Photonic-plasmonic mode coupling in nanopillar Ge-on-Si PIN photodiodes

Incorporating group IV photonic nanostructures within active top-illuminated photonic devices frequently requires light-transmissive contact schemes. Within this context, plasmonic nanoapertures in metallic films can’t simply be recognized using CMOS compatible metals and procedures, they may also actually influence the wave length-dependent device responsivities. Here, we investigate crescent-formed nanoapertures in close closeness to Ge-on-Si PIN nanopillar photodetectors in simulation and experiment. Within our geometries, the absorption inside the devices is principally formed through the absorption characteristics from the vertical semiconductor nanopillar structures (leaky waveguide modes). The plasmonic resonances may be used to influence how incident light couples in to the leaky modes inside the AZ-33 nanopillars. Our results may serve as a beginning indicate selectively tune our device geometries for applications in spectroscopy or refractive index sensing.