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Dissertations / Theses on the topic 'White LEDs'

Author: Grafiati
Published: 4 June 2021
Last updated: 27 July 2025

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1

Zeng, Lubin. "Indoor Optical Wireless Communications Using White Light LEDs." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515048.

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2

Ziegler, Jan. "Preparation and application of nanocrystals for white LEDs." Thesis, University of East Anglia, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443089.

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3

Alvi, Naveed ul Hassan. "Luminescence Properties of ZnO Nanostructures and Their Implementation as White Light Emitting Diodes (LEDs)." Doctoral thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-69155.

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In this thesis, luminescence properties of ZnO nanostructures (nanorods, nanotubes, nanowalls and nanoflowers) are investigated by different approaches for possible future application of these nanostructures as white light emitting diodes. ZnO nanostructures were grown by different growth techniques on different p-type substrates. Still it is a challenge for the researchers to produce a stable and reproducible high quality p-type ZnO and this seriously hinders the progress of ZnO homojunction LEDs. Therefore the excellent properties of ZnO can be utilized by constructing heterojunction with ot
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4

DE, TRIZIO LUCA. "Polymer nanocomposites for illumination: towards warm white light." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2013. http://hdl.handle.net/10281/41175.

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The aim of this PhD project, also called “warm white light project”, is to propose an alternative solid state lighting device that works using the same principles of color-conversion WLEDs. The idea is to create a polymer based nanocomposite that could work as a transparent glass in off-mode and as a “lamp” in on-mode. The new concept is to spatially decouple the light source and the converters in order to avoid all the thermal problems that affect the current LEDs (in which the color is “generated” within the chip and the epoxy case). To do so, a blue LED, made of Indium gallium nitride (InGa
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5

Bano, Nargis. "Fabrication and Characterization of ZnO Nanorods Based Intrinsic White Light Emitting Diodes (LEDs)." Doctoral thesis, Linköpings universitet, Fysik och elektroteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-71829.

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ZnO material based hetero-junctions are a potential candidate for the design andrealization of intrinsic white light emitting devices (WLEDs) due to several advantages overthe nitride based material system. During the last few years the lack of a reliable andreproducible p-type doping in ZnO material with sufficiently high conductivity and carrierconcentration has initiated an alternative approach to grow n-ZnO nanorods (NRs) on other ptypeinorganic and organic substrates. This thesis deals with ZnO NRs-hetero-junctions basedintrinsic WLEDs grown on p-SiC, n-SiC and p-type polymers. The NRs we
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6

Nogueira, Fernando José. "Avaliação experimental de luminárias empregando LEDs orientadas à iluminação pública." Universidade Federal de Juiz de Fora, 2013. https://repositorio.ufjf.br/jspui/handle/ufjf/931.

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7

Reineke, Sebastian. "Controlling Excitons: Concepts for Phosphorescent Organic LEDs at High Brightness." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-39520.

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This work focusses on the high brightness performance of phosphorescent organic light-emitting diodes (OLEDs). The use of phosphorescent emitter molecules in OLEDs is essential to realize internal electron-photon conversion efficiencies of 100 %. However, due to their molecular nature, the excited triplet states have orders of magnitude longer time constants compared to their fluorescent counterparts which, in turn, strongly increases the probability of bimolecular annihilation. As a consequence, the efficiencies of phosphorescent OLEDs decline at high brightness – an effect known as efficienc
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8

Chambion, Bertrand. "Etude de la fiabilité de modules à base de LEDs blanches pour applications automobile." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0163/document.

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Les composants dédiés et actuellement disponibles pour le marché automobileprésentent une grande diversité technologique tant au niveau puce que stratégie de packaging ouencore architecture module (mono-puce ou multi-puce) pour des performances équivalentes. Cetteétude s’est attachée à développer une méthodologie d’évaluation de la fiabilité de deux filièrestechnologiques particulières de modules de LEDs multi-puce : l’une intègre une technologie verticale(VTF pour Vertical Thin Film) tandis que la seconde est focalisée sur une structure par puce montéeretournée(TFFC pour Thin Film Flip Chip).
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9

Adam, Marcus. "Embedding of QDs into Ionic Crystals:." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-191160.

