Electronic conduction through 2D arrays of nanometer diameter metal clusters

An experimental study of electrical conduction through arrays of nanometer-diameter metallic clusters linked by organic molecules is presented. Gold clusters, having diameters of similar to 4 nm and encapsulated by a monolayer of dodecanethiol, are deposited from solution on to specially prepared substrates to form a close-packed cluster monolayer. Nearest-neighbors in this 2D array of encapsulated clusters are then covalently linked using a conjugated organic molecule approximately 2.2 nm in length having isocyanide groups at both ends. In order to allow both electrical characterization and TEM imaging, the duster arrays are deposited in 500 nm wide gaps between gold contacts on a free standing, insulating SiO2 film. Electronic conduction through linked 2D arrays approximately 80 clusters in length has been observed at room temperature. The structure of the arrays and current-voltage: relationships for the linked arrays are presented.