Colloidal quantum-dot light-emitting diodes with metal-oxide charge  

E-Print Network [OSTI]

across the pixel area, and fabrication required the specialized deposition technique of energy-neutral over previously reported structures8,10 . Previous efforts at building colloidal quantum-dot (QD) LEDs concentrations and energy-band

258

Green Light Emitting Diodes under Photon Modulation Yufeng Li1,2  

E-Print Network [OSTI]

Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY, 12180 ABSTRACT With an external laser periods of GaInN/GaN MQWs with well width of 3 nm were grown above. A 0.03 µm p-type AlGaN cladding layer

Wetzel, Christian M.

259

Electrical and Optical Enhancement in Internally Nanopatterned Organic Light-Emitting Diodes  

E-Print Network [OSTI]

Kao, K.C. , Hwang, W. Electrical Transport in Solids: withPress, 2009. Stallinga, P. Electrical Characterization offrom electrical model . 100

Fina, Michael Dane

2012-01-01T23:59:59.000Z

260

Electrical and Optical Enhancement in Internally Nanopatterned Organic Light-Emitting Diodes  

E-Print Network [OSTI]

incandescent bulbs and fluorescent bulbs). Solid-stateindex (CRI) than fluorescent bulbs. Common examples where

Fina, Michael Dane

2012-01-01T23:59:59.000Z

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

Low-voltage polariton electroluminescence from an ultrastrongly coupled organic light-emitting diode  

SciTech Connect (OSTI)

We demonstrate electroluminescence from Frenkel molecular excitons ultrastrongly coupled to photons of a metal-clad microcavity containing a 2,7-bis[9,9-di(4-methylphenyl)-fluoren-2-yl]-9,9-di(4-methylphenyl)fluorene emissive layer. Thin layers of molybdenum oxide and 4,7-diphenyl-1,10-phenanthroline are used as hole and electron injection layers, respectively. The fabricated devices exhibit an electroluminescence threshold of 3.1?V, a value that is below the bare exciton energy. This result is found to be independent of detuning and consistent with a two-step process for polariton formation. Moreover, we investigate the quantum efficiency of carrier to polariton to photon conversion and obtain an external quantum efficiency of 0.1% for the fabricated structures, an improvement of 5 orders of magnitude over previous reports.

Gubbin, Christopher R.; Maier, Stefan A. [Experimental Solid State Group, Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom); Kéna-Cohen, Stéphane, E-mail: s.kena-cohen@polymtl.ca [Department of Engineering Physics, École Polytechnique de Montréal, Montréal, Quebec H3C 3A7 (Canada)

2014-06-09T23:59:59.000Z

262

Studying collisions in the general physics laboratory with quadrature light emitting diode sensors  

Science Journals Connector (OSTI)

We have developed the means to measure position rapidly and precisely as a function of time in the general physics laboratory. These measurements are of sufficient quality that velocities and accelerations can be calculated from the position data using numerical derivatives. The precision of the measurements is such that any disagreement between theoretical expectations and experimental measurements is less than a few percent. Measurements of the system under study can be made as rapidly as every 200 ?s which is faster than the typical time scales over which the system changes. Measuring rapidly also allows one to investigate additional phenomena not previously accessible and to see features of the physics previously unobserved. The measurement system is based on commercially available sensors computer hardware and computer software (LABVIEW™). Many general physics laboratories based on this system have been developed but only an investigation of Newton’s second law will be described here.

P. A. DeYoung; B. Mulder

2002-01-01T23:59:59.000Z

263

Control of the emission wavelength of gallium nitride-based nanowire light-emitting diodes.  

E-Print Network [OSTI]

??Halbleiter-Nanosäulen (auch -Nanodrähte) werden als Baustein für Leuchtdioden (LEDs) untersucht. Herkömmliche LEDs aus Galliumnitrid (GaN) bestehen aus mehreren Kristallschichten auf einkristallinen Substraten. Ihr Leistungsvermögen wird… (more)

Wölz, Martin

2013-01-01T23:59:59.000Z

264

Spontaneous emission factor for semiconductor superluminescent diodes Yongsheng Zhao, Weihua Han, Junfeng Song, Xuemei Li, Yang Liu, Dingsan Gao,  

E-Print Network [OSTI]

Spontaneous emission factor for semiconductor superluminescent diodes Yongsheng Zhao, Weihua Han emission factor is an important parameter for the characterization of semiconductor light emitting devices difference involved in each device. In this article, the spontaneous emission factor for superluminescent

Cao, Hui

265

Continuous-wave electrically pumped 1.55-mu m edge-emitting platelet ridge laser diodes on silicon  

E-Print Network [OSTI]

We report the successful integration on silicon of small footprint, low-threshold electrically pumped edge-emitting lasers by a new approach incorporating microcleaving technology to produce 6-mum-thick platelet lasers ...

Rumpler, Joseph J.

266

Development of High Efficiency Green and Deep Green Light Emitters in Piezoelectric Group-III Nitrides  

Science Journals Connector (OSTI)

Green and deep-green light emitting diodes are still the weakest link in energy efficient Solid-State Lighting. We analyze the limiting factors of the external quantum efficiency and...

Wetzel, Christian

267

Hybrid sunlight/LED illumination and renewable solar energy saving concepts for indoor lighting  

Science Journals Connector (OSTI)

A hybrid method for using sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting is simulated and presented in this study. We can...

Tsuei, Chih-Hsuan; Sun, Wen-Shing; Kuo, Chien-Cheng

2010-01-01T23:59:59.000Z

268

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

269

Structure and Ultrafast Dynamics of White-Light-Emitting CdSe Nanocrystals  

SciTech Connect (OSTI)

White-light emission from ultrasmall CdSe nanocrystals offers an alternative approach to the realization of solid-state lighting as an appealing technology for consumers. Unfortunately, their extremely small size limits the feasibility of traditional methods for nanocrystal characterization. This paper reports the first images of their structure, which were obtained using aberration-corrected atomic number contrast scanning transmission electron microscopy (Z-STEM). With subangstrom resolution, Z-STEM is one of the few available methods that can be used to directly image the nanocrystal's structure. The initial images suggest that they are crystalline and approximately four lattice planes in diameter. In addition to the structure, for the first time, the exciton dynamics were measured at different wavelengths of the white-light spectrum using ultrafast fluorescence upconversion spectroscopy. The data suggest that a myriad of trap states are responsible for the broad-spectrum emission. It is hoped that the information presented here will provide a foundation for the future development and improvement of white-light-emitting nanocrystals.

Bowers, Michael J [Vanderbilt University; McBride, James [Vanderbilt University; Garrett, Maria Danielle [Vanderbilt University; Sammons, Jessica A. [Vanderbilt University; Dukes, Albert [Vanderbilt University; Schreuder, Michael A. [Vanderbilt University; Watt, Tony L. [Vanderbilt University; Lupini, Andrew R [ORNL; Pennycook, Stephen J [ORNL; Rosenthal, Sandra [Vanderbilt University

2009-01-01T23:59:59.000Z

270

Efficiency peaks in the transient electroluminescence of multilayer organic light-emitting devices  

SciTech Connect (OSTI)

It is shown that when multilayer organic light-emitting devices (OLEDs) containing hole (h{sup +}) and electron (e{sup -}) transporting layers (HTLs and ETLs, respectively) are biased with microsecond to millisecond voltage pulses higher than a threshold value V{sub th}, the electroluminescence (EL) intensity increases dramatically to a peak value which then relaxes to the lower dc value; the relaxation time decreases strongly with increasing pulse amplitude. Since the current waveforms are essentially rectangular, the transient EL is proportional to the external quantum efficiency {eta}. The value of V{sub th} coincides with the bias for maximum dc efficiency typically observed when {eta} is monitored vs V. This relation and the apparent absence of the transient peak in single-layer OLEDs suggest that it is due either to internal field redistribution processes in the ETL and HTL or to space charges, e.g., trapped polarons which accumulate at the HTL/ETL interface, and quench the emitting singlet excitons. It is concluded that highly efficient OLED operation may be achieved at high brightness by pulsed bias at an optimized duty cycle. (c) 2000 American Institute of Physics.

Savvate'ev, V. [Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3020 (United States)] [Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3020 (United States); Friedl, J. [Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3020 (United States)] [Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3020 (United States); Zou, L. [Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3020 (United States)] [Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3020 (United States); Oldham, W. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Shinar, J. [Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3020 (United States)] [Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3020 (United States)

2000-04-17T23:59:59.000Z

271

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

DOE Patents [OSTI]

A flip-chip semiconductor based Light Emitting Device (LED) can include an n-type semiconductor substrate and an n-type GaN epi-layer on the substrate. A p-type GaN epi-layer can be on the n-type GaN epi-layer and a metal ohmic contact p-electrode can be on the p-type GaN epi-layer, where the metal ohmic contact p-electrode can have an average thickness less than about 25 .ANG.. A reflector can be on the metal ohmic contact p-electrode and a metal stack can be on the reflector. An n-electrode can be on the substrate opposite the n-type GaN epi-layer and a bonding pad can be on the n-electrode.

Raffetto, Mark; Bharathan, Jayesh; Haberern, Kevin; Bergmann, Michael; Emerson, David; Ibbetson, James; Li, Ting

2014-06-24T23:59:59.000Z

272

Sandia National Laboratories: Brief History of Solid-State Lighting...  

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

electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

273

LED Lighting Basics | Department of Energy  

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

LED Lighting Basics LED Lighting Basics LED Lighting Basics 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 semiconductor devices that produce light when an electrical current is applied. Applying electrical current causes electrons to flow from the positive side of a diode to the negative side. Then, at the positive/negative 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 as small indicator lights on various electronic devices. Because of their long life, durability, and efficiency, LEDs are becoming more common in residential, commercial, and outdoor area lighting

274

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

SciTech Connect (OSTI)

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

Structurally Integrated Photoluminescence-Based Lactate Sensor Using Organic Light Emitting Devices (OLEDs) as the Light Source  

SciTech Connect (OSTI)

Multianalyte bio(chemical) sensors are extensively researched for monitoring analytes in complex systems, such as blood serum. As a step towards developing such multianalyte sensors, we studied a novel, structurally integrated, organic light emitting device (OLED)-based sensing platform for detection of lactate. Lactate biosensors have attracted numerous research efforts, due to their wide applications in clinical diagnosis, athletic training and food industry. The OLED-based sensor is based on monitoring the oxidation reaction of lactate, which is catalyzed by the lactate oxidase (LOX) enzyme. The sensing component is based on an oxygen-sensitive dye, Platinum octaethyl porphyrin (PtOEP), whose photoluminescence (PL) lifetime {tau} decreases as the oxygen level increases. The PtOEP dye was embedded in a thin film polystyrene (PS) matrix; the LOX was dissolved in solution or immobilized in a sol-gel matrix. {tau} was measured as a function of the lactate concentration; as the lactate concentration increases, {tau} increases due to increased oxygen consumption. The sensors performance is discussed in terms of the detection sensitivity, dynamic range, and response time. A response time of {approx}32 sec was achieved when the LOX was dissolved in solution and kept in a closed cell. Steps towards development of a multianalyte sensor array using an array of individually addressable OLED pixels were also presented.

Chengliang Qian

2006-08-09T23:59:59.000Z

276

Phosphine Oxide Based Electron Transporting and Hole Blocking Materials for Blue Electrophosphorescent Organic Light Emitting Devices  

SciTech Connect (OSTI)

We report the design, synthesis, thermal, and photophysical properties of two phosphine oxide based electron transport/hole blocking materials, 2,6-bis(4-(diphenylphosphoryl)phenyl)pyridine (BM-A11) and 2,4-bis(4-(diphenyl-phosphoryl)phenyl)pyridine (BM-A10) for blue electrophosphorescent organic light emitting devices (OLEDs). The use of these materials in blue OLED with iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N,C2’]picolinate (Firpic) as the phosphor was demonstrated. Using the dual host device architecture with BM-A10 as the ETM yields a maximum EQE of 8.9% with a power efficiency of 21.5 lm/W (4.0V and 35 cd/m2). When BM-A11 is used as the ETM, the maximum EQE and power efficiency improves to 14.9% and 48.4 lm/W, respectively (3.0V and 40 cd/m2).

Von Ruden, Amber L.; Cosimbescu, Lelia; Polikarpov, Evgueni; Koech, Phillip K.; Swensen, James S.; Wang, Liang; Darsell, Jens T.; Padmaperuma, Asanga B.

2010-10-26T23:59:59.000Z

277

AC-LED based Visible Light Communication Systems Using Multiple Transmitter Design for Reducing Latency  

Science Journals Connector (OSTI)

This work demonstrates by employing multiple alternating-current light-emitting-diode (AC-LED) communication modules, the transmission gap in time-domain caused by the LED threshold...

Liu, Y; Yeh, C; Chow, C W

278

Evidence for Light Wavelength-Specific Photoelectrophysiological Signaling and Memory of Excess Light Episodes in Arabidopsis  

Science Journals Connector (OSTI)

...80 mumol photons m2 s 4 h, 450 20 nm) and red light (120 mumol photons m2 s 4 h, 650 20 nm) supplied by light-emitting diode panels (Photon System Inst.). The above light conditions provided similar energy at the indicated spectral...

Magdalena SzechyÅ?ska-Hebda; Jerzy Kruk; Magdalena Górecka; Barbara KarpiÅ?ska; StanisÅ?aw KarpiÅ?ski

2010-07-16T23:59:59.000Z

279

Comparison of the Electromagnetic Spectra of Common Light Sources: A General Chemistry Laboratory Exercise  

Science Journals Connector (OSTI)

Compact fluorescent light (CFL); light emitting diode (LED). ... White LED light can be produced by mixing light from red, green, and blue LEDs. ... Students observe that the white light from a six LED flashlight array (Figure 5) arises from two major peaks and that the spectrum is less continuous than those of incandescent bulbs, but more continuous than those of CFLs. ...

Edward Maslowsky, Jr.

2013-10-03T23:59:59.000Z

280

Visible Light Communications (VLC) for Ambient Assisted Living  

Science Journals Connector (OSTI)

With the advent of high efficacy light emitting diode directional lamps as a key component in focal lighting, new possibilities emerge for re-designing the smart home scenario. A smart home scenario is characterized by enabled intelligent interworking ... Keywords: Ambient lighting, High connectivity, LED, Low rate, PD, VLC

Ambuj Kumar, Albena Mihovska, Sofoklis Kyriazakos, Ramjee Prasad

2014-10-01T23:59:59.000Z

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

Ultra-thin titanium nanolayers for plasmon-assisted enhancement of bioluminescence of chloroplast in biological light emitting devices  

SciTech Connect (OSTI)

Ultra-thin titanium films were deposited via ultra-high vacuum ion beam sputter deposition. Since the asymmetric electric field of the metal foil plane matches the B-band absorption of chlorophyll a, the ultra-thin titanium nanolayers were able to generate surface plasmon resonance, thus enhancing the photoluminescence of chlorophyll a. Because the density of the states of plasmon resonance increases, the enhancement of photoluminescence also rises. Due to the biocompatibility and inexpensiveness of titanium, it can be utilized to enhance the bioluminescence of chloroplast in biological light emitting devices, bio-laser, and biophotonics.

Hsun Su, Yen [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China) [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Hsu, Chia-Yun; Chang, Chung-Chien [Science and Technology of Accelerator Light Source, Hsinchu 300, Taiwan (China) [Science and Technology of Accelerator Light Source, Hsinchu 300, Taiwan (China); Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Tu, Sheng-Lung; Shen, Yun-Hwei [Department of Resource Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China)] [Department of Resource Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China)

2013-08-05T23:59:59.000Z

282

Fundamental limit of light trapping in grating Zongfu Yu, Aaswath Raman and Shanhui Fan+  

E-Print Network [OSTI]

­305 (1982). 5. M. A. Green, "Lambertian light trapping in textured solar cells and light-emitting diodes. I. Tobías, A. Luque, and A. Marti, "Light intensity enhancement by diffracting structures in solar of nanophotonic light trapping for solar cells," arXiv:1004.2902v2 [physics.optics] (2010). http

Fan, Shanhui

283

Single White-Light-Emitting Nanostructures Based on Förster Resonance Energy Transfer: Development, Characterization and Applications.  

