Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 8 of 8 for “"phonon propagation"”.
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High frequency phonon propagation and detection in III-V semiconductors
Low temperature propagation and detection of high frequency acoustic phonons in GaAs and InAs is studied. .Phonon imaging is used to study scattering of acoustic phonons in GaAs and angular dispersion of acoustic phonons in InAs. Photoluminescence spectroscopy is used to study the effects of …
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High-frequency phonon propagation and detection in III-V semiconductors
Low temperature propagation and detection of high frequency acoustic phonons in GaAs and InAs is studied. Phonon imaging is used to study scattering of acoustic phonons in GaAs and angular dispersion of acoustic phonons in InAs. Photoluminescence spectroscopy is used to study the effects of …
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Analysis of materials properties of thin film structures for thermoelectric and thermophotovoltaic applications
… to enhance the structure's ability to impede phonon propagation.
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Spectroscopic perspectives on ultrafast coupling phenomena in perovskite oxides
… I focus on the observation of coherent phonon propagation by time resolved Brillouin scattering: following the excition of metal transducer films with a femtosecond infrared pump pulse, coherent phonon dynamics in the GHz frequency range are triggered. Their propagation is monitored …
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Thermoelectrics : material advancements and market applications
… and kp is the thermal conductivity due to phonon propagation across a crystal lattice. From the mid-1940s until the 1970s there was very slow progress in increased thermoelectric material efficiency, which culminated in a ZT=1 with (Bi2Te3). For approximately 30 years progress stagnated. In …
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Study of phonon transmission through solid-solid interfaces and superlattices by phonon imaging
… work in this thesis explores the low-temperature propagation of heat pulses (phonons) through crystals and across solid-solid interfaces. The phonon imaging technique has been used to examine the angular and temporal dependence of the phonon-flux intensity in several systems, listed below. 1. …
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Structural dynamics of photoexcited nanolayered perovskites studied by ultrafast x-ray diffraction
… energy from local excitations via delocalized phonon modes of the samples. The complex deformations in tailored multilayers are identified to give rise to highly nonlinear x-ray diffraction responses due to transient interference effects. The understanding of such effects and the ability to …
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Phonon Spectroscopy and Low-Dimensional Electron Systems
The generation and propagation of pulses of nonequilibrium acoustic phonons and their interaction with semiconductor nanostructures are investigated. Such studies can give unique information about the properties of low-dimensional electron systems, but in order to interpret the experiments and to …