Дисертації з теми "White light producing materials"
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Zhao, Xinyue M. Eng Massachusetts Institute of Technology. "Commercialization of Quantum Dot White Light Emitting Diode technology." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37678.
Повний текст джерелаIncludes bibliographical references.
It is well known that the use of high-brightness LEDs for illumination has the potential to substitute conventional lighting and revolutionize the lighting industry over the next 10 to 20 years. However, successful penetration of this extremely large lighting market would require vast improvements in power conversion efficiencies, color index, light output per device and drastic reduction in cost. Quantum Dot white LED (QD WLED) technology may be one of the best choices, due to its higher energy efficiency, larger color render in index, better versatility and more importantly lower cost, compared to conventional blue LED plus YAG: Ce yellow phosphor technology. Due to the fundamental difference of the material structure, QD LEDs will win a steady position among existing white LED patents and a hybrid fabless plus IP business model has the best position to promote this technology to maximize its benefits and potential for the entire LED industry.
by Xinyue Zhao.
M.Eng.
Soon, Chian Myau. "White light emitting diode as liquid crystal display backlight." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42159.
Повний текст джерелаIncludes bibliographical references.
The discovery of high brightness (white) light emitting diode (LED) is considered as a real threat to the current lighting industry in various applications. One of the most promising sectors would be using white LED to replace the current Cold Cathode Fluorescent Light (CCFL) technology as the backlight of the large screen Liquid Crystal Display (LCD) screen due to the fact that LCD is a rapidly booming market.
by Chian Myau Soon.
M.Eng.
Little, Matthew Michael. "Feasibility of manipulating correlated color temperatures with a phosphor converted high-powered light emitting diode white light source." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/332.
Повний текст джерелаBohun, Michael H. "Several Non-Destructive Inspection Methods Applied to Quantify Fretting Fatigue Damage in Simulated Ti-6Al-4V Turbine Engine Dovetail Components." University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1332421987.
Повний текст джерелаYangui, Aymen. "Etude des propriétés optiques et structurales des matériaux hybrides organiques-inorganiques à base de Plomb : émission de lumière blanche." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV030/document.
Повний текст джерелаInorganic organic hybrid materials have attracted a great attention do to their special structure and important optical such as the high luminescence, even at room temperature. This relatively new research on this family of materials, offers a variety of technological opportunities. In this context, we are interested in the study of optical properties of both inorganic and organic hybrid materials (C6H11NH3)2[PbI4] and (C6H11NH3)2[PbBr4], and mainly their luminescence properties. The results shows that under ultraviolet excitation, (C6H11NH3)2[PbBr4] show a strong white light emission, even at room temperature, which open a great interest in the use of these materials as a source of the white light emission. The origin of this large emission has been studied by different techniques such as the time resolved photoluminescence measurements
Oliveira, Rafael Figueiredo de. "Evaluation of Proposed Natural Corrosion Inhibitors for X-52 Carbon Steel in Ethanol Media." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1448385629.
Повний текст джерелаOnelli, Olimpia Domitilla. "Complex photonic structures in nature : from order to disorder." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/273768.
Повний текст джерелаLee, Reiyun, and 李睿勻. "Photoinduced Relaxation Dynamics of White-Light OLED Materials." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/98956101992145140082.
Повний текст джерелаKuo, Chia Chen, and 郭家成. "Efficient Polymer White-Light-Emitting Devices Based on Phosphorescent Materials." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/44051185791789883748.
Повний текст джерела長庚大學
光電工程研究所
98
This thesis is divided into two parts. we have fabricated a series of highly efficient white-emitting polymer devices possessing a single emitting layer containing a hole-transporting host polymer, PVK, and electron-transporting auxiliary (OXD7), These doubly doped devices all exhibited an intense white light emission and close to the standard white light region. In the first part, the white emitting polymer device doped with blue-light-emitting iridium phosphor (FIrpic) and red-light-emitting osmium phosphor (Os(fppz)),and electron-transporting layer fabricated by TPBi. The CIE of the first white emitting polymer device is (0.33, 0.35), the maximum luminescence efficiency of 19.8cd/A and the maximum external quantum efficiency of 10.8 % was achieved. In the second part, the white emitting polymer device doped with blue-light-emitting phosphor (FIrpic) and red-light-emitting osmium phosphor (Os(bpftz)), After the modification of electron transporting layer in these WPLEDs, the maximum forward viewing luminescence efficiency of 46.6 cd/A (79.2 cd/A for total viewing) and power efficiency of 29.1 lm/W (49.5 lm/W for total viewing) was achieved, which is comparable to those reported for the state-of-the-art vacuum deposited small molecule WOLEDs.
