Gold (Au) and ITO bow-tie antenna sensors built on silicon carbide (SiC) substrates are designed and analyzed using the Comsol Multiphysics program. The study shows that the output electric field across the antenna ga...Gold (Au) and ITO bow-tie antenna sensors built on silicon carbide (SiC) substrates are designed and analyzed using the Comsol Multiphysics program. The study shows that the output electric field across the antenna gap decreases with gap separation but increases with metal thickness. The antenna width does not directly affect the output, but it indirectly increases the output as a result of increased radiation absorption and conductivity. The length does not affect the strength of the output, but it affects the resonant frequency. The output field from ITO antennas is found to be much lower than that from Au antennas, which can be attributed, in part, to the lower conductivity of ITO. Using the bow-tie antenna structure, it is possible to build either narrowband or wideband antenna or sensor arrays, for THz applications.展开更多
Reflectance and transmittance parameters of pulsed laser deposited barium strontium titanate (BST) were investigated using spectrophotometric methods. Three stoichiometries consisting of BaxSr1-xTiO3 (x = 0.30, 0.40, ...Reflectance and transmittance parameters of pulsed laser deposited barium strontium titanate (BST) were investigated using spectrophotometric methods. Three stoichiometries consisting of BaxSr1-xTiO3 (x = 0.30, 0.40, 0.50) were deposited on glass substrates using oxygen partial pressures of 1.3 Pa ± 0.13 Pa at 500oC. Subsequently, the measured optical parameters were employed to determine the refractive index (n), extinction coefficient (k), optical conductivity (σ), absorption coefficient (α) and optical bandgap (Eg) using swept spectra in the ultraviolet, visible and near-infrared range (200 nm - 1100 nm) as these have not been reported in the literature. The calculated parameters for Ba0.4Sr0.6TiO3 are reported in this experimental work. Minimal differences in the transmittance have been observed at the visible band edges when comparing each stoichiometry. Sharp cutoffs were observed at the bands edges and strong absorbance in the 200 nm - 300 nm band as attributed to the crystal structure based upon the oxygen partial pressure during the deposition process.展开更多
文摘Gold (Au) and ITO bow-tie antenna sensors built on silicon carbide (SiC) substrates are designed and analyzed using the Comsol Multiphysics program. The study shows that the output electric field across the antenna gap decreases with gap separation but increases with metal thickness. The antenna width does not directly affect the output, but it indirectly increases the output as a result of increased radiation absorption and conductivity. The length does not affect the strength of the output, but it affects the resonant frequency. The output field from ITO antennas is found to be much lower than that from Au antennas, which can be attributed, in part, to the lower conductivity of ITO. Using the bow-tie antenna structure, it is possible to build either narrowband or wideband antenna or sensor arrays, for THz applications.
文摘Reflectance and transmittance parameters of pulsed laser deposited barium strontium titanate (BST) were investigated using spectrophotometric methods. Three stoichiometries consisting of BaxSr1-xTiO3 (x = 0.30, 0.40, 0.50) were deposited on glass substrates using oxygen partial pressures of 1.3 Pa ± 0.13 Pa at 500oC. Subsequently, the measured optical parameters were employed to determine the refractive index (n), extinction coefficient (k), optical conductivity (σ), absorption coefficient (α) and optical bandgap (Eg) using swept spectra in the ultraviolet, visible and near-infrared range (200 nm - 1100 nm) as these have not been reported in the literature. The calculated parameters for Ba0.4Sr0.6TiO3 are reported in this experimental work. Minimal differences in the transmittance have been observed at the visible band edges when comparing each stoichiometry. Sharp cutoffs were observed at the bands edges and strong absorbance in the 200 nm - 300 nm band as attributed to the crystal structure based upon the oxygen partial pressure during the deposition process.
