Abstract

We investigate an interdigitated nanograting structure on a GaAs substrate for plasmonic metal–semiconductor–metal photodetector applications. This computational work has studied the effects that the taper angle of the nanograting sidewall and the light wave angle of incidence have on the optical and current enhancements in the device. The study, involving two types of taper angle structures—positive and negative—showed that both taper angle directions can generate more optical and electrical enhancements than perfectly vertical wall structures for light incident at both the Brewster angle and the normal incident angle. The enhanced electric field value at the optimum positive taper angle is $\sim 22\%$ and $\sim 120\%$ greater than the negative taper angle and vertical wall structure, respectively. In addition, the total weighted optical enhancement value for the optimal positive taper angle structure is $\sim 65\%$ and $\sim 120\%$ greater than the optimal negative taper angle and vertical wall structure, respectively. This work demonstrates that the increased enhancements are due to the nanoscale focusing of light and impedance matching. The incident wave angle along with the taper angle can significantly promote these enhancements, especially at the Brewster angle.

© 2019 Optical Society of America

Optical absorption enhancement of hybrid-plasmonic-based metal-semiconductor-metal photodetector incorporating metal nanogratings and embedded metal nanoparticles

Chee Leong Tan, Ayman Karar, Kamal Alameh, and Yong Tak Lee
Opt. Express 21(2) 1713-1725 (2013)

Plasmon-enhanced Ge-based metal-semiconductor-metal photodetector at near-IR wavelengths

Mario Lodari, Paolo Biagioni, Michele Ortolani, Leonetta Baldassarre, Giovanni Isella, and Monica Bollani
Opt. Express 27(15) 20516-20524 (2019)

Broadband THz radiation through tapered semiconductor gratings on high-index substrate

Truong Khang Nguyen, Phuc Toan Dang, Ikmo Park, and Khai Quang Le
J. Opt. Soc. Am. B 34(3) 583-589 (2017)

Numerical modeling of electromagnetic resonance enhanced silicon metal-semiconductor-metal photodetectors

David Crouse, Mark Arend, Jianping Zou, and Pavan Keshavareddy
Opt. Express 14(6) 2047-2061 (2006)

Light trapping plasmonic butterfly-wing-shaped nanostructures for enhanced absorption and efficiency in organic solar cells

Kamal Kumar, Uttam K. Kumawat, R. Mital, and A. Dhawan
J. Opt. Soc. Am. B 36(4) 978-990 (2019)