Patent ID: 7597788
Filing Date: 2009-10-06
Classification: B82Y,G01N,Y10S

Abstract:
1. A gas sensing device for selectively detecting electrophilic species comprising: an insulating substrate; two conducting electrode pads deposited on said substrate, separated by a gap greater than about 10 nm; and semiconducting carbon nanotube material deposited on said two electrode pads forming a conduction path, wherein about one half of said carbon nanotube material is in an undoped, instrinsic i-type electronic state and the remaining portion of said nanotube material is doped with a nucleophilic species to form an n-type semiconductor, such that an I—N junction is formed, wherein a P—N junction diode is formed in the presence of said electrophilic species; and circuitry connected to said electrode pads for measuring the conductivity characteristics of the diode structure, wherein the circuitry is configured to detect the presence of said electrophilic species by detecting the presence of a knee in a current-voltage curve for the semiconducting carbon nanotube material.