AVS 60th International Symposium and Exhibition
    Surface Science Friday Sessions
       Session SS-FrM

Paper SS-FrM5
Study of Low Density Sites on Planar Silicon Dioxide Surfaces using Fluorescent Probes

Friday, November 1, 2013, 9:40 am, Room 201 A

Session: Oxides and Semiconductors: Structure and Reactivity
Presenter: J.M. McCrate, University of Texas at Austin
Authors: J.M. McCrate, University of Texas at Austin
J.G. Ekerdt, University of Texas at Austin
Correspondent: Click to Email
Characterization of low density sites on planar oxide surfaces remains a challenging task. Such sites are believed to play an important role in catalysis and particle/film nucleation, although the inability to directly observe these sites limits our understanding of these processes. We have developed a technique that enables detection of low density sites on planar surfaces using fluorescent probe molecules. Derivatives of perylene, a high quantum yield fluorophore, with various functional groups are used to titrate surface sites in vacuum. The functional group is chosen to chemically bind to the desired site and in situ photoluminescence (PL) measurements are used to determine the density of sites and learn about their distribution. An estimated detection limit of < 1010 sites / cm2 is possible with this technique. We will discuss our work using fluorescent probes to study sites on the silica surface. In particular, results of our studies of strained siloxane with perylene-3-methanamine and oxygen vacancy defect (OVD) sites with 3-vinyl perylene will be presented.