Polyphosphide Precursor for Low-Temperature Solution-Processed Fibrous Phosphorus Thin Films

Crystalline red phosphorus has very recently emerged as a stable and cost-effective semiconductor material. However, despite its potentiality in electronics and optoelectronics, the widespread application of this material is still hampered by the limited synthetic route of the ampoule-based chemical vapor deposition that critically requires mineralizing agents. To address this issue, we report the chemical synthesis of soluble polyphosphide precursors that serve as inks for the solution-processed fabrication of crystalline fibrous phosphorus thin films. The purified polyphosphide precursor formed crystalline fibrous phosphorus via thermal annealing at a temperature as low as 250 °C without any mineralizing agents. This anionic polyphosphide functioned as a surface-capping ligand for nanoparticles including metals, semiconductors, and magnets. Therefore, the study investigates the possibility of solution-processed fibrous phosphorus thin films as active channel layers in field-effect transistors as well as photodetectors and demonstrates their initial performances on the charge-transport and photoresponsive characteristics of these devices. The effect of semiconducting PbS nanoparticles embedded in the fibrous phosphorus thin films on device performance was also studied. The synthesized polyphosphide precursor offers a vast opportunity for the facile preparation of crystalline red phosphorus and chemical design of nanoparticles.