Quasi-one-dimensional (quasi-1D) fibrous red phosphorus (RP) has triggered growing interest recently for its unique properties and promising applications in energy storage, sensing, and heterogeneous catalysis. However, attempts to explore its anisotropy and transport properties have progressed slowly. In this work, we report the fabrication of large-size and pure bulk fibrous RP crystals using a chemical vapor transport reaction by modifying growth kinetics. For the first time, the weak layer number-dependent anisotropic electronic structure of fibrous RP is revealed based on theoretical calculations. The b-axis-aligned fibrous RP nanoribbons with a high aspect ratio exceeding 1000 are easily prepared by facile liquid exfoliation. Impressively, the field-effect transistor device built with fibrous RP nanoribbons exhibits p-type transport behavior and a high mobility reaching 236.7 cm 2 V −1 s −1 with an On/Off ratio approaching 1.6 × 10 3 , which are superior to those of other reported RP-based materials in general. The results demonstrate the great potential of fibrous RP as a promising channel material and lay a solid foundation to further study the intrinsic properties of quasi-1D van der Waals materials.

The practical applications of fibrous red phosphorus (FRP), an emerging quasi-one-dimensional material, might be hindered by its environmental instability. Although other phosphorus allotropes such as white phosphorus, violet phosphorus, and black phosphorus are reported unstable under ambient conditions, the chemical stability of FRP remains unexplored. Herein, we investigate the degradation chemistry of FRP by combining experimental study and density functional theory calculations. The results reveal that both oxygen and water can react with FRP, while light illumination may accelerate these reactions. Furthermore, the degradation behavior of FRP shows a pseudo-first-order reaction in oxygenated water, while it follows a pseudo-zero-order reaction in deoxygenated water. Such different reaction kinetics originates from the preferable dissociative adsorption behaviors of O 2 molecular and H 2 O molecular on a FRP surface or at a FRP edge. A covalent modification approach using an aryl diazonium salt was adopted to passivate the surface of FRP flakes and significantly enhance their stability in air.