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Colloidal semiconductor quantum dots (QDs) have gained substantial interest as adjustable, bright and spectrally tunable fluorophores in the past decades. Besides their in-depth analyses in the scientific community, first industrial applications as color conversion and color enrichment materials were implemented. However, stability and processability are essential for their successful use in these and further applications. Methods to embed QDs into oxides or polymers can only partially solve this challenge. Recently, our group introduced the embedding of QDs into ionic salts, which holds sever
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10

Li, Fung Yuen Ken. "White LED for general illumination applications." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42151.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.<br>Includes bibliographical references.<br>In the 21st century, mankind faces problem of energy crisis through depletion of fossil fuels as well as global warning through the production of excessive greenhouse gases. Hence, there is an urgent need to look for new sources of renewable energy or ways to utilize energy more effectively. Solid state lighting (SSL) is a major area of research interest to use energy in a more efficient manner. Early light emitting devices (LEDs) were originally
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11

Mital, Rashmi. "Design and demonstration of a novel optical true time delay technique using polynomial cells based on white cells." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1111161542.

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Thesis (Ph. D.)--Ohio State University, 2005.<br>Title from first page of PDF file. Document formatted into pages; contains xiii, 195 p.; also includes graphics (some col.) Includes bibliographical references (p. 190-195). Available online via OhioLINK's ETD Center
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12

Chi, Chang Ching, and 蔣清淇. "Fabrication and Characteristics of White Light LEDs." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/96562662868864444150.

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碩士<br>國立中興大學<br>精密工程研究所<br>93<br>In the study, characteristic and feasibility study of photon recycling LED and YAG white LED and multi color LED for lighting at present. In the experiment, we fabricated three types white light LEDs. First photon recycling LED by wafer bonding with 570 nm AlGaInP different from fabrication of white LED presently. The principle is a photon of short wavelength incidence an emitting component of long wavelength, and the component absorbs to discharge a photon of long wavelength. InGaN + YAG phosphor is general fabrication of white light LED presently. As a resu
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13

Das, Onkar Kumar. "Lanthanide based phosphor materials for white LEDs." Thesis, 2014. http://ethesis.nitrkl.ac.in/6399/1/E-4.pdf.

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Semiconductor based white light-emitting diodes (WLEDs) are considered as a new class of lighting sources due to their excellent properties over the incandescent lightings. Currently the major challenges in WLEDs research are to achieve high luminous efficacy, high chromatic stability, brilliant color-rending properties, and price cheapness against fluorescent lamps, which rely critically on the phosphor properties. In recent years, several efforts have been made to develop single-phase white-light-emitting phosphors for near-ultraviolet or ultraviolet excitation to solve the above challenges
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14

Hsu, Yu-Wei, and 許煜偉. "White Light Sensing and Mixing of RGB LEDs." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/35885576473099514451.

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碩士<br>國立成功大學<br>電機工程學系碩博士班<br>97<br>The purpose of this thesis is to develop red, green and blue light emitting diode (LED) mixed light driving circuit for the backlight in the liquid crystal display (LCD). Comparing with the cold cathode fluorescent lamp (CCFL) for backlight, LED can make the image more colorful and saturate. The thesis lets eight LED be a string and uses a LED to sense and mix for LED string. First, analyzes the influence of LED brightness intensity versus color sensor circuit and using integrating sphere measurement system to measure the mixing white light of RGB LED forwar
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15

Li, Dun-Ru, and 李惇儒. "The study of package efficiency for white LEDs." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/62087352252567483707.

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碩士<br>國立中央大學<br>光電科學研究所<br>99<br>In this thesis, we study the package loss for six white LED package types. Based on the YAG phosphor model, we build up six white LED package types in our simulation. Under the same CCT, we calculate package loss between six different packages and analyze the effect of the different LED package types. We also discuss the influence of the package loss by changing the reflectivity of the substrate and the absorption coefficient of the die. In order to verify the simulation data, we try to do the experiments for investigation of the package loss of the six LED pac
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16

Wang, Jen-li, and 王仁里. "Luminescence properties of white-emitting phosphor SrSiO3 doped Dy3+ for use in white LEDs." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/2t8cw4.

