Investigating Rayleigh-Wood anomalies and surface plasmon resonances in optical and electrical enhancements for nano-grating structures and devices

We numerically investigate the role of Rayleigh-Wood anomalies and surface plasmons in optical and electrical enhancements for nano-grating structures. The affected enhancements studied here include absorption, reflection, transmission, incident electric field strength, and current density. In addition, we study the effects of the nano-grating sidewall taper angle and the incident wave angle on these enhancements. A single wavelength detection technique is used to determine the optimal structure. The results reveal a significant dependence of the enhancements on the taper and the incident wave angles, which could be used to improve photo-sensing devices. Plus, sharp and diffuse peaks and troughs belonging to Rayleigh-Wood anomalies and surface plasmon resonances are exhibited in the spectrum. Such results can be used to boost photodetector, solar cell, and SERS performances.