Abstract: Silicon (Si)-based materials with a super-hydrophobic surface were prepared using microscale rough surfaces, which were subsequently modified by organic compounds with low surface energies. However, the super-hydrophobicity was gradually lost because of the degradation of the organic compounds when applied to an outer environment. Herein, a Si-based film with a super-hydrophobic surface fabricated by chemical vapor deposition (CVD) using a liquid metal (tin) as the growth substrate is reported. We found that the film was composed of vertical Si/SiO₂ hierarchical wires upon characterization by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Reasons for the generation of this super-hydrophobicity are given using the Cassie model. We conclude that the special Si/SiO₂ hierarchical structure plays an important role in the super-hydrophobic performance of the film. Compared with the previous Si-based material with a super-hydrophobic surface, this novel structure promises to widen its area of application since its super-hydrophobicity is independent of chemical modification.

Key words: Super-hydrophobic, Core-shell structure, Silicon nanowire, Chemical vapor deposition, Film