E-Print Network [OSTI]

??Electric energy use associated with lighting reaches up to 3400 Terawatts hours and constitutes approximately 20 % of the world total electricity output per year.… (more)

Chirmanov, Vadim

2015-01-01T23:59:59.000Z

284

An ambipolar phosphine oxide-based host for high power efficiency blue phosphorescent organic light emitting devices  

SciTech Connect (OSTI)

We report blue electrophosphorescent organic light emitting devices (OLEDs) with a new ambipolar host material, 4-(diphenylphosphoryl)-N,N-diphenylaniline (HM-A1), doped with the blue phosphor iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N,C2’]picolinate (FIrpic). The ambipolar nature of the host was verified using single carrier devices. The power efficiency of devices that employed 2,8-bis(diphenylphosphoryl)dibenzothiophene (PO15) as the electron transport layer showed optimized device performance when the electron transport layer thickness was 500 Å, giving a peak power efficiency of 46 lm/W (corresponding external quantum efficiency of 17.1%). The external quantum efficiency and power efficiency at the brightness of 800 Cd/m2 were measured with no light outcoupling enhancement and found to be 15.4% and 26 lm/W, respectively.

Polikarpov, Evgueni; Swensen, James S.; Chopra, Neetu; So, Franky; Padmaperuma, Asanga B.

2009-06-01T23:59:59.000Z

285

Laser Diode Setup and Operation Eric Lochbrunner  

E-Print Network [OSTI]

Laser Diode Setup and Operation Eric Lochbrunner Diodes are a very important electrical of current. Laser diodes are complex semiconductors similar to regular diodes that convert an electrical of the diode to create laser activity. Light emitters are a key element in any fiber optic system

La Rosa, Andres H.

286

Control of light polarization using optically spin-injected vertical external cavity surface emitting lasers  

SciTech Connect (OSTI)

We fabricated and characterized an optically pumped (100)-oriented InGaAs/GaAsP multiple quantum well Vertical External Cavity Surface Emitting Laser (VECSEL). The structure is designed to allow the integration of a Metal-Tunnel-Junction ferromagnetic spin-injector for future electrical injection. We report here the control at room temperature of the electromagnetic field polarization using optical spin injection in the active medium of the VECSEL. The switching between two highly circular polarization states had been demonstrated using an M-shaped extended cavity in multi-modes lasing. This result witnesses an efficient spin-injection in the active medium of the LASER.

Frougier, J., E-mail: julien.frougier@thalesgroup.com; Jaffrès, H.; Deranlot, C.; George, J.-M. [Unité Mixte de Physique CNRS-Thales and Université Paris Sud 11, 1 av. Fresnel, 91767 Palaiseau (France)] [Unité Mixte de Physique CNRS-Thales and Université Paris Sud 11, 1 av. Fresnel, 91767 Palaiseau (France); Baili, G.; Dolfi, D. [Thales Research and Technology, 1 av. Fresnel, 91767 Palaiseau (France)] [Thales Research and Technology, 1 av. Fresnel, 91767 Palaiseau (France); Alouini, M. [Institut de Physique de Rennes, 263 Avenue Général Leclerc, 35042 Rennes (France)] [Institut de Physique de Rennes, 263 Avenue Général Leclerc, 35042 Rennes (France); Sagnes, I. [Laboratoire de Photonique et de Nanostructures, Route de Nozay, 91460 Marcoussis (France)] [Laboratoire de Photonique et de Nanostructures, Route de Nozay, 91460 Marcoussis (France); Garnache, A. [Institut d'électronique du Sud CNRS UMR5214, Université Montpellier 2 Place Eugene Bataillon, 34095 Montpellier (France)] [Institut d'électronique du Sud CNRS UMR5214, Université Montpellier 2 Place Eugene Bataillon, 34095 Montpellier (France)

2013-12-16T23:59:59.000Z

287

Cone–rod receptor spaces with illustrations that use CRT phosphor and light-emitting-diode spectra  

Science Journals Connector (OSTI)

The purpose of the study is to characterize the excitation of the three cone types and the rods in a colorimetric system. Two representations of photoreceptor activity are developed....

Shapiro, Arthur G; Pokorny, Joel; Smith, Vivianne C

1996-01-01T23:59:59.000Z

288

Synthesis of High-Triplet-Energy Host Polymer for Blue and White Electrophosphorescent Light-Emitting Diodes  

Science Journals Connector (OSTI)

A high-triplet-energy host polymer consisting of 9-(4-(bis(9-(2-ethylhexyl)-9H-carbazol-3-yl)methyl)phenyl)-9H-carbazole and tetraphenylsilane units was designed and synthesized. The triplet energy (2.67 eV) is one of the highest values reported for ...

Fei Xu; Ji-Hoon Kim; Hee Un Kim; Jae-Ho Jang; Kyoung Soo Yook; Jun Yeob Lee; Do-Hoon Hwang

2014-10-23T23:59:59.000Z

289

Surface plasmon dispersion engineering via double-metallic AU/AG layers for nitride light-emitting diodes  

DOE Patents [OSTI]

A double-metallic deposition process is used whereby adjacent layers of different metals are deposited on a substrate. The surface plasmon frequency of a base layer of a first metal is tuned by the surface plasmon frequency of a second layer of a second metal formed thereon. The amount of tuning is dependent upon the thickness of the metallic layers, and thus tuning can be achieved by varying the thicknesses of one or both of the metallic layers. In a preferred embodiment directed to enhanced LED technology in the green spectrum regime, a double-metallic Au/Ag layer comprising a base layer of gold (Au) followed by a second layer of silver (Ag) formed thereon is deposited on top of InGaN/GaN quantum wells (QWs) on a sapphire/GaN substrate.

Tansu, Nelson; Zhao, Hongping; Zhang, Jing; Liu, Guangyu

2014-04-01T23:59:59.000Z

290

Fully Printed Separated Carbon Nanotube Thin Film Transistor Circuits and Its Application in Organic Light Emitting Diode Control  

Science Journals Connector (OSTI)

The advantages of printed electronics and semiconducting single-walled carbon nanotubes (SWCNTs) are combined for the first time for display electronics. Conductive silver ink and 98% semiconductive SWCNT solutions are used to print back-gated thin film ...

Pochiang Chen; Yue Fu; Radnoosh Aminirad; Chuan Wang; Jialu Zhang; Kang Wang; Kosmas Galatsis; Chongwu Zhou

2011-11-03T23:59:59.000Z

291

Defect engineering in implantation technology of silicon light-emitting structures with dislocation-related luminescence  

Science Journals Connector (OSTI)

Results obtained in development of physical foundations of ion implantation technology for fabrication of silicon light- ... . The development of the concept of defect engineering in the technology of semiconduct...

N. A. Sobolev

2010-01-01T23:59:59.000Z

292

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

E-Print Network [OSTI]

LED Light Fixture Project ­ FC1 Director's Conference Room: Life Cycle Cost and Break-even Analysis sources. One of the emerging lighting technologies that facilities organizations are looking at are LEDs. A light-emitting diode (LED) is a solid-state lighting source that switches on instantly, is readily

Johnston, Daniel

293

Light & Engineering Svetotekhnika Vol. 16, No. 2, pp. 5-24, 2008 No. 2, 2008, pp. 4-11  

E-Print Network [OSTI]

greenhouse-gas reductions through the replacement of fossil-fuel-based lighting. In addition to present- ing5 Light & Engineering Svetotekhnika Vol. 16, No. 2, pp. 5-24, 2008 No. 2, 2008, pp. 4-11 White light-emitting diode (WLED) lighting systems have recently attained levels of efficien- cy and cost

Jacobson, Arne

294

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

E-Print Network [OSTI]

Off-grid energy services for the poor: Introducing LED lighting in the Millennium Villages Project 2009 Keywords: Solar Lighting Development a b s t r a c t Lanterns that use light-emitting diodes (LEDs as a cost-competitive alternative to kerosene and other fuel-based lighting technologies, offering brighter

Modi, Vijay

295

InGaAsBi alloys on InP for efficient near- and mid-infrared light emitting devices  

SciTech Connect (OSTI)

We present the band parameters such as band gap, spin-orbit splitting energy, band offsets and strain of InGaAsBi on InP based on recent experimental data. It is shown that InGaAsBi is promising for near- and mid-infrared photonic devices operating from 0.3–0.8?eV (1.5–4??m) on conventional InP substrates. We also show how bismuth may be used to form alloys whereby the spin-orbit splitting energy (?{sub SO}) is large and controllable and can, for example, be made larger than the band gap (E{sub g}) thereby providing a means of suppressing non-radiative hot-hole producing Auger recombination and inter-valence band absorption both involving the spin-orbit band. This is expected to improve the high-temperature performance and thermal stability of light emitting devices.

Jin, Shirong; John Sweeney, Stephen [Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

2013-12-07T23:59:59.000Z

296

Current-voltage model of LED light sources Szymon Bczkowski, Stig Munk-Nielsen  

E-Print Network [OSTI]

Current-voltage model of LED light sources Szymon Bczkowski, Stig Munk-Nielsen Department of Energy shifts caused by varying magnitude of LED driving current and nonlinear relationship between intensity radiation into visible light, are gradually being replaced by light-emitting diodes. The invention of LEDs

Munk-Nielsen, Stig

297

Arabidopsis Phytochrome B Promotes SPA1 Nuclear Accumulation to Repress Photomorphogenesis under Far-Red Light  

Science Journals Connector (OSTI)

...conditions for seedlings were as described previously (Yang et al., 2005a). FR and R light was supplied using light-emitting diode light sources (model E-30LEDL3; Percival Scientific), with irradiance fluence rates of 2.5 and 30.0...

Xu Zheng; Suowei Wu; Huqu Zhai; Peng Zhou; Meifang Song; Liang Su; Yulin Xi; Zhiyong Li; Yingfan Cai; Fanhua Meng; Li Yang; Haiyang Wang; Jianping Yang

2013-01-31T23:59:59.000Z

298

IMPACT OF NEW LIGHTING TECHNOLOGIES ON OFFICE ERGONOMICS  

E-Print Network [OSTI]

The goal of this study was to find the impact of cutting-edge light-emitting diodes (LED) lighting technologies on the office ergonomics in modern offices. An experiment was conducted in a windowless office at the University of Kansas...

Li, Linjie

2013-12-31T23:59:59.000Z

299

Flexible LEDs bring light to fingertips Oct 19, 2010  

E-Print Network [OSTI]

Flexible LEDs bring light to fingertips Oct 19, 2010 Glowing gloves Light-emitting diodes ­ or LEDs and colleagues have exploited a new printing technique for forming arrays of incredibly small red LEDs on flexible substrates. Like conventional LED manufacture, device fabrication begins by depositing a stack

Rogers, John A.

300

Let there be (a new kind of) light [NEWS  

Science Journals Connector (OSTI)

Recent events on the business front and advances in the lab could soon transform the way about lighting our homes and buildings. Significant strides in developing organic light-emitting diodes (OLEDs) may allow architects in the next few years to integrate ...

J. Boyd

2007-07-01T23:59:59.000Z

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


301

Light with nonzero chemical potential  

Science Journals Connector (OSTI)

Thermodynamic states and processes involving light are discussed in which the chemical potential of light is nonzero. Light with nonzero chemical potential is produced in photochemical reactions for example in a light emitting diode. The chemical potential of black-body radiation becomes negative upon a Joule expansion. The isothermal diffusion of light which is a common phenomenon is driven by the gradient in the chemical potential. These and other examples support the idea that light can be interpreted as a gas of photons with properties similar to a material gas.

F. Herrmann; P. Würfel

2005-01-01T23:59:59.000Z

302

Solid-state lighting technology perspective.  

SciTech Connect (OSTI)

Solid-State Lighting (SSL) uses inorganic light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs) to convert electricity into light for illumination. SSL has the potential for enormous energy savings and accompanying environmental benefits if its promise of 50% (or greater) energy efficiencies can be achieved. This report provides a broad summary of the technologies that underlie SSL. The applications for SSL and potential impact on U.S. and world-wide energy consumption, and impact on the human visual experience are discussed. The properties of visible light and different technical metrics to characterize its properties are summarized. The many factors contributing to the capital and operating costs for SSL and traditional lighting sources (incandescent, fluorescent, and high-intensity discharge lamps) are discussed, with extrapolations for future SSL goals. The technologies underlying LEDs and OLEDs are also described, including current and possible alternative future technologies and some of the present limitations.

Tsao, Jeffrey Yeenien; Coltrin, Michael Elliott

2006-08-01T23:59:59.000Z

303

Video through a light guide  

Science Journals Connector (OSTI)

Demonstrations are discussed to illustrate some basic principles of television transmission and reception. The aim of these demonstrations is to promote student understanding of how a picture is converted into an electrical signal sent to a remote receiver and correctly reproduced there. The demonstration setup includes a video camera a light emitting diode a light guide a photodiode and a video monitor. Electrical production of visual images is also discussed.

Yaakov Kraftmakher

2008-01-01T23:59:59.000Z

304

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

SciTech Connect (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.; Weiland, Mark A.

2001-01-30T23:59:59.000Z

305

Genomic Evidence for COP1 as a Repressor of Light-Regulated Gene Expression and Development in Arabidopsis  

Science Journals Connector (OSTI)

...red, far-red, and blue light or darkness for 6 days. The white light intensity was 152 mumol21. The color light-emitting diode growth chambers (E-30LED2/3 Percival Scientific, Perry, IA) had intensities of 16.2 mumol21 for blue...

Ligeng Ma; Ying Gao; Lijia Qu; Zhangliang Chen; Jinming Li; Hongyu Zhao; Xing Wang Deng

2002-09-16T23:59:59.000Z

306

High Resolution Optically Addressed Spatial Light Modulator based on ZnO Nanoparticles  

E-Print Network [OSTI]

temperatures. (d) Temporal current response with and without illumination. Samples are illuminated by 10 mW cm -2 of 365 nm light emitting diode with 6 V dc being applied throughout. Electrical characterization For conductivity measurement, two rectangular... of the corresponding dark/photo currents of the ITO-ZnO-ITO structures are carried out using Agilent 4156 together with a 365 nm light emitting diode light source of 2 mW cm-2. The conductivity, ? , of the sample is calculated as, dI LtV? ? (2) where, d...

Shrestha, Pawan Kumar; Chun, Young Tea; Chu, Daping

2015-01-01T23:59:59.000Z

307

The semiconductor diode as a rectifier, a light source, and a solar cell: A simple explanation  

Science Journals Connector (OSTI)

An explanation of the principles of a pn junction is proposed without recourse to the band model the space charge of the junction and the charge carrier depletion at the interface. The explanation assumes that the processes in a pn junction can be considered as a chemical reaction between electrons holes and photons and that an n -type material is a conductor for electrons and an insulator for holes and a p -type material is a conductor for holes and an insulator for electrons. We give a simple and concise explanation of rectification light emission and current generation by pn junctions.

F. Herrmann; P. Würfel

2006-01-01T23:59:59.000Z

308

Synthesis of visible light emitting self assembled Ge nanocrystals embedded within a SiO{sub 2} matrix  

SciTech Connect (OSTI)

As-grown light emitting self-assembled Ge nanocrystals (Ge-NCs) embedded in a SiO{sub 2} matrix were produced via a sequential deposition process of SiO{sub 2}/Ge/SiO{sub 2} layers employing a reactive radio frequency sputtering technique. Obtained Ge-NCs show a crystallographic phase, the proportion, size, quality, and specific orientation of which are determined by the oxygen partial pressure. Photoluminescence (PL) spectra indicate that the size distribution of Ge-NCs is reduced and centered on about 8 nm when higher oxygen partial pressure is employed; the formation of Ge-NCs is corroborated by transmission electron microscopy measurements, and their sizes are consistent with estimates from PL measurements. Resistivity measurements are explained by a near neighbors hopping process, with specific features depending on the Ge-NCs' size. The features of PL and resistivity measurements indicate that there is no appreciable dependence of the number of interfacial defects on the oxygen partial pressure.

