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This paper tries to explore the phosphor optical characteristics through reliability tests using white light emitting diodes (WLEDs) with a high color rendering index (CRI ,Ra¡Ö90). Based on light mixing principles and considering the high CRI, three color-coded powders were mixed separately with silicone into a phosphor, and then bottomed with blue chips into WLEDs. The three powders were oxide nitride (red), YAG (yellow), and silicate (green). Two kinds of samples were fabricated ¡V phosphor and emitters similar to commercial products. Both cool-white (CCT=5650~7000K, lumen efficiency¡Ö60 lum/w.) and warm-white (CCT=2850~3250K, lumen efficiency¡Ö50 lum/w.) samples passed the Bin Code distribution process and brightness measurement. The results indicate better lumen efficiency than previously published research. After the three kinds of mono-colored phosphors were created, .we implemented the reliability test in which three CREE standards were chosen. These standards were (1) high temperature with high humidity test (60¢J , 90% humidity) in operating and non-operating condition; (2) thermal shock test (-40¢J ~125¢J ); (3) life time test. The thermal shock test showed the decaying power of intensity for red, yellow, and green phosphors were 11.7%, 17.5%, and 19.3% respectively. These results demonstrate that the red phosphor has the best thermal resistance. However, after the high temperature with high humidity tests, the decaying power of intensity for red,yellow, and green phosphor were 15.7%, 10.1% and 6.4% correspondingly. These results show that the green phosphor has best aqua resistance. In the life time test of emitters, the decaying power of intensity for the cool-white emitter was 3.2%, while the warm-white emitter showed 4.2%. As such, cool-white emitters were concluded to have better reliability than warm-white emitters.

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 other p-type materials. The first part of the thesis includes paper I-IV. In this part, the luminescence properties of ZnO nanorods grown on different p-type substrates (GaN, 4H-SiC) and different ZnO nanostructures (nanorods, nanotubes, nanoflowers, and nanowalls) grown on the same substrate were investigated. The effect of the post-growth annealing of ZnO nanorods and nanotubes on the deep level emissions and color rendering properties were also investigated. In paper I, ZnO nanorods were grown on p-type GaN and 4H-SiC substrates by low temperature aqueous chemical growth (ACG) method. The luminescence properties of the fabricated LEDs were investigated at room temperature by electroluminescence (EL) and photoluminescence (PL) measurements and consistency was found between both the measurements. The LEDs showed very bright emission that was a combination of three emission peaks in the violet-blue, green and orange-red regions in the visible spectrum. In paper II, different ZnO nanostructures (nanorods, nanotubes, nanoflowers, and nanowalls) were grown on p-GaN and the luminescence properties of these nanostructures based LEDs were comparatively investigated by EL and PL measurements. The nanowalls structures were found to be emitting the highest emission in the visible region, while the nanorods have the highest emissions in the UV region due to its good crystal quality. It was also estimated that the ZnO nanowalls structures have strong white light with the highest color rendering index (CRI) of 95 with correlated color temperature (CCT) of 6518 K. In paper III, we have investigated the origin of the red emissions in ZnO by using post-growth annealing. The ZnO nanotubes were achieved on p-GaN and then annealed in different ambients (argon, air, oxygen and nitrogen) at 600 oC for 30 min. By comparative investigations of EL spectra of the LEDs it was found that more than one deep level defects are involved in the red emission from ZnO nanotubes/p-GaN LEDs. It was concluded that the red emission in ZnO can be attributed to oxygen interstitials (Oi) and oxygen vacancies (Vo) in the range of 620 nm (1.99 eV) to 690 nm (1.79 eV) and 690 nm (1.79 eV) to 750 nm (1.65 eV), respectively. In paper IV, we have investigated the effect of post-growth annealing on the color rendering properties of ZnO nanorods based LEDs. ZnO nanorods