Preparation and characterisation of silver quantum dot superlattice using self-assembled monolayers of pentanedithiol

A superlattice of silver nanoclusters was prepared using sequential self-as sembly of 1,5-pentanedithiol on an Au(111) substrate. The formation of high ly ordered silver nanocluster arrays was confirmed using AFM and also by th e longitudinal periodicity observed in the low angle X-ray diffraction patt ern. In contrast to the behaviour of dithiol self-assembled monolayers (SAM ) on gold substrates, which give only blocking behaviour, the superlattice exhibits interesting electrochemical properties in terms of redox accessibi lity of silver nanoclusters with respect to potential cycling. The room tem perature emission spectrum suggests the formation of minibands in the super lattice structure as evidenced by three distinct peaks at 320, 400 and 620 nm.