Absorption enhancement of 980 nm MSM photodetector with a plasmonic grating structure

We present finite-difference time-domain (FDTD) simulation to analyze the optical absorption enhancement of metal–semiconductor–metal (MSM) photodetectors employing plasmonic grating structures. Simulation results show that the combination of a subwavelength aperture and a nano-structured metal grating results in up to 16 times enhancement in optical absorption, in comparison to conventional MSM photodetector structures employing only a subwavelength aperture.