Near-Infrared Photodetector Based on MoS₂/Black Phosphorus Heterojunction

Abstract

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