Avancerad sökning

Visar resultat 1 - 5 av 14 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Charge Separation on Localized Surface Plasmon and Hot Carrier Transfer to Semiconductors

    Författare :Yocefu Hattori; Jacinto Sá; Stephan Link; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasmonics; hot carrier; metal nanoparticles; semiconductors; ultrafast transient absorption spectroscopy; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi;

    Sammanfattning : The relatively recent discovery that plasmonic nanoparticles generate energetic electron-hole pairs known as hot carriers has been the source of interest from many scientific groups. The capability to extract these short-lived hot carriers from metal nanoparticles (NPs) might potentially lead to applications in solar cells, photodetection, and photocatalysis. LÄS MER

  3. 2. Charge carrier dynamics in colloidal quantum dots: Tracking the dance of electrons and holes by ultrashort laser pulses

    Författare :Nils Lenngren; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CdSe; quantum dots; ultrafast spectroscopy; charge carrier dynamics;

    Sammanfattning : Quantum dots (QDs) are semiconductor nanocrystals with quantum confinement. This thesis uses various time-resolved spectroscopic techniques to study ultrafast charge carrier dynamics in colloidal CdSe quantum dots that are important both from a theoretical point of view and for their relevance for solar cell applications. LÄS MER

  4. 3. Time-Resolved Photoemission Electron Microscopy: Development and Applications

    Författare :Lukas Wittenbecher; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PEEM; time-resolved PEEM; ultrafast optics; pulse shaping; plasmonics; semiconductor nanowires; hot electrons; ultrafast microscopy; charge carrier relaxation;

    Sammanfattning : Time-resolved photoemission electron microscopy (TR-PEEM) belongs to a class of experimental techniquescombining the spatial resolution of electron-based microscopy with the time resolution of ultrafast opticalspectroscopy. This combination provides insight into fundamental processes on the nanometer spatial andfemto/picosecond time scale, such as charge carrier transport in semiconductors or collective excitations ofconduction band electrons at metal surfaces. LÄS MER

  5. 4. Charge and Energy Transport in Disordered Organic Semiconductors

    Författare :Hassan Abdalla; Martijn Kemerink; Ronald Österbacka; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Improvement of the performance of organic disordered semiconductors (OSC) is driven by the understanding   of the underlying charge transport mechanisms and systematic exploitation thereof. There exists a multitude of materials and material systems based on polymers and small molecules with promising performance for use in organic light emitting diodes, photovoltaics, organic field-effect transistors and thermoelectrics. LÄS MER

  7. 5. Electron-lattice dynamics in π-conjugated systems

    Författare :Magnus Hultell (Andersson); Sven Stafström; Alessandro Troisi; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; charge transport; electron-lattice dynamics; polaron; adiabatic transport; electron localization; internal conversion; Computational physics; Beräkningsfysik;

    Sammanfattning : The work presented in this thesis concerns the dynamics in π-conjugated hydrocarbon systems. Due to the molecular bonding structure of these systems there exists a coupling between the electronic system and the phonons of the lattice. LÄS MER