Electron tunneling between nanospaced electrodes provides a mechanism for directly transducing the presence of molecular analytes into electrical signals. Crossbar junctions with vertical separations on the order of a few nanometers were fabricated using a combination of electron-beam lithography and selective chemical etching. The current-voltage properties of the nanojunctions are highly sensitive to the chemical environment. The tunneling currents increase over one order of magnitude in response to water and organic vapors diluted with a background of pure nitrogen. The resistance of the junctions is also dependent on the concentration of the analyte. These results demonstrate that tunneling can be used to detect changes in the chemical environment.

Date Published: 5 May 2010
PDF: 7 pages
Proc. SPIE 7679, Micro- and Nanotechnology Sensors, Systems, and Applications II, 76791C (5 May 2010); doi: 10.1117/12.851308

Published in SPIE Proceedings Vol. 7679:
Micro- and Nanotechnology Sensors, Systems, and Applications II
Thomas George; M. Saif Islam; Achyut Kumar Dutta, Editor(s)