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碩士<br>國立中山大學<br>光電工程研究所<br>95<br>White light generation through phosphors excitation by UV-LED has become an important subject in WLED. In our study, compounds of SrSiO3：Dy3+ white-emitting phosphors are synthesized via hydrothermal method. In this study, the effects of annealing temperature, annealing time, contents of Dy3+ on the relative emission intensity of the phosphors are judicially investigated. Meanwhile, WLED produces a plenty of heat energy to cause phosphors high temperature when WLED is excited by electrical energy. The emission spectra of the phosphors are investigated excited b
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17

WU, YANG-CHEN, and 吳陽辰. "Fabrication of the White LEDs by Dual Color LEDs with Phosphors and Quantum Dots." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/63625007018080109433.

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碩士<br>國立臺南大學<br>電機工程學系碩博士班<br>105<br>This paper focuses on the use of recent research and development of dual-wavelength LED (yellow / green) to join the fluorescent powder and quantum dots to try to produce a white LED. We designed the total amount of 1.5g to deploy A, B glue to join the red fluorescent powder and add a little green and yellow fluorescent powder to fine-tune the proportion of the production of white LED, and the design of a fixed drop of red drops Quantum dots, green quantum dots, and simultaneous red / green quantum dots, and the finished products were compared with the gene
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18

Deng, Shun-Wen, and 鄧舜文. "Optical Design of Direct Backlight Modules with White LEDs." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/78792714625957672737.

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碩士<br>國立彰化師範大學<br>電機工程學系<br>96<br>This thesis mainly utilizes an optical software, LightTools, to design the designed backlight modules (BLMs) for a 17-inch and 30-inch LCDs. The BLMs use an upside-down cone-shaped structure, which is placed above each LED light source, combined with a designed sideward light-guide structure and dot pattern that the light rays can be uniformly distributed in the BLMs. The design and simulation results are used to analyze and compare the averaged luminance and illuminance uniformity of the BLMs between the designed and undesigned modules by using the 5-point, a
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19

Hsieh, Pin-hsuan, and 謝品萱. "Evaluation of Visual Physiological Effects of White-light LEDs." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/45855740479009644489.

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碩士<br>國立中央大學<br>光電科學研究所<br>99<br>Light-emitting diodes (LEDs) are a good candidate for next-generation lighting due to their numerous advantages over the traditional lighting installations, such as small volume, longlife time, high efficiency and no mercury pollution. The potential in energy saving, safety, and environmental protection has made the development and applications of LEDs an emerging research area. 　　Due to the distinct characteristics of LEDs from conventional light sources, such as the source size, the radiant direction and the spectral content, LED lamps are more probable to i
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20

Yang, Chih-Chiang, and 楊智強. "Research of White LEDs with Electrophoretic Deposition of Phosphor." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/33829789069277491949.

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碩士<br>崑山科技大學<br>電機工程研究所<br>98<br>White Light Emitting Diode (WLED) is an environment-friendly and energy-saving light source ; as compared to traditional light sources, the WLED has long life with power-saving, environment-friendly, and many other advantages, has been considered as the core of the solid state lighting in the future. The method of traditional packages for white LED is powder-doped with a large number of silicone, in this way, we will meet the problem of phosphor powder settlement in the baking process, the settlement of phosphor powder, results in the uneven white light, the em
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21

Chen, Ching-Yi, and 陳靜儀. "Study of multi-function phosphor modeling for white LEDs." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/41403929323744117088.

