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Angular variation of absorption and thermal emission enhancement from the two dimensional photonic crystals

Posted on:2011-12-28Degree:M.SType:Thesis
University:Iowa State UniversityCandidate:Zhao, WeijunFull Text:PDF
GTID:2440390002464720Subject:Engineering
Abstract/Summary:
Photonic crystal structures and their applications are an active growing research area in the scientific community. The photonic crystals can have a complete bandgap for proper choice of the structure and dielectric contrast. Photonic crystal structures are very useful in many areas such as photovoltaic devices, infrared sources and optic fibers.;The photonic crystal structures have been used in the thermal photovoltaic devices and as a narrow band infrared emitter. In this thesis we investigate the angular variation of absorption and thermal emission from the two-dimensional metallic and metal-dielectric photonic crystal structures by using rigorous scattering matrix method. We found that the thermal emission of these photonic crystals at different wavelengths is redistributed into different emission angles. The photon emission are partially suppressed at long wavelengths and enhanced at the shorter wavelength range. We utilized the surface plasmon models to describe the angular dependent absorption. The strong spectral variation of the thermal emission with angle should be accounted for the thermo-photovoltaic devices utilizing photonic crystals.;We also propose a metallic photonic crystal for incandescent filaments. We simulated the tungsten photonic crystals and found that by using the photonic crystals it is possible to increase the lifetime and brightness of light bulbs. We also present results for metal-dielectric patches at infrared length scales and find absorption peaks can be tuned by the geometry of the patch.
Keywords/Search Tags:Photonic crystals, Thermal emission, Absorption, Angular, Variation
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