Hernandez-Hernandez, A.; De Moure-Flores, F.; Quinones-Galvan, J. G.; Santoyo-Salazar, J.; Melendez-Lira, M. [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, A.P. 14740, C.P. 07300, Mexico, Distrito Federal (Mexico); Rangel-Kuoppa, V. T. [Institute of Semiconductor and Solid State Physics, Johannes Kepler Universitaet, A-4040 Linz (Austria); Plach, Thomas [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterization, Center for Surface and Nanoanalytics, Johannes Kepler Universitaet, A-4040 Linz (Austria); Zapata-Torres, M. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria IPN, Calzada Legaria 694, Col. Irrigacion, 11500 Mexico, Distrito Federal (Mexico); Hernandez-Hernandez, L. A. [Escuela Superior de Fisica y Matematicas del Instituto Politecnico Nacional, Edificio 9 U.P. Adolfo Lopez Mateos, Col. San Pedro Zacatenco, C.P. 07730 (Mexico)

2012-02-15T23:59:59.000Z

309

LED Lighting | Department of Energy  

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

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

310

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

311

Polarization methods for diode laser excitation of solid state lasers  

DOE Patents [OSTI]

A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. A Yb-doped gain medium can be used that absorbs light having a first polarization and emits light having a second polarization. Using such pumping with laser cavity dispersion control, pulse durations of less than 100 fs can be achieved.

Holtom, Gary R. (Richland, WA)

2008-11-25T23:59:59.000Z

312

Energy-Department Supported Scientist Receives Nobel Prize for Blue Light LED  

Office of Energy Efficiency and Renewable Energy (EERE)

This week, three scientists—two from Japan and one from the United States—received the Nobel Prize in physics for their work on the LED light. The trifecta, Isamu Akasaki, Hiroshi Amano and Shuji Nakamura, earned the prestigious award specifically for their invention of the blue light emitting diode, a game-changer in the history of LED lights. The American scientist, Shuji Nakamura, a pioneer in the lighting industry, is the founder of LED company Soraa, which has a history of working with the Department of Energy—both through EERE and our Advanced Research Projects Agency-Energy (ARPA-E)—on the subject of blue light diodes.

313

Secretary Chu Announces More than $37 Million for Next Generation Lighting  

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

than $37 Million for Next Generation than $37 Million for Next Generation Lighting Secretary Chu Announces More than $37 Million for Next Generation Lighting January 15, 2010 - 12:00am Addthis WASHINGTON, DC - Energy Secretary Steven Chu today announced more than $37 million in funding from the American Recovery and Reinvestment Act to support high-efficiency solid-state lighting projects. Solid-state lighting, which uses light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs) instead of incandescent bulbs, has the potential to be ten times more energy-efficient than traditional incandescent lighting. Lighting accounts for approximately 24 percent of the total electricity generated in the United States today - by 2030, the development and widespread deployment of cost-effective solid-state

314

Lighting Group: Sources and Ballasts: OLED Cathodes  

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

OLED Cathodes OLED Cathodes Development of New Cathodes for OLED's Objective The objective of this project is to develop improved cathodes for use in organic light emitting diodes (OLEDs). Approach A major challenge for organic light emitting diode (OLED) technology is to improve electron injection into the organic electroluminescent layer, which limits the efficiency of the device and the luminous flux per unit area. This project aims at overcoming such barriers by developing “structured cathodes” based on functional materials (nanotubes and nanoclusters) with characteristic size smaller than the optical wavelength. The incorporation of such nanostructured cathodes in OLEDs can significantly improve device efficiency by lowering operating voltage, and increase device stability and light extraction.

315

Energy 101: Lighting Choices | Department of Energy  

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

101: Lighting Choices 101: Lighting Choices Energy 101: Lighting Choices August 13, 2013 - 2:38pm Addthis Learn about energy-efficient light bulbs that can light your home for less money. For many years, researchers have been working on new lighting options that produce the same light with less energy. Many of those designs are now on the market. This edition of Energy 101 features newer energy-saving light bulbs that provide the choices in colors and light levels you've come to expect, but with higher efficiencies-so they save you money. Upgrading 15 of the inefficient incandescent light bulbs in your home to energy-saving incandescent, compact fluorescent lamp (CFL), or light emitting diode (LED) bulbs could save you about $50 per year. For more information on lighting choices from the Office of Energy

316

Energy 101: Lighting Choices | Department of Energy  

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

Energy 101: Lighting Choices Energy 101: Lighting Choices Energy 101: Lighting Choices August 13, 2013 - 2:38pm Addthis Learn about energy-efficient light bulbs that can light your home for less money. For many years, researchers have been working on new lighting options that produce the same light with less energy. Many of those designs are now on the market. This edition of Energy 101 features newer energy-saving light bulbs that provide the choices in colors and light levels you've come to expect, but with higher efficiencies-so they save you money. Upgrading 15 of the inefficient incandescent light bulbs in your home to energy-saving incandescent, compact fluorescent lamp (CFL), or light emitting diode (LED) bulbs could save you about $50 per year. For more information on lighting choices from the Office of Energy

317

Synthesis of Fluorescent C2-Bridged Teraryls and Quateraryls for Blue, Sky-Blue, and Green Color Light-Emitting Devices  

Science Journals Connector (OSTI)

Synthesis of Fluorescent C2-Bridged Teraryls and Quateraryls for Blue, Sky-Blue, and Green Color Light-Emitting Devices ... UV–vis, fluorescence spectra, and cyclic voltammograms of 6a–e and 9a–c; atom coordinates and absolute energies and TGA plots of 6a, and 9a,b; X-ray data of 6b; NMR spectra of 3c,e, 4a–c, 4e, 6a–e, and 9a–c. ...

Atul Goel; Ashutosh Sharma; Madhu Rawat; R. S. Anand; Ruchir Kant

2014-10-23T23:59:59.000Z

318

Effects of Fuel Sulfur Content and Diesel Oxidation Catalyst on PM Emitted from Light-Duty Diesel Engine  

Science Journals Connector (OSTI)

This work aims at the particle number concentrations and size distributions, sulfate and trace metals emitted from a diesel engine fueled with three different sulfur content fuels, operating with and without DOC. ... Figure 2. Sulfate emission rate and fuel consumption as a function of sulfur content at engine speed of 2690 rpm. ... Thus, the use of low metal fuels and lubricating oil is as important to the environment and human health as low sulfur fuels, especially for engines with after-treatment devices. ...

Hong Zhao; Yunshan Ge; Xiaochen Wang; Jianwei Tan; Aijuan Wang; Kewei You

2010-01-05T23:59:59.000Z

319

L&E - high efficiency lighting for parking structure | The Better Buildings  

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

structure structure Activities Technology Solutions Teams Lighting & Electrical Space Conditioning Plug & Process Loads Food Service Refrigeration Laboratories Energy Management & Information Systems Public Sector Teams Market Solutions Teams Adopt high-efficiency lighting for your parking structure Parking structures and garages are typically lighted by older HID lighting technology without any energy-saving controls. The latest high-efficiency alternatives with energy-saving controls-including light-emitting diode (LED), induction, and fluorescent technology options-can save building owners over 40% on their parking lot lighting bills while delivering additional benefits such as better-lighted spaces. The Lighting & Electrical team developed a performance specification that

320

L&E: Adopt high-efficiency lighting for your parking lot | The Better  

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

lot lot Activities Technology Solutions Teams Lighting & Electrical Space Conditioning Plug & Process Loads Food Service Refrigeration Laboratories Energy Management & Information Systems Public Sector Teams Market Solutions Teams Adopt high-efficiency lighting for your parking lot Most parking lots are illuminated by older high-intensity discharge (HID) lighting technology without any energy-saving controls. New light-emitting diode (LED) technology can cut parking lot lighting energy bills by 40%, or much more with controls, while delivering additional benefits including long life, reduced maintenance costs, and improved lighting uniformity. The Lighting & Electrical team developed a performance specification to help building owners take advantage of these improved lighting

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

Exciting White Lighting | Department of Energy  

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

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

322

Solid-State Lighting: Why SSL  

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

Why SSL to someone by E-mail Why SSL to someone by E-mail Share Solid-State Lighting: Why SSL on Facebook Tweet about Solid-State Lighting: Why SSL on Twitter Bookmark Solid-State Lighting: Why SSL on Google Bookmark Solid-State Lighting: Why SSL on Delicious Rank Solid-State Lighting: Why SSL on Digg Find More places to share Solid-State Lighting: Why SSL on AddThis.com... Why SSL LED Basics OLED Basics Using LEDs R&D Challenges Market Challenges Why SSL Resources Solid-State Lighting: Brilliant Solutions for America's Energy Future PDF Energy Savings Potential of SSL PDF Energy Savings Estimates of LEDs PDF More Resources Since 2003, the U.S. Department of Energy has invested with industry partners in research and development of solid-state lighting (SSL)-including both light-emitting diode (LED) and organic light

323

Infrared electroluminescence from GeSn heterojunction diodes grown by molecular beam epitaxy  

SciTech Connect (OSTI)

Infrared electroluminescence was observed from GeSn/Ge p-n heterojunction diodes with 8% Sn, grown by molecular beam epitaxy. The GeSn layers were boron doped, compressively strained, and pseudomorphic on Ge substrates. Spectral measurements indicated an emission peak at 0.57 eV, about 50 meV wide, increasing in intensity with applied pulsed current, and with reducing device temperatures. The total integrated emitted power from a single edge facet was 54 {mu}W at an applied peak current of 100 mA at 100 K. These results suggest that GeSn-based materials maybe useful for practical light emitting diodes operating in the infrared wavelength range near 2 {mu}m.

Gupta, Jay Prakash; Bhargava, Nupur; Kim, Sangcheol; Kolodzey, James [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States)] [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States); Adam, Thomas [Nanofab, University of Albany, SUNY, Albany, New York 12203 (United States)] [Nanofab, University of Albany, SUNY, Albany, New York 12203 (United States)

2013-06-24T23:59:59.000Z

324

Identification of a Photosystem II Phosphatase Involved in Light Acclimation in Arabidopsis  

Science Journals Connector (OSTI)

...immobilized metal ion affinity chromatography|HA, to be defined|pNPP, para-nitrophenyl phosphate|LED, light-emitting diode|MS, mass spectrometry|Ni-NTA, to be defined| INTRODUCTION The primary reactions of plant and algal photosynthesis...

Iga Samol; Alexey Shapiguzov; Björn Ingelsson; Geoffrey Fucile; Michèle Crèvecoeur; Alexander V. Vener; Jean-David Rochaix; Michel Goldschmidt-Clermont

2012-06-15T23:59:59.000Z

325

Electronic and excitonic processes in light-emitting devices based on organic materials and colloidal quantum dots  

E-Print Network [OSTI]

technologies requiring high spec- tral quality lighting. Solubility of colloidal QDs in organic solvents- lished green, red, and orange QD-LEDs exhibit peak effi- ciencies in the range of 1%­2%,8,9 while

326

Effects of emission layer doping on the spatial distribution of charge and host recombination rate density in organic light emitting devices: A numerical study  

SciTech Connect (OSTI)

Based on drift-diffusion theory, a numerical model of the doping of a single energy level trap in the emission layer of an organic light emitting device (OLED) was developed, and the effects of doping of this single energy level trap on the distribution of the charge density, the recombination rate density, and the electric field in single- and double-layer OLEDs were studied numerically. The results show that by doping the n-type (p-type) emission layer with single energy electron (hole) traps, the distribution of the recombination rate density can be tuned and shifted, which is useful for improvement of the device performance by reduced electrode quenching or for realization of desirable special functions, e.g., emission spectrum tuning in multiple dye-doped white OLEDs.

Li, Yanli; Zhou, Maoqing; Zheng, Tingcai; Yao, Bo [Institute of Microelectronics, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); Peng, Yingquan, E-mail: yqpeng@lzu.edu.cn [Institute of Microelectronics, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China)

2013-12-28T23:59:59.000Z

327

Emitron: microwave diode  

DOE Patents [OSTI]

The invention comprises a new class of device, driven by electron or other charged particle flow, for producing coherent microwaves by utilizing the interaction of electromagnetic waves with electron flow in diodes not requiring an external magnetic field. Anode and cathode surfaces are electrically charged with respect to one another by electron flow, for example caused by a Marx bank voltage source or by other charged particle flow, for example by a high energy charged particle beam. This produces an electric field which stimulates an emitted electron beam to flow in the anode-cathode region. The emitted electrons are accelerated by the electric field and coherent microwaves are produced by the three dimensional spatial and temporal interaction of the accelerated electrons with geometrically allowed microwave modes which results in the bunching of the electrons and the pumping of at least one dominant microwave mode.

Craig, G.D.; Pettibone, J.S.; Drobot, A.T.

1982-05-06T23:59:59.000Z

328

Abscisic acid signalling determines susceptibility of bundle sheath cells to photoinhibition in high light-exposed Arabidopsis leaves  

Science Journals Connector (OSTI)

...imaging For APX2 gene expression experiments, plants were exposed to a PPFD of 1500 micromol m2 s1 from a white light emitting diode (LED) array (Isolight; Technologica Ltd, Colchester UK). Leaf surface temperature reached 27C after 5 min...

2014-01-01T23:59:59.000Z

329

PIF4 and PIF5 Transcription Factors Link Blue Light and Auxin to Regulate the Phototropic Response in Arabidopsis  

Science Journals Connector (OSTI)

...Three-day-old dark-grown seedlings on vertical plates were unilaterally illuminated with 2 micromol m2 s1 BL from a light-emitting diode (Wan et al., 2012). Images were recorded with a digital camera at specific time points. Hypocotyl bending...

Jiaqiang Sun; Linlin Qi; Yanan Li; Qingzhe Zhai; Chuanyou Li

2013-06-11T23:59:59.000Z

330

Theories of phosphorescence in organo-transition metal complexes - from relativistic effects to simple models and design principles for organic light-emitting diodes  

E-Print Network [OSTI]

We review theories of phosphorescence in cyclometalated complexes. We focus primarily on pseudooctahedrally coordinated $t_{2g}^6$ metals (e.g., [Os(II)(bpy)$_3$]$^{2+}$, Ir(III)(ppy)$_3$ and Ir(III)(ptz)$_3$) as, for reasons that are explored in detail, these show particularly strong phosphorescence. We discuss both first principles approaches and semi-empirical models, e.g., ligand field theory. We show that together these provide a clear understanding of the photophysics and in particular the lowest energy triplet excitation, T$_1$. In order to build a good model relativistic effects need to be included. The role of spin-orbit coupling is well-known, but scalar relativistic effects are also large - and are therefore also introduced and discussed. No expertise in special relativity or relativistic quantum mechanics is assumed and a pedagogical introduction to these subjects is given. It is shown that, once both scalar relativistic effects and spin-orbit coupling are included, time dependent density function...

Powell, B J

2015-01-01T23:59:59.000Z

331

Optoelectrical characteristics of green light-emitting diodes containing thick InGaN wells with digitally grown InN/GaN  

Science Journals Connector (OSTI)

Compared with conventionally grown thin InGaN wells, thick InGaN wells with digitally grown InN/GaN exhibit superior optical properties. The activation energy (48 meV) of thick InGaN...

Yu, Chun-Ta; Lai, Wei-Chih; Yen, Cheng-Hsiung; Hsu, Hsu-Cheng; Chang, Shoou-Jinn

2014-01-01T23:59:59.000Z

332

Enhanced performance of organic light-emitting diodes (OLEDs) and OLED-based photoluminescent sensing platforms by novel microstructures and device architectures  

SciTech Connect (OSTI)

After a general introduction to OLEDs and OLED-based PL sensors, the transient emission mechanism of guest-host OLEDs is described both experimentally and theoretically. A monolithic and easy-to-apply process is demonstrated for fabricating multicolor microcavity OLEDs (that improve the sensor platform). The outcoupling issues of OLEDs at the substrate/air interface are addressed by using a microstructured polymer film resulting from a PS and polyethylene glycol (PEG) mixture. Based on the understanding of OLEDs and their improvement, research was done in order to realize integrated all organic-based O{sub 2} and pH sensors with improved signal intensity and sensitivity. The sensor design modification and optimization are summarized

Liu, Rui [Ames Laboratory

2012-08-01T23:59:59.000Z

333

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

E-Print Network [OSTI]

nitrogen atmosphere for acceptor activation, thus making an LED p-i-n structure.. For simplicity, hereafter we will refer to structures grown using 120 sccm of TMI as QW1 and LED1, and those grown using 300 sccm as QW2 and LED2. A second set of In... was provided by a HeCd laser source and the PL emission collected and dispersed within a 0.85 m single grating spectrometer. LED samples were processed into side-contacted structures as follows: mesas were formed with a Cl2-Ar inductively coupled plasma...