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博士<br>國立中央大學<br>光電科學與工程學系<br>101<br>In this thesis, we studies the precise phosphor modeling of the white LEDs. We have developed the CRI calculation modeling, optical modeling, and thermal modeling of the phosphor. It can be applied for the material selection before the white light LED packaging and analysis of efficiency and color performance of white LEDs. The color variation due to the heating can be further analyzed. Firstly, the prediction calculation of CRI performance have been performed by a linearly calculation model. The mapping of CRI distribution on the color coordinate has been c
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Tsai, Shang-Lin, and 蔡尚麟. "Simulation System of the CIE Coordinate for White LEDs." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/k287yd.

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碩士<br>國立虎尾科技大學<br>光電與材料科技研究所<br>102<br>The industry''s production of white LED multi-use dispensing packaging process, the yellow fluorescent powder mixed plastic packaging, within a point of reflection into the bracket so that the package plastic lid covering the blue chips to produce white light, fluorescent powder to be controlled in this way and the proportion of plastic material, to achieve the required brightness white LED production, CIE address and color temperature. 　　In order to meet customer needs white LED brightness, CIE address and color temperature requirements, the paper will
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Tu, Huang-Tsung, and 凃皇總. "The characteristics of white LEDs with curved remote phosphor layer." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/92338106137051542844.

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碩士<br>明新科技大學<br>電子工程研究所<br>102<br>For the phosphor-converted LEDs (pcLEDs), the enhancement of the package efficiency is always an important issue. For the typical structures of the pcLEDs, a phosphor layer is close to the contour of the LED chip. Then a large portion of converted light from the phosphor would impinge on the LED chip and be absorbed by the LED chip. Therefore, the package efficiency of the pcLEDs will be low. To improve the package efficiency for pcLEDs, the remote phosphor structure with the phosphor layer placed at a sufficiently large distance from the LED chip was propose
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Huang, Jian-li, and 黃建歷. "Optical Design of High-Power White-Light LEDs for Illumination." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/34609764851758954337.

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碩士<br>國立臺灣科技大學<br>電子工程系<br>97<br>White light LEDs have more advantages than those of traditional incandescent lamps and the fluorescent lamps; e.g. high stability, long life time and low power consuming etc. Therefore, white light LEDs have been regarded as the most potential light source of solid-state lighting (SSL) in the future. In this thesis, we focus on the white light LED optical design and illumination analyses. For the optical design issue, our purpose is to design a 300-Lux lamp on the work plane which is 2 meter away with LED with 4 square meters in size plane and has uniformity il
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Wu, Hsin-mei, and 吳信美. "The study for stabilization of color performance of white LEDs." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/58233087291465964565.

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碩士<br>國立中央大學<br>光電科學研究所<br>99<br>In this study, the thermal effects on LED color performance, such as CCT and chromaticity coordinate, were studied. As the temperature rises , the spectrum of bare chip will red shift that will let the efficiency increase or decrease. This phenomenon will be helpful to compensate the decay of the yellow light which results from thermal quenching, and it will achieve the stability of color performance. The purpose of this study is to achieve the minimum deviation of CCT and color coordinate by combining the bare chip with specific peak wavelength and phospho
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Lan, Yu-Ping, and 藍鈺邴. "Design of auto-low-beam based on white-light LEDs." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/20672482667853827614.

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碩士<br>國立中央大學<br>光電科學研究所<br>94<br>In this thesis, we study automobile low beam for ECE regulation based on white-light LEDs. First at all, we study the optical model of phosphor-based LED with scattering model of phosphor. Then, we design the headlamp for ECE low beam. In the design, a 15° wedge structure for special package is proposed. We also design the imaging lens, and based on it, we study the energy efficiency as well as the management of étendue. Finally, we simulate the light pattern by the headlamp and check the pattern with ECE regulation.
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Lin, Nan-Ming, and 林男明. "Improvement of GaN-based LEDs and Packaged White LEDs by Optical Thin Films and ZnO Nanoparticles." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/3trjc7.

