Sökning: "out of band emission"

Visar resultat 16 - 20 av 29 avhandlingar innehållade orden out of band emission.

  1. 16. Dynamic local structural symmetries and luminescence properties of the yellow emitting phosphor Ce3+-doped Y3Al5O12

    Författare :Yuan-Chih Lin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; free electron laser; neutron scattering; vibrational spectroscopy; phosphor; light emitting diode; luminescence; thermal quenching; garnet;

    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

  2. 17. O2 and OH airglow in the mesosphere through the lens of Odin/OSIRIS Infrared Imager

    Författare :Anqi Li; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Satellite limb observation; mesospheric ozone; photochemistry; airglow; atmospheric waves; mesosphere;

    Sammanfattning : Observing airglow emissions allows us to explore the chemical composition and dynamics of the upper mesosphere. The Odin satellite has routinely measured O2(a1∆g) and OH Meinel band airglow emissions from 2001 until 2015. In this thesis, the Odin/OSIRIS infrared imager data have been studied in some depth for the first time. LÄS MER

  3. 18. Experimental Studies of Neutron Deficient Nuclei in the A ≈ 110 and A ≈ 170 Mass Regions

    Författare :Wei Zhang; Bo Cederwall; Piotr Bednarczyk; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics;

    Sammanfattning : This doctoral thesis describes several experimental studies on the structures of neutron-deficient nuclei with mass numbers A≈110 and A≈170. The experiments were carried out at the Accelerator Laboratory of the University of Jyväskylä, Finland, using heavy-ion fusion-evaporation reactions induced by beams of energies around 5 megaelectronvolts/nucleon. LÄS MER

  4. 19. Circumventing Spectrum Mismatch - Studies of Triplet-Triplet Annihilation Upconversion, Singlet Fission and Two-Photon Absorption in Photoactive Materials

    Författare :Deise Fernanda Barbosa de Mattos; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; singlet fission; solar energy conversion; two-photon absorption; energy transfer; triplet-triplet annihilation upconversion; spectroscopy.; carbon nitride quantum dots; self-assembly gels; photochemistry;

    Sammanfattning : Solar energy stands out for its potential to supply the global energy demand by itself. Therefore, it is of great value to expand the use of processes that involve light such as conversion to electricity or fuels, or to drive high-energy reactions. LÄS MER

  5. 20. Spontaneous and stimulated X-ray Raman scattering

    Författare :Yu-Ping Sun; Faris Gel'mukhanov; Vincenzo Carravetta; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; resonant X-ray scattering; resonant Auger scattering; rotational Doppler broadening; XFEL pulse; Atomic and molecular physics; Atom- och molekylfysik; Spectroscopy; Spektroskopi;

    Sammanfattning : The present thesis is devoted to theoretical studies of resonant X-ray scattering and propagation of strong X-ray pulses. In the first part of the thesis the nuclear dynamics of different molecules is studied using resonant X-ray Raman and resonant Auger scattering techniques. LÄS MER