Epitaxial ZnS/Si core–shell nanowires and single-crystal silicon tube field-effect transistors

Epitaxial single-crystal ZnS/Si core–shell nanowires have been synthesized via a two-step thermal evaporation method. The epitaxial growth is due to the close match of crystal structure between zinc blende ZnS and diamond-like cubic Si. The nanowires have a uniform diameter of 80–200 nm and a length of several to several tens of micrometers. Single-crystal Si nanotubes can be obtained by chemical etching of the ZnS/Si core–shell structure. Characteristics of field-effect transistors (FETs) fabricated from the Si nanotubes suggests that the Si tubes show weak n-type semiconductivity with a mobility of about 3.7×10−2 cm2/(V s), which is 1 order larger than that of intrinsic Si.