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博士<br>國立臺南大學<br>電機工程學系碩博士班<br>104<br>In this dissertation, first, optical software and ion-assistede-gun evaporation with radio frequency neutralizer were applied to simulate and fabricate a broadband reflector, respectively. It can almost reach 100 % between 400 and 630 nm and between 400 and 580 nm with light incident angles of 5° and 45°, respectively. With 350-mA current injection, it was found that we achieved 34 % enhancement in the GaN-based blue LEDs output power by the formation of a broadband reflector. Furthermore, it can be seen clearly that the optical microscopes images of the LE
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Cheng, Mian-ru, and 程勉儒. "Optical Design of Adaptive Automotive Headlamp Based on White-light LEDs." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/58rrcb.

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碩士<br>國立中央大學<br>光電科學與工程學系<br>102<br>In this thesis, we design an adaptive headlamp with high optical utilization factor. The light pattern is designed to meet the ECE R112 regulation for automotive low beam and high beam. A projection lens with a specific cutting shape to enhance the contrast is designed and applied to the low beam in the study. In the adaptive high beam, we propose a specific packaging structure with a parallel mirror pair to extend the illuminating region in the vertical axis, and also reduce the need of LED number. Finally, experiments with the prototype are done to verify
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Ting, Zi-yan, and 丁姿妍. "Optical Modeling of YAG Phosphor in Higher Concentration for White LEDs." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/u724se.

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碩士<br>國立中央大學<br>照明與顯示科技研究所<br>102<br>In this thesis, we have successfully built up an optical modeling of YAG phosphor in higher concentration with conformal coating. The optical modeling process includes scattering modeling, absorption coefficient and conversion efficiency. We simulate the scattering properties in YAG phosphor with Mie scattering theory based on Monte Carlo ray tracing. The simulation includes the optical behaviors of blue lights and yellow lights. The experimental measurement results are applied to figure out the absorption coefficient and conversion efficiency. Since the ab
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Wang, Jung-Chi, and 王榮祺. "Improvement of Light Efficiency and Heat Dissipation of White Light LEDs." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/16347942818601444393.

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碩士<br>國立臺灣科技大學<br>電子工程系<br>98<br>In this thesis, we focus on the subject of improvement of luminosity efficiency and cooling ability of heat dissipation for white light LEDs lamp. The purpose is to replace the conventional lamp. At beginning, we focus on the researches to achieve high luminosity efficiency of commercial white light LED. The study leads us to propose a concept of making a light bulb by a 3×3 LED array. A prototype is made. A serious measurement is performed to validate the concept. At present, the efficiency is about 60 to 70 lumens per watt for the commercial white light LED l
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Chen, You-Lun, and 陳又綸. "A study of solid-state white LEDs for backlight module applications." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/59349249816564366652.

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碩士<br>國立中興大學<br>精密工程學系所<br>94<br>The main purpose of this study is to develop an novel three-wavelength white LED light source for 20” LCD edge-lighting backlight module. We developed a SMD package technique of large area LED which had high power and high thermal dissipation. After combining with solid-state AlGaInP epi-layer, the novel YAG-based phosphor white light LEDs and all-solid-state white light LEDs which has better color representation. The device structure of the white LEDs is composed of a GaN-based blue LEDs, green LEDs and AlGaInP epi-layer. Then the GaN-based LEDs can generate t
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Hung, Chi-Tseng, and 洪基層. "Study of Environmental Temperature Effect on Optical Properties of White LEDs." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/80359097198149145040.

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碩士<br>正修科技大學<br>電機工程研究所<br>101<br>To understand the effect of ambient temperature change on characteristics of LED lighting, this thesis do the ambient temperature change experiments for eight white LEDs, whose drivers include the DC and AC types, colors covering white, warm white, and natural white, ignition types contain blue LED light with yellow phosphor, and blending the RGB LED lights. Experimental approach is to combine the aluminum substrate of LED chips with controlled thermoelectric cooling modules to simulate the change of environmental temperature from -20 ℃ to 60 ℃. At the same ti
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Ke, Fu-Yao, and 柯富耀. "Optimization and Verification of Package Design for Side-View White LEDs." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/38446031061450370900.

