A Yagi-Uda-like optical nanoantenna consisting of metallo-dielectric core–shell nanoparticles has been proposed, and its major characteristics have been investigated theoretically and numerically. Compared with all-dielectric nanoantennas and plasmonic nanoantennas, the proposed nanoantenna may exhibit better directivity and Purcell factor. In addition, the antenna shows high radiation efficiency over 65% for broadband operation as well. This core–shell nanoantenna, allowing a more compact design, may find potential applications in nanoscale lasers, photovoltaic, and energy-harvesting devices.
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