Silicon Nanotubes Fabricated by Wet Chemical Etching of ZnO/Si Core-Shell Nanowires

Silicon nanotubes (SiNTs) have garnered a great deal of interest for both their synthesis and their potential for application to high-capacity energy storage, biosensors, and selective transport. In this study, we report a convenient and low-cost route to the fabrication of vertically aligned SiNTs via a wet-etching process that enables the control of the wall thickness of SiNTs by varying the gas flux and growth temperature. Transmission electron microscopy (TEM) characterization showed the resultant SiNTs to have an amorphous nature and a hexagonal hollow core. These SiNTs can be crystallized by thermal annealing.