Controlling the Microstructure of Monomolecular Layers

This review reports on the range of lateral structures which have been detected in ultrathin organic films using the newly‐developed techniques of fluorescence microscopy and X‐ray scattering, together with more conventional methods. A number of unusual low‐dimensional ordering processes have been revealed. Hexagonal, lamellar or fractal domain structures are observed and shown to result from an interplay of electrostatic forces due to molecular alignment at interfaces, line energy between different phases and growth kinetics. On a molecular level the microstructure is distinguished by low coherence length of positional order but long coherence length concerning the orientation of crystallographic axes. It is demonstrated that the ideas presented are also relevant to adsorbate structures at interfaces and to the protein arrangement in monolayers.