SiGe Mie resonators grown on photoactive silicon nanodisks for high-performance photodetection

This article presents a successful fabrication method for hemispheric SiGe nanocrystal-based Mie resonators on photoactive silicon nanodisks on an insulator, achieved through an innovative and scalable approach. This method combines solid-state dewetting of an ultra-thin silicon-on-insulator film (UT-SOI) with germanium growth via molecular beam epitaxy (MBE). The results demonstrate the formation of Mie resonators on silicon nanodisks with precisely defined hemispherical shapes and a homogeneous distribution of germanium in the SiGe core. Three-dimensional finite-difference time-domain (3D FDTD) simulations of the optical properties of SiGe/Si Mie resonators emphasize their capability to generate very high optical loss. This discovery sets the stage for designing compact and high-performance photodetectors with efficient photoactive silicon nanodisks. Moreover, post-integration electrical characterization of these Mie resonators in a MIS-type photodetector reveals their ability to induce a photovoltaic effect while preserving fundamental electrical characteristics. These findings represent a significant advancement in both the fabrication and integration of SiGe-based Mie resonators into optoelectronic devices, opening new avenues in the realms of integrated photonics and advanced optoelectronic technologies.