RESUMO
Solid-state quantum emitters are in high demand for emerging technologies such as advanced sensing and quantum information processing. Generally, these emitters are not sufficiently bright for practical applications, and a promising solution consists in coupling them to plasmonic nanostructures. Plasmonic nanostructures support broadband modes, making it possible to speed up the fluorescence emission in room-temperature emitters by several orders of magnitude. However, one has not yet achieved such a fluorescence lifetime shortening without a substantial loss in emission efficiency, largely because of strong absorption in metals and emitter bleaching. Here, we demonstrate ultrabright single-photon emission from photostable nitrogen-vacancy (NV) centers in nanodiamonds coupled to plasmonic nanocavities made of low-loss single-crystalline silver. We observe a 70-fold difference between the average fluorescence lifetimes and a 90-fold increase in the average detected saturated intensity. The nanocavity-coupled NVs produce up to 35 million photon counts per second, several times more than the previously reported rates from room-temperature quantum emitters.
RESUMO
This paper reports the enhanced performance of dye-sensitized solar cells (DSSCs) with microcavity-embedded nanoporous TiO2 photoanodes. For DSSCs with photoanodes composed of a stack TiO2 sublayers with microcavity concentrations arranged from low to high on the light illumination path, the short-circuit current density and the conversion efficiency were improved. A pronounced increase in optical absorption and incident monochromatic photon-to-current conversion efficiency in the long-wavelength region indicated that the enhancement of cell performance was due to the multiple scattering of light by the microcavities and the light confinement by the stack of TiO2 sublayers with a high-to-low effective index of refraction.
