New Chemical Sensors Based on Point Heterocontact Between Carbon Nanotubes and Metals
Gennadiy V. Kamarchuk, Igor G. Kolobov, Andrei V. Khotkevich, Igor K. Yanson, Alexander P. Pospelov, Igor A. Levitsky, William B. Euler, Sensors and Actuators B Chemical, 2008, 134, 1022 – 1026
Abstract
The effect on the gas sensitivity of point heterocontact between single walled nanotubes (SWNTs) and a gold microwire is demonstrated for the first time. Au-SWNT heterocontact sensors exhibit high sensitivity to NH3 and NO2 vapors with fast response and relaxation and demonstrate that these two gases can be distinguished based on the direction of charge transfer between the analyte and the SWNTs. The mechanism of sensing is associated with formation of a thin conductive channel between Au and SWNT, but the sign of the resistance change is controlled by the SWNT.