Sub-wavelength Si-based plasmonic light emitting tunnel junction

Here we report the effect a metal grating on the light emission enhancement of a light emitting tunnel junction (LETJ). The device utilizes the finite probability of tunneling electrons to scatter inelastically, i.e. emit a photon over a phonon. Here a Fermi sea was electrically biased against the conduction band of a doped semiconductor. While functional, the external emission efficiency is low due to high absorption from the top metal. Here we experimentally show that introducing a grating to this top metal layer will enhance the emission intensity. Additional simulation results provide inside into the light-coupling process. Our result show a 12 times enhancement.