Carbon Nanotube Schottky Diode via Selective Electrochemical Metal Deposition

A single walled carbon nanotube (SWNT) Schottky diode was fabricated via selective electrochemical metal deposition on a prefabricated SWNT field effect transistor device. By electrochemically depositing Pd on only one of the prepatterned Ti electrodes, asymmetric Ohmic (at Pd-SWNT) and Schottky (at SWNT-Ti) contacts were resolved, resulting in efficient current rectification. The selective electrochemical deposition was performed by electrically isolating two Ti electrodes connected through a SWNT by depleting hole carriers in the SWNT upon the simultaneous application of high positive gate voltage during the deposition process. The successful selective deposition of Pd metals was confirmed by X-ray photoelectron spectroscopy.