Spatial and spectral tailoring of visible light emission with mie resonances in silicon nanoantenna arrays

Similar to their plasmonic counterparts, dielectric nanoantennas have the ability to manipulate the emission properties of nanoscale emitters placed in their vicinity. Most importantly, they can increase the radiative decay rate of emitters by coupling to Mie-type resonances and/or shape the emission into directional patterns [1]. While considerable theoretical work has been dedicated to the study of coupled system consisting of Mie-resonant dielectric nanoantennas and nanoemitters [2, 3], experimental realizations of such systems are sparse due to the difficulty of integrating suitable nanoemitters with designed dielectric nanoantennas in a defined way [4]. Here we experimentally investigate visible light emission from square arrays (lattice constant is 560 nm) of silicon nanoantennas exhibiting dipolar magnetic Mie-type resonances. The nanoantennas are fabricated by electron beam-lithography on thin-films of hydrogenated amorphous silicon (a-Si:H) on a glass substrate. The unstructured wafers show an intrinsic photoluminescence (PL) centered at 740 nm. A scanning-electron micrograph (SEM) of a typical sample is shown in Fig. 1 (a).