Current anisotropy of carbon nanotube diodes: Voltage and work function dependence

Here, we report a performance analysis on carbon nanotube (CNT) Schottky diodes using source-drain current anisotropy. An analytical model is derived based on thermionic field emission and used to correlate experimental data from Pd-Hf, Ti-Hf, Cr-Hf, Ti-Cr, and Pd-Au mixed metal devices fabricated on one single 6 mm long CNT. Results suggest that the difference in work functions of the two contact-metals, and not a dominant Schottky contact, determines diode performance. Results are further applied and demonstrated in a reversible polarity diode.