Enhanced electrical transport between the metal nano-particles by covering of monolayer C60 Original Research Article

Electrical insulating metal granular films were prepared at room temperature and then C60 molecules were slowly deposited on top of the metal films at the same vacuum. In situ measurements of electrical conductivity were made during the deposition of C60, and the results indicated that the conductivity depends on the thickness of C60 film. Transitions of insulating–conducting–insulating were observed, and the maximum conductivity (σmax) of the metal/C60 films was measured when the coverage of C60 is about one monolayer. A possible explanation of this unusual conductivity enhancement phenomenon based on metal–fullerene charge transfer effect is discussed.