Wafer‐Scale Fabrication of Graphene‐Based Plasmonic Photodetector with Polarization‐Sensitive, Broadband, and Enhanced Response

Abstract

Graphene‐based photodetectors draw tremendous interests for broadband photodetection in optical communications, sensing, and hyperspectral imaging. However, the extremely low light absorption coefficient of graphene posts a great challenge for high‐efficiency photodetection. Although plasmonic nanostructures provide resonant absorption enhancement and impressive responsivity, the current fabrication techniques suffer from being time‐consuming, low‐yield, and potentially high‐cost. In this work, a wafer‐scale graphene‐Au nanogratings (Gra‐Au NGs) plasmonic photodetector array is fabricated via two‐beam holographic lithography, which achieves a photosensitive area of 1 mm2, showing balanced abilities of polarization‐sensitive, broadband, and enhanced photoresponse from visible to near‐infrared regions. The maximum polarization extinction ratio and responsivity of the Gra‐Au NGs photodetector reach 6.65 and 2.95 mA W−1. The surface plasmon resonance of Au NGs and near‐field coupling with graphene render strong electric field confinement and enhanced light absorption, which improve the device photoresponse and polarization sensitivity. The hot electrons generation and transportation models in the Gra‐Au NGs heterojunction are proposed, perfectly matching with the photocurrent mapping and equalized energy band distribution. This work enlightens the wafer‐scale fabrication of graphene‐based plasmonic photodetectors, and it can trigger the advances of free‐space detection, such as remote sensing and satellite communication.

Low-dimensional van der Waals materials for linear-polarization-sensitive photodetection: materials, polarizing strategies and applications

“…Importantly, the DR can approach infinity at the polarity-transition point, allowing the subtle measurement of polarization-angle perturbation down to 0.02 • Hz −1/2 in the mid-infrared spectral range. Most recently, Fan et al have constructed broadband polarization-resolved photodetectors by integrating graphene atop the Au nanogratings [256]. Importantly, a maximum linear DR of 6.65 has been achieved upon 1310 nm light excitation.…”

Smart alloy metalized novel photonic NEMS photodiode with CuAlV/n-Si/Al junction structure

“…Responsivity of photodetectors often depends on wavelength and generally becomes maximum within or near the visible wavelength region, and gradually goes to zero limit beyond the opposite border end sides of this region, ie toward the directions of infrared and UV light wavelength regions. For example, a graphene based photodetector [59] fabricated recently to use in optical communications has a responsivity reaching to its maxima of 2.95 and 6.65 mA W −1 near the resonant wavelength of 1327 nm.…”

Plasmon-induced hot carrier dynamics and utilization

“…The introduction of plasmonic metals into photodetectors realizes the sub-gap detection with which photons with energy less than the band gap of semiconductors can also be detected by triggering hot electron transfer from metal to semiconductors. It should be noted that several plasmonic photodetectors have utilized the light concentration ability of plasmon to increase the absorption of semiconductors such as graphene and transition metal dichalcogenides [346][347][348][349][350][351][352] but do not belong to plasmon-induced hot carrier applications. The first plasmonic photodetector based on hot carriers was reported by Knight et al in an Au/ Si heterostructure [353] .…”