Controlled fabrication of nanowire sensors.

Leonard, Francois

Sandia National Laboratories

关键词: Sensors.;    Field Effect Transistors;    Nanowires.;    Quantum Wires;    Miniaturization;   

DOI  :  10.2172/920825
RP-ID  :  SAND2007-6190
RP-ID  :  AC04-94AL85000
RP-ID  :  920825

美国|英语

来源: UNT Digital Library

【 摘 要 】

We present a simple top down approach based on nanoimprint lithography to create dense arrays of silicon nanowires over large areas. Metallic contacts to the nanowires and a bottom gate allow the operation of the array as a field-effect transistor with very large on/off ratios. When exposed to ammonia gas or cyclohexane solutions containing nitrobenzene or phenol, the threshold voltage of the field-effect transistor is shifted, a signature of charge transfer between the analytes and the nanowires. The threshold voltage shift is proportional to the Hammett parameter and the concentration of the nitrobenzene and phenol analytes. For the liquid analytes considered, we find binding energies of 400 meV, indicating strong physisorption. Such values of the binding energies are ideal for stable and reusable sensors.