Sökning: "light-emitting diode"

Visar resultat 1 - 5 av 35 avhandlingar innehållade orden light-emitting diode.

  1. 1. Functional and Flexible Light-Emitting Electrochemical Cells

    Författare :Amir Asadpoordarvish; Ludvig Edman; Jun Gao; Umeå universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; all-ambient fabrication; ambient-air lifetime; encapsulation; flexible; light-emitting electrochemical cells; light-emitting paper; fysik; Physics;

    Sammanfattning : The introduction of artificial illumination has brought extensive benefits to mankind, and during the last years we have seen a tremendous progress in this field with the introduction of the energy-efficient light-emitting diode (LED) and the high-contrast organic LED display. These high-end technologies are, however, produced using costly and complex processes, and it is anticipated that the next big thing in the field will be the advent of a low-cost and “green” illumination technology, which can be fabricated in a cost- and material-efficient manner using non-toxic and abundant raw materials, and which features attractive form factors such as flexibility, robustness and light-weight. LÄS MER

  2. 2. Synthesis of Conjugated Polymers and Small Molecules for Organic Light-Emitting Devices and Photodetectors

    Författare :Petri Henrik Murto; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; solution processing; conjugated polymers; fluorescence; near-infrared; light-emitting electrochemical cell; organic photodetector; organic light-emitting diode;

    Sammanfattning : Production cost and environmental impact are the two major concerns that are related to the conventional optoelectronic devices. It is desirable for the modern semiconductors that they are free of toxic/costly metals, they can be processed with low-cost solution-based methods, and their optical, electronic, and mechanical properties can be easily tuned depending on the target application. LÄS MER

  3. 3. Design and Fabrication of Light-Emitting Electrochemical Cells

    Författare :Andreas Sandström; Ludvig Edman; Ronald Österbacka; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Light-emitting electrochemical cell; fabrication; organic semiconductors; organic electronics; ambient fabrication; roll-to-roll; fysik; Physics;

    Sammanfattning : Glödlampan, en gång symbolen för mänsklig uppfinningsförmåga, är idag på väg att försvinna. Lysdioder och lågenergilampor har istället tagit över då dessa har betydligt längre livstid och högre effektivitet. LÄS MER

  4. 4. Light emitting devices based on silicon nanostructures

    Författare :Nenad Lalic; KTH; []
    Nyckelord :;

    Sammanfattning : Although silicon is the dominant semiconductor today, lightemitting devices are currently based on compound semiconductorsdue to their direct band-gap, which promotes fast radiativerecombination. However, in nanometer-size silicon structures,carrier confinement enhances the radiative recombination,while, at the same time, suppresses diffusion to non-radiativerecombination centra, resulting in a significant increase inlight emission efficiency. LÄS MER

  5. 5. Fabrication and Characterization of ZnO Nanorods Based Intrinsic White Light Emitting Diodes (LEDs)

    Författare :Nargis Bano; Omer Nour; Magnus Willander; David Rogers; Linköpings universitet; []
    Nyckelord :Zinc Oxide nanorods; White light emitting diode; Photoluminescence; Cathodoluminescence; Electroluminescence; Deep level transient spectroscopy DLTS ;

    Sammanfattning : 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. LÄS MER