Sökning: "light emitting diodes"

Visar resultat 1 - 5 av 42 uppsatser innehållade orden light emitting diodes.

  1. 1. Black-box optimization of simulated light extraction efficiency from quantum dots in pyramidal gallium nitride structures

    Master-uppsats, Linköpings universitet/Matematiska institutionen

    Författare :Karl-Johan Olofsson; [2019]
    Nyckelord :Black-box optimization; Radial basis functions; Gallium nitride; light extraction efficiency; FDTD; surrogate functions; semiconductors; global optimization;

    Sammanfattning : Microsized hexagonal gallium nitride pyramids show promise as next generation Light Emitting Diodes (LEDs) due to certain quantum properties within the pyramids. One metric for evaluating the efficiency of a LED device is by studying its Light Extraction Efficiency (LEE). LÄS MER

  2. 2. Microscopy techniques for studying polymer-polymer blends

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Sandra Mattsson; [2019]
    Nyckelord :CLEM; correlative light and electron microscopy; correlative microscopy; fluorescence microscopy; scanning electron microscopy; phase contrast microscopy; polymer blend; morphology; super yellow; PEO; poly ethylene oxide ; CLEM; korrelativ ljus- och elektronmikroskopi; korrelativ mikroskopi; fluorescensmikroskopi; svepelektronmikroskopi; faskontrastsmikroskopi; polymerblandning; morfologi; super yellow; PEO; poly etylenoxid ;

    Sammanfattning : Semiconductors are used in many electronic applications, for example diodes, solar cells and transistors. Typically, semiconductors are inorganic materials, such as silicon and gallium arsenide, but lately more research and development has been devoted to organic semiconductors, for example semiconducting polymers. LÄS MER

  3. 3. ErgoDesk : Automatic height adjustment of a desk

    Kandidat-uppsats, KTH/Mekatronik; KTH/Mekatronik

    Författare :OLIVIA EKMAN; AXEL FYRESKÄR; [2018]
    Nyckelord :mechatronics; automatic desk height; ergonomics; computer vision; colour tracking; mekatronik; automatisk skrivbordshöjd; datorseende; färgspårning; ergonomi;

    Sammanfattning : The purpose of this project was to track the posture of a person sitting by a desk, and then use the information to adjust the desk to achieve an optimal height for the user. The solution was to track the angle of the users forearm relative to the desk’s horizontal plane, which should be around zero degrees for an ergonomic posture. LÄS MER

  4. 4. Selective Area Growth of AlGaN pyramid with GaN Multiple Quantum Wells

    Master-uppsats, Linköpings universitet/Halvledarmaterial

    Författare :Hsin-Yu Chen; [2018]
    Nyckelord :selective area growth; MOCVD; AlGaN pyramid; GaN multiple quantum wells; undesired deposition;

    Sammanfattning :   Since Shuji Nakamura, Hiroshi Amano, and Isamu Akasaki won the 2014 Nobel prize in Physics owing to theircontributions on the invention of efficient blue GaN light emitting diodes, GaN became an even more appealingmaterial system in the research field of optoelectronics. On the other hand, quantum structures or low-dimensionalstructures with properties derived from quantum physics demonstrate superior and unique electrical and opticalproperties, providing a significant potential on novel optoelectronic applications based on the employment of quantumconfinement. LÄS MER

  5. 5. Creating nanopatterned polymer films for use in light-emitting electrochemical cells

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Thomas Moberg; [2018]
    Nyckelord :Thermal nanoimprint lithography; soft stamp; intermediate polymer stamp; Light-emitting electrochemical cell; LEC; Super Yellow; polystyrene; poly ethylene oxide ; nanopattern;

    Sammanfattning : Thermal nanoimprint lithography (T-NIL) is a cheap and fast technique to produce nanopatterns in polymeric materials. It creates these patterns by pressing a stamp down into a polymer film that has been heated above its glass transition temperature. LÄS MER