Wavelength selective surface plasmons enhanced infrared photodetectors

Over the decades, Mercury Cadmium Telluride (HgCdTe) has been widely used as a detecting material in conventional IR photodetectors. While HgCdTe material properties have been well understood to use for the semiconductor structures, they have not yet been extensively exploited for the use in metasurfaces, i.e., by engineering the dispersion of surface plasmon in metasurfaces, the incident electromagnetic light is being absorbed and spatially sorted according to different wavelengths. We deposited HgCdTe on the metal substrate to enable surface plasmon modes between the metal-insulator interfaces. We propose various designs of IR photodetectors which are enhanced by the localized or propagating surface plasmon modes. In this work, we use HgCdTe dielectric material is used to absorb the incident light, channel different IR spectral bands, and generate the free carriers. The proposed designs can simultaneously capture light based on the coupling of free space electromagnetic energy to a sub-wavelength plasmonic mode and exhibit efficient light splitting and absorption for the desired dual or multiple bands. The schematics, the absorption in each medium, the operating frequencies, the equivalent models, the electric field distributions, and the Poynting vector fields are provided.