were grown on p-GaN by using ACG method. The as grown nanorods were annealed in nitrogen, oxygen, argon, and air ambients at 600 oC for 30 min. The color rendering indices (CRIs) and correlated color temperatures (CCTs) were estimated from the spectra emitted by the LEDs. It was found that the annealing ambients especially air, oxygen, and nitrogen were found to be very effective. The LEDs based on nanorods annealed in nitrogen ambient, have excellent color rendering properties with CRIs and CCTs of 97 and 2363 K in the forward bias and 98 and 3157 K in the reverse bias. In the 2nd part of the thesis, the junction temperature of n-ZnO nanorods based LEDs at the built-in potential was modeled and experiments were performed to validate the model. The LEDs were fabricated by ZnO nanorods grown on different p-type substrates (4H-SiC, GaN, and Si) by the ACG method. The model and experimental values of the temperature coefficient of the forward voltage near the built-in potential (~Vo) were compared. It was found that the series resistance has the main contribution in the junction temperature of the fabricated devices. In the 3rd part of the thesis, the influence of helium (He+) ion irradiation bombardment on luminescence properties of ZnO nanorods based LEDs were investigated. ZnO nanorods were grown by the vapor-liquid-solid (VLS) growth method. The fabricated LEDs were irradiated by using 2 MeV He+ ions with fluencies of ~ 2×1013 ions/cm2 and ~ 4×1013 ions/cm2. It was observed that the He+ ions irradiation affects the near band edge emissions as well as the deep level emissions in ZnO. A blue shift about 0.0347 eV and 0.082 eV was observed in the PL spectra in the near band emission and green emission, respectively. EL measurements also showed a blue shift of 0.125 eV in the broad green emission after irradiation. He+ ion irradiation affects the color rendering properties and decreases the color rendering indices from 92 to 89.

A solar fiber optic lighting system, SP3 from the Swedish company Parans Solar Lighting AB, has been installed in a study area/corridor test site. A collector is tracking the sun during daytime, focusing the direct sun irradiance via Fresnel lenses into optical fibers, which guide the solar light into the building. The illumination properties of the system have been characterized. The energy saving due to reduced need of artificial lighting have been calculated and methods for balancing the artificial lights in the test site have been evaluated. The illumination at the test site using solar light was at least as high as when using the artificial lights and even higher at very clear days. The luminous flux output (500 lm) was somewhat lower than specified by the manufacturer (550 lm) at 100 000 lx direct sun illuminance. The output at 130 000 lx was high 767±33 lm the sunlight coupling efficiency 23 %. However, for a 20 m SP3 system the luminous flux output (400 lm) at 100 000 lx was higher than specified (350 lm). The SP3 system of Parans provides high quality solar light. It has a fuller spectrum close to the spectrum of the sun compared to the fluorescent lights at the test site. The correlated color temperature of the system was 5800±300 K and the color rendering index 84.9±0.5. The lighting energy saved due to decreased need for artificial light was estimated to 19 % in Uppsala which has 1790 annual sun hours. The savings in Italy, which has 3400 sun hours, is 46 %. Additional saving, especially in warmer countries can be obtained due to decreased need for cooling in the building as the solar luminaires provide negligible heat to the indoor air. Economical saving could also be realized by improved well-being of the occupants spending time under the solar luminaires. Three ways of balancing the artificial light due to sunshine fluctuations have been investigated. The global horizontal irradiance could not be used as a control signal for balancing the artificial lights but a pyranometer attached to the SP3 sun tracking collector was usable. Also the signal from an indoor luxmeter sensor could be used for balancing the light. However the signal from the light sensor which makes the SP3 collector to track the sun is probably the most cost effective method as it would serve two purposes; tracking the sun and balancing the artificial lights.

