Steven E Kooi | Massachusetts Institute of Technology (MIT) (original) (raw)
Papers by Steven E Kooi
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Bulletin of the American Physical Society, Mar 5, 2014
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arXiv (Cornell University), Oct 7, 2021
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Advanced Functional Materials, Oct 5, 2007
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arXiv (Cornell University), Sep 28, 2022
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Conference on Lasers and Electro-Optics, 2020
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Bulletin of the American Physical Society, Mar 7, 2018
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Bulletin of the American Physical Society, Mar 14, 2016
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Proceedings of SPIE, Sep 18, 2013
ABSTRACT Nanoparticles and nanostructures with plasmonic resonances are currently being employed ... more ABSTRACT Nanoparticles and nanostructures with plasmonic resonances are currently being employed to enhance the efficiency of solar cells. Ag stripe arrays have been shown theoretically to enhance the short-circuit current of thin silicon layers. Such Ag stripes are combined with 200 nm long and 60 nm wide "teeth", which act as nanoantennas, and form vertical rectifying metal-insulator-metal (MIM) nanostructures on metallic substrates coated with thin oxides, such as Nb/NbOx films. We characterize experimentally and theoretically the visible and near-infrared spectra of these "stripeteeth" arrays, which act as microantenna arrays for energy harvesting and detection, on silicon substrates. Modeling the stripe-teeth arrays predicts a substantial net a.c. voltage across the MIM diode, even when the stripe-teeth microrectenna arrays are illuminated at normal incidence.
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Angewandte Chemie, Apr 15, 2002
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Physical Review X, Jan 17, 2017
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Advanced Materials, Jun 4, 2008
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Journal of Polymer Science Part B, Feb 6, 2017
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Lightweight, portable solar blankets, constructed from thin film photovoltaics, are of great inte... more Lightweight, portable solar blankets, constructed from thin film photovoltaics, are of great interest to hikers, the military, first responders, and third-world countries lacking infrastructure for transporting heavy, brittle solar cells. These solar blankets, as large as two square meters in area, come close to satisfying specifications for commercial and military use, but they still have limited absorption due to insufficient material efficiency, and therefore are large and too heavy in many cases. Metasurfaces, consisting of monolayers of periodic and semi-random plasmonic particles patterned in a scalable manner, are explored to enhance scattering into thin photovoltaic films (currently of significant commercial and military value), in order to enhance absorption and efficiency of solar blankets. Without nano-enhancement, absorption is limited by the thickness of the thin photovoltaic active layer in the long-wavelength region. In this study, lithographically patterned, periodic Al nanostructure arrays demonstrate experimentally a large absorption enhancement, resulting in a predicted increase in short-circuit current density of at least 35% and as much as 70% for optimized arrays atop 200-nm amorphous silicon thin films. Optimized arrays extend thin-film absorption to the near infrared region. This impressive absorption enhancement and predicted increase in short-circuit current density may significantly increase the efficiency and reduce the weight of solar blankets, enabling their use for commercial and military applications.
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Conference on Lasers and Electro-Optics, 2017
We present experimental results demonstrating multiple order Smith-Purcell radiation in high aspe... more We present experimental results demonstrating multiple order Smith-Purcell radiation in high aspect ratio Silicon Nanowires structures using low-energy electrons (2.5–10keV). These produce emission spanning the visible, paving the way to a fully tunable ultraviolet source.
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Journal of Physical Chemistry A, Dec 1, 1998
ABSTRACT The photodissociation of Co(CO)3NO was studied near 225 nm. Apparent two-photon dissocia... more ABSTRACT The photodissociation of Co(CO)3NO was studied near 225 nm. Apparent two-photon dissociation of the parent compound produces Co* in a number of excited states that emit in the range of 340−360 nm. Both quartet and doublet states of Co* are observed, implying the existence of spin-conserving and nonspin-conserving dissociation channels. Assignment of the Co* emission is used to calculate an upper limit for the average metal−ligand bond dissociation energy of 36.2−38.6 kcal/mol with no spin-conservation restrictions and 41.2−43.9 kcal/mol with spin-conservation restrictions. The Co* emission intensities are used to determine the relative populations of particular J and spin states and to demonstrate that J states within a particular LS configuration are statistically populated. The NO photoproduct was detected by fluorescence excitation spectroscopy. The NO appears to follow dual Boltzmann statistics with rotational temperatures of 580 ± 70 K for Erot < 500 cm-1 and 2800 ± 300 K for Erot > 500 cm-1.
