Strategies for two-dimensional growth of organic molecular films

After a brief summary of the thermodynamic background on which strategies for driving molecular film growth can be pointed out, we present some recent results on the growth of oligothiophene thin films by organic molecular beam deposition, as obtained studying the film morphology by atomic force microscopy and monitoring the film growth in situ and in real-time by reflectance anisotropy spectroscopy. Three-dimensional and two-dimensional nucleation and growth are obtained by properly tuning the process conditions, such as, in particular, the substrate type and temperature, the molecular flux, and the substrate surface quality. Finally, the tuning of these parameters is used for reaching the condition of a stable layer-by-layer epitaxial growth at room temperature, fully equivalent to that well assessed for inorganics.