Controlling the Self-Assembly and Polymerization of Organic Molecules on Alkali Halide Surfaces
Résumé
Achieving control over the formation of molecular one dimensional (1D) and 2D structures on insulating substrates is important for designing novel functional materials and devices. In order to achieve this goal, we decided to combine, (i) atomically clean ionic substrate with different lattice constants, (ii) on-demand synthezised molecules with various functional groups, and (iii) well adapted growth conditions. In such a way we were able to control the self-assembly of large domains of defect-free organic layers [1], to understand the role of molecular flexibility and enthropy in the nucleation and growth of these layers [2], and to initiate a novel, UV-light induced chain-polymerization of 1D fibres on a pure insulator [3, Fig. 1]. The key issue in all of these experiments is to balance the molecule-molecule and molecule-substrate interactions in such a way that the desired interactions govern the growth mode and that the (pre-) designed structures can be formed.