Sökning: "solid state lighting"
Visar resultat 1 - 5 av 13 avhandlingar innehållade orden solid state lighting.
1. Optical properties of point defects in insulators and of transition metal dichalcogenides
Sammanfattning : There is a need for new or modified materials, both to improve current devices and to create novel functionalities. Engineering materials to target specific functionalities requires a better understanding of how microscopic processes impact materials properties. LÄS MER
2. Bilayer Light-Emitting Electrochemical Cells for Signage and Lighting Applications
Sammanfattning : Artificial light surrounds us in a manifold of shapes. It is mainly utilized for illumination, but also for graphical communication of complex and evolving messages and information, among other things. It can be generated in different ways with incandescent lamps and fluorescent tubes constituting two common examples. LÄS MER
3. Understanding the interactions between vibrational modes and excited state relaxation in garnet structured phosphors
Sammanfattning : This thesis concerns investigations of the local structural environments and vibrational dynamics of the three garnet type oxide phosphors Ce3+-doped Y3Al5O12 (YAG:Ce3+), Ca3Sc2Si3O12 (CSS:Ce3+), and Sr3Y2Ge3O12 (SYG:Ce3+), which show promising optical properties as luminescent materials used in solid state white lighting technologies. The study focuses on a comprehensive analysis of the nature of the long-range vibrations (phonons) in terms of local atomic and molecular motions of the garnet structure, as well as their dependence on the nature of the garnet chemical composition, Ce3+ concentration and temperature. LÄS MER
4. Thermal evaporation of small molecules-A study of interfacial, bulk and device properties for molecular electronics
Sammanfattning : Electronic devices based on organic materials have recently become an emerging technology for many applications. Promising aspects are the compatibility with almost any substrate and low cost processing methods. LÄS MER
5. Dynamic local structural symmetries and luminescence properties of the yellow emitting phosphor Ce3+-doped Y3Al5O12
Sammanfattning : This thesis centers on investigations of the local structure and vibrational properties of the oxide garnet Y3Al5O12 (YAG), which when substituted with a few percent of the activator ion Ce3+ to replace Y3+ (Y3−xCexAl5O12, YAG:Ce3+) is one of the most important phosphors for solid state lighting. The study builds on a comprehensive analysis of the nature of the phonons and localized vibrational modes in YAG:Ce3+ and how these depend on the Ce3+ concentration and temperature and how they affect key optical properties, such as the intensity and frequency of the emitted light. LÄS MER
