Study on infrared photodetectors based on black phosphorus

Black phosphorus is a novel two-dimensional semiconductor with a special structure and excellent properties. It belongs to the natural P-type narrow bandgap semiconductor, which has a direct bandgap from bulk to monolayer, and can fill the gap between zero bandgap graphene and wide bandgap transition metal chalcogenides. This article mainly conducts a comparative study on the electrical properties of three-layer and thick layer black phosphorus field-effect transistors, exploring the advantages of their application in infrared photoelectric detection. The results show that the device made of three-layer black phosphorus has a smaller dark current and a faster response speed of 8 ms, making it more sensitive in detecting near-infrared light; The carrier mobility of multilayer black phosphorus devices is higher, reaching 68.4 cm² V⁻¹ s ⁻¹ when subjected to a bias voltage of 1 V. At the same time, the photoresponsivity is also higher, reaching up to 0.5 mA/W, and the photoelectric conversion ability is stronger.