Lithography-free in situ Pd contacts to templated single-walled carbon nanotubes

We report a metalization technique for electrically addressing templated vertical single-walled carbon nanotubes (SWNTs) using in situ palladium (Pd) nanowires. SWNTs are synthesized from an embedded catalyst in a modified porous anodic alumina (PAA) template. Pd is electrodeposited into the template to form nanowires that grow from an underlying conductive layer beneath the PAA and extend to the initiation sites of the SWNTs within each pore. In this way, individual vertical channels of SWNTs are created, each with a vertical Pd nanowire back contact. Further Pd deposition results in annular Pd nanoclusters that form on portions of SWNTs extending onto the PAA surface. Two-terminal electrical characteristics produce linear I-V relationships, indicating ohmic contact in the devices.