DFT study of alkanethiol self-assembled monolayers on gold(111) surfaces [Elektronische Ressource] / von Edmanuel Torres

DFT Study of AlkanethiolSelf-assembled Monolayers onGold(111) SurfacesDISSERTATIONzurErlangung des Grades,,Doktors der Naturwissenschaften”an der Fakult¨at fu¨r Physik und Astronomieder Ruhr-Universit¨at BochumvonEdmanuel TorresausKolumbienBochum20091. Gutachter Prof. Dr. J¨org Neugebauer2. Gutachter Prof. Dr. Dr. h.c. Hartmut ZabelDatum der Disputation 6. Juli 2009AbstractSelf-assembled monolayers (SAMs) of thiols on gold surfaces are of great interestbecause of the growing number of potential applications in fields such as molecularelectronics, nanotechnology or biosciences. The development of future applications ofalkanethiol SAMs in nanosciences requires methods that can reproduce with precisionthe desired properties.√ √◦Alkanethiols on gold(111) surfaces adopt a ( 3× 3)R30 commensurate latticeand may manifest c(4×2) superlattice modulations in the high density regime. Untilnow six different high density phases have been reported. Alkanethiol SAMs havebeen intensively studied during the last two decades. In spite of this, experimentand theoretical calculations have persistently disagreed. One of the most remarkablecontroversies is whether the molecules adsorb on top or at a site close to the bridgesite.In this thesis, the SAM structures for alkanethiols with short and intermediatechains were studied on unreconstructed and reconstructed gold(111) surfaces. Thepresented results shed light on some of the thiol SAM controversies.