Preparation and Characterization of Molecule-Based Transistors with a 50 Nanometer Source-Drain Separation Using Shadow Deposition Techniques: Towards Faster, More Sensitive Molecule-Based Devices.

Preparation of Au microelectrode arrays having spacings of 50-100 nm and available electrode areas of 10 to the -7th power sq cm is described. The dimensions are qualitatively smaller than previously reported and lead directly to faster switching and smaller switching energy for molecule-based transistors. Such microelectrodes can be functionalized with redox active polymers by oxidation of aniline to give polyaniline or by electrochemically assisted deposition of N,N-bisp-trimethoxysilylbenzyl-4,4-bipyridinium promoting Si-OMe hydrolysis to give the redox polymer BPQ2n. The fabrication procedure begins with a microelectrode array consisting of eight, individually addressable AU microelectrodes each approx. 50 micron long x approx 2.5 micron wide x approx. 0.1 micron thick with a spacing of approx. 1.5 micron between the microelectrodes.