High‐Speed and High‐Responsivity Hybrid Silicon/Black‐Phosphorus Waveguide Photodetectors at 2 µm

Abstract

Silicon photonics is being extended from the near-infrared window of 1.3-1.5 µm for optical fiber communications to the mid-infrared (mid-IR) wavelength-band of 2 µm or longer for satisfying the increasing demands in many applications. Mid-IR waveguide photodetectors on silicon have attracted intensive attention as one of the indispensable elements for various photonic systems. However, when combining traditional semiconductor materials with silicon, there are some challenges due to lattice mismatch and thermal expansion mismatch. As an alternative, two-dimensional (2D) materials provide a new and promising option for enabling active photonic devices on silicon. Here black-phosphorus (BP) thin films with optimized medium thicknesses (40 nm) are introduced as the active material for light absorption and silicon/BP hybrid ridge waveguide photodetectors at 2 µm are demonstrated with a high responsivity of 306.7 mA W −1 at a low bias voltage of 0.4 V. The 3 dB-bandwidth is up to 1.33 GHz and an experiment of a 4.0 Gbit s −1 data receiving is also demonstrated.

High-performance silicon−graphene hybrid plasmonic waveguide photodetectors beyond 1.55 μm

“…In contrast, two-dimensional materials provide a new and promising option for enabling active photonic devices on silicon [13][14][15][16] . In particular, currently graphene 14,15 and black-phosphorus (BP) [16][17][18][19] have been popular for realizing waveguide photodetectors on silicon. Recently, we reported a silicon-BP hybrid waveguide photodetector with a 3 dB-bandwidth of 1.33 GHz and a high-speed operation of 4.0 Gbps as well as high responsivity of ~0.3 A/W at 2 μm 19 .…”

“…Recently, we reported a silicon-BP hybrid waveguide photodetector with a 3 dB-bandwidth of 1.33 GHz and a high-speed operation of 4.0 Gbps as well as high responsivity of ~0.3 A/W at 2 μm 19 . It is noted that the bandwidth of the reported BP photodetectors is still limited, e.g., less than 3 GHz [17][18][19] . In addition, the fabrication is still not easy because the large-size high-quality BP sheet is not available yet and the BP sheet needs some special protection.…”

Two-Dimensional Tellurium: Progress, Challenges, and Prospects

“…As one of the chalcogens (group-VI materials), tellurium (Te) is well known as a p-type semiconductor with a bandgap of 0.35 eV at room temperature and possesses a wealth of intriguing properties [1] such as photoconductivity [2], thermoelectricity [3], and piezoelectricity [4]. Since atomically thin graphene flakes were discovered in 2004 [5,6], two-dimensional (2D) materials have triggered intensive research interest for the fabrication of nanodevices on an industrial scale [7][8][9][10][11][12][13][14][15]. However, the development of 2D materials faces significant challenges, such as the zero bandgap of graphene [16,17], the environmental instability of black phosphorus (BP) [18][19][20][21][22], the low current mobility of transition metal dichalcogenides (TMDCs) [23], and the lack of large-scale and efficient synthesis methods.…”

Highly Efficient Silicon Photonic Microheater Based on Black Arsenic–Phosphorus

“…For practical application, a poly(methyl methacrylate) can be coated on b‐AsP materials as an upper‐cladding layer. It can help preventing the b‐AsP thin film from oxidization and keep the material stable over several months . Moreover, the large‐area synthesis technique of wafer‐scale b‐AsP films has been reported, which can enable the mass‐fabrication of the heater proposed in this work.…”