Title

Analysis of nano-grating-assisted light absorption enhancement in metal-semiconductor-metal photodetectors patterned using focused ion-beam lithography

Document Type

Journal Article

Publisher

Elsevier

Faculty

Faculty of Computing, Health and Science

School

Electron Science Research Institute (ESRI)

RAS ID

12556

Comments

Originally published as: Das, N., Karar, A., Vasiliev, M., Tan, C.L., Alameh, K., & Lee, Y.T. (2011). Analysis of nano-grating-assisted light absorption enhancement in metal–semiconductor–metal photodetectors patterned using focused ion-beam lithography. Optics Communications, 284, (6), 1694–1700. Original article available here

Abstract

We present finite-difference time-domain (FDTD) analysis results of light absorption enhancement factor dependence on the profile shape of nano-gratings etched into the surfaces of metal–semiconductor–metal photodetector (MSM-PD) structures. The MSM-PDs patterned by nano-gratings are optimized geometrically, improving the light absorption near the design wavelength through plasmon-assisted electric field concentration effects. FDTD simulation results show about 50 times light absorption enhancement prediction for 850 nm light due to improved optical signal propagation through the nano-gratings in comparison with the conventional MSM-PD designs employing only a subwavelength aperture. We also report on the nano-grating profile shapes obtained typically in our experiments using focused ion-beam lithography and discuss the dependency of light absorption enhancement on the geometric parameters of nano-gratings inscribed into MSM-PDs. --------------------------------------------------------------------------------

DOI

10.1016/j.optcom.2010.11.065

 

Link to publisher version (DOI)

10.1016/j.optcom.2010.11.065