Effective Conduction Path of a C₆₀ Chain in a Nanogap Electrode

The electrical current path of fullerene-derived films between microfabricated sharpened metal electrodes (gaps of 10–20 nm) was evaluated. When a high voltage was applied, a space-charge-limited current (SCLC) flowed through the fullerene film. The effective conduction path length estimated from the SCLC voltage was slightly longer than the shortest distance between the electrodes. This indicates that the effective current path was tortuous because of the amorphous packing of the spherical fullerenes. Correlations between the effective path length and switching parameters such as operating voltages were used to show that the minimum operating power required for a minimum-sized fullerene switch is expected to be in the subpicowatt range.