Cette thèse a été réalisée en parallèle avec le projet de recherche « ENG05 lighting », un programme européen de recherche en métrologie réunissant une quinzaine d’instituts nationaux de métrologie en Europe. L'apparition de nouvelles solutions d’éclairage utilisant des diodes à électroluminescence (DEL) n’apporte pas seulement une efficacité en termes de diminution de puissance consommée mais elles doivent également répondre à des critères dequalité delumière pour l’utilisateur selon l’environnement.L'étude se concentre sur les problématiques du confort visuel ainsi que sur les indices du rendu des couleurs conformes à ceux de la Commission International de l'Eclairage (CIE) qui ne permettent pas de prédire une évaluation fiable en ce qui concerne ces nouveaux éclairages à l’état solide.Cette recherche s’appuie sur les calculs informatisés des métriques existantes, les résultats de plusieurs expériences subjectives réalisées dans un environnement contrôlé et reproductible et leurs caractérisations. Un premier modèle capable de prédire le confort visuel d'un scénario d'éclairage est réalisé et décrit. Plusieurs axes d'amélioration des métriques du rendu des couleurs sont étudiés.L'ensemble des expériences intègre des solutions d'éclairages traditionnelles. A l’aide de carte de luminance, les résultats obtenus sont comparés aux performances des sources respectives.Mots-clefs : Rendu des couleurs, confort visuel, qualité des éclairages, expérience subjective, DEL, DEL, UGR, IRC, CRI, éblouissement, carte de luminance. / The ENG05 project funded by the European Research Metrology Programme (EMRP) addresses measurement aspects of both quantity and quality of new lighting such as solid-state lighting (SSL).The current Colour Rendering Index (CRI) of the CIE (International Commission on Illumination) fails to predict the subjective ranking of the lighting sources based on DEL (light emitting diode). Along with a study of colour rendering metrics based on an extensive computation of relevant metrics and colorimetric calculations, a study on visual comfort is performed and both are presented in this thesis.For interior lighting standards it doesn’t exist a metric able to predict the visual comfort of an environment. Therefore, the aim of this study consists in a contribution to the human visual comfort characterization according to various realistic configurations considering the comparison between DEL luminaries and traditional lighting technologies (fluorescent, halogen).The analysis of the results DEL to develop a model which could be deemed worthy of consideration by CIE.Keywords: color rendering, visual comfort, lighting quality, subjective experiment, DEL, UGR, CRI, glare, luminance maps.

Ljus påverkar människan psykiskologiskt och fysiskt, trots detta är de krav som idag finns på belysningen inte tillräckliga för att beakta de miljöegenskaper ljuset bidrar med. Ett visst ljus i kombination med en viss färg och material påverkar människan på olika sätt. De krav som ställs tar bara hänsyn till de tekniska aspekterna. Hur ljus estetiskt påverkar ett rum är en faktor detta arbete tar hänsyn till, då det påverkar människans välmående. Detta projekt behandlar två olika rum, ett rum för träning och behandling samt ett väntrum på en sjukgymnastikavdelning tillhörande Södersjukhuset i Stockholm. Dessa två rum har genomgått en ljusstudie och ljusplanering med syfte att skapa en ljussättning som är anpassad för sitt ändamål och som upplevs trivsam och behaglig. Vissa skillnader mellan projektets framtagna förslag och ett verkligt projekterat förslag har även jämförts. För att genomföra ljusstudien och ljusplaneringen har beräkningar utförts i belysningsprogrammet RELUX. På grund av att ljus inte enbart kan simuleras med hjälp av datorprogram har även fysiska modeller byggts för att analysera valet av färgtemperatur. Studiebesök på sjukgymnastpraktiker och träningsanläggningar har gjorts för att få inspiration. Även intervjuer med sjukgymnaster har gjorts för att få förståelse för vilka faktorer som måste tas hänsyn till vid en ljusplanering för denna typ av verksamhet. Litteraturstudier har gjorts för att få en djupare kunskap i hur ljus agerar i olika miljöer. Ljusplaneringen har resulterat i en jämn och god belysning i de två rummen. Kraven för belysning enligt SS-EN 12464–1:2011, har uppfyllts. Ljuskällornas färgtemperaturer har fastställts med hänsyn till färgerna i rummen, varmvit i väntrummet och neutral i tränings-/behandlingsrummet. Armaturer med uppljus och nedljus har valts i syfte att minska bländning och luminansskillnader. Downlights har valts för att belysa väggar och föremål. För att skapa en upplivande atmosfär i rummen har även dekorbelysning använts. Slutsatsen av detta arbete har visat att det är viktigt att ta hänsyn till en jämn belysning, anpassa belysningen och ljuskällans färgtemperatur efter färgsättning och material samt att anpassa belysningen efter alla synuppgifter som kan komma att krävas av personen som skall utföra arbetsuppgifter i rummet. / Light affects humans psychologically and physically, despite this the lighting requirements does not