Light-trapping in the near field: the case for plasmonic thin-film solar cells

We study the plasmonic and the non-plasmonic regimes of operation of a thin-film amorphous-silicon solar cell. By rigorous calculation, we discuss the impact of the cell geometry on the nature of its optical resonances

Light confinement effect of non-spherical nanoscale solid immersion lenses

We report on the light confinement effect observed in nonideally shaped (i.e., nonspherical) nanoscale solid immersion lenses (SIL). To investigate this effect, nanostructures of various shapes are fabricated by electron-beam lithography. When completely melted in reflow, these noncircular pillars become spherical, while incomplete melting results in nonspherically shaped SILs. Optical characterization shows that nonideal SILs exhibit a spot size reduction comparable with that of spherical SILs. When the size of the SIL is of wavelength scale or smaller, aberrations are negligible due to the short optical path length. This insensitivity to minor variations in the shape implies a large tolerance in nano-SIL fabricatio

High Quality Factor Confinement Of Bloch Surface Waves At Visible Wavelengths

We report the first experimental demonstration of high quality factor confinement of Bloch surface waves at visible wavelengths. The cavities consist of planar Fabry-Perot resonators that are fabricated on top of a Bloch surface supporting substrate. This work presents the design and fabrication methods used for the setting up of the experiment. Quality factors of the order of 2000 are measured. This work demonstrates that optical surface waves can be efficiently confined, and thus constitute a viable alternative to guided waves for on chip optical components and operations

Factors and Dynamics of Cu Nanocrystal Reconstruction under CO₂ Reduction

Cu nanocrystals as catalysts for CO2 reduction are a subject of considerable contemporary interest, but their stability has not been considered as extensively. Herein, we report on the reconstruction of Cu nanocrystals during CO2 reduction and discuss the factors influencing the observed changes with computer-based quantitative analysis and spectroscopic techniques. The timelines of opposing phenomena, sintering and declustering, previously reported separately, are detailed with a focus on two forces affecting the final morphology: Applied potential and reaction intermediates. This intriguing system demonstrates the need for fundamental understanding of catalyst behavior preceding the ability to control its performance. Copyright © 2019 American Chemical Society

Factors and Dynamics of Cu Nanocrystal Reconstruction under CO2 Reduction

Copyright © 2019 American Chemical Society. Cu nanocrystals as catalysts for CO2 reduction are a subject of considerable contemporary interest, but their stability has not been considered as extensively. Herein, we report on the reconstruction of Cu nanocrystals during CO2 reduction and discuss the factors influencing the observed changes with computer-based quantitative analysis and spectroscopic techniques. The timelines of opposing phenomena, sintering and declustering, previously reported separately, are detailed with a focus on two forces affecting the final morphology: Applied potential and reaction intermediates. This intriguing system demonstrates the need for fundamental understanding of catalyst behavior preceding the ability to control its performance