Surface Plasmon Enhanced Schottky Detectors

Abstract

Surface plasmon Schottky detectors combine a structured metal contact that supports surface plasmons with a semiconductor, forming a rectifying metal-semiconductor junction. Internal photoemission occurs in such junctions via the excitation of hot carriers in the metal due to the absorption of surface plasmons therein, leading to photocurrent collected in the semiconductor. The cut-off wavelength of such detectors is determined by the Schottky barrier height, enabling detection below the bandgap of the semiconductor. The metal contact can be structured as a waveguide, grating or antenna on which surface plasmons are supported. Surface plasmon sub-wavelength confinement and field enhancement lead to significant enhancement of the internal photoelectric effect. The operating principles behind surface plasmon detectors based on internal photoemission are reviewed, the literature on the topic is surveyed, and avenues that appear promising are highlighted.