Massabuau, F. C.-P.; Davies, M. J.; Oehler, F.; Pamenter, S. K.; Thrush, E. J.; Kappers, M. J.; Kovács, A.; Williams, T.; Hopkins, M. A.; Humphreys, C. J.; Dawson, P.; Dunin-Borkowski, R. E.; Etheridge, J.; Allsopp, D. W. E.; Oliver, R. A.

2014-09-19T23:59:59.000Z

334

Enhanced Performance in Fluorene-Free Organometal Halide Perovskite Light Emitting Diodes using Tunable, Low Electron-Affinity Oxide Electron-Injectors  

E-Print Network [OSTI]

(N,N-di-p-methoxyphenylamine)-9,9’-spiro-bifluorene (spiro-OMeTAD)[17] or F8, thus finding new electrode materials that overcome these limitations is essential for the commercial application of perovskite optoelectronics. Stable metal oxide electrodes, such as Zn...

Hoye, Robert L. Z.; Chua, Matthew R.; Musselman, Kevin P.; Li, Guangru; Lai, May-Ling; Tan, Zhi-Kuang; Greenham, Neil C.; MacManus-Driscoll, Judith L.; Friend, Richard H.; Credgington, Dan

2015-01-09T23:59:59.000Z

335

Gas-source molecular beam epitaxial growth and characterization of the (Al,In,Ga)NP/GaP material system and Its applications to light-emitting diodes  

E-Print Network [OSTI]

T.P. , IEE Proceedings-Optoelectronics 144, 1 (1997). Kishof Energy (BTS) and the Optoelectronics Industry Developmentin semiconductor optoelectronics in recent years. Within two

Odnoblyudov, Vladimir

2006-01-01T23:59:59.000Z

336

Surface plasmon-enhanced nanoporous GaN-based green light-emitting diodes with Al2O3 passivation layer  

Science Journals Connector (OSTI)

A surface plasmon (SP)-enhanced nanoporous GaN-based green LED based on top-down processing technology has been successfully fabricated. This SP-enhanced LED consists of nanopores...

Yu, Zhi-Guo; Zhao, Li-Xia; Wei, Xue-Cheng; Sun, Xue-Jiao; An, Ping-Bo; Zhu, Shi-Chao; Liu, Lei; Tian, Li-Xin; Zhang, Feng; Lu, Hong-Xi; Wang, Jun-Xi; Zeng, Yi-Ping; Li, Jin-Min

2014-01-01T23:59:59.000Z

337

DOE Lighting Program Update: LED Validation Activities  

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

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:

338

Demonstration of high-speed multi-user multi-carrier CDMA visible light communication  

Science Journals Connector (OSTI)

Abstract We experimentally demonstrated a high-speed multi-user multi-carrier code-division multiple access (MC-CDMA) visible light communication (VLC) system. By employing a commercially available red light emitting diode (LED) and an avalanche photo diode (APD), we achieved a 16-user VLC system enabled by MC-CDMA, pre- and post-equalization, with an overall bit rate of 750 Mb/s over 1.5 m free-space transmission. The measured bit error ratio (BER) of each user is below the 7% pre-forward-error-correction (pre-FEC) threshold of 3.8×10?3.

Chao Yang; Yuanquan Wang; Yiguang Wang; Xingxing Huang; Nan Chi

2015-01-01T23:59:59.000Z

339

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

340

2010 Minerals Yearbook U.S. Department of the Interior  

E-Print Network [OSTI]

circuits (ICs) and optoelectronic devices [laser diodes, light-emitting diodes (LEDs), photodetectors

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

FAQ of Overview of Solid-State Lighting  

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

342

Band-filling effect on the light emission spectra of InGaN/GaN quantum wells with highly doped barriers  

Science Journals Connector (OSTI)

We investigate spectra of InGaN/GaN quantum well (QW) light-emitting diode (LED) structures with heavily doped barriers at different excitation levels. We model the spectral shape and energy position in frames of dominating mechanism of free electron ... Keywords: Band filling, Doped barriers, Emission spectra, Quantum well

B. Arnaudov; D. S. Domanevskii; S. Evtimova; Ch. Ivanov; R. Kakanakov

2009-02-01T23:59:59.000Z

343

The transparent testa4 Mutation Prevents Flavonoid Synthesis and Alters Auxin Transport and the Response of Arabidopsis Roots to Gravity and Light  

Science Journals Connector (OSTI)

...and the bending root was followed for an additional 6 to 8 h. The seedling was illuminated with an infrared light-emitting diode and the image produced was captured with a CCD camera and analyzed with Multi-ADAPT software (Mullen et al...

Charles S. Buer; Gloria K. Muday

2004-04-20T23:59:59.000Z

344

Which LED Lighting Products Would You Consider Trying? | Department of  

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

Which LED Lighting Products Would You Consider Trying? Which LED Lighting Products Would You Consider Trying? Which LED Lighting Products Would You Consider Trying? August 5, 2010 - 7:30am Addthis On Monday, Chris discussed his upcoming project to replace the lighting in his kitchen and family room. Chris is considering LED (light-emitting diode) lighting, especially for his kitchen, where they can be installed under the cabinets. LEDs can also be used for other applications, including task lighting, recessed downlights, and holiday lighting. Which LED lighting products would you consider trying? Or, if you're already using LEDs, what do you think of them? Each Thursday, you have the chance to share your thoughts on a question about energy efficiency or renewable energy for consumers. Please comment with your answers, and also feel free to respond to other comments.

345

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

E-Print Network [OSTI]

lighting using incandescent lights and fluorescent lamps, asenergy used for the incandescent lamp is wasted as infraredsource to replace incandescent and fluorescent lighting [2].

Han, Jinkyu

2013-01-01T23:59:59.000Z

346

Radiative cooling of bulk silicon by incoherent light pump  

SciTech Connect (OSTI)

In contrast to radiative cooling by light up conversion caused exclusively by a low-entropy laser pump and employing thermally assisted fluorescence/luminescence as a power out, we demonstrate light down conversion cooling by incoherent pumps, 0.47–0.94??m light emitting diodes, and employing thermal emission (TE) as a power out. We demonstrate ?3.5?K bulk cooling of Si at 450?K because overall energy of multiple below bandgap TE photons exceeds the energy of a single above bandgap pump photon. We show that using large entropy TE as power out helps avoid careful tuning of an incoherent pump wavelength and cool indirect-bandgap semiconductors.

Malyutenko, V. K., E-mail: malyut@isp.kiev.ua; Bogatyrenko, V. V.; Malyutenko, O. Yu. [V. E. Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine)] [V. E. Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine)

2013-12-23T23:59:59.000Z

347

Solid-State Lighting: R&D Projects  

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

R&D R&D Projects Printable Version Share this resource Send a link to Solid-State Lighting: R&D Projects to someone by E-mail Share Solid-State Lighting: R&D Projects on Facebook Tweet about Solid-State Lighting: R&D Projects on Twitter Bookmark Solid-State Lighting: R&D Projects on Google Bookmark Solid-State Lighting: R&D Projects on Delicious Rank Solid-State Lighting: R&D Projects on Digg Find More places to share Solid-State Lighting: R&D Projects on AddThis.com... R&D Highlights R&D Projects DOE leadership and support spur advances in the efficacy and performance of light-emitting diode (LED) and organic LED (OLED) technologies-advances that might not otherwise be achieved without DOE funding. (Some of the following documents are available as Adobe Acrobat PDFs. Download Adobe

348

Keeping Pace with LED Lighting Trends | Department of Energy  

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

Keeping Pace with LED Lighting Trends Keeping Pace with LED Lighting Trends Keeping Pace with LED Lighting Trends October 23, 2013 - 10:41am Addthis This year's SSL Market Introduction Workshop will take place in Portland, Oregon. | Photo courtesy of Travel Portland This year's SSL Market Introduction Workshop will take place in Portland, Oregon. | Photo courtesy of Travel Portland Jim Brodrick Lighting Program Manager Rapid advances in solid-state lighting (SSL) technology are reducing the cost, improving the performance and quality, and bringing new lighting options--light emitting diodes (LEDs) to the market. But for lighting and energy efficiency industry professionals this seemingly good news can be "too much of a good thing." Imagine the challenge of making smart institutional purchasing decisions or designing

349

Save Money with LED Holiday Light Strings | Department of Energy  

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

Money with LED Holiday Light Strings Money with LED Holiday Light Strings Save Money with LED Holiday Light Strings December 1, 2009 - 11:19am Addthis Allison Casey Senior Communicator, NREL It's hard to believe, but the holidays are in full swing and many of you are starting to decorate your homes. Those of you who started around Halloween are probably feeling pretty smart because you got your decorating done while the weather was nice. I see you there, snacking on your Thanksgiving leftovers, laughing at me shivering in the cold and struggling to undo the knot in my lights. Don't look so smug. Those of us who haven't started decorating yet may actually be the smart ones this year, because we still have a chance to buy LED light strings. LED (or light emitting diode) light strings can use 90% less energy than

350

Performance Comparison of Bottom and Top Emitting LWIR (8 ?m) LED Devices  

Science Journals Connector (OSTI)

For similar substrate thickness, flip-chip mount bottom emitting LWIR LED device has higher light intensity than top emitting device. Enhanced emission is attributed to better cooling...

Das, Naresh C; Chang, Wayne

351

Lighting the Way for Big Energy Savings in Los Angeles | Department of  

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

Lighting the Way for Big Energy Savings in Los Angeles Lighting the Way for Big Energy Savings in Los Angeles Lighting the Way for Big Energy Savings in Los Angeles November 14, 2013 - 1:10pm Addthis A Los Angeles lighting project is saving the city $7 million a year in electricity costs. | Photo courtesy of Los Angeles Bureau of Street Lighting A Los Angeles lighting project is saving the city $7 million a year in electricity costs. | Photo courtesy of Los Angeles Bureau of Street Lighting Jim Brodrick Lighting Program Manager The world's largest light emitting diode (LED) conversion project to date is under way in Los Angeles, California. In the project's first phase alone, the city retrofitted over 141,000 streetlights, reducing energy use by 63% and saving the city $7 million a year in electricity costs. The project is expected to reduce carbon

352

How Energy-Efficient Light Bulbs Compare with Traditional Incandescents |  

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

Energy-Efficient Light Bulbs Compare with Traditional Energy-Efficient Light Bulbs Compare with Traditional Incandescents How Energy-Efficient Light Bulbs Compare with Traditional Incandescents July 29, 2012 - 6:25pm Addthis Energy-efficient light bulbs are available today and could save you about $50 per year in energy costs when you replace 15 traditional incandescent bulbs in your home. Energy-efficient light bulbs are available today and could save you about $50 per year in energy costs when you replace 15 traditional incandescent bulbs in your home. Compared to traditional incandescents, energy-efficient lightbulbs such as energy-saving incandescents, compact fluorescent lamps (CFLs), and light emitting diodes (LEDs) have the following advantages: Typically use about 25%-80% less energy, saving you money

353

Deterministic polarization chaos from a laser diode  

E-Print Network [OSTI]

Fifty years after the invention of the laser diode and fourty years after the report of the butterfly effect - i.e. the unpredictability of deterministic chaos, it is said that a laser diode behaves like a damped nonlinear oscillator. Hence no chaos can be generated unless with additional forcing or parameter modulation. Here we report the first counter-example of a free-running laser diode generating chaos. The underlying physics is a nonlinear coupling between two elliptically polarized modes in a vertical-cavity surface-emitting laser. We identify chaos in experimental time-series and show theoretically the bifurcations leading to single- and double-scroll attractors with characteristics similar to Lorenz chaos. The reported polarization chaos resembles at first sight a noise-driven mode hopping but shows opposite statistical properties. Our findings open up new research areas that combine the high speed performances of microcavity lasers with controllable and integrated sources of optical chaos.

Martin Virte; Krassimir Panajotov; Hugo Thienpont; Marc Sciamanna

2014-07-22T23:59:59.000Z

354

SAR-controlled adaptive off-time technique without sensing resistor for achieving high efficiency and accuracy LED lighting system  

Science Journals Connector (OSTI)

A successive approximation register (SAR) is utilized to control adaptive off-time in order to regulate accurate light-emitting diode (LED) current and improve efficiency of LED driver. The proposed SAR-controlled adaptive off-time technique without ... Keywords: adaptive off-time, hysteretic current control (HCC), on-chip low-side current sensing, peak current control (PCC), pulsewidth modulation (PWM) dimming, successive approximation register (SAR)

Chao-Hsuan Liu; Chun-Yu Hsieh; Yu-Chiao Hsieh; Ting-Jung Tai; Ke-Horng Chen

2010-06-01T23:59:59.000Z

355

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

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

Briefing for Media and Retailers - Lighting eere.energy.gov Briefing for Media and Retailers - Lighting eere.energy.gov 1 Consumer Light Bulb Changes: Briefing and Resources for Media and Retailers Briefing for Media and Retailers - Lighting eere.energy.gov 2 * Briefing: - To schedule interviews, please contact DOE Public Affairs at 202-586-4940 * Terms: - Lumens: Commonly a measure of brightness (technically "luminous flux") - CFL: Compact Fluorescent Lamp: The curly fluorescent bulbs - LED: Light Emitting Diode: more recently emerging technology, also called "solid state lighting" as it is light produced by a solid-state (chip) device - General Service Incandescent Lamp: The most common residential light bulb in use, with a medium screw base, and a lumen range of 310 to 2,600 lumens

356

Fluorene-based macromolecular nanostructures and nanomaterials for organic (opto)electronics  

Science Journals Connector (OSTI)

...hybrid organic/inorganic light-emitting diode using azide-functionalized...azide hybridized on near-UV light emitting diode for high color rendering index...hybrid organic/inorganic light emitting diode using azide functionalized...

2013-01-01T23:59:59.000Z

357

Distinct and Cooperative Functions of Phytochromes A, B, and C in the Control of Deetiolation and Flowering in Rice  

Science Journals Connector (OSTI)

...otherwise described, we used R light-emitting diode panel (Model LED-R; EYELA), FR light-emitting diode panel (Model LED-FR; EYELA), and blue light-emitting diode panel (Model LED-B; EYELA...

Makoto Takano; Noritoshi Inagaki; Xianzhi Xie; Natsu Yuzurihara; Fukiko Hihara; Toru Ishizuka; Masahiro Yano; Minoru Nishimura; Akio Miyao; Hirohiko Hirochika; Tomoko Shinomura

2005-11-08T23:59:59.000Z

358

TIFR Centre for Interdisciplinary Sciences, Narsingi, Hyderabad 500075  

E-Print Network [OSTI]

FE) nanowires has been demonstrated as capable of lighting a commercial light emitting diode. The template

Shyamasundar, R.K.

359

Advanced laser diodes for sensing applications  

SciTech Connect (OSTI)

The authors have developed diode lasers for short pulse duration and high peak pulse power in the 0.01--100.0 m pulsewidth regime. A primary goal of the program was producing up to 10 W while maintaining good far-field beam quality and ease of manufacturability for low cost. High peak power, 17 W, picosecond pulses have been achieved by gain switching of flared geometry waveguide lasers and amplifiers. Such high powers area world record for this type of diode laser. The light emission pattern from diode lasers is of critical importance for sensing systems such as range finding and chemical detection. They have developed a new integrated optical beam transformer producing rib-waveguide diode lasers with a symmetric, low divergence, output beam and increased upper power limits for irreversible facet damage.

