Near-Infrared Photodetector Based on MoS₂/Black Phosphorus Heterojunction

Abstract

Two-dimensional (2D) materials present their excellent properties in electronic and optoelectronic applications, including in ultrafast carrier dynamics, layer-dependent energy bandgap, tunable optical properties, low power dissipation, high mobility, transparency, flexibility, and the ability to confine electromagnetic energy to extremely small volumes. Herein, we demonstrate a photodetector with visible to near-infrared detection range, based on the heterojunction fabricated by van der Waals assembly between few-layer black phosphorus (BP) and few-layer molybdenum disulfide (MoS2). The heterojunction with electrical characteristics which can be electrically tuned by a gate voltage achieves a wide range of current-rectifying behavior with a forward-to-reverse bias current ratio exceeding 103. The photoresponsivity (R) of the photodetector is about 22.3 A W–1 measured at λ = 532 nm and 153.4 mA W–1 at λ = 1.55 μm with a microsecond response speed (15 μs). In addition, its specific detectivity D* is calculated to have the maximum values of 3.1 × 1011 Jones at λ = 532 nm, while 2.13 × 109 Jones at λ = 1550 nm at room temperature.

High‐Performance, Self‐Driven Photodetector Based on Graphene Sandwiched GaSe/WS2 Heterojunction

“…In contrast, the forward bias voltage decreases the electrical field in the heterojunction. [31] It is worth noting that a photoresponsivity up to 149 A W −1 is obtained at V ds = 2 V with an illumination intensity P = 0.05 mW cm −2 and λ = 410 nm, which is larger than most of the reported heterojunction photodetectors based on TMDCs, such as 22.3 A W −1 in MoS 2 /black phosphorus and 30.7 A W −1 in WS 2 /Bi 2 Te 3 . [20,29] As shown in Figure 2d, the photoresponsivity (R = I ph /PS, S is the in-plane area (50 µm 2 ) of the device, P is the incident light intensity on the device) increases with decreasing light intensity, which is consistent with the sublinear behavior of the photocurrent.…”

“…The increased recombination of photogenerated carriers with longer transit time leads to a smaller α at source drain voltages of 2 V. A similar sublinear dependence has also been reported, such as MoS 2 /WS 2 and WSe 2 /GaSe heterostructures. [31,32] The corresponding detectivity (D* = RS 1/2 /(2eI dark ) 1/2 ) is about 4.3 × 10 12 Jones. Under zero bias, the photogenerated electronhole pairs are swept in opposite directions across the junction into the graphene electrodes by the built-in electric field in the heterojunction (Figure 3b).…”

Arrayed Van Der Waals Broadband Detectors for Dual‐Band Detection

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TMDs), [16,21,[27][28][29][30] which have suitable bandgap energy. A challenge still remains for achieving large-format, high detectivity, fast response, and multiband detection taking the natural advantages of 2D materials, and no research on this aspect has been reported.

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Multilayer Black Phosphorus Near-Infrared Photodetectors

“…We further calculated the photo-gain ( G = ( I ph · η ext /e)/( P in / h υ)) given a value of R (Figure 5d). From the results, the maximum G operating under 830 nm is close to 0.9, which is larger than the near-infrared photodetector based on the MoS 2 /BP heterojunction [16]. …”