We investigated the electronic properties of highly ordered three-dimensional colloidal crystals of gold nanocrystals (7 ± 0.4 nm), called supracrystals. Two kinds of Au supracrystals with typical thicknesses of 300 nm and 5 ! m, respectively, are probed for the first time with scanning tunneling microscopy/spectroscopy at 5 K revealing similar power law behavior and showing homogeneous conductance with the fingerprint of isolated nanocrystal. Potential applications evading the size-related risks of nanocrystals could be then considered.
Source : Unexpected electronic properties of micrometer-thick supracrystals of Au nanocrystal. P.Yang, I. Arfaoui, T. Cren, N. Goubet and M.P. Pileni. Nano Lett., 2012, 12, 2051-2055.