VAWTER,GREGORY A.; MAR,ALAN; CHOW,WENG W.; ALLERMAN,ANDREW A.

2000-01-01T23:59:59.000Z

360

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

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

E-Print Network 3.0 - average power semiconductor Sample Search...  

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

externalexternal, and power, and power efficiencyefficiency 12;25 Optoelectronic Semiconductor... cavity light emitting diodesResonant cavity light emitting diodes...

362

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

363

Lighting  

SciTech Connect (OSTI)

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

364

Side-emitting fiber optic position sensor  

DOE Patents [OSTI]

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

365

The solid state lighting initiative: An industry/DOE collaborativeeffort  

SciTech Connect (OSTI)

A new era of technology is emerging in lighting. It is being propelled by the dramatic improvements in performance of solid state light sources. These sources offer an entirely new array of design aspects not achievable with current light sources. At the same time, their performance characteristics continue to improve and are expected to eclipse those of the most common light sources within the near future. High efficiency is one of these performance attributes motivating the Department of Energy (DOE) to work with the manufacturers of this new technology to create a program plan sufficiently comprehensive to support an industry-driven Solid State Lighting Initiative before Congress. The purpose of the initiative is to educate Congress about the potential of this technology to reduce the electric lighting load within the United States and, consequently, to realize the associated environmental benefits. The initiative will solicit congressional support to accelerate the development of solid state technology through investment in the research and development necessary to overcome the technical barriers that currently limit the products to niche markets. While there are multiple technologies being developed as solid state light sources, the two technologies which hold the most promise for application to general illumination are Light Emitting Diodes (LEDs) and Organic Light Emitting Diodes (OLEDs). The form of these sources can be quite different from current sources, allowing exciting new design uses for the products. Being diffuse sources, OLEDs are much lower in intensity per unit area than LEDs. The manufacturing process for OLEDs lends itself to shapes that can be formed to different geometries, making possible luminous panels or flexible luminous materials. Conversely, LEDs are very intense point sources which can be integrated into a small space to create an intense source or used separately for less focused applications. Both OLED and LED sources are expected to be thinner than other comparable sources; this thinness offers additional design opportunities.

Johnson, Steve

2000-10-01T23:59:59.000Z

366

Lighting Group: Sources and Ballasts: LED Reflector Lamp  

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

367

2011 Minerals Yearbook U.S. Department of the Interior  

E-Print Network [OSTI]

Cs) and optoelectronic devices [laser diodes, light-emitting diodes (lEDs), photodetectors, and solar cells]. Gallium

368

phys. stat. sol. (b) 216, 683 (1999) Subject classification: 68.55.Jk; S7.14; S7.15  

E-Print Network [OSTI]

such as window layers for UV light emitting diodes [1, 2], cladding layers for violet and UV laser diodes

Wetzel, Christian M.

369

600 New Lights Bulbs to Improve Energy Efficiency at DOE | Department of  

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

600 New Lights Bulbs to Improve Energy Efficiency at DOE 600 New Lights Bulbs to Improve Energy Efficiency at DOE 600 New Lights Bulbs to Improve Energy Efficiency at DOE November 18, 2010 - 10:30am Addthis Ingrid Kolb Director of the Office of Management Starting in September, the Department of Energy has been steadily replacing all 600 light fixtures under our Washington, D.C., Forrestal North Building canopy with state of the art Light Emitting Diode (LED) fixtures. Every new bulb now uses just 23 watts instead of 205 watts. That translates into almost half a million kilowatts hours saved every year. and will cut annual energy consumption at the Department of Energy Headquarters by about 1%. The final new LED fixture under the canopy was installed on October 28, but these lights are just part of a full program to reduce energy consumption

370

Trial Demonstration of Area Lighting Retrofit: Yuma Border Patrol, Yuma Arizona  

SciTech Connect (OSTI)

The Yuma Sector Border Patrol Area is a high flux lighting application in a high temperature environment, presenting a formidable challenge for light-emitting diodes (LEDs). This retrofit is an Energy Savings Performance Contract ENABLE project under the U.S. Department of Energy (DOE) Federal Energy Management Program. If high flux LED technology performs well in a region with high ambient temperature and solar radiation, it can perform well in most outdoor environments. The design process for the Yuma retrofit has already provided valuable knowledge to CBP and DOE. The LED lighting system selected for the retrofit is expected to reduce energy consumption 69% compared to the incumbent quartz metal halide (QMH) lighting system. If the LED lighting system is installed, GATEWAY will continue to document and disseminate information regarding the installation and long-term performance so that others may also gain valuable knowledge from the Yuma Sector Border Patrol Area lighting retrofit.

Wilkerson, Andrea M.; McCullough, Jeffrey J.

2014-12-30T23:59:59.000Z

371

Diode pumped alkali vapor fiber laser  

DOE Patents [OSTI]

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

2006-07-26T23:59:59.000Z

372

Diode pumped alkali vapor fiber laser  

DOE Patents [OSTI]

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

2007-10-23T23:59:59.000Z

373

Phosphor suspended in silicone, molded/formed and used in a remote phosphor configuration  

DOE Patents [OSTI]

A light emitting package comprising a support hosting at least one light emitting diode. A light transmissive dome comprised of a silicone including a phosphor material positioned to receive light emitted by the diode. A glass cap overlies said dome.

Kolodin, Boris; Deshpande, Anirudha R

2014-09-16T23:59:59.000Z

374

The European Commission's light bulb decree: Another costly regulation?  

Science Journals Connector (OSTI)

Since September 2009, Regulation 244/2009 of the European Commission enforces the gradual phase-out of incandescent light bulbs. As of September 2012, only energy-efficient lighting sources will be allowed for sale. Among these are halogen light bulbs, light-emitting diodes (LED), or compact fluorescent light bulbs—often referred to as energy-saving light bulbs. The Commission's justification for the phase-out of conventional light bulbs maintains that a reduction in the electricity consumed will not only lead to lower energy cost for private households and industrial consumers, but at the same time lead to a decrease in greenhouse gas emissions. This article discusses possible reasons for the slow market diffusion of energy-saving light bulbs and shows that the investment in energy-efficient light bulbs does not necessarily lead to significant cost reductions. Drawing on some illustrative examples, we demonstrate that the use of cheaper incandescent bulbs instead of energy-saving light bulbs can be economically rational in cases of rather low usage times, in which the higher initial purchasing price might only pay off after very long time spans. Furthermore, due to the coexistence with the European Emissions Trading Scheme (ETS), this regulation attains no additional emission reductions beyond those achieved by the ETS alone. We thus conclude that the general ban of incandescent light bulbs is inappropriate and should be abolished by the Commission.

Manuel Frondel; Steffen Lohmann

2011-01-01T23:59:59.000Z

375

The Junction Diode Basic Operation  

E-Print Network [OSTI]

section of the diode. The junction is the dividing line between the n-type and p-type sides. Thermal biased diode. Figure 1(b) shows the diode with a battery connected across it. The polarity of the battery. Figure 1(c) shows the diode with the battery polarity reversed. The battery now tends to cancel out

Leach Jr.,W. Marshall

376

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

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

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

377

Excitonic Materials for Hybrid Solar Cells and Energy Efficient Lighting  

Science Journals Connector (OSTI)

Conventional photovoltaic technology will certainly contribute this century but to generate a significant fraction of our global power from solar energy a radically new disruptive technology is required. Research primarily focused on developing the physics and technologies being low cost photovoltaic concepts are required. The materials with carbon?based solution processible organic semiconductors with power conversion efficiency as high as ?8.2% which have emerged over the last decade as promising alternatives to expensive silicon based technologies. We aim at exploring the morphological and optoelectronic properties of blends of newly synthesized polymer semiconductors as a route to enhance the performance of organic semiconductor based optoelectronic devices like photovoltaic diodes (PV) and Light Emitting Diodes (LED). OLED efficiency has reached upto 150 lm/W and going to be next generation cheap and eco friendly solid state lighting solution. Hybrid electronics represent a valuable alternative for the production of easy processible flexible and reliable optoelectronic thin film devices. I will be presenting recent advancement of my work in the area of hybrid photovoltaics PLED and research path towards realization electrically injectable organic laser diodes.

Dinesh Kabra; Li Ping Lu; Yana Vaynzof; Myounghoon Song; Henry J. Snaith; Richard H. Friend

2011-01-01T23:59:59.000Z

378

Light  

Science Journals Connector (OSTI)

Sunlight contains energy which can be directly converted into electricity in solar cells of various types. This is an example of what is called 'direct conversion', involving no moving parts or heat conversion processes. This chapter looks at photovoltaic and photoelectric devices and also at other ideas for using light energy, some of which operate in the infrared part of the spectrum. Solar electric power is a rapidly developing field, opening up many opportunities for novel applications, as well as requirements, including for storage, with one idea being solar-powered hydrogen production and then direct conversion to electricity in fuel cells. Direct conversion is not always efficient, and this chapter introduces the concept of 'energy return on energy invested'. In speculative mood this chapter also looks at the idea of a global grid, allowing daytime solar generation to be used on the night side of the planet.

David Elliott ? Pages 4-1 to 4-20

379

JOURNAL DE PHYSIQUE N ColloqueC6,supplkmentau Journal de Physique111,Vol. 1, dkembre 1991  

E-Print Network [OSTI]

as solarcell, photodetectorsand light emitting diodes which could benefit of the enhancementin the luminescence

Paris-Sud XI, Université de

380

A R T I C L E www.rsc.org/materials  

E-Print Network [OSTI]

chemically synthesized for applications in organic light emitting diodes.16 The immobilization of negatively

Pfeifer, Holger

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

INPUT/OUTPUT DEVICES AND INTERACTION TECHNIQUES Ken Hinckley, Microsoft Research  

E-Print Network [OSTI]

light emitting diodes), speakers, or tactile and force feedback devices (sometimes referred to as haptic

Jacob, Robert J.K.

382

A Genetic Algorithm Method for Multi-spot Diffuse Infrared Wireless Communications  

E-Print Network [OSTI]

optoelectronic devices, such as light emitting diodes (LEDs) and silicon detectors [2]. However there are two

Haddadi, Hamed

383

N D'ORDRE 2008-Anne 2008 Prsente pour obtenir le grade de  

E-Print Network [OSTI]

diffusion." Abstract This work reports on color control of organic light-emitting diodes (OLEDs), which

Boyer, Edmond

384

Simple gaze-contingent cues guide eye movements in a realistic driving simulator  

E-Print Network [OSTI]

implemented using two arrays of light-emitting diodes horizontally fitted below and above the simulated

385

"Did you pack your keys?" Smart Objects And Forgetfulness  

E-Print Network [OSTI]

of ten light-emitting diodes (LEDs), piezo and Radio Frequency Identification Reader (RFID) connected

Purver, Matthew

386

Nottingham Trent University, PhD Studentship Opportunities in Art and Design, October 2014 Research Group: Supervisor  

E-Print Network [OSTI]

incorporating light-emitting diode (LED) chips. However, the group now plans to develop an automated

Evans, Paul

387

Transport Equations for Semiconductors Prof. Dr. Ansgar Jungel  

E-Print Network [OSTI]

- cations have been invented; for instance, semiconductor lasers, solar cells, light-emitting diodes (LED

Jüngel, Ansgar

388

Probabilistic Phase Unwrapping for Time-of-Flight Cameras David Droeschel, Dirk Holz and Sven Behnke  

E-Print Network [OSTI]

. They employ an array of light emitting diodes (LEDs) that illuminate the environment with modulated near

Behnke, Sven

389

"Developing terahertz spectroscopy to be used for the study of bio-materials."  

E-Print Network [OSTI]

and photonic materials and devices including uncooled photodetectors, photovoltaics and light-emitting diodes

Acton, Scott

391

Low dimensionality spectral sensing for low cost material discrimination and identi cation  

E-Print Network [OSTI]

.6 Light Emitting Diodes as Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . 32 3.7 Other

Bove Jr., V. Michael

392

DEPARTMENT OF CHEMICAL ENGINEERING DEPARTMENT OF MECHANICAL AND INDUSTRIAL ENGINEERING  

E-Print Network [OSTI]

-oxide-semiconductor field effect transistor (MOSFET) o Light emitting diodes (LEDs): principles and characteristics o

Massachusetts at Amherst, University of

393

The rapid progress of nanoscale science and technology challenges the optoelectronics community to develop ever smaller lasers and other optoelectronic devices compatible with  

E-Print Network [OSTI]

The miniaturization of optoelectronic devices such as light emitting diodes or semiconduc- tor lasers, is expected

Wu, Shin-Tson

394

DOCTORAL CANDIDATE: Raju Shrestha DEGREE: Philosophiae Doctor (PhD)  

E-Print Network [OSTI]

and technologies: multi- camera (MCMSI), filter array (FAMSI), and LED (Light Emitting Diode) illumination (LEDMSI

Løw, Erik

395

Structural Phase Contrast in Polycrystalline Organic Semiconductor  

E-Print Network [OSTI]

electronics", with devices such as light- emitting diodes, lasers, photovoltaic cells, field-effect transis

Peinke, Joachim

396

California's Energy Future - The View to 2050  

E-Print Network [OSTI]

Lawrence Livermore National Laboratory LDV Light-duty vehicles LED light emitting diode LWR Light water reactor NIF

2011-01-01T23:59:59.000Z

397

California’s Energy Future: The View to 2050 - Summary Report  

E-Print Network [OSTI]

Lawrence Livermore National Laboratory LDV Light-duty vehicles LED light emitting diode LWR Light water reactor NIF

Yang, Christopher

2011-01-01T23:59:59.000Z

398

A high-energy, low-threshold tunable intracavity terahertz-wave parametric oscillator with surface-emitted configuration  

Science Journals Connector (OSTI)

A high-energy, low-threshold THz-wave output has been experimentally demonstrated with an intracavity terahertz-wave parametric oscillator based on a surface-emitted configuration, which was pumped by a diode-side-pumped Q-switched Nd:YAG laser. Different beam sizes and repetition rates of the pump light have been investigated for high-energy and high-efficiency THz-wave generation. The maximum THz-wave output energy of 283 nJ/pulse was obtained at 1.54 THz under an intracavity 1064 nm pump energy of 59 mJ. The conversion efficiency was 4.8 ? 10?6, corresponding to a photon conversion efficiency of 0.088%. The pump threshold was 12.9 mJ/pulse. A continuously tunable range from 0.75 to 2.75 THz was realized.

