Highly Efficient and Air-Stable Infrared Photodetector Based on 2D Layered Graphene–Black Phosphorus Heterostructure

Abstract

The presence of a direct band gap and high carrier mobility in few-layer black phosphorus (BP) offers opportunities for using this material for infrared (IR) light detection. However, the poor air stability of BP and its large contact resistance with metals pose significant challenges to the fabrication of highly efficient IR photodetectors with long lifetimes. In this work, we demonstrate a graphene-BP heterostructure photodetector with ultrahigh responsivity and long-term stability at IR wavelengths. In our device architecture, the top layer of graphene functions not only as an encapsulation layer but also as a highly efficient transport layer. Under illumination, photoexcited electron-hole pairs generated in BP are separated and injected into graphene, significantly reducing the Schottky barrier between BP and the metal electrodes and leading to efficient photocurrent extraction. The graphene-BP heterostructure phototransistor exhibits a long-term photoresponse at near-infrared wavelength (1550 nm) with an ultrahigh photoresponsivity (up to 3.3 × 10 A W), a photoconductive gain (up to 1.13 × 10), and a rise time of about 4 ms. Considering the thickness-dependent band gap in BP, this material represents a powerful photodetection platform that is able to sustain high performance in the IR wavelength regime with potential applications in remote sensing, biological imaging, and environmental monitoring.

Tunable self‐powered n‐SrTiO3 photodetectors based on varying CuS‐ZnS nanocomposite film (p‐CuZnS, p‐CuS, and n‐ZnS)

“…Therefore, the p‐CZS/n‐STO photodetector with high performance can be maintained for several months in the surrounding environment. As compared with two‐dimensional materials (black phosphorus and InSe nanosheets), the p‐CZS/n‐STO device show better stability and simpler preparation …”

“…As compared with twodimensional materials (black phosphorus and InSe nanosheets), the p-CZS/n-STO device show better stability and simpler preparation. [42][43][44] To have a better understanding of the large open-circuit voltage, a thorough study on the I-V characteristics of the p-CZS/n-STO, p-CuS/STO, and n-ZnS/STO were performed, and displayed in Figure 4A. The dark current of CZS/STO device is almost the same as that of CuS/STO but much lower than that of ZnS/STO.…”

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

“…Under illumination, photocarriers generated in BP are injected into graphene. The ultrahigh carrier mobility of graphene and suppressed Schottky barrier give rise to efficient photocurrent extraction as exemplified by the ultrahigh photoresponsivity of 3.3 × 10 3 A W −1 . The strong in‐plane anisotropy of BP can also be utilized in polarization‐dependent photodetectors .…”

Self‐Powered Photodetectors Based on 2D Materials

“…The photodetector is an electronic device that can convert an optical signal into an electrical signal . Photodetectors are widely used in many fields, such as ray measurement and detection, infrared thermal imaging, infrared remote sensing, and so on.…”