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碩士<br>國立中興大學<br>精密工程學系所<br>98<br>The study of this paper is The Structure of Assembly of Side View LED; main purpose is to increase the luminous flux and increase efficiency of luminosity of side view LED by changing the structure of assembly. The proposition is to use D.O.E. (Design of experiment) to find out the main factor which caused influence of efficiency of luminous flux on side view LED; and, two main factors were found – depth and optical degree of inner structure. Experimenting with different combination and simulate by using SPEOS optics system; after analysis test results, select
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Lin, Chia-nan, and 林家南. "Analysis for luminous efficiency of white LEDs with Pulse Width Modulation." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/02199595573650116932.

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碩士<br>國立中央大學<br>光電科學研究所<br>99<br>This thesis seeks to research an “analysis for luminous efficiency of white LEDs with pulse width modulation” system, the system used in all kinds of backlight module, Solid State Lighting apparatus which general used in lighting is driven by DC and AC power supply, in order to improve the luminous efficiency, we design the pulse-width modulation (PWM) circuit to drive the LED. Circuit design of “analysis for luminous efficiency of white LEDs with pulse-width modulation” system in accordance with the characteristics of light-emitting diode, with the objective t
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Weng, Po-Hao, and 翁伯豪. "Applications of Bismuth Oxide Powder on Package of White-light LEDs." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/85380759602307737873.

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碩士<br>逢甲大學<br>電機工程所<br>100<br>In this thesis, a design of RGB phosphor-converted white light-emitting diode was proposed which is coated with a layer of photocatalyst on the surface of LED package. Utilize the characteristic of absorption spectrum in blue and UV regions of bismuth oxide photocatalyst, the blue light and UV leakage problems can be significantly reduced. In addition, the coating layer of photocatalyst can properly play a role of diffuser to ease the glare problem. The bismuth oxide photocatalyst was synthesized by spray pyrolysis. The energy gap of the synthesized Bi2O3 photocat
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Cheng, Han-Hsiang, and 鄭翰翔. "Study of Emission Properties with Acceleration Aging of Phosphor-based White LEDs." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/mp8hze.

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碩士<br>國立中央大學<br>光電科學與工程學系<br>102<br>In this thesis, we measured and analyzed several blue LEDs emitting different peak wavelengths with YAG phosphor, and observed the variations in emission properties under specific accelerating condition. In the aging tests of LEDs, severe high temperature condition was applied to accelerate the whole measurement duration. After analyzing spectra of different samples within the aging process, the best choice of blue light chip with YAG phosphor has been decided for stable color performance over the whole lifetime of LEDs. Besides, in the thesis, a fitting mod
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Lin, Hsin-ying, and 林欣瑩. "Study of Packaging Efficiency of White LEDs with Different Phosphor Coating Patterns." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/cv8585.

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碩士<br>國立中央大學<br>光電科學與工程學系<br>102<br>In this thesis, we develop the high-concentration white-LED packaging with phosphor matrix. Based on the high-concentration phosphor optical model, we change different phosphor patterns, the height of sidewall of cup, and the angles of sidewall of cup to construct our encapsulation structure under the same correlated color temperature. By varying the different simulation parameters, we analyze how the packaging efficiency will be influenced. In the following process, we have verification between simulation and experiment in order to analyze their differences
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Yang, Shang-Fu, and 楊上賦. "The Study of Blue Leaking Blocker in Aged Phosphor Converted White LEDs." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/6jd5nv.

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碩士<br>國立中央大學<br>光電科學與工程學系<br>103<br>In this thesis, we added the thermochromic materials into the pcW-LED to solve the blue light leakage during the pcW-LED aging process. The thermochromic materials could change their color and absorb the leaking blue light immediately when the temperature of the phosphor was too high. Furthermore, to begin with, we measured and analyzed several different materials in the experiment. Also, we predicted the temperature distribution inside the LED by applying thermal simulation in order to find the best location and shapes of the materials. Finally, we comp
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Shu-ChiHuang and 黃姝綺. "Combustion Synthesis of Red Nitride CaAlSiN3:Eu2+ Phosphor for White Light LEDs." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/34x2pg.