pay regard to the environmental characteristics that light contributes with. A specific light in combination with a specific color and material affects the human being in different ways. The lighting requirements only takes the technical aspects into account. In this project consideration will be given to how the light aesthetic affects the well-being. In this project two rooms will be processed, a waiting room as well as a room meant for rehabilitation. The rooms are placed in a building that includes physiotherapy at Södersjukhuset in Stockholm. The rooms have participated in a light study to create a light environment that is adjusted to its purpose as well as it is pleasantly perceived. Some differences between this lighting project and an actual lighting project have been compared. To perform this light study, various calculations have been done in the lighting planning software RELUX. Light can not solely be simulated with computer software, therefore physical models have been built to analyze the choice of color temperature. Visits to physiotherapy practices and training facilities have been done for inspirational purposes. Interviews with physiotherapists have also been done to reach a better understanding of what factors are needed to be taken under consideration while planning the lighting. Literature studies have been made to get a deeper knowledge in how light reacts in different environments. The lighting planning has resulted in an even lighting in both rooms. The requirements for lighting according to SS-EN 12464-1:2011 have been fulfilled. The different color temperatures of the light sources have been determined regarding the colors of the rooms, warm white in the waiting room and neutral in the rehabilitation room. Armatures with up and down lights have been chosen with the purpose of decreasing glare luminary differences. Downlights have been chosen to lighten up the walls and various objects. To create an uplifting atmosphere in the room, decor lighting have also been used. The conclusion of this work has shown that it is important to take luminance uniformity, adapt the light and color temperature to the room and its colors and materials into account. It is also important to adapt the light to all the different visual works that can take place in the room.

Organic semiconducting materials have received a lot of attention in recent years and can now be found in many applications. One of the applications, the light emitting electrochemical cell (LEC) has emerged due to its flat and lightweight device structure, low operating voltage, and possibility to be fully solution processed. Today LECs can emit light of various colors, but to be applicable in the lighting industry, white light need to be produced in an efficient way. White light on the other hand, is one of the toughest "colors" to achieve in an efficient way, and is of particular interest in general lighting applications, where high color-rendering index devices are necessary. In this thesis I show that blue light can be partially converted, into white light, by utilizing the photoluminescence of color conversion layers (CCLs). Furthermore, I show that a high color-quality white light can be attained by adopting a blue-emitting LEC with a CCL. Particularly, three different color-conversion materials were embedded onto a blue bottom-emitting LEC, to study the resulting spectrum. One of the materials, MEH-PPV, have good absorption compatibility with the electroluminescence of the blue emitters, but the materials photoluminescence do not cover the red to deep-red range of the spectrum. These parts of the spectrum are necessary to obtain high color rendering indices (≥80). A single layer of MEH-PPV adapted onto a blue-emitting LEC, led to a cold white LEC with CIE-coordinates x = 0.29, and y = 0.36, color-rendering index = 71, and correlated color temperature = 7200 K. These properties makes it potentially useful in outdoor-lighting applications. The photoluminescence of another studied color-converting material, polymer red, covers the red to deep-red range of the spectrum but the material lacks absorption in the green parts of the blue emitters electroluminescence spectrum. Thus it is necessary to combine it with MEH-PPV to be able to absorb all wavelengths from the blue-emitter and get a broad light-spectrum out of the device. In order to preserve a part of the blue light, a new device configuration was designed. It features a top-emitting blue LEC with a dual-layer CCL which reach an impressive color rendering index = 89 at a correlated color temperature = 6400 K (CIE-coordinates x = 0.31, y = 0.33). The color-rendering index is the highest reported for a white LEC. The absence of UV-, and IR-radiation, together with the high color rendering properties make the white LEC a possible candidate for even the most demanding lighting-applications, such as art galleries, and shop display windows, together with indoor lighting. In this thesis, I show that the CCLs function well. However, for the LECs to be worthy competitors, the efficiency and lifetime of the blue emitter need improvements.

