| AVS 54th International Symposium | |
| Surface Science | Friday Sessions |
| Session SS2+EM+TF-FrM |
| Session: | Organic Films II: Semiconductors and C@sub 60@ |
| Presenter: | T.M. Willey, Lawrence Livermore National Lab. |
| Authors: | T.M. Willey, Lawrence Livermore National Lab. J.D. Fabbri, Stanford Univ. J.R.I. Lee, Lawrence Livermore National Lab. P.R. Schreiner, Justus-Liebig Univ. Giessen, Germany A.A. Fokin, Justus-Liebig Univ. Giessen, Germany B.A. Tkachenko, Justus-Liebig Univ. Giessen, Germany N.A. Fokina, Justus-Liebig Univ. Giessen, Germany J.E. Dahl, MolecularDiamond Tech. R.M.K. Carlson, MolecularDiamond Tech. S.G. Liu, MolecularDiamond Tech. T. van Buuren, Lawrence Livermore National Lab. N.A. Melosh, Stanford Univ. |
| Correspondent: | Click to Email |
Higher diamondoids, hydrocarbon cages with a diamond-like structure, have evaded laboratory synthesis and have only recently been purified from petroleum sources. Initial calculations on these unique diamond-like molecules show they may have negative electron affinity, a desirable property for electron emission. Readily available adamantane, the smallest diamondoid, can be thiolated and has shown to absorb on gold with high coverage. The availability of diamantane, triamantane, and tetramantanes opens new possibilities for surface-modification as multiple sites are available for thiol or other chemical functionalization. Surface-attached diamondoids have technological possibilities as high-efficiency electron emitters, as well as crystals for diamond growth or other nanotechnological applications, and fundamental studies of the electronic and structural properties of these molecular monolayers are a necessary precursor. We have investigated the effects of thiol substitution position, polymantane order, and metal substrate on diamondoid film morphology. Using Near-Edge X-ray Absorption Fine Structure Spectroscopy (NEXAFS) we show that the orientation of the diamondoids within each type of monolayer depends highly upon these parameters. We thus demonstrate control over the assembly, and hence the surface properties, of this exciting new class of diamond-like carbon molecules.