An international team of researchers recently reported its success in creating a new type of graphene-based photodetector.
The team integrated three concepts to achieve the new device: metallic plasmonic antennas, ultra sub-wavelength waveguiding of light and graphene photodetection. Specifically, the 2D-material hexagonal boron nitride was used as the waveguide for hyperbolic phonon polaritons, which can highly confine and guide mid-infrared light at the nanoscale. By carefully matching the nano-antenna with the phonon polariton waveguide, they efficiently funnel incoming light into a nanoscale graphene junction. By using this approach, they were able to overcome intrinsic limitations of graphene, such as its low absorption and its small photoactive region near the junction.