Self-assembled gold nanoparticle thin films with nonmetallic optical and electronic properties

Self-assembled multilayer thin films consisting of alternating layers of similar to 6-nm Au nanoparticles and alpha,omega-dithiols have been prepared on glass substrates. They have been studied by UV/Vis spectroscopy, ellipsometry, scanning tunneling microscopy, and temperature-dependent conductivity measurements. The electronic and optical properties of the thin film material are nonmetallic, and the Au particles maintain their individual character without fusion to larger units. Electronic conduction within the films occurs via activated electron hopping.