Plasmonically enhancing 2D WSe₂ light absorption for photodetection

2D material semiconductors have the potential for future photodetection applications in remote sensing, robotics and wearables due to their strong light-matter coupling, unique excitonic properties and lack of dangling bonds. Surface plasmonics are a nanoscale, size-tunable solution for enhancing light absorption in 2D materials. Our design incorporates periodic nanoplasmonic structures below 2D WSe₂ and tunes its design parameters to improve the performance of a WSe₂ photodetector. We simulate polarization-sensitive designs for plasmonic Au nanoellipse and nanohole arrays and calculate up to 27% absorption in 2D WSe₂ at 745 nm. We achieve up to a 16% difference in WSe₂ absorption between TE and TM modes. We also fabricate plasmonic ellipses. By incorporating a periodic pattern consisting of nanoplasmonic structures below WSe₂ and tuning the plasmonic design parameters, the performance of a WSe₂ photodetector can be improved at targeted wavelengths and polarization modes.