High-Speed and High-Responsivity Silicon/Black-Phosphorus Hybrid Plasmonic Waveguide Avalanche Photodetector

Abstract

Two-dimensional materials have attracted much interest for realizing novel optoelectronic devices, e.g., photodetectors. In this work, we demonstrate a high-performance black-phosphorus avalanche photodetector based on a silicon hybrid plasmonic waveguide with double nanoslots, in which way the light absorption by black phosphorus is enhanced and the carrier transit time is reduced simultaneously. Benefiting from the avalanche multiplication process in black phosphorus, the present waveguide avalanche photodetector exhibits high responsivities of 66 A/W (@optical power of 2.9 μW) and 125 A/W (@optical power of 1.4 μW) for the wavelength bands of 1.55 and 1.95 μm, respectively. The measured 3 dB-bandwidth is 1.05 GHz, which is at least three orders of magnitude higher than those reported high-gain photodetectors based on two-dimensional materials. The present high-performance silicon/BP waveguide avalanche photodetector provides a promising option toward the applications of optical sensing, optical imaging, and optical communications in the wavelength band of 1.55/1.95 μm and even beyond.

High-Bandwidth Zero-Biased Waveguide-Integrated p-n Homojunction Graphene Photodetectors on Silicon for a Wavelength Band of 1.55 μm and Beyond

“…The present GPD is based on a thin-silicon slot waveguide, which is fabricated with a 100 nm-thick silicon core layer used in our previous work. , Two metal (Au/Al) pads, respectively, connect the two silicon regions (the left/right part), which are covered with a 10 nm-thick Al 2 O 3 insulator layer. The metal–graphene metal structure is placed on top of the Al 2 O 3 layer.…”

“…The frequency responses of the devices were measured by using a setup including a commercial 40 GHz optical modulator and a vector network analyzer (VNA, 40 GHz bandwidth). Before testing the device, the measurement system was calibrated by a commercial PD . The high-frequency response was obtained from the measured S 21 calibrated with the RF probe (GGB, 40 GHz) response (more details in Note S3).…”

“…Before testing the device, the measurement system was calibrated by a commercial PD. 15 The highfrequency response was obtained from the measured S 21 calibrated with the RF probe (GGB, 40 GHz) response (more details in Note S3). As shown in Figure 5a, when operating with V bias = 0 V and P in = 4.2 mW at 1.55 μm, device #1 has a high-frequency response showing no roll-off in the measured frequency range, which suggests that the 3 dB bandwidth is >40 GHz (setup-limited).…”

“…As discussed in our previous review, it is still a challenge for 2DM PDs to realize the overall high-performance of responsivity, bandwidth, sensitivity, and linearity. The black phosphorus PDs have limited bandwidths of ∼3 GHz − that need special care in fabrication to avoid oxidation. For the graphene photoconductors/bolometers, the dark current is too large and the normalized photo-dark current ratio (NPDR) is as low as ∼10 3 W – 1 . − In addition, the 2DM heterostructure PDs (such as BP-TMDCs, graphene-Si, etc.)…”

2D Material Infrared Photonics and Plasmonics

“…A later work by Huang et al (2019) demonstrated that the spectral range of a Si waveguide-integrated BP photodetector utilizing a Si grating coupler could be extended to 4 μm. To increase the responsivity of these devices, efforts have also been made to further enhance the light–matter interaction via strategies such as the integration of hybrid photonic waveguides and photonic crystal waveguides . Very recently, MoTe 2 /BP vdW heterojunctions have been used to enable charge separation at the vdW interface in these devices, thereby increasing responsivity and reducing dark current.…”