Nanotube schottky diodes for high-frequency applications

摘要

Described is a Schottky diode using semi-conducting single-walled nanotubes (s-SWNTs) with titanium Schottky and platinum Ohmic contacts for high-frequency applications. The diodes are fabricated using angled evaporation of dissimilar metal contacts over an s-SWNT. The devices demonstrate rectifying behavior with large reverse-bias breakdown voltages of greater than −15 V. In order to decrease the series resistance, multiple SWNTs are grown in parallel in a single device, and the metallic tubes are burnt-out selectively. At low biases, these diodes showed ideality factors in the range of 1.5 to 1.9. Modeling of these diodes as direct detectors at room temperature at 2.5 terahertz (THz) frequency indicates noise equivalent powers (NEP) comparable to that of the state-of-the-art gallium arsenide sold-state Schottky diodes, in the range of 10-13 W/square-root (√) Hz.