Photodetection with Active Optical Antennas

Nanoantennas are key optical components for light harvesting; photodiodes convert light into a current of electrons for photodetection. We show that these two distinct, independent functions can be combined into the same structure. Photons coupled into a metallic nanoantenna excite resonant plasmons, which decay into energetic, "hot" electrons injected over a potential barrier at the nanoantenna-semiconductor interface, resulting in a photocurrent. This dual-function structure is a highly compact, wavelength-resonant, and polarization-specific light detector, with a spectral response extending to energies well below the semiconductor band edge.

• NS
  National Science Foundation

  Award: DGE-0504425
• UD
  U.S. Department of Defense

  Award: N00244-09-1-0067
• OO
  Office of Naval Research

  Award: N00014-10-1-0989
• AF
  Air Force Office of Scientific Research

  Award: F49620-03-C-0068