Y Y Wang; D G Xu; H Jiang; K Zhong; J Q Yao

2013-01-01T23:59:59.000Z

399

Considerations REQUEST BY ACUITY BRANDS LIGHTING, INC., FOR AN ADVANCE WAIVER OF DOMESTIC AND  

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

REQUEST BY ACUITY BRANDS LIGHTING, INC., FOR AN ADVANCE WAIVER OF DOMESTIC AND REQUEST BY ACUITY BRANDS LIGHTING, INC., FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN RIGHTS IN SUBJECT INVENTIONS MADE IN THE COURSE OF OR UNDER DOE GRANT NO. DE-EE0004534; DOE WAIVERDOCKETW(A)2010-059 [ORO-801] Petitioner, Acuity Brands Lighting, Inc., (ACUITy) has made a timely request for an advance waiver to worldwide rights in Subject Inventions made in the course of or under DOE Grant No. DE-EEOOO4534 entitled, "Energy Saving Phosphorescent OLED Luminaires." The scope of the project includes ACUITY working as a subcontractor to, and in cooperation with Universal Display Corporation (UDC) as the prime contractor in the development of phosphorescent organic light-emitting diode (OLED) luminaires. In the first phase, UDC will be responsible for the basic OLED

400

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

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

Researchers Say They've Solved the Mystery of LED Lighting "Droop" Researchers Say They've Solved the Mystery of LED Lighting "Droop" Researchers Say They've Solved the Mystery of LED Lighting "Droop" May 5, 2011 - 3:32pm Addthis An illustration of nitride-based LEDs.| Courtesy of the National Energy Research Scientific Computing Center. An illustration of nitride-based LEDs.| Courtesy of the National Energy Research Scientific Computing Center. Margie Wylie Communications Specialist, Berkeley Lab Computing Sciences Team. Despite being cool, ultra-efficient and long lasting, the light-emitting diode (LED) faces a problem called "efficiency droop." New findings from simulations carried out at the National Energy Research Scientific Computer Center (NERSC) have unearthed droop's elusive cause, researchers

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


401

Edison Revisited: Should we use DC Circuits for Lighting in Commercial  

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

Edison Revisited: Should we use DC Circuits for Lighting in Commercial Edison Revisited: Should we use DC Circuits for Lighting in Commercial Buildings? Speaker(s): Brinda Thomas Date: March 7, 2012 - 12:30pm Location: 90-3122 Seminar Host/Point of Contact: Chris Marnay This seminar summarizes work from a forthcoming Energy Policy paper and thoughts on future work to understand the economics of DC building circuits. We examined the economic feasibility of a general application of DC building circuits to operate commercial lighting systems. We compare light-emitting diodes (LEDs) and fluorescents that are powered by either a central DC power supply or traditional AC grid electricity, with and without solar photovoltaics (PV) and battery back-up. We find that there are limited life-cycle ownership cost and capital cost benefits of DC

402

Graphene-Silicon Schottky Diodes  

Science Journals Connector (OSTI)

Graphene-Silicon Schottky Diodes ... We have fabricated graphene-silicon Schottky diodes by depositing mechanically exfoliated graphene on top of silicon substrates. ... The I–V characteristics measured at 100, 300, and 400 K indicate that temperature strongly influences the ideality factor of graphene–silicon Schottky diodes. ...

Chun-Chung Chen; Mehmet Aykol; Chia-Chi Chang; A. F. J. Levi; Stephen B. Cronin

2011-04-25T23:59:59.000Z

403

I Have Seen the Light and It's Green...or Pink, or Blue, or Purple. Shucks,  

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

I Have Seen the Light and It's Green...or Pink, or Blue, or Purple. I Have Seen the Light and It's Green...or Pink, or Blue, or Purple. Shucks, it's LED Solid-State Lighting. I Have Seen the Light and It's Green...or Pink, or Blue, or Purple. Shucks, it's LED Solid-State Lighting. May 5, 2009 - 5:00am Addthis John Lippert When it comes to lighting, light-emitting diodes (LEDs) are the new kid on the block. LEDs are a form of solid-state lighting. As such, they are following the example of their siblings in the computer industry, improving in performance at an astonishing pace. In this blog I'm going to cover my personal experiences with LED lighting. I'll go over LED lighting in general, providing consumer buying tips, in a future blog. You may already be using LED lighting. They have become a popular holiday lighting option around Christmas time since they consume a fraction of the

404

I Have Seen the Light and It's Green...or Pink, or Blue, or Purple. Shucks,  

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

Have Seen the Light and It's Green...or Pink, or Blue, or Purple. Have Seen the Light and It's Green...or Pink, or Blue, or Purple. Shucks, it's LED Solid-State Lighting. I Have Seen the Light and It's Green...or Pink, or Blue, or Purple. Shucks, it's LED Solid-State Lighting. May 5, 2009 - 5:00am Addthis John Lippert When it comes to lighting, light-emitting diodes (LEDs) are the new kid on the block. LEDs are a form of solid-state lighting. As such, they are following the example of their siblings in the computer industry, improving in performance at an astonishing pace. In this blog I'm going to cover my personal experiences with LED lighting. I'll go over LED lighting in general, providing consumer buying tips, in a future blog. You may already be using LED lighting. They have become a popular holiday lighting option around Christmas time since they consume a fraction of the

405

THE PROMISE OF SOLID STATE LIGHTING FOR GENERAL ILLUMINATION  

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

Conclusions and Recommendations Conclusions and Recommendations from OIDA Technology Roadmaps Co-sponsored by DOE (BTS) and OIDA 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 Building Technology, State and Community Programs Energy Efficiency and Renewable Energy U.S. Department of Energy Published by: Optoelectronics Industry Development Association 1133 Connecticut Avenue NW, Suite 600 Washington, DC 20036 Phone: (202) 785-4426 Fax: (202) 785-4428 Internet: http://www.oida.org 1 The Promise of Solid State Lighting for General Illumination s Light Emitting Diodes (LEDs) © 2001 Optoelectronics Industry Development Association Executive Summary In the midst of the rising fuel prices and the blackouts in California there is silent rev-

406

Comparative study of energy saving light sources  

Science Journals Connector (OSTI)

Techno-economic performance comparison of compact fluorescent lamps (CFL) with light emitting diodes (LED), electrode less fluorescent lamps (EEFL), fluorescent tubes, incandescent bulbs, photovoltaic (PV) and fiber optic lighting systems was carried out in view of worsening power and energy crisis in Pakistan. Literature survey showed 23 W CFL, 21 W EEFL, 18 W fluorescent tube or 15 W LED lamps emit almost same quantity of luminous flux (lumens) as a standard 100 W incandescent lamp. All inclusive, operational costs of LED lamps were found 1.21, 1.62. 1.69, 6.46, 19.90 and 21.04 times lesser than fluorescent tubes, CFL, EEFL, incandescent bulbs, fiber optic solar lighting and PV systems, respectively. However, tubes, LED, CFL and EEFL lamps worsen electric power quality of low voltage networks due to high current harmonic distortions (THD) and poor power factors (PF). Fluorescent lamps emit UV and pollute environment by mercury and phosphors when broken or at end of their life cycle. Energy consumption, bio-effects, and environmental concerns prefer LED lamps over phosphor based lamps but power quality considerations prefer EEFL. CFL and EEFL manufacturers claim operating temperatures in range of ?20 °C LED lamps may be five to ten times higher that high THD and low PF lamps. Choice of a lamp depends upon its current THD, PF, life span, energy consumption, efficiency, efficacy, color rendering index (CRI) and associated physical effects. This work proposes manufacturing and user level innovations to get rid of low PF problems. Keeping in view downside of phosphor based lamps our research concludes widespread adoption of LED lamps. Government and commercial buildings may consider full spectrum hybrid thermal photovoltaic and solar fiber optic illumination systems.

N. Khan; N. Abas

2011-01-01T23:59:59.000Z

407

Electrolytic photodissociation of chemical compounds by iron oxide photochemical diodes  

DOE Patents [OSTI]

Chemical compounds can be dissociated by contacting the same with a p/n type semi-conductor photochemical diode having visible light as its sole source of energy. The photochemical diode consists of low cost, readily available materials, specifically polycrystalline iron oxide doped with silicon in the case of the n-type semi-conductor electrode, and polycrystalline iron oxide doped with magnesium in the case of the p-type electrode. So long as the light source has an energy greater than 2.2 electron volts, no added energy source is needed to achieve dissociation.

Somorjai, Gabor A. (Berkeley, CA); Leygraf, Christofer H. (Berkeley, CA)

1985-01-01T23:59:59.000Z

408

Infrared photoemitting diode having reduced work function  

DOE Patents [OSTI]

In electro-optical detectors which include as elements a photoemitting photocathode and anode, a photoemitting diode is fabricated which lowers the diode's work function, thus reducing the cooling requirement typically needed for this type of device. The work function is reduced by sandwiching between the photocathode and anode a liquid meidum of the formula NR/sub 3/ and having an electron affinity for the electrons of the photocathode, which liquid medium permits free electrons leaving the photocathode to remain as stable solvated species in the liquid medium. Thus, highly light-absorbent, and therefore thin, metallic layers can be used for detection, thereby reducing dark current at a given temperature, with a consequent reduction in cooling requirements at constant detector performance.

Hirschfeld, T.B.

1982-05-06T23:59:59.000Z

409

Length Scaling of Carbon Nanotube Electric and Photo Diodes down to Sub-50 nm  

Science Journals Connector (OSTI)

Yet, the scaling of CNT p–n diodes or photodiodes, basic elements for most optoelectronic devices, is held back on a scale of micrometers.5?8 ... As elementary building blocks, such tiny electric and photodiodes could be used in nanoscale rectifiers, photodetectors, light sources, and high-efficiency photovoltaic devices. ... The I–V characteristic of the diode may be described by a modified diode equation(1)where Is is the reverse saturation current, Rs is the effective series resistance of the device, Rsh is the shunt resistance, q is the electron charge, k is the Boltzmann constant, T is temperature, and n denotes the ideality factor of the diode. ...

Haitao Xu; Sheng Wang; Zhiyong Zhang; Lian-Mao Peng

2014-08-12T23:59:59.000Z

410

Household transitions to energy efficient lighting  

Science Journals Connector (OSTI)

Abstract New energy efficient lighting technologies can significantly reduce household electricity consumption, but adoption has been slow. A unique dataset of German households is used in this paper to examine the factors associated with the replacement of old incandescent lamps (ILs) with new energy efficient compact fluorescent lamps (CFLs) and light emitting diodes (LEDs). The ‘rebound’ effect of increased lamp luminosity in the transition to energy efficient bulbs is analyzed jointly with the replacement decision to account for household self-selection in bulb-type choice. Results indicate that the EU ban on \\{ILs\\} accelerated the pace of transition to \\{CFLs\\} and LEDs, while storage of bulbs significantly dampened the speed of the transition. Higher lighting needs and bulb attributes like energy efficiency, environmental friendliness, and durability spur IL replacement with \\{CFLs\\} or LEDs. Electricity gains from new energy efficient lighting are mitigated by 23% and 47% increases in luminosity for CFL and LED replacements, respectively. Model results suggest that taking the replacement bulb from storage and higher levels of education dampen the magnitude of these luminosity rebounds in IL to CFL transitions.

Bradford Mills; Joachim Schleich

2014-01-01T23:59:59.000Z

411

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

412

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

413

High Efficiency Organic Light Emitting Devices for Lighting  

SciTech Connect (OSTI)

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

414

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

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

415

STATEMENT OF CONSIDERATIONS REQUEST BY CREE LIGHTING COMPANY, FOR AN ADVANCE WAIVER OF DOMESTIC AND  

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

20 2001 09:52 FR IPL DOE CH 630 252 2779 TO FGCP-HQ P.02/04 20 2001 09:52 FR IPL DOE CH 630 252 2779 TO FGCP-HQ P.02/04 * * STATEMENT OF CONSIDERATIONS REQUEST BY CREE LIGHTING COMPANY, FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN INVENTION RIGHTS UNDER DOE COOPERATIVE AGREEMENT NO. DE-FC26- 00NT40985 W(A)-01-002, CH-1055 The Petitioner, Cree Lighting Company, (Cree), was awarded this cooperative agreement for the performance of work entitled, "Energy Efficient Solid State Lamp". The purpose 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 state lamps capable of replacing less energy efficient incandescent and halogen reflector lamps. When compared with current incandescent reflector lamps, this revolutionary new lamp is expected to be three times more

416

Journal of Microscopy, Vol. 241, Pt 1 2011, pp. 101110 doi: 10.1111/j.1365-2818.2010.03413.x Received 8 December 2009; accepted 22 April 2010  

E-Print Network [OSTI]

instruments because they provide a good SNR even with low-power light sources such as light emitting diodes

Rieger, Bernd

417

INAUGURAL -DISSERTATION Erlangung der Doktorwurde  

E-Print Network [OSTI]

at specular points on the water surface. Two artificial light sources consisting of Light Emitting Diodes (LED

Jaehne, Bernd

418

Another Side of Light - D  

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

419

An Brief Overview Of Using LEDs In Lab  

E-Print Network [OSTI]

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

Baas, Bevan

420

Electron-beam-driven nanoscale metamaterial light sources  

Science Journals Connector (OSTI)

We show experimentally that beams of free electrons can induce light emission from nanoscale planar photonic metamaterials. Wavelengths of emitted light are determined by both the...

Adamo, Giorgio; Ou, Jun-Yu; MacDonald, Kevin; De Angelis, Francesco; Di Fabrizio, Enzo; Zheludev, Nikolay

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


421

The “Green Lab”: Power Consumption by Commercial Light Bulbs  

Science Journals Connector (OSTI)

Going “green” is a slogan that is very contemporary both with industry and in the political arena. Choosing more energy-efficient devices is one way homeowners can “go green.” A simple method is to change home lighting from hot incandescent bulbs to compact fluorescent lights (CFLs). But do they really save energy? How do their illuminations compare? Even if the CFLs are more energy efficient they still add to our pollution problem because of the mercury inside them. Light-emitting diodes(LEDs) could be the answer but they are not available at our local stores. Can LEDs be made to screw right into a standard socket? How expensive are they? What are the power consumptions of so-called “60-W” and “100-W” CFL and LED light bulbs? These are the questions that are answered during this lab activity. Students measure the voltage and current for each of the three types of bulbs and then calculate the electrical power required by each. An optional experiment is to set the light outputs of each bulb so they are equal in intensity and then determine the power consumed. While not practical in the home this experiment gives students an understanding of value for their buck.

James A. Einsporn; Andrew F. Zhou

2011-01-01T23:59:59.000Z

422

Sustainability constraints in techno-economic analysis of general lighting retrofits  

Science Journals Connector (OSTI)

Abstract Several governmental programs seek the adoption of measures to promote energy efficiency through the substitution of old incadescent light bulbs by \\{CFLs\\} (compact fluorescent lamps). However, fluorescent lamps emit UV, pollute the environment with mercury and rare earths if disposed recklessly. These also present higher performance degradation levels, lower efficiency and shorter lifespans if compared to \\{LEDs\\} (light emitting diodes), which require higher initial investment. We advocate that retrofits shall have a broader scope, pursuing beyond the achievement of short term efficiency and profitability, but the long term sustainability. Thus, selecting which technology to use in a retrofit requires thorough feasibility study comparing alternatives. We propose a framework using equivalent annual costs (EAC) as a metric for comparing substitute technologies in lighting retrofits, considering sustainability constraints as reverse logistics, waste management, performance degradation, lifespan, luminous efficiency and energy prices. The results of a simulated general lighting retrofit comparing LED tubes, \\{CFLs\\} and fluorescent tubulars demonstrate CFL as the highest annual cost and toxic waste disposal in most scenarios, fluorescent tubular as the most economic alternative, but if their lifespans shorten, LED prices drop or achieve higher efficiency LED becomes the most sustainable and economically attractive alternative.

Fabrício P. Vahl; Lucila M.S. Campos; Nelson Casarotto Filho

2013-01-01T23:59:59.000Z

423

Growth and pigment content of Gracilaria tikvahiae McLachlan under fluorescent and LED lighting  

Science Journals Connector (OSTI)

Abstract Light emitting diode (LED) technology has significant potential advantages over other light sources in algal aquaculture. This study investigated \\{LEDs\\} as light sources for the culture of Gracilaria tikvahiae. We cultured a wild-type and a green mutant strain of G. tikvahiae, comparing growth rate and tissue chlorophyll a, total carotenoids, and phycobiliprotein concentrations under high output cool white fluorescent, pure primary color LED, and mixed LED lighting. Under monochromatic light, the growth rates under high output cool white fluorescent lighting were significantly higher than rates under pure LED light (all three colors for wild strain and green and blue for green mutant). However, when pure color LED lighting was mixed (50%/50%), the red + green (wild-type strain and green mutant) and the green + blue LED combinations (wild-type only) showed growth rates similar to those under high output cool white fluorescent lighting. In the trichromatic experiment, growth of the wild-type strain under mixed three-color (40%/40%/20%) LED light was indistinguishable from those of the fluorescent control lighting. Chlorophyll a and carotenoid concentrations of Gracilaria grown in the dichromatic light experiment were 55% and 74% higher, respectively, under red + blue LED lighting than under the other light treatments. The wild-type strain of G. tikvahiae possessed significantly greater concentrations of chlorophyll a, and phycoerythrin than did the green mutant, while green mutant thalli had higher phycocyanin levels. With rising LED efficiency and energy savings, \\{LEDs\\} will be an increasingly better choice for indoor seaweed cultivation, especially if control of pigment production and morphogenesis by selective use of particular wavelengths is desirable.

