Switchable Electrically Driven Optical Antenna Based on Ultrathin Amorphous Silica

Abstract Electrically driven optical antenna (EDOA) attracts considerable interest thanks to its capability of converting electronic signal to light within an ultrafast timescale and on a highly compact dimension. However, active control of EDOA, such as its emission wavelength, is still challenging because of the lack of an efficient way to reversibly change the size, gap, or dielectric environment of a nanoscale device. Here, an emission wavelength switchable EDOA is developed by applying a bias on Au@SiO₂ core–shell nanoparticle bridged on two gold electrodes. The tuning of the light emission is based on the formation and elimination of conductive filaments within the ultrathin amorphous silica shell, which allows a reversible switching of the conductivity in the junction. This leads to the modifications of both the inelastic electron tunneling and the plasmonic response of the EDOA, resulting in an emission wavelength shift as large as 115 nm. The results offer new opportunities for developing switchable EDOA toward integrated optoelectronic circuits, nanoscale sensing, and high‐resolution display.