Controlled Growth of One-Dimensional Metal–Semiconductor and Metal–Carbon Nanotube Heterojunctions

Aligned and diameter-controlled one-dimensional nickel–carbon nanotubes and Ag–Si heterojunctions (see Figure) have been synthesized by a novel combination of electrochemical deposition and chemical vapor deposition with anodic aluminum oxide templates. No external catalysts are introduced in the chemical reactions. In the joint regions of the heterojunctions, no amorphous layers are found. These heterojunctions are significant for the development of electronics.