Sökning: "photo-induced phase transition"

Hittade 5 avhandlingar innehållade orden photo-induced phase transition.

  1. 1. Photo-induced Structural Dynamics in Transition Metal Dichalcogenides

    Författare :Shaozheng Ji; Jonas Weissenrieder; James Gardner; Oscar Tjernberg; Fabrizio Carbone; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ultrafast electron microscope; coherent shear phonon; photo-induced phase transition; 1T-TaSe2; Td-WTe2; charge density wave; ultrasnabbt elektronmikroskop; koherent skjuvphonon; fotoinducerad fasövergång; 1T-TaSe2; Td-WTe2; laddningsdensitetsvåg; Material and Nano Physics; Material- och nanofysik;

    Sammanfattning : Ultrafast electron microscope (UEM), a combination of transmission electron microscopy and laser-based pump-probe techniques, facilitates ultrafast imaging, diffraction, and electron-spectroscopy with high spatial resolution. The unique advantages of UEM enable local ultrafast dynamic studies in materials, nano-system, and biology. LÄS MER

  3. 2. Ultrafast Photo-induced Reaction Dynamics of Small Molecules

    Författare :Malin Kadi; Jan Davidsson; Eva Åkesson; Sören Keiding; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; pump-probe spectroscopy; reaction dynamics; photodissociation; aryl halides; spin-orbit coupling; ab initio calculations; molecular dynamics; vibrational wavepackets; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : The main focus of this thesis is the investigation of the dissociation dynamics of aryl halides using femtosecond pump-probe spectroscopy. In the monohalogenated aryl halides, iodo-, bromo- and chlorobenzene, the rate of dissociation following excitation at 266 nm in the gas phase increased with increasing mass of the halogen atom. LÄS MER

  4. 3. Characterization of Ultrashort Pulses And Ultrafast Dynamics of Molecules In the Liquid Phase

    Författare :Ming Liu; KTH; []
    Nyckelord :Ultrafast Spectrascopy;

    Sammanfattning : This thesis reports an alternative method for fully acomplete characterization of the UV pump pulse and white lightcontinuum probe pulse, which is commonly used in the pump-probeexperiments to investigate the ultrafast dynamics of molecules.Besides that, real dynamics of infrared cyanine dye molecules(Methyl-DOTCI) and photo-induced dissociation of trihalide ions(I3-or I2Br-) solvated in different organic solvent has alsobeen carefully investigated. LÄS MER

  5. 4. Super-resolution Luminescence Micro-Spectroscopy : A nano-scale view of solar cell material photophysics

    Författare :Aboma Merdasa; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; super-resolution microscopy; Single Molecule Spectroscopy; J-aggregates; perovskites; photophysics;

    Sammanfattning : Optical microscopy is a fundamental tool in a range of disciplines encompassed by the physical and biological sciences. At the dawn of this millennium, a break-through was made in optical microscopy where super-resolution methods emerged and declared imaging beyond the optical diffraction limit a possibility. LÄS MER

  7. 5. Luminescent Polymer Films in Layered Devices : A Theoretical and Experimental Study on Light Emission from Polymer-based Devices

    Författare :Thomas Granlund; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis concerns optical modelling and characterisation of thin film layered structures, including luminescent conjugated polymers, with respect to the emission properties. Included in the study were three different types of devices: Organic light-emitting diodes, microcavities and half cavities. LÄS MER