MOLECULAR-BEAM EPITAXIAL-GROWTH OF ORGANIC THIN-FILMS

Good quality ultrathin organic films have been successfully grown on various substrates using molecular beam epitaxy. Many kinds of organic films have been epitaxially grown on such substrates with van der Waals surfaces as cleaved faces of layered materials regardless of the large lattice mismatch between the grown organic crystals and the substrates. It has also been found that the epitaxial growth of organic films is possible on such technologically important materials as silicon and GaAs, if the surfaces of those substrates are changed into quasi van der Waals ones by the proper termination of surface dangling bonds with suitable atoms. As for organic molecules with asymmetric charge distribution, such ionic crystals as alkali halides can also be used as good substrates; epitaxial growth is achieved in this situation with the aid of electrostatic interaction.