Polycrystalline tubular nanostructures of germanium

The saturated vapor adsorption (SVA) method is adopted to fabricate nanorods, nanotubes, and special nanostructures with the assistance of template. Here, germanium tubular structures with several diameters (50-200 nm) were produced with porous anodic alumina (PAA) template via SVA. The germanium tubular structures grew inside the nanopores, whose size agreed with that of Ge nanotubes, and then expanded to outside of PAA template, forming pipette-like structures. The Ge tubular structure growth process can be explained by both the vapor-solid and oxide-assisted growth mechanisms, which is different from the mechanism for nanorod growth.