Sequence-Dependent Assembly to Control Molecular Interface Properties

摘要

Functional molecular materials have been obtained by liquid/ vapor-phase epitaxy or layer-by-layer (LbL) assembly with 1) electro-optic responses sufficiently high to build highspeed electro-optical modulators, 2) high-k dielectrics for fabricating organic field effect transistors (OFETs), and 3) ultra-low-β materials to generate molecular wires. Moreover, combining metal-ligand coordination chemistry with stepwise solution-based deposition resulted in the formation of crystalline assemblies, including highly porous metal-organic frameworks (MOFs) on inorganic surfaces. The key for fabricating these and other molecular materials is frequently found in a highly conserved assembly sequence that directs them towards their unique properties and desired function. Similarly, nature dictates the function of enzymes and the genetic information encoded in DNA/RNA by means of the sequence in which the amino acids and nucleotides are arranged. Yet nature is able to create diverse functionalities with the same molecular building blocks. An intriguing question thus remains; can we harvest new and useful material properties by only changing the assembly sequence of the molecular components?