We present an optimized design for a plasmonic metal-semiconductor-metal photodetector with interdigitated electrodes with subwavelength dimensions and a single GaInNAs quantum well (QW) as an absorbing layer. The excitation of surface plasmons at the metal-semiconductor interface leads to a strong field enhancement near the metallic electrodes. This results in an increased absorption in the QW, allowing both fast electrical response of the photodetector and high quantum efficiencies. With a grating periodicity of 820 nm and electrode finger width of 460 nm a 16-fold increase in the absorption of p-polarized light in the QW is achieved in comparison to the case without electrodes.
- MSM photodetector
- Surface plasmons