GROWTH AND CHARACTERIZATION OF ORGANIC MULTILAYERS ON GOLD GROWN BY ORGANIC MOLECULAR-BEAM DEPOSITION

In this contribution, we discuss the growth and characterization of mo lecular layers for the formation of oligo-azomethine. The substrate is Au(111) on mica. Monolayers of 4-aminothiophenol are deposited by sel f-assembly from solution (SAM) or by evaporation in vacuum, both techn iques establishing chemisorption of the oligomer on the substrate thro ugh a covalent sulphur-gold bond. This is followed by evaporation of t erephthalaldehyde in vacuum employing imine-formation (-N=C-) by conde nsation polymerisation as a starting sequence of an in-situ synthesis of the oligo-azomethine. In-situ ellipsometry and quartz crystal frequ ency measurements are used to monitor the growth. Chemical surface com position is verified by X-ray photoelectron spectroscopy. Morphology a nd electronic properties are examined ex-situ by scanning tunnelling m icroscopy. Scanning induces pit formation on the SAM films, whereas no pits are found on the evaporated films On the SAM films, a staircase- like pattern in tunnel spectroscopy I-V curves is observed while the e vaporated films show diode-like behaviour. (C) 1998 Elsevier Science B .V.