AVS 47th International Symposium
    Thin Films Friday Sessions
       Session TF+NS-FrM

Paper TF+NS-FrM7
Scanning Probe Investigations of Passivated and Bare Au Nanoclusters on H:Si(111)

Friday, October 6, 2000, 10:20 am, Room 203

Session: Nanostructured Thin Films
Presenter: M.D.R. Taylor, University of Nottingham, UK
Authors: M.D.R. Taylor, University of Nottingham, UK
P. Moriarty, University of Nottingham, UK
M. Brust, University of Liverpool, UK
Correspondent: Click to Email
Non-contact atomic force microscopy (NC-AFM) and scanning tunnelling microscopy (STM) have been used to characterise the morphology of thin films of decanethiol-capped 6 nm Au clusters spin-coated onto hydrogen-passivated (HF/NH4F treated) Si(111). Prior to cluster deposition, NC-AFM images taken under ambient conditions reveal that the H:Si(111) surface is atomically flat, typically consisting of 30-50 nm wide terraces separated by a mixture of single and multiple atomic steps. Following deposition of passivated clusters onto H:Si(111), a network of branched, dendritic islands (6 nm high) is observed with NC-AFM. The clousters forming these islands are remarkably loosely bound and may be swept aside by the AFM tip to fom agglomerates of clusters via minor modification of the non-contact mode feedback parameters. The underlying layers consist of poorly ordered clusters which are stable under STM imaging conditions with tunnel currentsup to 5 nA. This stability faciltates photon emission STM investigations of the passivated clusters. The results of comparative studies of STM-induced light emission from passivated and bare clusters (and from evaporated Au films) will be presented.