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博士<br>國立成功大學<br>化學工程學系<br>104<br>White light LED lighting is believed to replace the conventional lighting and becomes the next generation lighting device due to its advantages such as energy efficiency, long lifetime, compactness, environment friendliness and designable features. Phosphors are essential materials for the fabrication of the LED lighting devices and their properties significantly affect the performance of the devices. Among various types of phosphor, the type with red emission is considered to be the most urgent one to be developed for two main reasons: Its use can improve the
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Chen, Bing-Qi, and 陳炳圻. "Dual phosphor-converted white LEDs modeling by using near-field chromatic data." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/97276560743385908536.

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碩士<br>國立臺灣科技大學<br>色彩與照明科技研究所<br>102<br>An innovative way of dual phosphors-converted white LED modeling is established and demonstrated. We use near-field chromatic luminance measurement data to investigate the effect of modeling parameters in Lighttools and propose some key parameters to predict characteristics of LEDs accurately. Because of dual phosphors LEDs, there are many varied parameters to affect results of simulation. It is not only overloading in Lightools but also inefficient. In order to decrease interaction of each parameter, there is an efficient method to be provided as well. T
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Chen, Yung-jen, and 陳勇仁. "Ceramic Leadframe Optics Simulation Optimization and reliability verifying of White-Light LEDs." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/33603754164253275674.

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碩士<br>國立成功大學<br>工程科學系專班<br>97<br>White light LED(White LED) will be the mainstream of the green energy-conserving Product in the future The main part of this thesis is the reliability test of ceramic packaging structure and the improvement of light emitting efficiency by optic simulations. Currently, the normal type of LED Package is Plastic Leaded Chip Carrier (PLCC) .However, for long time lighting, it will become unstable. Also, it may become yellowing and influence the optic characteristics of LEDs. Besides PLCC, the other LED package Uses ceramic of low temperature sintering technology an
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Fang, Ying-Chien, and 方盈倩. "Preparation and Characterization of Zinc-based nanophosphors for UV-white light LEDs." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/20204987556040475899.

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碩士<br>國立成功大學<br>電機工程學系碩博士班<br>94<br>Abstract Zinc sulfide (ZnS), as II-VI semiconductors with a wide band gap energy of 3.68eV, have received much attention due to their excellent luminescence properties and are commercially used in electroluminescence devices. They are candidate materials for phosphors that emit visible light. The major and important applications of phosphors are used as light sources, display devices, radiation detectors and so on. In this study, we prepare the nano-scaled ZnS based phosphors using solid state method and chemical precipitation method. Different dopants
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Su, Ying-Yong, and 蘇英陽. "Fabrication and characterization of white LEDs using a semiconductor wavelength-convertion layer." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/45413167647908263487.

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碩士<br>國立中興大學<br>精密工程研究所<br>93<br>This thesis presents the fabrication and properties of the white light-emitting diodes (white LEDs) using a semiconductor wavelength-convertion layer. LEDs inherently have narrow emission linewidth as compared with the conventional phosphors or incandescent sources, and therefore pose a challenge for the generation of white light. To fabricate the white light using LEDs, it usually achieves by a mixture of several emission colors from multiple single-color LEDs. In this study, we demonstrate the white LED fabricated by an AlGaInP semiconductor wavelength-conver
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Yueh-YingChiang and 江岳頴. "Design with White-Light-LEDs for an Automotive Low Beam Projector Headlamp." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/00886329847216000837.

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碩士<br>國立成功大學<br>工程科學系<br>103<br>This thesis researched on automotive low beam LED headlamp design. There were many types of optical systems, such as multi-reflector, free-form reflector and projection as headlamp design. Designing an automotive low beam projector LED headlamp used TracePro. Simulating a commercial automobile applied LED headlamp which was combining one multi-reflector and two projection systems as low beam LED module, and compared the simulation results with headlamp regulations to prove that the headlamp CAD model and boundary conditions were correct and similar to reality
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jeng, Yow-shiuan, and 鄭又瑄. "The studies of power efficiency with different phosphor parameters in white LEDs." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/04603491135103694114.

