Direct observation of the epitaxial growth of molecular layers on molecular single crystals

In this letter the authors use the evolution of reflectance anisotropy spectra with film thickness during the growth of organic molecular films of a prototype molecular system (α -quarterthiophene grown onto a single crystal of the same material) to demonstrate homoepitaxy. The real time monitoring of the optical anisotropy of a thin film during deposition by organic molecular beam epitaxy is assessed as a powerful tool to achieve an effective in situ control of the growth starting from the very early deposition stages. © 2006 American Institute of Physics.