EPITAXY AT THE ORGANIC-INORGANIC INTERFACE

We describe an X-ray diffraction study of the epitaxy of organic thin films on well-defined inorganic substrates. These include alkyl-thiol monolayers (''self-assembled monolayers'') and films of PTCDA (3, 4, 9 , 10 perylenetetracarboxylic dianhydride) on Au(111) surfaces. Althoug h each of these films are grown by very different methods (liquid phas e self-assembly, versus molecular beam epitaxy), we find that the mole cular degrees of freedom have an important impact upon the film struct ure and its dependence upon the him thickness. We discuss the generali ty of these observation for organic/inorganic growth systems.