Impact of Nanograting Phase-Shift on Light Absorption Enhancement in Plasmonics-Based Metal-Semiconductor-Metal Photodetectors

Abstract

The finite difference time-domain (FDTD) method is used to simulate the light absorption enhancement in a plasmonic metalsemiconductor-metal photodetector (MSM-PD) structure employing a metal nanograting with phase shifts. The metal fingers of the MSM-PDs are etched at appropriate depths to maximize light absorption through plasmonic effects into a subwavelength aperture. We also analyse the nano-grating phase shift and groove profiles obtained typically in our experiments using focused ion beam milling and atomic force microscopy and discuss the dependency of light absorption enhancement on the nano-gratings phase shift and groove profiles inscribed into MSM-PDs. Our simulation results show that the nano-grating phase shift blue-shifts the wavelength at which the light absorption enhancement is maximum, and that the combined effects of the nano-grating groove shape and phase shift degrade the light absorption enhancement by up to 50%.

A Comprehensive Analysis of Plasmonics-Based GaAs MSM-Photodetector for High Bandwidth-Product Responsivity

“…Focused ion beam (FIB) lithography technique is used to develop nanofabrications and nanogratings are successfully patterned in plasmonic-based MSM-PDs. The observation of SEM images represents the nanogratings with taper walls rather than the rectangular nanogratings [3,41] and the simulation results confirm the capability of some trapezoidal nanogratings under special design which enhances the LAEF more than the rectangular one, while the reverse is true for some other structures. Here, several numerical simulation results for the enhancement of optical absorption in MSM-PDs are presented.…”

Nano-grating Assisted Light Absorption Enhancement for MSM-PDs Performance Improvement: An Updated Review

“…The rectangular nanograting structures can enable MSM-PDs to absorb incoming light (around 850 nm) 50 times more efficiently than traditionally built MSM-PDs. However, this research group has continued to work on improving the light absorption of different aspects of MSM-PDs where a nano-structured of metal gratings has been placed onto the device's metal layer (simulation performances have been published numerous times) [33][34][35]37,38,[41][42][43][76][77][78]. They have also studied the effects of nanograting profile (various width ratios, 0-1.10), sub-wavelength aperture slit width, and grating thickness on light absorption enhancement by modeling and analyzing the features of MSM-PDs.…”

“…While good conductor materials such as gold (Au) and silver (Ag) have negative real parts of complex dielectric constants below plasma frequency, it is necessary to study thoroughly using multiple modes such as the Lorentz-Drude model and the frequency domain. Many scientists and researchers have studied and published in the literature the theoretical explanation of the working mechanism of MSM-PDs modeling using FDTD simulating tools (including Lorentz-Drude model, frequency domain, and other aspects) [34,35,37,38,[73][74][75]. Figure 4 shows the working flow of MSM-PDs modeling using FDTD simulating tools together with the nano-structure grating assisted modeling feature, and various designs of nano-structure gratings.…”

“…As a result, light can be trapped in very narrow spaces (or small areas). However, this trapped light has a higher order of magnitude in contrast to standard aperture theory (i.e., a conventional type MSM-PDs) and does the improvement of light absorption through stirring the SPPs into the devices [27][28][29][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46].…”

Enhancement of Light Absorption in Plasmonic Based Photodetector with Double Nanograting Structure

“…Masouleh et al [16] have obtained 1.56 LAEF at 1.4 µm using gold material for nanogratings with 450 nm SWA width and also compared the different plasmonic nanogratings pro le to enhance the light absorption in nanostructured device [17]. Daneshmandi et al [18] have proposed extra ordinary transmission (EOT) structure based photodetector to improve the light transmission within the device whereas, Das et al [19] have analyzed the effect of nanogratings phase-shift on device performance and examined that maximum device performance has been achieved at 0 o but it start decreases by increasing the phase-shift beyond 0 o . Fan et al [20] have reported the plasmonic based MSM-PD with aluminum nanogratings and also obtained the light re ection factor (LRF).…”