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

Nano-patterned high-responsivity GaAs metal-semiconductor-metal photodetector

“…4, the theoretical enhancement in transmission is 8 times (for top nano-gratings). The discrepancy (factor of 2) between the theoretical and experimental results is attributed to (i) the grating phase shift near the slit and (ii) the trapezoidal shape of the nano-grating grooves both reducing the transmission enhancement as reported by Das et al [20,21]. …”

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

“…The continuing progress in plasmonic interaction with nanostructures and their outstanding design instruction in metal-semiconductor-metal photodetectors (MSM-PDs) has developed a unique context for futuregeneration optoelectronic systems, such as, optical fiber communication systems, high speed chip-to-chip interconnects, and high-speed sampling [3]. The conventional MSM-PD is a symmetrical device which is equivalent to two back-to-back connected Schottky diodes on a semiconductor substrate [4], such as GaAs which as a direct band gap semiconductor collects and emits photons more efficiently than indirect semiconductors such as Si and Ge [5].…”

“…When an electric field (or a voltage) is applied between the electrodes and the device's active region is under illumination, then the electric carriers (i.e., electrons and holes) are generated and drifted towards the opposite electrodes due to the electric field, and can form a photocurrent. Improvement of recombination between electrons and holes can lead to enhance the light absorption in the subwavelength aperture region [3,7,8]. Over the decade, an interesting effect of light interacting with metallic structures has been revealed.…”

“…Finite-difference time-domain (FDTD) simulation tool is a full wave modeling technique that demonstrates significant light-capturing performance through the periodic 1D slit arrays [25] for the design of ultrafast MSM-PDs [3]. The FDTD algorithm was originally proposed by Yee in 1966 [26] and introduces a modeling technique to solve the Maxwell's curl equations in time domain.…”

High-responsivity plasmonics-based GaAs metal-semiconductor-metal photodetectors

“…A plane Gaussian-modulated continuous wave with TM polarization was used as an excitation source, as reported in Ref. 15. By simulating the electric flux transmitted into the active area for the same device with and without the nano-gratings, the light transmission enhancement factor (C), defined as the ratio of the transmitted optical power with the nanogratings to that without nano-gratings, was easily calculated.…”