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Nano Letters, Feb 20, 2001
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Nature Physics, Jul 16, 2018
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Journal of the American Chemical Society, Jul 1, 2007
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Bulletin of the American Physical Society, Mar 5, 2014
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arXiv (Cornell University), Oct 7, 2021
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Advanced Functional Materials, Oct 5, 2007
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arXiv (Cornell University), Sep 28, 2022
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Conference on Lasers and Electro-Optics, 2020
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Bulletin of the American Physical Society, Mar 7, 2018
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Bulletin of the American Physical Society, Mar 14, 2016
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Proceedings of SPIE, Sep 18, 2013
ABSTRACT Nanoparticles and nanostructures with plasmonic resonances are currently being employed ... more ABSTRACT Nanoparticles and nanostructures with plasmonic resonances are currently being employed to enhance the efficiency of solar cells. Ag stripe arrays have been shown theoretically to enhance the short-circuit current of thin silicon layers. Such Ag stripes are combined with 200 nm long and 60 nm wide "teeth", which act as nanoantennas, and form vertical rectifying metal-insulator-metal (MIM) nanostructures on metallic substrates coated with thin oxides, such as Nb/NbOx films. We characterize experimentally and theoretically the visible and near-infrared spectra of these "stripeteeth" arrays, which act as microantenna arrays for energy harvesting and detection, on silicon substrates. Modeling the stripe-teeth arrays predicts a substantial net a.c. voltage across the MIM diode, even when the stripe-teeth microrectenna arrays are illuminated at normal incidence.
Bookmarks Related papers MentionsView impact
Angewandte Chemie, Apr 15, 2002
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Physical Review X, Jan 17, 2017
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Advanced Materials, Jun 4, 2008
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Journal of Polymer Science Part B, Feb 6, 2017
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Lightweight, portable solar blankets, constructed from thin film photovoltaics, are of great inte... more Lightweight, portable solar blankets, constructed from thin film photovoltaics, are of great interest to hikers, the military, first responders, and third-world countries lacking infrastructure for transporting heavy, brittle solar cells. These solar blankets, as large as two square meters in area, come close to satisfying specifications for commercial and military use, but they still have limited absorption due to insufficient material efficiency, and therefore are large and too heavy in many cases. Metasurfaces, consisting of monolayers of periodic and semi-random plasmonic particles patterned in a scalable manner, are explored to enhance scattering into thin photovoltaic films (currently of significant commercial and military value), in order to enhance absorption and efficiency of solar blankets. Without nano-enhancement, absorption is limited by the thickness of the thin photovoltaic active layer in the long-wavelength region. In this study, lithographically patterned, periodic Al nanostructure arrays demonstrate experimentally a large absorption enhancement, resulting in a predicted increase in short-circuit current density of at least 35% and as much as 70% for optimized arrays atop 200-nm amorphous silicon thin films. Optimized arrays extend thin-film absorption to the near infrared region. This impressive absorption enhancement and predicted increase in short-circuit current density may significantly increase the efficiency and reduce the weight of solar blankets, enabling their use for commercial and military applications.
Bookmarks Related papers MentionsView impact
Conference on Lasers and Electro-Optics, 2017
We present experimental results demonstrating multiple order Smith-Purcell radiation in high aspe... more We present experimental results demonstrating multiple order Smith-Purcell radiation in high aspect ratio Silicon Nanowires structures using low-energy electrons (2.5–10keV). These produce emission spanning the visible, paving the way to a fully tunable ultraviolet source.
Bookmarks Related papers MentionsView impact
Journal of Physical Chemistry A, Dec 1, 1998
ABSTRACT The photodissociation of Co(CO)3NO was studied near 225 nm. Apparent two-photon dissocia... more ABSTRACT The photodissociation of Co(CO)3NO was studied near 225 nm. Apparent two-photon dissociation of the parent compound produces Co* in a number of excited states that emit in the range of 340−360 nm. Both quartet and doublet states of Co* are observed, implying the existence of spin-conserving and nonspin-conserving dissociation channels. Assignment of the Co* emission is used to calculate an upper limit for the average metal−ligand bond dissociation energy of 36.2−38.6 kcal/mol with no spin-conservation restrictions and 41.2−43.9 kcal/mol with spin-conservation restrictions. The Co* emission intensities are used to determine the relative populations of particular J and spin states and to demonstrate that J states within a particular LS configuration are statistically populated. The NO photoproduct was detected by fluorescence excitation spectroscopy. The NO appears to follow dual Boltzmann statistics with rotational temperatures of 580 ± 70 K for Erot < 500 cm-1 and 2800 ± 300 K for Erot > 500 cm-1.
Bookmarks Related papers MentionsView impact
Nano Letters, Feb 20, 2001
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Nature Physics, Jul 16, 2018
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Journal of the American Chemical Society, Jul 1, 2007
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