Controlled assembly of conducting monomers for molecular electronics

We report controlled self-assemblies of two molecules as crystalline arrays on gold substrates at room temperature. The size, shape, orientation, and ordered assemblies of molecular wires can be engineered through a delicate interplay of the intermolecular pi-pi stacking and chemisorptive substrate-linker interactions. In particular, the molecule based on a fused aromatic, anthracene, forms an ordered 2D stacked array. Through scanning tunneling spectroscopy, we demonstrate changes in the electronic behavior of single molecules that form into superlattices. The ability to assemble predictable 2D crystals and understand the order-related electronic behavior of single molecular components could allow for the future design of nanopatterned arrays as a controlled platform toward further miniaturization of electronic devices.