Plasmon-based photosensors comprising a very thin semiconducting region

Abstract

We theoretically investigate an elementary subwavelength plasmonic sensor comprising a very thin active region. High quantum efficiency (QE), broad spectral band and nearly no sensitivity to the incidence angle and polarization can be achieved. We particularly discuss different examples based on HgCdTe for infrared detection: QEs of 75% are obtained for active layers λ/(8n) thin, corresponding to a tenfold absorption enhancement.