Ping-I, Shih, and 施秉彝. "Blue and White Phosphorescent Organic Light -Emitting Diodes: Materials and Devices." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/27527004151813880554.
Повний текст джерела國立交通大學
應用化學系所
97
This thesis is divided into two parts, part A regarding the synthesis and characterization of two novel host materials for phosphorescent OLEDs; part B regarding the fabrication and character discussion of the highly efficient white polymer light emitting devices. In first section of part A, we report the synthesis and characterization of a novel silane/fluorene hybrid, TPSi-F, used as the host material for blue phosphorescent devices. TPSi-F is constructed by linking both tetraphenylsilane and phenyl substituted fluorene moieties through a non-conjugated, sp3-hybrided carbon atom (C-9) to enhance its thermal and morphological stabilities, while maintaining the much needed, higher singlet and triplet energy gap. Highly efficient sky-blue phosphorescent OLEDs were obtained when employing TPSi-F as the host and FIrpic as the guest, the maximum external quantum efficiency (max. EQE) of this device reached as high as 15 % (30.6 cd/A). Furthermore, upon switching the guest from FIrpic to a new blue phosphor FIrfpy, the saturated-blue OLEDs were realized with the max. EQE being 9.4 % (15.1 cd/A). These TPSi-F based blue phosphorescent devices show a 2-fold enhancement in the device efficiency, comparing with reference devices based on conventional host material mCP. In second section of part A, we report a novel host material TFTPA that contains a triphenylamine core and three 9-phenyl-9-fluorenyl peripheries, was effectively synthesized through a Friedel–Crafts-type substitution reaction. Owing to the presence of its sterically bulky 9-phenyl-9-fluorenyl groups, TFTPA exhibits a high glass transition temperature (186 °C) and is morphologically and electrochemically stable. In addition, as demonstrated from atomic force microscopy measurements, the aggregation of the triplet iridium dopant is significantly diminished in the TFTPA host, resulting in a highly efficient full-color phosphorescence. The performance of TFTPA-based devices is far superior to those of the corresponding mCP- or CBP-based devices, particularly in blue- and red-emitting electrophosphorescent device systems. The efficiency of the FIrpic-based blue-emitting device reached 12% (26 cd/A) and 18 lm/W at a practical brightness of 100 cd/m2; the Ir(piq)2acac-based red-emitting device exhibited an extremely low turn-on voltage (2.6 V) and a threefold enhancement in device efficiency (9.0 lm/W) relative to those of reference devices based on the CBP host material. In part B, we have fabricated a series of highly efficient white emitting polymer devices possessing a single emitting layer containing a hole-transporting host polymer, PVK, and electron-transporting auxiliary (PBD or OXD7), doped with blue-light-emitting dye and red-light-emitting osmium phosphor. These doubly doped devices all exhibited an intense white light emission and close to the standard white light region. After the modified of electron transporting layer in these WPLEDs, the maximum forward viewing luminescence efficiency of 36.1 cd/A (61.4 cd/A for total viewing) and power efficiency of 23.4 lm/W (39.8 lm/W for total viewing) was achieved, which is comparable to those reported for the state-of-the-art vacuum deposited small molecule WOLEDs.
Ko, Li-Chun, and 柯力群. "White polymer light emitting diode using three phosphorescent materials with various doping ratio." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/03226813278281435661.
Повний текст джерела國立交通大學
電子物理系所
98
This dissertation aims to utilize blade-coating method to fabricate efficient phosphorescent multilayer polymer light-emitting diode (PLED). Iridium complexes are mixed with poly-(vinylcarbazole) (PVK) to form the emissive layer. For yellow phosphorescent PLED, tris[2-(p-tolyl)pyridine]iridium(III) (Ir(mppy)3) and tris[2-(4-n-hexylphenyl)quinoline)]iridium(III) (Hex-Ir(phq)3) are used as green and red dopants respectively. The blending ratio of Ir(mppy)3 and Hex-Ir(phq)3 is 13:1. The efficiency of 23 cd/A and the luminance of 30000cd/m2 are obtained. As for white phosphorescent PLED with single emissive layer, Hex-Ir(phq)3, Ir(mppy)3 and bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III) (FIrpic) are used as dopants in the ratio of 1:0.5:45. The efficiency of 8.1 cd/A and the luminance 6000cd/m2 are achieved. The Commission Internationale de l’Eclairage (CIE) coordinates are stable from 8V to 15 V and only slight changes can be observed from (0.35, 0.42) to (0.36, 0.43). By substituting Hex-Ir(phq)3 with deep red Hex-Ir(piq)3, CIE coordinate (0.35, 0.35) is obtained as the blending ratio Hex-Ir(piq)3 : Ir(mppy)3 : FIrpic = 15:1:480. The light from device uses Hex-Ir(piq)3 is more close to pure white.