本論文為探索性的個案研究架構，從「知識管理活動」觀點來看工廠的知識管理作法。並經由「知識管理關鍵因子」與「知識管理活動」相互關連性來探討「知識管理關鍵因子」對於個案LED廠的「知識管理活動」之影響。 對於知識管理流程的運作得到的結論有： （一）、外部知識與內隱知識同為個案企業在知識取得及創造重要來源 但由個案探討發現要讓知識取得及創造能更有效果的方法，有賴激勵制度及高階主管全力支持以促使團隊合作發展才能達到目的。 （二）、由個案跨國企業知識蓄積及分享而言，IT及網際網路科技應用是必要且影響甚鉅的，但必須搭配資深或技術人員為載體，知識蓄積及分享效果才為顯著。 （三）、教育、評核及激勵制度推動師徒制及專案團隊與跨廠區、部門合作，促進知識流通、移轉及轉換。 對於知識管理關鍵因子與知識管理流程關聯性得到結論有： 1. IT及網際網路可協助知識管理活動更加有效率及組織化。 2. 科技產品的應用對遠距離、跨區域公司的知識管理式可收事半功倍之效果。 3. 信任與自私為一體兩面，沒有相對高階的絕對支持及相對資源投入，就無以產生絕對信任。知識導入及轉移至同化是否能達效果，此為一大主因。 4. 高階主管的認知及全力支持是知識管理落實、有效執行的關鍵。 5. 相同制度用在不同地區未必可得到一致效果，因地制宜因勢利導方可收知識管理之功效。 6. 使命與榮譽感需配合評核及有效激勵制度才能成為知識傳承重要動力。 / The thesis architecture is base on exploratory case study . Base on the point view of Knowledge management to discuss the activities of factories . Base on the inter-related “ key factors of knowledge management ” and “knowledge management activities ” . We try to find the impact from“ key factors of knowledge management ” to " knowledge management activities ”in the case study. The conclusion of the knowledge management process: 1. External knowledge and implicit knowledge are equal important resource for the case company in the knowledge acquisition and creation. However, the case study found that to make knowledge acquisition and the creation can be more effective is depends on the incentive system and top managers full support to promote the development of teamwork to achieve the purpose. 2. For knowledge accumulation and sharing of multinational enterprises , IT and Internet technology application is necessary and a great influence .It will be more powerful if senior technical staff as a carrier of knowledge accumulation and sharing . 3. Education、assessment and incentive system encourage apprenticeship and project teams to work more powerful in cross-plant .That promote the circulation of knowledge, transfer and conversion. We study the relationship between key factors of knowledge management and knowledge management process . Conclusion as following： 1. IT and Internet can make knowledge management activities more efficient and organized. 2. the application of technology products on the type of long-distance, inter-regional knowledge management can get maximum effect. 3. Trust and selfishness is two side of the same coin. If there is no absolute support and the relative resources from top managers . There will be no absolute trust . It’s the main key point of knowledge import 、transfer 、 assimilation . 4. Top managers awareness and fully support to knowledge management will be the key to effective implementation. 5. The same system in different regions may not be obtained consistent results. Capitalize on the trend will be the best efficacy of knowledge management. 6. Mission and sense of honor must comply with the assessment and effective incentive system in order to become an important driving force of knowledge transmission.