Jang K. Kim; Yunxiang Mao; George Kraemer; Charles Yarish

2015-01-01T23:59:59.000Z

424

Responses of supplemental blue light on flowering and stem extension growth of cut chrysanthemum  

Science Journals Connector (OSTI)

Abstract To determine the effects of blue (B) spectrum supplemental lighting on flower bud formation and stem elongation growth of cut chrysanthemum, plants of ‘Zembla’ cultivar were grown for 42 days under 4 different light treatments. Treatments comprised: RB (11 h of mixed red and blue [RB] light), RB + B (11 h of mixed RB light and then 4 h of supplemental B light), LRB + B (15 h of mixed RB light and then 4 h of supplemental B light) and RB + LB (11 h of mixed RB light and then 13 h of B light) by using light-emitting diodes. Diurnal patterns in the net assimilation rate were observed, depending on light-quality combinations. Under mixed RB light, the net assimilation rate increased rapidly, then slightly decreased under B light, and finally dropped to negative values during darkness. Final stem length was the highest in plants grown under RB + LB, followed by LRB + B, RB + B and then RB treatment. The stem lengths under RB + B, LRB + B and RB + LB were 1.3, 1.5 and 1.7 times longer than that of RB treatment, respectively. However, fully developed flower buds were formed under RB and RB + B treatments only. The extended final stem length of RB + B plants was determined by internode extension. Overall, our results indicate that supplemental B light, at least in part, may promote stem and internode elongation growth without any inhibitory effect on flower bud formation. The results of this study present a useful practical technique for optimizing cut chrysanthemum production in greenhouse horticulture.

Sung Woo Jeong; Sander W. Hogewoning; Wim van Ieperen

2014-01-01T23:59:59.000Z

425

Enhanced vbasis laser diode package  

DOE Patents [OSTI]

A substrate having an upper surface and a lower surface is provided. The substrate includes a plurality of v-grooves formed in the upper surface. Each v-groove includes a first side and a second side perpendicular to the first side. A laser diode bar assembly is disposed within each of the v-grooves and attached to the first side. The laser diode bar assembly includes a first adhesion layer disposed on the first side of the v-groove, a metal plate attached to the first adhesion layer, a second adhesion layer disposed over the metal plate, and a laser diode bar attached to the second adhesion layer. The laser diode bar has a coefficient of thermal expansion (CTE) substantially similar to that of the metal plate.

Deri, Robert J.; Chen, Diana; Bayramian, Andy; Freitas, Barry; Kotovsky, Jack

2014-08-19T23:59:59.000Z

426

OLEDS FOR GENERAL LIGHTING  

SciTech Connect (OSTI)

The goal of this program was to reduce the long term technical risks that were keeping the lighting industry from embracing and developing organic light-emitting diode (OLED) technology for general illumination. The specific goal was to develop OLEDs for lighting to the point where it was possible to demonstrate a large area white light panel with brightness and light quality comparable to a fluorescence source and with an efficacy comparable to that of an incandescent source. it was recognized that achieving this would require significant advances in three area: (1) the improvement of white light quality for illumination, (2) the improvement of OLED energy efficiency at high brightness, and (3) the development of cost-effective large area fabrication techniques. The program was organized such that, each year, a ''deliverable'' device would be fabricated which demonstrated progress in one or more of the three critical research areas. In the first year (2001), effort concentrated on developing an OLED capable of generating high illumination-quality white light. Ultimately, a down-conversion method where a blue OLED was coupled with various down-conversion layers was chosen. Various color and scattering models were developed to aid in material development and device optimization. The first year utilized this approach to deliver a 1 inch x 1 inch OLED with higher illumination-quality than available fluorescent sources. A picture of this device is shown and performance metrics are listed. To their knowledge, this was the first demonstration of true illumination-quality light from an OLED. During the second year, effort concentrated on developing a scalable approach to large area devices. A novel device architecture consisting of dividing the device area into smaller elements that are monolithically connected in series was developed. In the course of this development, it was realized that, in addition to being scalable, this approach made the device tolerant to the most common OLED defect--electrical shorts. This architecture enabled the fabrication of a 6 inch x 6 inch OLED deliverable for 2002. A picture of this deliverable is shown and the performance metrics are listed. At the time, this was the highest efficiency, highest lumen output illumination-quality OLED in existence. The third year effort concentrated on improving the fabrication yield of the 6 inch x 6 inch devices and improving the underlying blue device efficiency. An efficiency breakthrough was achieved through the invention of a new device structure such that now 15 lumen per watt devices could be fabricated. A 2 feet x 2 feet OLED panel consisting of sixteen 6 inch x 6 inch high efficiency devices tiled together was then fabricated. Pictures of this panel are shown with performance metrics listed. This panel met all project objectives and was the final deliverable for the project. It is now the highest efficiency, highest lumen output, illumination-quality OLED in existence.

Anil Duggal; Don Foust; Chris Heller; Bill Nealon; Larry Turner; Joe Shiang; Nick Baynes; Tim Butler; Nalin Patel

2004-02-29T23:59:59.000Z

427

Fiber optic coupling of a microlens conditioned, stacked semiconductor laser diode array  

DOE Patents [OSTI]

The output radiation from the two-dimensional aperture of a semiconductor laser diode array is efficiently coupled into an optical fiber. The two-dimensional aperture is formed by stacking individual laser diode bars on top of another in a "rack and stack" configuration. Coupling into the fiber is then accomplished using individual microlenses to condition the output radiation of the laser diode bars. A lens that matches the divergence properties and wavefront characteristics of the laser light to the fiber optic is used to focus this conditioned radiation into the fiber.

Beach, Raymond J. (Livermore, CA); Benett, William J. (Livermore, CA); Mills, Steven T. (Antioch, CA)

1997-01-01T23:59:59.000Z

428

Detection of space shuttle insulation foam defects by using a 0.2 THz Gunn diode oscillator and pyroelectric detector  

Science Journals Connector (OSTI)

We report detection of space shuttle insulation foam defects by using a 0.2 THz Gunn diode oscillator as the light source, and a pyroelectric camera as the detector. The size and...

Zhong, Hua; Karpowicz, Nick; Xu, Jingzhou; Deng, Yanqing; Ussery, Warren; Shur, Michael; Zhang, Xi-Cheng

429

Plant-wide Systems | Department of Energy  

Energy Savers [EERE]

Outdoor Area Lighting LED T8 Replacement Lamps Demonstration Assessment of Light-Emitting Diode (LED) Freezer Case Lighting 2010 U.S. Lighting Market Characterization Building...

430

MOntage Builders NORTHERN FOREST NORTHERN FOREST MOntage  

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

of light: incandescent (as a control), compact florescent lighting (CFL), and light emitting diode (LED). LIGHTING AND APPLIANCES Comparison P oint LED CFL Incandescent Watt B...

431

Copyright 2007 American Scientific Publishers All rights reserved  

E-Print Network [OSTI]

emitting diodes, laser diodes, and novel transistors. The number of available Author to whom considerable excitement in semiconductors research with the success in fabricating short wavelength light

432

(Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1996. Two companies in  

E-Print Network [OSTI]

in optoelectronic devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar in research and development, specialty alloys, and other applications. Optoelectronic devices were used

433

(Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2006. One company in Utah  

E-Print Network [OSTI]

circuits. Optoelectronic devices, which include light-emitting diodes (LEDs), laser diodes, photodetectors, specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace

434

(Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1998. Two companies in  

E-Print Network [OSTI]

in optoelectronic devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar and development, specialty alloys, and other applications. Optoelectronic devices were used in areas

435

(Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2000. Two companies in  

E-Print Network [OSTI]

in optoelectronic devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar and development, specialty alloys, and other applications. Optoelectronic devices were used in areas

436

(Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2008. One company in Utah  

E-Print Network [OSTI]

circuits (ICs). Optoelectronic devices, which include laser diodes, light-emitting diodes (LEDs and development, specialty alloys, and other applications. Optoelectronic devices were used in areas

437

(Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2005. One company in Utah  

E-Print Network [OSTI]

circuits. Optoelectronic devices, which include light-emitting diodes (LEDs), laser diodes, photodetectors, specialty alloys, and other applications. Optoelectronic devices were used in areas such as aerospace

438

(Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2007. One company in Utah  

E-Print Network [OSTI]

circuits (ICs). Optoelectronic devices, which include light-emitting diodes (LEDs), laser diodes and development, specialty alloys, and other applications. Optoelectronic devices were used in areas

439

(Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2009. One company in Utah  

E-Print Network [OSTI]

circuits (ICs). Optoelectronic devices, which include laser diodes, light-emitting diodes (LEDs and development, specialty alloys, and other applications. Optoelectronic devices were used in areas

440

(Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 2010. One company in Utah  

E-Print Network [OSTI]

circuits (ICs). Optoelectronic devices, which include laser diodes, light-emitting diodes (LEDs and development, specialty alloys, and other applications. Optoelectronic devices were used in areas

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


441

(Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1999. Two companies in  

E-Print Network [OSTI]

in optoelectronic devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar and development, specialty alloys, and other applications. Optoelectronic devices were used in areas

442

(Data in kilograms of gallium content, unless otherwise noted) Domestic Production and Use: No domestic primary gallium recovery was reported in 1997. Two companies in  

E-Print Network [OSTI]

in optoelectronic devices, which include light-emitting diodes (LED's), laser diodes, photodetectors, and solar and development, specialty alloys, and other applications. Optoelectronic devices were used in areas

443

Polarization-multiplexed 2×2 phosphor-LED wireless light communication without using analog equalization and optical blue filter  

Science Journals Connector (OSTI)

Abstract We propose and experimentally demonstrate a 380 (2×190) Mbps phosphor-light-emitting-diode (LED) based visible light communication (VLC) system by using 2×2 polarization-multiplexing design for in-building access applications. To the best of our knowledge, this is the first time of employing polarization-multiplexing to achieve a high VLC transmission capacity by using phosphor-based white-LED without optical blue filter. Besides, utilizing the optimum resistor–inductor–capacity (RLC) bias-tee design, it can not only perform the function of combining the direct-current (DC) and the electrical data signal, but also act as a simple LED-Tx circuit. No optical blue filter and complicated post-equalization are required at the Rx. Here, the orthogonal-frequency-division-multiplexing (OFDM) quadrature-amplitude-modulation (QAM) with bit-loading is employed to enhance the transmission data rate.

C.H. Yeh; H.Y. Chen; Y.L. Liu; C.W. Chow

2015-01-01T23:59:59.000Z

444

Key issues for mid–infrared emission  

Science Journals Connector (OSTI)

...the conduction band. The problems which limit light-emitting diode (LED) and laser operation by keeping efficiencies...the conduction band. The problems which limit light-emitting diode (LED) and laser operation by keeping e ciencies...

2001-01-01T23:59:59.000Z

445

Self-assembled lamellar MoS2, SnS2 and SiO2 semiconducting polymer nanocomposites  

Science Journals Connector (OSTI)

...demonstrated by integrating the nanocomposite films into light-emitting diode structures. The devices based on polymer-incorporated...demonstrated in a simple single-layer polymer light-emitting diode comprising the tricolour polymer blend interacted...

2007-01-01T23:59:59.000Z

446

Energy Department Announces $10 Million for Innovative, Energy...  

Energy Savers [EERE]

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

447

Designing solution-processable air-stable liquid crystalline crosslinkable semiconductors  

Science Journals Connector (OSTI)

...liquid crystal (LC) displays, flexible organic light emitting diode displays, low frequency radio frequency identification...liquid crystal (LC) displays, flexible organic light emitting diode displays, low frequency radio frequency identification...

2006-01-01T23:59:59.000Z

448

Recent developments in the controlled synthesis and manipulation of electroactive organic polymers  

Science Journals Connector (OSTI)

...effect transistor/electro-optic switch or a light emitting diode device structure. Two examples will be discussed...effect transistor/electro-optic switch or a light emitting diode device structure. Two examples will be discussed...

1997-01-01T23:59:59.000Z

449

Structural and Functional Modularity of the Orange Carotenoid Protein: Distinct Roles for the N- and C-Terminal Domains in Cyanobacterial Photoprotection  

Science Journals Connector (OSTI)

...chromatography|AEC, anion exchange chromatography|LED, light-emitting diode| INTRODUCTION The water-soluble orange carotenoid...OCPO was converted to OCPR using strong, blue light-emitting diode (LED) illumination (470 nm lambdamax; Philips...

Ryan L. Leverenz; Denis Jallet; Ming-De Li; Richard A. Mathies; Diana Kirilovsky; Cheryl A. Kerfeld

2014-01-07T23:59:59.000Z

450

Tomato GDSL1 Is Required for Cutin Deposition in the Fruit Cuticle  

Science Journals Connector (OSTI)

...immersion objective. Excitation was conducted by a light-emitting diode at 485 nm, and emission was collected between...immersion objective. Excitation was conducted by a light-emitting diode at 561 nm, and emission was collected between...

Anne-Laure Girard; Fabien Mounet; Martine Lemaire-Chamley; Cédric Gaillard; Khalil Elmorjani; Julien Vivancos; Jean-Luc Runavot; Bernard Quemener; Johann Petit; Véronique Germain; Christophe Rothan; Didier Marion; Bénédicte Bakan

2012-07-17T23:59:59.000Z

451

Genetic and Chemical Reductions in Protein Phosphatase Activity Alter Auxin Transport, Gravity Response, and Lateral Root Growth  

Science Journals Connector (OSTI)

...seedling was illuminated from behind with an infrared light-emitting diode. The Petri dish was oriented vertically and held...charge-coupled device camera, computer, infrared light-emitting diode, and software were purchased from the Plant Growth...

Aaron M. Rashotte; Alison DeLong; Gloria K. Muday

452

EECBG Success Story: Lighting Retrofit Improving Visibility,...  

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

Retrofit Improving Visibility, Saving Energy August 27, 2010 - 10:05am Addthis New LED lighting fixtures (right) emit a whiter light than existing high-pressure sodium cobra...

453

Effect of plasmonic losses on light emission enhancement in quantum-wells coupled to metallic gratings  

SciTech Connect (OSTI)

Recent experimental work has shown significant luminescence enhancement from near-surface quantum-well (QW) structures using metallic grating to convert surface plasmon (SP) modes into radiative modes. This work introduces a detailed theoretical study of plasmonic losses and the role of SPs in improving light extraction from grated light-emitting QW structures, using the fluctuational electrodynamics method. The method explains experimental results demonstrating emission enhancement, light scattering, and plasmonic coupling in the structures. We study these effects in angle-resolved reflectometry and luminescence setups in InGaN QW structures with silver grating. In contrast to experiments, our model allows direct calculation of the optical losses. The model predicts that the plasmonic coupling and scattering increases light emission by a factor of up to three compared to a flat semiconductor structure. This corresponds to reducing the absorption losses from approximately 93% in the ungrated metallic structure to 75% in the grated structure. Lower losses are associated with a significant emission enhancement enabled by the SPs of silver/GaN interfaces, which are present in the blue/green wavelength range, and can be optimized by carefully nanostructuring the metal layer and by the positioning of the QW. In general, the enhancement results from the interplay of mode scattering, conversion of SP energy directly into light, and losses in the metallic grating. The reported losses are very high when compared to the losses present in modern light-emitting diodes (LEDs). Albeit, our work provides tools needed for further optimization of plasmonic light extraction, eventually leading to highly efficient LEDs.

