Plasmonic Metasurface Integrated Black Phosphorus‐Based Mid‐Infrared Photodetector with High Responsivity and Speed

Abstract

Black Phosphorus (BP), a van der Waals (vdW) semiconducting material, is studied intensively due to its unique structural and anisotropic optical properties. BP exhibits optical anisotropy with thickness tunable direct bandgap from 0.3–2.0 eV. Many BP‐based photodetectors operating in the mid‐infrared (MIR) band are proposed, but their performance is still limited due to the small optical absorption cross section at room temperature. In this work, a plasmonic metasurface that has localized surface plasmon resonance (LSPR) at 3.7 µm is designed, matching well with the band edge of a BP flake and field confinement around the edge of Au‐disk as confirmed by finite difference time domain simulation and Fourier‐transform infrared spectroscopy measurement results. In addition, a BP flake is integrated on the plasmonic metasurface and a significant quenching (twelve‐fold) is observed in the photoluminescence owing to the Förster resonance energy transfer effect induced by dipole–dipole coupling. Following that, a BP‐based MIR photodetector is fabricated on the plasmonic metasurface. Here, the demonstrated BP/plasmonic metasurface‐based photodetector achieves the peak responsivity of 495.85 mAW−1 and ultrahigh operation speed (>10 MHz) at the power of 8.55 µW under 3.7 µm incident wavelength. This demonstrated photodetector opens a new opportunity for optoelectronic applications in the MIR region.

Superior Visible Photoelectric Response with Au/Cu2NiSnS4 Core–Shell Nanocrystals

“…These excited excitons disassociated under an applied field across the two electrodes (drain and source) and drifted toward opposite polarities, resulting in the net photocurrents. To investigate the photoresponse characteristic of the photodetector, the key parameters, e.g., photoresponsivity ( R λ ), specific detectivity ( D* ), and the EQE, were calculated by the following (eqs –): , R = I photo P D * = R λ 2 q I d a r k A D * = AB NEP EQE = false( ℏ c R λ false) q λ …”

Enhancing Extended SWIR Al0.3InAsSb PIN Photodetectors with All-Dielectric Amorphous Germanium Photon-Capturing Gratings

“…Compared to directly etching the photodetector into microstructures to enhance light absorption, , placing an a-Ge grating on top does not introduce a significant additional surface leakage current that would increase the dark current (Figure S2). Furthermore, when compared to the utilization of metal nanostructures, − an all-dielectric a-Ge grating avoids substantial optical loss. It is cost-effective and much easier to fabricate through plasmonic dry etching.…”

“…Digital alloy Al x In 1– x As y Sb 1– y has been demonstrated as a tunable material system that can be used to create eSWIR separate absorption, charge and multiplication (SACM) avalanche photodiodes (APDs). − Previously, we have reported light absorption enhancement in SACM digital alloy Al 0.3 InAsSb APDs operating at 2 μm. , This enhancement was achieved by implementing a photon-trapping structure created by using gold (Au). Other papers also report using Au nanostructure to enhance the field of photodetector through plasmonic effect. − However, gold, being a noble metal, presents challenges due to its cost and the complexity of fabricating dense nanostructures with high aspect ratios by using conventional lift-off techniques. In addition, the loss of the nature of metal nanostructures limits their application.…”

hBN‐Encapsulated Graphene Coupled to a Plasmonic Metasurface via 1D Electrodes for Photodetection Applications

“…The past two decades have seen a rush of new optical devices based on 2D material's unique optical properties. [1][2][3] There are numerous examples in the literature, from photoconductors, [4][5][6][7] bolometers, [8][9][10][11][12] photothermovoltaic devices, [13,14] optical field-effect transistors, [15][16][17] and heterostructure devices. [18,19] Photodetectors based on graphene are of particular note, as these devices offer optical detection across the entire electromagnetic spectrum, [1] a result of graphene's gapless dispersion relation and unique uniform optical absorption of ≈2.3% for most wavelengths.…”