Tunable white-armaturer utgör idag en stor del av marknaden och förväntas öka ytterligare under de kommande åren. Då många leverantörer idag producerar och marknadsför sina egna lösningar för att skapa ett dynamiskt ljus kan det vara svårt att veta vilken standard dessa lösningar håller och hur väl den tekniska specifikationen stämmer överens med verkligheten. Syftet med denna studie har varit att undersöka om informationen mot beställare är tillräcklig samt om den redovisade data av Tunable White-armaturer är korrekt. Studien bygger på två delar. En experimentell undersökning genomfördes där fem tunable white-armaturers CRI (färgåtergivning) mättes mellan olika CCT-nivåer (färgtemperatur) och sedan jämfördes det med vad leverantörer har specificerat på deras hemsidor. En enkätundersökning genomfördes sedan som riktades mot 144 ljusdesigners i Sverige, varav 52 valde att besvara enkäten. Frågorna berörde redovisning av Tunable white-armaturer samt vikten av en god ljuskvalitet med inriktning på CRI. Resultaten från författarnas experimentella undersökning visar att alla tunable white-armaturer som testades skiftar i CRI under olika färgtemperaturintervaller. Den största skillnaden som mättes var på fabrikat 3 där det skiftade 9 CRI mellan 2700K-6000K. En jämförelse kunde sedan göras och visade att två av fem leverantörers specifikationer inte stämmer överens med vad som redovisats i respektive produktdatablad. Av att tyda svaren från enkätundersökningen kunde slutsatsen dras att det finns mycket skilda åsikter angående de tekniska specifikationerna gällande tunable white-armaturer. En del ansåg att det redovisas tillräckligt väl idag medan andra ansåg att det inte redovisas tillräckligt väl. Majoriteten ansåg att det är mycket viktigt med en god CRI när man föreskriver tunable white-armaturer i sina projekt. Man kunde också se att många ljusdesigners önskade att man redovisade färgåtergivning i TM-30-15 istället för CRI-metoden eller att man bör redovisa i givna färgtemperaturer. Det som kan fastställas av denna studie är att det finns en tendens till att vissa armaturleverantörer har sämre CRI än vad företaget i fråga redovisat. Denna studie enbart mätt TW-armaturer från fem företag verksamma i Sverige samt endast vid 100% ljusflöde. Författarna anser dock att denna studie kan leda till en diskussion om bättre redovisning av tunable white-armaturer behövs, samt ge läsaren en ökad förståelse för komplexiteten inom området. / Tunable white luminaires today form a large part of the market and are expected to increase further in the upcoming years. As many manufacturers today produce and market their own solutions to create a dynamic light, it can be hard to know what quality these solutions have and how well the technical specification is. The purpose of this study were to investigate whether the information to the user is sufficient and whether the presented data of tunable white luminaires is correct. This study is based on two parts. An experimental study where five tunable white luminaires CRI (color rendering) were measured between different CCT levels (color temperature) and then compared these to what providers have specified on their websites. The second part was a survey was conducted to 144 lighting designers based in Sweden, 52 of whom chose to answer the questionnaire. The questions concerned the presented information of tunable white luminaires as well as the importance of a good light quality focusing on CRI. The results from the authors experimental survey showed that all tunable white luminaires that where tested are changing in CRI under different color temperature intervals. The biggest difference that was measured was on manufacturer 3 where 9 CRI shifted between 2700K-6000K. A comparison could be made and showed that two of five of the suppliers specifications did not match with the authors measurements. By analyzing the answers from the survey, some conclusions could be drawn. There were very different opinions regarding the technical specifications of tunable white luminaires. Some felt that it is enough as it is today, while others felt that more information was needed. The majority considered it very important to have a good CRI when selecting tunable white luminaires in their projects. One could also see that many lighting designers wanted to present color reproduction in TM-30-15 instead of the CRI method or to present CRI at given color temperatures. What can be determined by this study is that there is a tendency for some luminaire suppliers to have worse CRI than presented. This study only measured tunable white fixtures from five companies operating in Sweden and only at 100% luminosity. However, the authors consider that this study could lead to a discussion about better specifications for tunable white luminaires, as well as giving the reader an increased understanding of the complexity of the subject.

This thesis deals with the processing of light technical parameters and performance of key LED chips for their applications in lighting systems. The aim is to create a laboratory model for measuring the qualitative and quantitative parameters of highly luminous light LED emitted depending on the angle, using a spherical integrator 0.3 m, goniometer and fiber spektroradiometr /luxmeters. Goniometer is designed using modular optomechanical parts company Thorlabs. Due to the current passing through the LED chips heat up considerably. To light LED chip parameters tested were not affected by heat from the chip is required to pay the heat generated by a passive radiator. Another part of this thesis is the reconstruction of an older model spherical integrator. Reconstruction must be undertaken so as to ensure sufficient cooling again tested LEDs. Light scattered in the ball of the integrator is led by the optical cable to the spektroradiometr that are subsequently recorded its parameters. The second element used to measure the light produced by the LED source is photocell. Spherical integrator must be appropriately modified to indicate the two measuring elements and also meet the standards of determining the correctness of measurement. At the end of the measurement results will be compared with catalog values provided by the manufacturer.