劉家銘. "Characteristics of White-Light Continuum produced by interactions of femtosecond laser pulses with dielectric materials." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/65189390306747360198.
Повний текст джерела國立清華大學
物理學系
91
The generation of white-light continuum by femtosecond laser pulses in transparent dielectric materials is investigated with 800-nm pump wavelength and self-phase modulation is the main process to produce the physical phenomenon. Our research is focused on the characterizations of white-light spectra width, polarization, pulse width, and frequency chirping with different materials like water, alcohol, methanol, sapphire, quartz, pyrex glass, calcite etc. For white-light polarization, a self-induced change in polarization of the white-light continuum is observed in trigonal crystal structure. For white-light spectra width, we find that the ratio of the medium’s bandgap energy to the photon energy of the incident wavelength determines the amount of spectrum broadening. After the investigation of polarization, the frequency chirp of the white-light continuum is characterized by the Kerr-gate method with 140 fs temporal and 20 nm wavelength resolution. By the investigation of white-light continuum, we can apply to femtosecond time-resolved luminescence spectroscopy, optical pulse compression for generation of ultrashort pulses etc.
Su, Min-Ju, and 蘇敏如. "White Light Emitting Diodes by Encapsulating InGaN with UV Curable Transparent Polysiloxane/Inorganic Hybrid Materials." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/40568877740156016377.
Повний текст джерела逢甲大學
化學工程學系
104
Polysiloxane based organic-inorganic hybrid (O-I hybrid) encapsulants with high transparency, high refractive index, and thermal resistance were prepared by the sol-gel and UV curing reaction. The chemical structures of the encapsulants were analyzed by Fourier Transform Infrared Spectroscopy (FT-IR) and Si29 NMR. The effects of chemical structure on the refractive index, surface hardness, thermal resistance, and transmittance of encapsulants were investigated through refractometer, nanoindenter, thermogravimetric analysis, and UV/Vis spectrometer. In the second part, graphene was mixed with UV-curable encapsulant to prepare the composite material .The O-I hybrid oligomer encapsulants with and without graphene were mixed with phosphor, and photoinitiator. The mixture was coated on InGaN devices and UV-cured to fabricate white light emitting diodes (WLEDs). The optical, mechanical, and thermal properties of the encapsulants can be tuned by changing their chemical structures. The O-I hybrid materials are encapsulants with high refractive index (n=1.56), good transparency and thermal resistance. After being baked at 150 oC for 48h, the transmittance of encapsulant at 470 nm wavelength decreased from 87% to 86%. Effects of encapsulants on the performance of white light emitting diodes were measured. After continuous lighting, the changes in surface temperature, luminous efficiency, color rendering index, the Commission Internationale de l’Éclairage coordinates, and correlated color temperature (CCT), were investigated to evaluate the stability of the WLED. The WLED surface temperatures of V7g10r1, V7g10r1.5, and V7G4g10r1.5 were 47.5, 46.4, and 44.4℃, respectively. The luminous efficiency, color rendering index, and CCT of V7g10r1 WLED are 130 lm/W(20mA), 84.1, and 4951 K, respectively. After continuous lighting for 20 days, the luminous efficiency, color rendering index, and CCT of V7g10r1 WLED are 113 lm/W(20mA), 82.9, and 4772 K, respectively. For the V7g10r1.5 samples without graphene, the luminous efficiency, color rendering index, and CCT of V7g10r1 WLED are 97.3 lm/W (20mA), 89.8, and 4653 K, respectively. After continuous lighting for 10 days, the luminous efficiency, color rendering index, and CCT of V7g10r1 WLED are 91.5 lm/W (20mA), 86.8, and 3983 K, respectively. For the encapsulants with graphene, the luminous efficiency, color rendering index, and CCT of V7G4g10r1 WLED are 90.1 lm/W (20mA), 89.5, and 4555 K, respectively. After continuous lighting for 10 days, the luminous efficiency, color rendering index, and CCT of V7G4g10r1 WLED are 89.5 lm/W (20mA), 89.2, and 4566 K, respectively. Incorporation of graphene helps to improve the stability of WLED.
Chirakkara, Saraswathi. "Tuning Zinc Oxide Layers Towards White Light Emission." Thesis, 2012. http://etd.iisc.ernet.in/handle/2005/2324.
