Electric Field-driven Near-infrared Light-emitting Diodes from Excitons in Few-layer Black Phosphorus

Abstract Two-dimensional (2D) semiconductors characterized by atomic-layer thickness and van der Waals integra tion capability exhibit exciton-dominated luminescence at room temperature making them frontier materials for micro/na no optoelectronic devices.Electrically driven exciton light-emitting devices are crucial for exploring novel luminescent physics and advancing integrated optoelectronics applications.Currently exciton-based light-emitting devices in 2D semi conductors primarily focus on the visible spectrum while the fabrication of near-infrared (communication band) electrolu minescent devices remains challenging.This study demonstrates electric-field-modulated excitonic near-infrared emission in bilayer and trilayer black phosphorus and constructs injection-free exciton light-emitting devices driven by lateral elec tric fields.These devices operate at wavelengths around 1 150 nm and 1 500 nm respectively.The realization of electri cally driven near-infrared exciton devices using few-layer black phosphorus expands the spectral range of 2D materialbased electroluminescent devices providing new materials and pathways for near-infrared light-emitting devices.Key words two-dimensional materials black phosphorus exciton near-infrared light-emitting diodes