AVS 50th International Symposium
    Surface Science Wednesday Sessions
       Session SS-WeP

Paper SS-WeP11
Chemisorption of Sulfur on Au(111), Au(100) and Au(110) by Means of UHV and Electrochemical Adsorption

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: Y.W. Yang, National Synchrotron Radiation Research Center, Taiwan
Authors: Y.W. Yang, National Synchrotron Radiation Research Center, Taiwan
L.J. Fan, National Synchrotron Radiation Research Center, Taiwan
Correspondent: Click to Email
Reaching a detailed understanding of the interaction between sulfur and gold surfaces has become more urgent due to their wide usage in constructing self-assembled monolayers in nanoengineering research. Here, we report on a detailed structural and energetic study of molecular S@sub 2@ adsorbed on Au(111), Au(100) and Au(110) surfaces by means of LEED, SR-XPS and TPD. A comparative study of sulfur adsorption from electrochemical (EC) deposition is also investigated with ECSTM. For all three surfaces, LEED study reveals the presence of a series of ordered adsorption structures. TDS data show the presence of strong repulsive interaction among sulfur adsorbates and, interestingly, the existence of several unusual binding states on all three surfaces. These binding states are characterized by sharp features of less than 30 K in desorption peak width. The overall change of S 2p core levels is found to be small in spite of a strong variation of adsorption structure and adsorption site among three gold surfaces. The observed S 2p@sub 3/2@ core levels fall between 161.0 and 161.3 eV. The rather constant S 2p@sub 3/2@binding energy suggests the importance of final-state metallic screening. ECSTM shows the presence of additional ordered structures not observable from UHV adsorption but stabilized by the coadsorbed ions from the solution. UHV and EC adsorption structure data will be discussed together.