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 9 of 9 for “"excitonic effects"”.
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Temperature dependent excitonic effects in silicon
… of bandgap energy can be obtained by adding the excitonic binding energy and the corresponding phonon energy to the optically measured threshold. Observing excitonic effects in the absorption process is an effective means of understanding the phonon and exciton behaviour and the material’s …
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A method for the calculation of excitonic effects in certain metals
Due to the long-range screening behavior of electrons in metals, interactions between excited electrons and their corresponding holes are few and are generally ignored. In this thesis, we attempt to include this electron-hole interaction into the calculation by randomly choosing a finite number of …
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The electronic, optical and excitonic effects of high hydrostatic pressure on semiconductors
This thesis describes the results from high pressure experiments on semiconductors, and some theoretical background for those experiments. The primary goal is to better understand the properties of these useful materials through studies of the effect of hydrostatic pressure.
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Monte Carlo studies of ground state and optical properties of multiexcitonic complexes in semiconductors
Excitonic complexes, consisting of several electron-hole pairs bound by mutual Coulomb interactions, play an important role in the photoluminescence of direct- and indirect-gap semiconductors and semiconductor impurities. We calculate the ground-state and optical properties of several multiexciton …
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MULTIPHOTON ABSORPTION IN MONOLAYER TRANSITION METAL DICHALCOGENIDES
… absorption (3PA) with two-dimensional (2D) excitonic effects are studied in single-layer molybdenum disulfide (1L-MoS2). Both 2PA and 3PA coefficients of 1L-MoS2 are theoretically predicted to be enhanced by 10-1000 times in the near-infrared (NIR), as compared with those of bulk …
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Electroabsorption effects near the direct and indirect edges of germanium
… leffect dear a M edge, o modified by excitonic effects; in the case of the indirect edge they are due to the electric-field-induced change in the optical absorption assisted by phonon emission and absorption. The electric field dependence of the width of the oscillations in 6a above …
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Screening and the effective fine structure constant in graphene
… nature, but evidence of strong-correlation effects and non-Fermi liquid behavior remains limited. We describe a method to probe the strength of these interactions, characterized by an effective fine-structure constant α∗(q, ω), as measured with inelastic x-ray scattering (IXS) on graphite. …
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Monte Carlo studies of ground-state & optical properties of multiexcitonic complexes in semiconductors
Excitonic complexes, consisting of several electron-hole pairs bound by mutual Coulomb interactions, play an important role in the photoluminesence of direct- and indirect-gap semiconductors and semiconductor impurities. We calculate the ground-state and optical properties of several multiexciton …
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Photophysical Properties of Emerging 2D Materials
… as light-absorbing materials due to their strong excitonic effects and favourable optical properties. Despite their promise, perovskite crystals present significant challenges for device integration, as they are prone to structural degradation under ambient exposure and highly susceptible to the …