Real-Time Intelligent Chemical and Biological Nanosensors on Flexible Platform; Final rept. 1 Oct 2006-30 Sep 2007

摘要

As a first step toward realizing real-time nanoscale electronic sensors for chemical and biological agents, we have successfully fabricated arrays of switching elements in open-channel configurations using single-walled carbon nanotubes (SWNTs) as the carrier transport medium. Using a chemical- vapor deposition process, we have grown long strands of SWNT bundles and used them to fabricate multiple arrays of switching devices with the channel length of 3, 5, 7, and 10 micron on a 15- x 15-mm SiO2-on-Si substrate. Regardless of the channel length, a large majority of the fabricated devices show current rectification characteristics, with a very high throughput of current in the forward bias. The exact physical mechanism of the observed current rectification could not be established. However, the atomic force microscopic analysis of the device structure and morphology of the SWNT suggest the observed rectification to result either from cross-tube junctions or a mixture of metallic and semiconducting tubes in the SWNT bundles.