Size-Induced Metal to Semiconductor Transition in a Stabilized Gold Cluster Ensemble

A size-induced transition from a positive to a negative temperature coefficient of electrical conductivity is displayed by thin films of a series of six dodecanethiol-stabilized gold cluster complexes with the gold core diameter progressively increasing from 1.7 to 7.2 nm. The size of the gold core may influence both its intrinsic conductivity and the charging energy barrier for tunneling to an adjacent monolayer-encapsulated cluster.