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碩士<br>國立中央大學<br>光電科學研究所<br>99<br>In this thesis, we studied on the power efficiency with different phosphor concentrations and thicknesses in white LEDs. Based on our silicate phosphor model, we used a blue light laser to excite phosphor plates with different concentrations and thicknesses and analysis the forward power, sideward power and backward power of each phosphor plate in the first time. We also did the experiment to verify our simulation and then used the measurement results to analysis the power efficiency in white LEDs later. Secondly, we changed the light source from a blue light l
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Chiu, Chih-yu, and 邱志煜. "The study of angular correlated color temperature deviation for white light LEDs." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/18895466566316556939.

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碩士<br>國立中央大學<br>光電科學研究所<br>100<br>In this thesis, we study color uniformity of white light LEDs with different package types. Based on the YAG phosphor model, we analyze the angular correlated color temperature deviation (ACCTD) for white light LEDs with different package types and find out which one is lowest. After that, we modify the ACCTD of specific package types with the same correlated color temperature by changing the structure of the package. Finally, we study the ACCTD changes in mid-field region for white light LEDs and define the distance of quasi far-field in color.
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Chen, Chih-Wei, and 陳志瑋. "The Optimal Design for White-light LEDs with high color rendering index." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/80320662216050285377.

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碩士<br>國立雲林科技大學<br>電子與光電工程研究所碩士班<br>100<br>A procedure is the high color rendering index of lamp type hybrid optical modules is discussed in this study. The experiment divided into two steps in this study,first is modules design and simulation. Second is fabrication and measurement.After measure the LED’s property, calculating the ratio of each colored LEDs by using Grassmann’s Law,modeling by Solidworks, and simulating the front study by optical software TracePro. Using four-color mixing with self-developed formula to avoid the present white light emitting diode patent, and the four-color gra
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Chen, Hou Jen, and 陳厚任. "Optoelectronic Properties of Phosphor Free Quantum Dot White Light Flip-Chip LEDs." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/74050396178000314091.

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碩士<br>長庚大學<br>光電工程研究所<br>101<br>The large lattice mismatch between InN and GaN caused. Growth film instability and spinodal decomposition thus no-uniform distribution of indium-rich aggregates with designed single and concentration formatted in this work behaved as self-assembled Quantum Dots (QDs). Fabricated can construct the phosphor free White light-emitting InGaN/GaN diode(LED), whose electroluminescence measurements show that the correspondent emitted white light is composed of wavelengths from 440 to 700 nm. The Flip-Chip (FC) structure here we proposed can let the heat sink of the QD L
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Xue, Zhen, and 薛震. "Sidewall Effect on the Blue/White Light Pattern of Sapphire-based LEDs." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/qn8uy5.

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碩士<br>國立中央大學<br>光電科學與工程學系<br>105<br>In this thesis, we analyzed the sidewall effect of the sapphire-based LED on the light pattern both blue light and white light. By using the ASAP software, we built up the light source model of sapphire-based LED in the case of the highly matched on the light pattern both bare LED and LED with lens. On the basis of the phosphor optical models developed in the solid-state lighting laboratory whose supervisor is Dr. Ching-Cherng Sun, yellow phosphor has been well established. We regarded the light pattern recorded from light source model of LED with lens as th
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CHENG, SHIH-HSIN, and 鄭世鑫. "The Measurement Method of Compact Spectrometer using White LEDs with Multiple Emissions." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/f434z5.

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碩士<br>明新科技大學<br>光電系統工程系碩士班<br>106<br>Follow the idea of equal-energy white light, we have created a new type of calibration light source using LEDs with different wavelengths, where the energy of each wavelength in visible spectral range is corrected as much as possible. With the short turn-on time of LED’s, we can calibrate the light source in 3 to 5 minutes, a saving of 30 to 40 minutes compared with traditional Halogen calibration methods. In addition, a standard LED has a lifetime of up to 60,000 hours. Using the new type of calibration light source in this study, we measure the standard s
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