Sadi, Toufik; Oksanen, Jani; Tulkki, Jukka [Department of Biomedical Engineering and Computational Sciences, Aalto University, P.O. Box 12200, FI-00076 Aalto (Finland)

2013-12-14T23:59:59.000Z

454

A stereo vision system for support of planetary surface exploration  

E-Print Network [OSTI]

and for controlling the motion of the rover, using light emitting diodes on the payload cab of the rover

Pollefeys, Marc

455

Real-Time Spatio-Temporal Query Processing in Mobile Ad-Hoc Sensor Networks  

E-Print Network [OSTI]

that has multiple sensors (e.g., mo- tion sensors, acoustic sensors, infrared light emitting diodes, and pa

456

Digital Object Identifier (DOI) 10.1007/s00138-002-0097-7 Machine Vision and Applications (2003) 14: 514 Machine Vision and  

E-Print Network [OSTI]

of the planetary terrain is computed, and for controlling the motion of the rover, using light emitting diodes

Pollefeys, Marc

457

Calibration, Terrain Reconstruction and Path Planning for a Planetary Exploration System  

E-Print Network [OSTI]

and localization of the rover. The lat- ter makes use of four Light Emitting Diodes on the rover payload cab

Pollefeys, Marc

458

IEEE TRANSACTIONS ON IMAGE PROCESSING, 2013 1 Optimizing Apparent Display Resolution  

E-Print Network [OSTI]

are available today. With active-matrix organic light-emitting diode (AMOLED) technology even higher refresh

Magnor, Marcus

459

ACM Reference Format Raskar, R., Nii, H., deDecker, B., Hashimoto, Y., Summet, J., Moore, D., Zhao, Y., Westhues, J., Dietz, P.,  

E-Print Network [OSTI]

appearance using the simplest possible optical devices ­ a light-emitting diode (LED) with a pas- sive binary

Columbia University

460

JOURNAL DE PHYSIQUE Colloque CS, supplment au n12, Tome 43, dcembre 1982 page C5-323  

E-Print Network [OSTI]

in optical communications. MOVPE growth of GaAs, P , the classical mate- rial for light emitting diodes (LED

Boyer, Edmond

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

Segmentation of Crystalline Lens in Photorefraction Video Mark Wendt and Shishir K. Shah  

E-Print Network [OSTI]

of infrared light emitting diodes (IR-LED) is located on this occlud- ing device. The system of video camera

462

welch@cs.unc.edu Gary Bishop  

E-Print Network [OSTI]

- mounted infrared light-emitting diodes that could be tracked in a one-cubic-meter volume. Beyond the Hi

Fuchs, Henry

463

Structural recovery of ion implanted ZnO nanowires G. Perillat-Merceroz,1, 2, a)  

E-Print Network [OSTI]

applications, ZnO nanowires are studied for making light- emitting diodes (LEDs) because of the advantages

Boyer, Edmond

464

Precise Multi-Spectral Dermatological Imaging David Delgado Gomez, Jens Michael Carstensen, Bjarne Kjr Ersbll  

E-Print Network [OSTI]

of an integrating sphere, light emitting diodes and a generic monochromatic camera. The system can collect up to 10

465

A Novel Neighbor Discovery Protocol for Ultraviolet Wireless Networks  

E-Print Network [OSTI]

in terms of building advanced low cost, low power and small size light emitting diodes (LEDs) that operate

Krishnamurthy, Srikanth

466

IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE MAY/JUNE 2006 570739-5175/06/$20.002006IEEE A Novel Method  

E-Print Network [OSTI]

consists of an infrared light-emitting diode (LED) and a photodiode that can be clamped to the ear lobes

467

Reduced Order Modeling and Control of Thin Film Growth in an HPCVD Reactor  

E-Print Network [OSTI]

circuits, transistors, and DRAM chips, as well as UV detectors and green and blue light emitting diodes

468

Reducing LED Costs Through Innovation  

Broader source: Energy.gov [DOE]

A Wisconsin-based company is developing an innovative way to reduce manufacturing costs of light-emitting diodes (LEDs).

469

Semiconductor Nanowires: What's Next?  

E-Print Network [OSTI]

sensors, lasers, light emitting diodes, and solar panels. Bysolar cells, and piezoelectric generators we discussed here, as well as sensors,

Yang, Peidong

2011-01-01T23:59:59.000Z

470

Research Frontiers Cutting-Edge Research  

E-Print Network [OSTI]

Shale Gas Fracturing with carbon dioxide instead of water. RESOURCE-ENG The Light Emitting Diode (LED

Takada, Shoji

471

Employment after UC Graduation: 2005 2007: Assistant Professor, Department of Electrical Engineering, California Polytechnic State  

E-Print Network [OSTI]

and Educational Activity on Gallium-Nitride (GaN) Lasers and Light Emitting Diodes (LEDs)" International Journal

Boolchand, Punit

472

E-Print Network 3.0 - alters peripheral vascular Sample Search...  

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

inserted... , interventional radiology; IV, intravenous; OLED, organic light-emitting diode; PICC, peripherally inserted Source: Stetten, George - Department of...

473

Guided optical modes in randomly textured ZnO thin films imaged by near-field scanning optical K. Bittkau* and R. Carius  

E-Print Network [OSTI]

relevance. In particular, when designing thin-film solar cells and light emitting diodes LEDs , ran- domly

Peinke, Joachim

474

Thermal analysis of injectable, cellular-scale optoelectronics with pulsed power  

Science Journals Connector (OSTI)

...analysis|optoelectronics|light-emitting diode|scaling law| 1. Introduction...analysis for a single inorganic light-emitting diode in the tissue In the device...Thermal analysis for inorganic light-emitting diode arrays in the tissue The results...

2013-01-01T23:59:59.000Z

475

Transgenic Nude Mouse with Ubiquitous Green Fluorescent Protein Expression as a Host for Human Tumors  

Science Journals Connector (OSTI)

...detected with a simple blue-light-emitting diode flashlight with a central...detected with a simple blue-light-emitting diode flashlight with a central...detected with a simple blue-light-emitting diode flashlight with a central...

Meng Yang; Jose Reynoso; Ping Jiang; Lingna Li; Abdool R. Moossa; Robert M. Hoffman

2004-12-01T23:59:59.000Z

476

DOI: 10.1002/adma.200601908 Piezoelectric Gated Diode of a Single ZnO Nanowire**  

E-Print Network [OSTI]

Institute of Physics. DOI: 10.1063/1.2193468 Electrical and optoelectronic devices such as field class of organic optoelectronic devices has been demonstrated, i.e., organic light-emitting transistors

Wang, Zhong L.

477

The environmental regulation of maturation in goldfish, Carassius auratus: Effects of various LED light spectra  

Science Journals Connector (OSTI)

Abstract While there have been a number of studies on the effects of photoperiod and duration of light and dark exposure, much less information is available on the importance of light intensity. This study investigated the effects of exposure of goldfish, Carassius auratus exposed to white fluorescent bulbs, and red (peak at 630 nm), and green (530 nm) light emitting diodes (LEDs) at approximately 0.9 W/m2 (12-h light:12-h dark) for four months on a number of hormones of the hypothalamus–pituitary–gonad (HPG) axis, in vivo and in vitro. We investigated the effects of native GnRH molecules (gonadotropin-releasing hormones; salmon GnRH, sGnRH; and chicken GnRH-II, cGnRH-II), gonadotropin hormones (GTH?; follicle-stimulating hormone, FSH-?; luteinizing hormone, LH-?2), kisspeptin 1 (Kiss1) and G protein-coupled receptor 54 (GPR54) mRNA levels. Furthermore, we measured LH and 17?-hydroxypregnenolone levels in plasma and we performed gonad histological observations. GnRHs, Kiss1, GPR54 and GTH mRNA and plasma LH and 17?-hydroxypregnenolone levels in the in vivo and in vitro groups exposed to green \\{LEDs\\} were significantly higher than the other groups. Histological analysis revealed the presence of oocytes in the yolk stage in fish exposed to green light. These results suggest that green wavelengths regulate the HPG axis and enhance sexual maturation in goldfish.

Hyun Suk Shin; Hamid R. Habibi; Cheol Young Choi

2014-01-01T23:59:59.000Z

478

Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings  

DOE Patents [OSTI]

A long-lifetime light source with sufficiently low intensity to be used for reading a map or other writing at nighttime, while not obscuring the user's normal night vision. This light source includes a diode electrically connected in series with a small power source and a lens properly positioned to focus at least a portion of the light produced by the diode.

Frank, Alan M. (Livermore, CA); Edwards, William R. (Modesto, CA)

1983-01-01T23:59:59.000Z

479

What's New - U.S. Energy Information Administration (EIA)  

Gasoline and Diesel Fuel Update (EIA)

in efficiency and quality Nov 4, 2014 Improvements in lighting technology for light-emitting diode (LED) bulbs have increased lighting efficiency, or efficacy, as well as color...

480

Download Full-text PDF  

Science Journals Connector (OSTI)

Fe addition were prepared as control experiments. The bottles were incubated in a laboratory incubator with artificial light (white light-emitting diode). The light.

2014-04-03T23:59:59.000Z

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

E-Print Network 3.0 - advanced microstructural study Sample Search...  

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

Collection: Engineering 15 Light extraction efficiency enhancement of InGaN quantum wells light-emitting diodes with Summary: microstructures on the light extraction efficiency...

482

Sandia National Laboratories: Genetic Algorithm for Innovative...  

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

semiconductor device design and optimization. Tagged with: III-V Nitride * light-emitting diode * Solid-State Lighting * solid-state lighting science * SSLS EFRC Comments are...

483

Polymer and small molecule based hybrid light source  

DOE Patents [OSTI]

An organic electroluminescent device, includes: a substrate; a hole-injecting electrode (anode) coated over the substrate; a hole injection layer coated over the anode; a hole transporting layer coated over the hole injection layer; a polymer based light emitting layer, coated over the hole transporting layer; a small molecule based light emitting layer, thermally evaporated over the polymer based light emitting layer; and an electron-injecting electrode (cathode) deposited over the electroluminescent polymer layer.

Choong, Vi-En (Carlsbad, CA); Choulis, Stelios (Nuremberg, DE); Krummacher, Benjamin Claus (Regensburg, DE); Mathai, Mathew (Monroeville, PA); So, Franky (Gainesville, FL)

2010-03-16T23:59:59.000Z

484

Megahertz organic/polymer diodes  

DOE Patents [OSTI]

Featured is an organic/polymer diode having a first layer composed essentially of one of an organic semiconductor material or a polymeric semiconductor material and a second layer formed on the first layer and being electrically coupled to the first layer such that current flows through the layers in one direction when a voltage is applied in one direction. The second layer is essentially composed of a material whose characteristics and properties are such that when formed on the first layer, the diode is capable of high frequency rectifications on the order of megahertz rectifications such as for example rectifications at one of above 100KHz, 500KhZ, IMHz, or 10 MHz. In further embodiments, the layers are arranged so as to be exposed to atmosphere.

Katz, Howard Edan; Sun, Jia; Pal, Nath Bhola

2012-12-11T23:59:59.000Z

485

Light-Material Interactions in Energy Conversion - Energy Frontier...  

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

connecting to RG2, RG3, and RG4. We focus on manipulation of emitted and scattered light from the solar cells, investigating photonic structures that enable photon...

486

Blue diode-pumped solid-state-laser based on ytterbium doped laser crystals operating on the resonance zero-phonon transition  

DOE Patents [OSTI]

The invention provides an efficient, compact means of generating blue laser light at a wavelength near .about.493+/-3 nm, based on the use of a laser diode-pumped Yb-doped laser crystal emitting on its zero phonon line (ZPL) resonance transition at a wavelength near .about.986+/-6 nm, whose fundamental infrared output radiation is harmonically doubled into the blue spectral region. The invention is applied to the excitation of biofluorescent dyes (in the .about.490-496 nm spectral region) utilized in flow cytometry, immunoassay, DNA sequencing, and other biofluorescence instruments. The preferred host crystals have strong ZPL fluorecence (laser) transitions lying in the spectral range from .about.980 to .about.992 nm (so that when frequency-doubled, they produce output radiation in the spectral range from 490 to 496 nm). Alternate preferred Yb doped tungstate crystals, such as Yb:KY(WO.sub.4).sub.2, may be configured to lase on the resonant ZPL transition near 981 nm (in lieu of the normal 1025 nm transition). The laser light is then doubled in the blue at 490.5 nm.

Krupke, William F. (Pleasanton, CA); Payne, Stephen A. (Castro Valley, CA); Marshall, Christopher D. (Livermore, CA)

2001-01-01T23:59:59.000Z

487

Quantum Cascade Lasers Emitting below 3 µm  

Science Journals Connector (OSTI)

First quantum cascade lasers emitting below 3 µm are demonstrated. The lasers based on the InAs/AlSb material system emit at 2.95-2.97 µm at 83 K and operate up to room temperature.

Devenson, Jan; Teissier, Roland; Cathabard, Olivier; Baranov, Alexei N

488

Computer Processing of Tunable Diode Laser Spectra  

Science Journals Connector (OSTI)

A computer-controlled tunable diode laser spectrometer and spectral analysis software are described. The three-channel system records simultaneously the transmission of a subject...

May, Randy D

1989-01-01T23:59:59.000Z

489

E-Print Network 3.0 - active fabry-perot semiconductor Sample...  

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

Physics 45 The Laser DiodeThe Laser Diode Jason HillJason Hill Summary: to a Light Emitting Diode Active medium is a semiconductor pActive medium is a semiconductor p--n...

490

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

491

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

492

Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store  

E-Print Network [OSTI]

Laser Safety Laser-emitting tools and equipment are common to many work situations. Lasers in printers, grocery store scanners, construction tools, and laser pointers are generally lower powered lasers emit high-intensity, directional light beams that vary in strength, they are a particular hazard

Burke, Peter

493

SciTech Connect: Broad Spectrum Photoelectrochemical Diodes for...  

Office of Scientific and Technical Information (OSTI)

Broad Spectrum Photoelectrochemical Diodes for Solar Hydrogen Generation Citation Details In-Document Search Title: Broad Spectrum Photoelectrochemical Diodes for Solar Hydrogen...

494

Highly efficient blue organic light emitting devices with indium...  

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

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...

495

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'Andrade, Brian

2013-02-12T23:59:59.000Z

496

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

497

Laser diode package with enhanced cooling  

DOE Patents [OSTI]

A laser diode package assembly includes a reservoir filled with a fusible metal in close proximity to a laser diode. The fusible metal absorbs heat from the laser diode and undergoes a phase change from solid to liquid during the operation of the laser. The metal absorbs heat during the phase transition. Once the laser diode is turned off, the liquid metal cools off and resolidifies. The reservoir is designed such that that the liquid metal does not leave the reservoir even when in liquid state. The laser diode assembly further includes a lid with one or more fin structures that extend into the reservoir and are in contact with the metal in the reservoir.

Deri, Robert J. (Pleasanton, CA); Kotovsky, Jack (Oakland, CA); Spadaccini, Christopher M. (Oakland, CA)

2012-06-12T23:59:59.000Z

498

Laser diode package with enhanced cooling  

DOE Patents [OSTI]

A laser diode package assembly includes a reservoir filled with a fusible metal in close proximity to a laser diode. The fusible metal absorbs heat from the laser diode and undergoes a phase change from solid to liquid during the operation of the laser. The metal absorbs heat during the phase transition. Once the laser diode is turned off, the liquid metal cools off and resolidifies. The reservoir is designed such that that the liquid metal does not leave the reservoir even when in liquid state. The laser diode assembly further includes a lid with one or more fin structures that extend into the reservoir and are in contact with the metal in the reservoir.

Deri, Robert J.; Kotovsky, Jack; Spadaccini, Christopher M.

2012-06-26T23:59:59.000Z

499

Laser diode package with enhanced cooling  

DOE Patents [OSTI]

A laser diode package assembly includes a reservoir filled with a fusible metal in close proximity to a laser diode. The fusible metal absorbs heat from the laser diode and undergoes a phase change from solid to liquid during the operation of the laser. The metal absorbs heat during the phase transition. Once the laser diode is turned off, the liquid metal cools off and resolidifies. The reservoir is designed such that that the liquid metal does not leave the reservoir even when in liquid state. The laser diode assembly further includes a lid with one or more fin structures that extend into the reservoir and are in contact with the metal in the reservoir.

Deri, Robert J. (Pleasanton, CA); Kotovsky, Jack (Oakland, CA); Spadaccini, Christopher M. (Oakland, CA)

2011-09-13T23:59:59.000Z

500

LED traffic lights: New technology signals major energy savings  

SciTech Connect (OSTI)

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

Houghton, D.

1994-12-31T23:59:59.000Z