Повний текст джерелаChen, Tsung-Chieh, and 陳宗杰. "A Study of Photoelectronic Characteristics for White Organic Light-Emitting Diodes with Different High Energy-Gap Emitting Host Materials." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/52856000262545441953.
Повний текст джерела國立中正大學
光機電整合工程所
93
Organic light emitting devices were deposited on Indium tin oxide (ITO) substrate by high vacuum evaporator system. In our study, the device configurations of white organic light emitting diodes (WOLEDs) using multilayer structure were ITO/NPB /Host:Firpic:Ir(DBQ)2(acac) /TPBI /Mg:Ag. Three different host materials, including mCP, TCTA, and CBP, are individually used in the emitting layer to fabricate the devices. Effects of different host materials on the photoelectronic characteristics of white-light organic light-emitting diodes have been systematically investigated. It is proved that with the use of suitable high energy-gap host materials, the brightness of WOLEDs can be significantly improved. Evidence showed that the use of the high energy-gap materials make the energy transfer between the host and guest materials easier. Hence, the brightness of OLED can be further enhanced. In this study, the energy is transferred from the high energy-gap host material to the guest materials Firpic and Ir(DBQ)2(acac), and then the blue and red light is produced by the Firpic and Ir(DBQ)2(acac), respectively. By the mixture of the red and blue light, the white light emission is achieved.
"White Organic Light Emitting Diodes for Solid State Lighting - A Path towards High Efficiency and Device Stability." Master's thesis, 2016. http://hdl.handle.net/2286/R.I.38561.
Повний текст джерелаDissertation/Thesis
Masters Thesis Materials Science and Engineering 2016
Fang, Ming. "Lanthanide-doped inorganic materials and organic-inorganic hybrids for solid-state lighting." Doctoral thesis, 2020. http://hdl.handle.net/10773/30894.
Повний текст джерелаA Agência Internacional de Energia estimou que o sector de iluminação representa cerca de 19% do consumo total de energia mundial. Os díodos emissores de luz (LEDs) têm maior eficiência em comparação com as fontes de iluminação convencionais. Os LEDs brancos comerciais (WLEDs) são baseados na combinação de LEDs azuis baseados em InGaN com o luminóforo Y3Al5O12:Ce3+ (YAG:Ce). Este material, que é um emissor de banda larga na região espectral do amarelo. é depositado de forma simples e a baixo custo sobre o LED azul. No entanto, a emissão deste WLEDs baseia-se na adição de duas cores tendo um índice de reprodução de cor baixo (CRI, geralmente <75), elevada temperatura de cor (CCT, > 6500 K) e variação de cromaticidade, que são claras desvantagens em aplicações de iluminação e retroiluminação. Para além destas desvantagens, estes LEDs ainda apresentam emissão na região do verde relativamente menos eficiente (usualmente designado em linguagem inglesa como ³green gap issue´). Uma estratégia alternativa a estes LEDs baseia-se na utilização de dispositivos emissores nas regiões espectrais do ultravioleta próximo (NUV) e do azul combinados com um material capaz de desviar esta emissão para a região do visível. Assim, novos materiais emissores eficientes quer de luz verde quer de luz branca para as aplicações em LEDs são necessários. Nesta tese, híbridos orgânicos-inorgânicos (ureasils, d-U(600)) dopados com complexos à base de Tb3+ emissores no verde foram combinados com NUV-LED comerciais para fabricar protótipos de LED verdes eficientes. Para melhorar o CRI e CCT dos WLEDs comerciais, novos luminóforos de La2Ce2O7:Eu3+ com emissão no vermelho e excitados com LEDs azuis foram, também, sintetizados e caracterizados. Na parte final da tese discute-se a contribuição de novos materiais emissores de luz branca sintonizável baseados em híbridos d-U(600) dopados com complexos de iões lantanídeos (Ln3+=Tb3+, Eu3+), corantes fluorescentes e pontos de carbono com propriedades óticas (CCT, CRI e fotoestabilidade) melhoradas, face ao estado da arte.
Programa Doutoral em Ciência e Engenharia de Materiais
Sadhanala, Hari Krishna. "Hydrothermal Synthesis of Carbon Nanoparticles for Various Applications." Thesis, 2016. http://hdl.handle.net/2005/3147.
Повний текст джерелаMukherjee, Sanjoy. "Investigations of Structure-Property Relationships in NPI and BODIPY Based Luminescent Material." Thesis, 2015. http://etd.iisc.ernet.in/2005/3933.
Повний текст джерела