Keshmiri, S. H. (2017). Loss mitigation in binary-sequenced plasmonic waveguides [Dissertation, Technische Universität Wien]. reposiTUm. http://hdl.handle.net/20.500.12708/79616
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Number of Pages:
100
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Abstract:
The strong coupling of light to surface plasmon-polaritons that originate from collective oscillations of conduction electrons at metallic surfaces allows tight confinement of its energy. Such plasmonic confinement of the electromagnetic field allows bridging between dimensions dictated by the sub-micrometer wavelength of light in visible and near infrared part of spectrum and nanoscale size of species which are often utilized as emitting or photo-absorbing materials. This dissertation describes the metal-mediated losses in plasmonic waveguide components and binary-sequenced devices, with a particular focus on novel optical materials. Centered on a rigorous theoretical investigation, a class of multidiffractive plasmonic structures for broadband light absorbing was established. It is based on a corrugated metallic grating with multi-periodic modulations for diffraction coupling of light to surface plasmons. This approach combines the advantages of regular binary and random sequences as it allows for strong as well as broadband light trapping. This study is extended to a complete organic photovoltaic solar cell model to discuss the interplay of plasmonic and dielectric waveguide modes in broadening the absorption bands selectively in the active layer, and the effect on the profile of their field and damping that affects the spatial distribution of dissipated light energy in the layered structure. Model comparison of the cell geometry with both conformal and non-conformally corrugated layers also reveals that conformal structure outperforms non-conformal in enhancing of photon absorption.
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Keywords:
plasmon; waveguide; defrective optics; loss mitigation; binary sequences