Widely tunable black phosphorus mid-infrared photodetector

Abstract

Lately rediscovered orthorhombic black phosphorus (BP) exhibits promising properties for near- and mid-infrared optoelectronics. Although recent electrical measurements indicate that a vertical electric field can effectively reduce its transport bandgap, the impact of the electric field on light-matter interaction remains unclear. Here we show that a vertical electric field can dynamically extend the photoresponse in a 5 nm-thick BP photodetector from 3.7 to beyond 7.7 μm, leveraging the Stark effect. We further demonstrate that such a widely tunable BP photodetector exhibits a peak extrinsic photo-responsivity of 518, 30, and 2.2 mA W−1 at 3.4, 5, and 7.7 μm, respectively, at 77 K. Furthermore, the extracted photo-carrier lifetime indicates a potential operational speed of 1.3 GHz. Our work not only demonstrates the potential of BP as an alternative mid-infrared material with broad optical tunability but also may enable the compact, integrated on-chip high-speed mid-infrared photodetectors, modulators, and spectrometers.

Optical and Optoelectronic Properties of Black Phosphorus and Recent Photonic and Optoelectronic Applications

“…Under a moderate displacement field, the detection region can be extended up to 7.7 µm, which is far beyond the cutoff wavelength of pristine BP. The intrinsic responsivities are 28.7, 1.6, and 0.122 A W −1 at 3.4, 5, and 7.7 µm …”

“…Photodetectors can convert information stored in light to electrical signals that can be processed by standard electronic equipment. Because of the direct bandgap and high carrier mobility, BP is promising in building broadband phototransistors for photodetection and imaging . The first 2D BP‐based photodetector was fabricated by Buscema et al in 2014.…”

Multimechanism Synergistic Photodetectors with Ultrabroad Spectrum Response from 375 nm to 10 µm

“…[16][17][18] Devices based on MoS 2 , a typical member of the TMDs family, exhibit ultrasensitive and ultrahigh gain characteristics for photodetector applications. [17,[20][21][22][23] Limited by absorption efficiency, these infrared detectors typically have low photocurrent gain and low quantum efficiency. 2D semiconductors with narrow bandgaps, such as platinum diselenide (PtSe 2 ), black phosphorene, and black arsenic phosphorus, were recently discovered and used to fabricate the infrared detectors.…”

Multistate Logic Inverter Based on Black Phosphorus/SnSeS Heterostructure

“…[8][9][10][11][12][13] Among these 2D materials, BP has attracted extensive attention because of its high carrier mobility (up to 1000 cm 2 V −1 s −1 at room temperature), moderate tunable direct bandgap on thickness (from 0.3 eV for bulk to 2.0 eV for monolayer), and intrinsic anisotropy arising from the puckered structure. [8][9][10][11][12][13] Among these 2D materials, BP has attracted extensive attention because of its high carrier mobility (up to 1000 cm 2 V −1 s −1 at room temperature), moderate tunable direct bandgap on thickness (from 0.3 eV for bulk to 2.0 eV for monolayer), and intrinsic anisotropy arising from the puckered structure.…”

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Graphene, transition metal-dichalcogenides (TMDs), and black phosphorus (BP) are widely exploited as building blocks for such vdWs heterostructure due to their unique electrical and optical properties. [14][15][16][17] In the past years, a host of BP-based vdWs heterostructures such as graphene/ BP, TMDs/BP, and h-BN/BP architecture, have been fabricated to explore their electronic and photoelectric properties, which have shown promising applications for fieldeffect transistors (FETs), [18][19][20] photodetectors, [8,21,22] flexible devices, [23] memory device, [24] logic circuits, [25] and so on. [14][15][16][17] In the past years, a host of BP-based vdWs heterostructures such as graphene/ BP, TMDs/BP, and h-BN/BP architecture, have been fabricated to explore their electronic and photoelectric properties, which have shown promising applications for fieldeffect transistors (FETs), [18][19][20] photodetectors, [8,21,22] flexible devices, [23] memory device, [24] logic circuits, [25] and so on.

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